CN105337275A - Medium-voltage power distribution network power supply capacity evaluation method based on reliability of power distribution system - Google Patents

Abstract

Translated fromChinese

一种基于配电系统可靠性的中压配电网供电能力评估方法：建立基于配电系统可靠性的中压配电网供电能力评估模型；给出基于配电系统可靠性的中压配电网供电能力评估模型的求解方法，一是配电系统可靠性的求解计算，并检验是否满足可靠性约束；二是配电系统供电能力计算；提出基于配电系统可靠性的中压配电网供电能力评估流程。本发明能够从配电系统网架结构的角度出发，对已有配电网网架结构的可靠性进行分析，并且以配电系统中的可靠性指标作为约束条件，进而有针对性的在满足配电系统可靠性约束的前提下释放配电系统供电能力的裕度，挖掘供电潜能。本发明能够为现有配电网结构供电能力的提高提供支撑，促进城市电网建设结构与规划技术的合理发展。

A method for evaluating the power supply capacity of medium-voltage distribution network based on the reliability of the distribution system: establishing a model for evaluating the power supply capacity of the medium-voltage distribution network based on the reliability of the distribution system; The solution method of the power supply capacity evaluation model of the power grid, one is the solution calculation of the reliability of the distribution system, and checks whether the reliability constraints are met; the other is the calculation of the power supply capacity of the distribution system; a medium-voltage distribution network based on the reliability of the distribution system is proposed Power supply capacity assessment process. The present invention can analyze the reliability of the existing distribution network grid structure from the perspective of the grid structure of the power distribution system, and use the reliability index in the power distribution system as a constraint condition, and then specifically satisfy the Under the premise of the reliability constraints of the distribution system, the margin of the power supply capacity of the distribution system is released, and the potential of power supply is tapped. The invention can provide support for improving the power supply capacity of the existing distribution network structure, and promote the rational development of urban power grid construction structure and planning technology.

Description

Translated fromChinese

一种基于配电系统可靠性的中压配电网供电能力评估方法A method for evaluating power supply capacity of medium voltage distribution network based on distribution system reliability

技术领域technical field

本发明涉及一种中压配电网供电能力评估方法。特别是涉及一种用于城市配电网规划的基于配电系统可靠性的中压配电网供电能力评估方法。The invention relates to a method for evaluating the power supply capacity of a medium-voltage distribution network. In particular, it relates to a method for evaluating the power supply capacity of medium-voltage distribution networks based on distribution system reliability for urban distribution network planning.

背景技术Background technique

配电系统作为电能生产、传输和使用的重要环节，是联系用户与发、输电系统的纽带，科学、合理地计算配电系统的供电能力是当前城市电网评估发展的关键部分。考虑到在城市地区，很难再从配电系统的规划和改造中获取新建变电站站址和新设馈线的地下通道。因此，合理评估现有配电系统的供电能力并挖掘其优化后的供电潜力受到了越来越多的关注，供电能力也逐渐成为评价配电网的一项主要指标，对配电网的规划和运行具有重要的指导意义。As an important link in the production, transmission and use of electric energy, the power distribution system is the link between users and the power generation and transmission systems. Scientifically and reasonably calculating the power supply capacity of the power distribution system is a key part of the evaluation and development of the current urban power grid. Considering that in urban areas, it is difficult to obtain the site of the new substation and the underground passage of the new feeder from the planning and transformation of the power distribution system. Therefore, more and more attention has been paid to rationally evaluating the power supply capacity of the existing distribution system and tapping its optimized power supply potential, and the power supply capacity has gradually become a major indicator for evaluating the distribution network. And operation has important guiding significance.

有关配电系统供电能力的计算方法目前主要体现为两类，即基于配电网潮流计算的方法和基于配电网安全准则的方法。在基于配电网潮流计算的方法中，主要考虑的是尝试法，即通过不断改变系统负荷并进行潮流计算来获取系统所能承受的最大负荷量值；以及其他基于各种潮流模型所提出的供电能力计算方法，这类方法可在节点电压、回路功率等系统约束条件下求得配电系统所能承受的最大负荷，并以此作为评估系统供电能力的依据。在基于配电网安全准则的方法中，最典型的是计及N-1安全准则的配电网供电能力评估方法，从供电连续性的角度出发，并且考虑主变互联关系，变电站间的负荷转移等因素，在N-1准则下校验其供电能力。At present, there are two main types of calculation methods for the power supply capacity of distribution systems, namely, methods based on distribution network power flow calculations and methods based on distribution network security criteria. In the method based on distribution network power flow calculation, the main consideration is the trial method, that is, to obtain the maximum load value that the system can bear by continuously changing the system load and performing power flow calculation; and other methods based on various power flow models The calculation method of power supply capacity, this method can obtain the maximum load that the power distribution system can bear under the system constraints such as node voltage and loop power, and use it as the basis for evaluating the power supply capacity of the system. Among the methods based on the distribution network safety criterion, the most typical one is the distribution network power supply capacity evaluation method that takes into account the N-1 safety criterion, starting from the perspective of power supply continuity, and considering the interconnection relationship of the main transformer and the load between substations. Transfer and other factors, verify its power supply capability under the N-1 criterion.

然而，对于常用的计及N-1安全准则的配电系统供电能力计算方法，所采用的是一种刚性约束，在实际的规划中存在一定的问题。第一，鉴于设备负载率与系统可靠性之间的复杂关系，N-1准则更趋向于一个必要性准则，因此单独考虑已不足以保证系统可以具有良好的供电质量；第二，由于配电网负荷峰值的持续时间很短，尖峰负荷通常是均值负荷的数倍，并且不同类型的负荷对于供电可靠性的需求也存在一定的差异，因此，根据N-1准则所求得的系统供电能力会有一定的裕度。考虑到电力系统可靠性在配电系统规划中的重要性，提出基于系统可靠性这一柔性指标的配电网供电能力评估方法，使其能够更加适应配电网建设和运行的特点，进而挖掘配电网的供电潜力、更大地发挥配电网的资源利用效能，提升电网建设与运行的经济性。However, for the commonly used calculation method of distribution system power supply capacity considering N-1 safety criterion, a rigid constraint is adopted, and there are certain problems in actual planning. First, in view of the complex relationship between equipment load rate and system reliability, the N-1 criterion tends to be a necessity criterion, so considering it alone is not enough to ensure that the system can have good power supply quality; second, due to the power distribution The duration of the network load peak is very short, the peak load is usually several times the average load, and different types of loads have different requirements for power supply reliability. Therefore, the system power supply capacity obtained according to the N-1 criterion There will be a certain margin. Considering the importance of power system reliability in power distribution system planning, a distribution network power supply capacity evaluation method based on system reliability, a flexible index, is proposed to make it more adaptable to the characteristics of distribution network construction and operation, and then to explore The power supply potential of the distribution network can be maximized, the resource utilization efficiency of the distribution network can be maximized, and the economy of power grid construction and operation can be improved.

发明内容Contents of the invention

本发明所要解决的技术问题是，提供一种能够为现有配电网结构供电能力的提高提供支撑的基于配电系统可靠性的中压配电网供电能力评估方法。The technical problem to be solved by the present invention is to provide a method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system, which can provide support for the improvement of the power supply capacity of the existing distribution network structure.

本发明所采用的技术方案是：一种基于配电系统可靠性的中压配电网供电能力评估方法，包括如下步骤：The technical solution adopted in the present invention is: a method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system, including the following steps:

1)建立基于配电系统可靠性的中压配电网供电能力评估模型1) Establish a power supply capacity assessment model for medium-voltage distribution networks based on distribution system reliability

以可靠性作为柔性约束条件构建配电系统供电能力模型，目标函数为满足系统可靠性要求下的配电网最大负荷供应能力，对于含有多个相互联络变电站的配电网而言，供电能力计算公式如下：The power supply capacity model of the distribution system is constructed with reliability as the flexible constraint condition. The objective function is to meet the maximum load supply capacity of the distribution network under the system reliability requirements. For a distribution network with multiple interconnected substations, the power supply capacity calculation The formula is as follows:

$\mathrm{<span><span>max</span>max</span>}\mathrm{<span><span>p</span>p</span>}\mathrm{<span><span>s</span>the\; s</span>}\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\underset{\mathrm{<span><span>i</span>i</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>)</span>)</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式中，psc为所计算配电系统的供电能力；R_i为第i台主变的额定容量；T_i为第i台主变的负载率；In the formula, psc is the power supply capacity of the calculated power distribution system; R_i is the rated capacity of the i-th main transformer; T_i is the load rate of the i-th main transformer;

2)基于配电系统可靠性的中压配电网供电能力评估模型的求解方法2) The solution method of the power supply capacity evaluation model of the medium-voltage distribution network based on the reliability of the distribution system

整个计算过程包含两个方面，一是配电系统可靠性的求解计算，并检验是否满足可靠性约束；二是配电系统供电能力计算；The whole calculation process includes two aspects, one is the solution calculation of the reliability of the distribution system, and check whether the reliability constraints are satisfied; the other is the calculation of the power supply capacity of the distribution system;

3)提出基于配电系统可靠性的中压配电网供电能力评估流程。3) A power supply capability assessment process for medium-voltage distribution networks based on distribution system reliability is proposed.

步骤1)所述的以可靠性作为柔性约束条件，是结合配电系统自身运行特点，有以下几个约束条件：In step 1), reliability is used as a flexible constraint condition, which is combined with the operating characteristics of the power distribution system itself, and there are the following constraints:

(1)可靠性等式约束条件、(2)可靠性不等式约束条件、(3)负荷约束条件和(4)负载率约束条件。(1) Reliability equality constraints, (2) Reliability inequality constraints, (3) Load constraints and (4) Load rate constraints.

所述的可靠性等式约束，是根据配电系统结构所得到的相应可靠性指标，在评估系统的供电能力时选取可靠性指标中的平均供电可用度ASAI作为等式约束，平均供电可用度的含义是指在规定的时间内用户经受的不停电小时数与用户要求的总供电小时数之比，具体的计算方法为：The reliability equation constraint mentioned above is based on the corresponding reliability index obtained from the power distribution system structure. When evaluating the power supply capacity of the system, the average power supply availability ASAI in the reliability index is selected as the equation constraint. The average power supply availability The meaning of is the ratio of the number of hours of non-power supply experienced by the user to the total number of hours of power supply required by the user within a specified period of time. The specific calculation method is:

式中，T为在规定时间内的需电小时数；U_j为负荷节点j的年停运时间；T_j为负荷节点j的用户数；N_j为负荷节点j的用户数。In the formula, T is the number of hours of electricity demand within the specified time; U_j is the annual outage time of load node j; T_j is the number of users of load node j; N_j is the number of users of load node j.

所述的可靠性不等式约束条件，是根据不同配电系统结构对于可靠性的要求所设定的不同可靠性目标，具体表现形式为：The reliability inequality constraints mentioned above are different reliability goals set according to the reliability requirements of different power distribution system structures, and the specific expressions are as follows:

ASAI≥E(3)ASAI≥E(3)

式中，E为结合配电系统运行基础所设定的可靠性目标。In the formula, E is the reliability target set in combination with the operation basis of the power distribution system.

所述的负荷约束条件，是配电系统中各主变与所连接馈线之间的容量关系，具体表现形式为：The load constraint mentioned above is the capacity relationship between each main transformer and the connected feeder in the power distribution system, and the specific expression is as follows:

${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>q</span>q</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}<span><span>)</span>)</span>$

式中，R_iq表示与第i台主变相连的第q条馈线的额定容量；T_iq表示与第i台主变相连的第q条馈线的负载率。In the formula, R_iq represents the rated capacity of the qth feeder connected to the i-th main transformer; T_iq represents the load rate of the q-th feeder connected to the i-th main transformer.

所述的负载率约束条件表示的是所述的每一台主变负载率T_i和每一条馈线负载率T_iq的取值范围，具体表现形式为：The load rate constraint condition represents the value range of each main transformer load rate T_i and each feeder load rate T_iq , and the specific expression is as follows:

0≤T_i≤1(5)0≤T_i ≤1(5)

0≤T_iq≤1(6)。0 ≤ T_iq ≤ 1 (6).

步骤2)中所述的配电系统可靠性计算，是采用馈线分区的方法，并结合系统内各元件的可靠性参数计算系统的平均供电可用度ASAI，步骤1)的(1)中给出了平均供电可用度的计算方法，在具体计算的过程中负荷节点j的用户数N_j采用下式进行计算：The distribution system reliability calculation described in step 2) adopts the method of partitioning feeders, and combines the reliability parameters of each component in the system to calculate the average power supply availability ASAI of the system, given in (1) of step 1) The calculation method of the average power supply availability is given. In the specific calculation process, the number of users N_j of the load node j is calculated by the following formula:

N_j＝n_jT_j(7)N_j =n_j T_j (7)

式中，n_j为负荷节点j所在馈线的负载能力达到100％时，负荷节点j的用户数；T_j为负荷节点j所在馈线的负载率；In the formula, n_j is the number of users of load node j when the load capacity of the feeder where load node j is located reaches 100%; T_j is the load rate of the feeder where load node j is located;

故平均供电可用度又表示为：Therefore, the average power supply availability is expressed as:

$\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>\&Sigma;U</span>\&Sigma;U</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}{{\mathrm{<span><span>T\&Sigma;n</span>T\&Sigma;n</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>8</span>8</span>}<span><span>)</span>)</span>$

式中，负荷点j的年停运时间U_j在完全失去连通性时间下的可靠性评估中的计算方式为：In the formula, the calculation method of the annual outage time U_j of the load point j in the reliability evaluation under the time of complete loss of connectivity is:

${\mathrm{<span><span>U</span>u</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>r</span>r</span>}<span><span>\&Element;</span>\&Element;</span>{\mathrm{<span><span>I</span>I</span>}}_{\mathrm{<span><span>P</span>P</span>}}<span><span>(</span>(</span>\mathrm{<span><span>j</span>j</span>}<span><span>)</span>)</span>}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>p</span>p</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>t</span>t</span>}}_{\mathrm{<span><span>r</span>r</span>}\mathrm{<span><span>j</span>j</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>9</span>9</span>}<span><span>)</span>)</span>$

式中，I_P(j)集合中的元件r发生破坏性故障时将引起负荷点j的持续停电；p_r为元件r发生破坏性故障时对应动作的自动开关装置的可靠动作率；λ_r为元件r的平均年破坏性故障率；t_rj为元件r发生破坏性故障时造成负荷点节点j的停电时间，t_rj可能为故障修复时间或故障切换时间。In the formula, when the component r in the I_P(j) set has a destructive fault, it will cause a continuous power outage at the load point j; p_r is the reliable operation rate of the automatic switching device corresponding to the action when the component r has a destructive fault; λ_r is the average annual destructive failure rate of component r; t_rj is the power outage time of load point node j caused by destructive failure of component r, and t_rj may be the fault repair time or failover time.

步骤2)中所述的配电系统供电能力计算，是在满足可靠性约束的前提下，对馈线的负载率进行优化，优化的目标函数为系统的供电能力最大，基于可靠性的配电系统供电能力计算模型具体如下：The calculation of the power supply capacity of the distribution system described in step 2) is to optimize the load rate of the feeder under the premise of satisfying the reliability constraints. The optimized objective function is the maximum power supply capacity of the system, and the distribution system based on reliability The power supply capacity calculation model is as follows:

$\mathrm{<span><span>max</span>max</span>}\mathrm{<span><span>p</span>p</span>}\mathrm{<span><span>s</span>the\; s</span>}\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\underset{\mathrm{<span><span>i</span>i</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>)</span>)</span>$

s.t.s.t.

$\left\{\begin{array}{c}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>\&Sigma;U</span>\&Sigma;\; U</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}{{\mathrm{<span><span>T\&Sigma;n</span>T\&Sigma;n</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}\\ {\mathrm{<span><span>U</span>u</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>r</span>r</span>}<span><span>\&Element;</span>\&Element;</span>{\mathrm{<span><span>I</span>I</span>}}_{\mathrm{<span><span>P</span>P</span>}}<span><span>(</span>(</span>\mathrm{<span><span>j</span>j</span>}<span><span>)</span>)</span>}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>p</span>p</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>t</span>t</span>}}_{\mathrm{<span><span>r</span>r</span>}\mathrm{<span><span>j</span>j</span>}}\\ \mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>\mathrm{<span><span>E</span>E.</span>}\\ {\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>q</span>q</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}\\ \mathrm{<span><span>0</span>0</span>}<span><span>\&le;</span>\&le;</span>{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>\&le;</span>\&le;</span>\mathrm{<span><span>1</span>1</span>}\\ \mathrm{<span><span>0</span>0</span>}<span><span>\&le;</span>\&le;</span>{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>\&le;</span>\&le;</span>\mathrm{<span><span>1</span>1</span>}\end{array}\right.<span><span>.</span>.</span>$

步骤3)所述的基于配电系统可靠性的中压配电网供电能力评估流程，包括：The evaluation process of the power supply capacity of the medium-voltage distribution network based on the reliability of the distribution system described in step 3) includes:

(1)系统可靠性分析：根据元件的故障率，分析单一元件故障所造成负荷点的停电时间，并依此建立系统的故障模式影响分析表FMEA表；(1) System reliability analysis: According to the failure rate of the components, analyze the outage time of the load point caused by the failure of a single component, and establish the FMEA table of the system failure mode impact analysis table accordingly;

(2)可靠性指标的求解：设定系统中馈线的初始负载率，并结合系统的故障模式影响分析表FMEA表计算系统中各负荷点的年停运时间，从而求解系统的平均供电可用度；(2) Solving the reliability index: set the initial load rate of the feeder in the system, and calculate the annual outage time of each load point in the system in combination with the failure mode impact analysis table FMEA table of the system, so as to solve the average power supply availability of the system ;

(3)约束条件校验：比较步骤2)中计算出的平均供电可用度ASAI指标与系统设置的可靠性目标E的大小关系，如果满足ASAI≥E关系，则计算在此情况下的初始供电能力；否则，优化系统中馈线的负载率后重新计算系统的平均供电可用度ASAI指标。(3) Constraint condition verification: compare the relationship between the average power supply availability ASAI index calculated in step 2) and the reliability target E set by the system, and if the ASAI≥E relationship is satisfied, then calculate the initial power supply in this case capacity; otherwise, recalculate the average power supply availability ASAI index of the system after optimizing the load rate of the feeder in the system.

(4)馈线负载率优化：利用遗传算法优化系统中馈线的负载率，并重复步骤(3)中的计算过程，每进行一次优化后都需要校验是否满足系统的可靠性目标E，若能够满足则进行供电能力的计算，否则淘汰当前的馈线负载率，继续进行优化，直到计算结果趋于稳定或计算达到相应的迭代次数为止。(4) Feeder load rate optimization: use the genetic algorithm to optimize the load rate of the feeder in the system, and repeat the calculation process in step (3). After each optimization, it is necessary to check whether the reliability target E of the system is met. If it is satisfied, calculate the power supply capacity; otherwise, eliminate the current feeder load rate and continue to optimize until the calculation result tends to be stable or the calculation reaches the corresponding number of iterations.

(5)系统供电能力分析：通过基于可靠性的配电系统供电能力计算模型，利用Matlab求解系统的最大供电能力。(5) System power supply capacity analysis: Through the calculation model of power distribution system power supply capacity based on reliability, Matlab is used to solve the maximum power supply capacity of the system.

本发明的一种基于配电系统可靠性的中压配电网供电能力评估方法，能够从配电系统网架结构的角度出发，对已有配电网网架结构的可靠性进行分析，并且以配电系统中的可靠性指标作为约束条件，进而有针对性的在满足配电系统可靠性约束的前提下释放配电系统供电能力的裕度，挖掘供电潜能。本发明能够为现有配电网结构供电能力的提高提供支撑，有利于提升城市配电网规划的管理水平，促进城市电网建设结构与规划技术的合理发展。A method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system of the present invention can analyze the reliability of the existing distribution network structure from the perspective of the grid structure of the distribution system, and Taking the reliability index in the power distribution system as the constraint condition, the margin of the power supply capacity of the power distribution system is released on the premise of satisfying the reliability constraints of the power distribution system, and the potential of power supply is tapped. The invention can provide support for the improvement of the power supply capacity of the existing distribution network structure, is conducive to improving the management level of urban distribution network planning, and promotes the rational development of urban power grid construction structure and planning technology.

附图说明Description of drawings

图1是基于配电系统可靠性的中压配电网供电能力评估方法的流程图；Figure 1 is a flowchart of a method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system;

图2是系统主变联络关系示意图；Figure 2 is a schematic diagram of the main transformer contact relationship in the system;

图3是可靠性目标与系统供电能力之间关系。Figure 3 is the relationship between the reliability target and the system power supply capability.

具体实施方式detailed description

下面结合实施例和附图对本发明的一种基于配电系统可靠性的中压配电网供电能力评估方法做出详细说明。A method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system of the present invention will be described in detail below with reference to the embodiments and the accompanying drawings.

如图1所示，本发明的一种基于配电系统可靠性的中压配电网供电能力评估方法，包括如下步骤：As shown in Figure 1, a method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system of the present invention includes the following steps:

1)建立基于配电系统可靠性的中压配电网供电能力评估模型1) Establish a power supply capacity assessment model for medium-voltage distribution networks based on distribution system reliability

配电系统可靠性是指电力系统按能够接受的质量标准和所需数量不间断地向电力用户提供电力和电量的能力的量度，主要用以度量和评估电力系统向电力用户提供不间断的合格电能的能力。The reliability of power distribution system refers to the measurement of the power system's ability to provide power and electricity to power users without interruption according to acceptable quality standards and required quantities. power capacity.

供电能力是指在满足一定安全准则的条件下，一定区域内配电网最大能供应用户用电的能力，即配电网满足一定安全准则所能通过的最大功率量。The power supply capacity refers to the maximum power supply capacity of the distribution network in a certain area under the condition of meeting certain safety criteria, that is, the maximum amount of power that the distribution network can pass through to meet certain safety criteria.

本发明所提出的是在满足可靠性约束条件下中压配电系统的最大供电能力，即以高压变电站为源，中压馈线为网，并且考虑站间主变的联络转供关系计算系统的最大供电能力。The present invention proposes the maximum power supply capacity of the medium-voltage power distribution system under the condition of satisfying the reliability constraints, that is, the high-voltage substation is used as the source, the medium-voltage feeder is used as the network, and the calculation system of the connection and transfer relationship between the main transformers between stations is considered. Maximum power supply capacity.

以可靠性作为柔性约束条件构建配电系统供电能力模型，目标函数为满足系统可靠性要求下的配电网最大负荷供应能力，对于含有多个相互联络变电站的配电网而言，供电能力计算公式如下：The power supply capacity model of the distribution system is constructed with reliability as the flexible constraint condition. The objective function is to meet the maximum load supply capacity of the distribution network under the system reliability requirements. For a distribution network with multiple interconnected substations, the power supply capacity calculation The formula is as follows:

$\mathrm{<span><span>max</span>max</span>}\mathrm{<span><span>p</span>p</span>}\mathrm{<span><span>s</span>the\; s</span>}\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\underset{\mathrm{<span><span>i</span>i</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>)</span>)</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式中，psc为所计算配电系统的供电能力；R_i为第i台主变的额定容量；T_i为第i台主变的负载率；In the formula, psc is the power supply capacity of the calculated power distribution system; R_i is the rated capacity of the i-th main transformer; T_i is the load rate of the i-th main transformer;

以可靠性作为约束条件，结合配电系统自身运行特点，约束条件有以下几个：Taking reliability as the constraint condition, combined with the operating characteristics of the distribution system itself, the constraint conditions are as follows:

(1)可靠性等式约束(1) Reliability equality constraints

所述的可靠性等式约束条件表示的是根据配电系统结构所得到的相应可靠性指标，在评估系统的供电能力时选取可靠性指标中的平均供电可用度ASAI作为等式约束，平均供电可用度的含义是指在规定的时间内用户经受的不停电小时数与用户要求的总供电小时数之比，具体的计算方法为：The reliability equality constraints described above represent the corresponding reliability indicators obtained according to the power distribution system structure. When evaluating the power supply capacity of the system, the average power supply availability ASAI in the reliability indicators is selected as the equation constraint, and the average power supply The meaning of availability refers to the ratio of the uninterrupted hours experienced by the user to the total power supply hours required by the user within a specified period of time. The specific calculation method is:

式中，T为在规定时间内的需电小时数；U_j为负荷节点j的年停运时间；T_j为负荷节点j的用户数；N_j为负荷节点j的用户数。In the formula, T is the number of hours of electricity demand within the specified time; U_j is the annual outage time of load node j; T_j is the number of users of load node j; N_j is the number of users of load node j.

(2)可靠性不等式约束(2) Reliability inequality constraints

所述的可靠性不等式约束条件表示的是根据不同配电系统结构对于可靠性的要求所设定的不同可靠性目标，具体表现形式为：The reliability inequality constraints described above represent different reliability goals set according to the reliability requirements of different power distribution system structures, and the specific expressions are as follows:

ASAI≥E(3)ASAI≥E(3)

式中，E为结合配电系统运行基础所设定的可靠性目标。In the formula, E is the reliability target set in combination with the operation basis of the power distribution system.

(3)负荷约束(3) Load constraints

所述的负荷约束条件表示的是配电系统中各主变与所连接馈线之间的容量关系，具体表现形式为：The load constraints described above represent the capacity relationship between the main transformers and the connected feeders in the power distribution system, and the specific expressions are as follows:

${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>q</span>q</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}<span><span>)</span>)</span>$

式中，R_iq表示与第i台主变相连的第q条馈线的额定容量；T_iq表示与第i台主变相连的第q条馈线的负载率。In the formula, R_iq represents the rated capacity of the qth feeder connected to the i-th main transformer; T_iq represents the load rate of the q-th feeder connected to the i-th main transformer.

(4)负载率约束(4) Load rate constraints

所述的负载率约束条件表示的是所述的每一台主变负载率T_i和每一条馈线负载率T_iq的取值范围，具体表现形式为：The load rate constraint condition represents the value range of each main transformer load rate T_i and each feeder load rate T_iq , and the specific expression is as follows:

0≤T_i≤1(5)0≤T_i ≤1(5)

0≤T_iq≤1(6)0≤T_iq ≤1(6)

2)基于配电系统可靠性的中压配电网供电能力评估模型的求解方法2) The solution method of the power supply capacity evaluation model of the medium-voltage distribution network based on the reliability of the distribution system

由上一部分对于配电系统供电能力模型的分析可知，基于可靠性的供电能力评估问题是一个包含多个变量、多个约束的非线性最优规划问题。整个计算过程包含两个方面，即系统可靠性的求解，并检验是否满足可靠性约束；以及系统供电能力的求解。下面将对这两个部分进行具体的说明。From the analysis of the distribution system power supply capacity model in the previous part, it can be seen that the reliability-based power supply capacity assessment problem is a nonlinear optimal programming problem with multiple variables and constraints. The whole calculation process includes two aspects, that is, the solution of system reliability and checking whether the reliability constraints are satisfied; and the solution of system power supply capacity. These two parts will be described in detail below.

(1)配电系统可靠性计算(1) Distribution system reliability calculation

采用馈线分区的方法，并结合系统内各元件的可靠性参数计算系统的平均供电可用度ASAI，步骤1)的(1)中给出了平均供电可用度的计算方法，在具体计算的过程中负荷节点j的用户数N_j采用下式进行计算：The average power supply availability ASAI of the system is calculated by using the feeder zoning method and combining the reliability parameters of each component in the system. The calculation method of the average power supply availability is given in (1) of step 1). In the specific calculation process The number of users N_j of load node j is calculated using the following formula:

N_j＝n_jT_j(7)N_j =n_j T_j (7)

式中，n_j为负荷节点j所在馈线的负载能力达到100％时，负荷节点j的用户数；T_j为负荷节点j所在馈线的负载率。In the formula, n_j is the number of users of load node j when the load capacity of the feeder where load node j is located reaches 100%; T_j is the load rate of the feeder where load node j is located.

故平均供电可用度又可以表示为：Therefore, the average power supply availability can be expressed as:

$\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>\&Sigma;U</span>\&Sigma;U</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}{{\mathrm{<span><span>T\&Sigma;n</span>T\&Sigma;n</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>8</span>8</span>}<span><span>)</span>)</span>$

式中，负荷点j的年停运时间U_j在完全失去连通性(TLOC)事件下的可靠性评估中的计算方式为：In the formula, the annual outage time U_j of load point j in the reliability assessment under the total loss of connectivity (TLOC) event is calculated as:

${\mathrm{<span><span>U</span>u</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>r</span>r</span>}<span><span>\&Element;</span>\&Element;</span>{\mathrm{<span><span>I</span>I</span>}}_{\mathrm{<span><span>P</span>P</span>}}<span><span>(</span>(</span>\mathrm{<span><span>j</span>j</span>}<span><span>)</span>)</span>}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>p</span>p</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>t</span>t</span>}}_{\mathrm{<span><span>r</span>r</span>}\mathrm{<span><span>j</span>j</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>9</span>9</span>}<span><span>)</span>)</span>$

式中，I_P(j)集合中的元件r发生破坏性故障时将引起负荷点j的持续停电；p_r为元件r发生破坏性故障时对应动作的自动开关装置的可靠动作率；λ_r为元件r的平均年破坏性故障率；t_rj为元件r发生破坏性故障时造成负荷点节点j的停电时间，t_rj可能为故障修复时间或故障切换时间。In the formula, when the component r in the I_P(j) set has a destructive fault, it will cause a continuous power outage at the load point j; p_r is the reliable operation rate of the automatic switching device corresponding to the action when the component r has a destructive fault; λ_r is the average annual destructive failure rate of component r; t_rj is the power outage time of load point node j caused by destructive failure of component r, and t_rj may be the fault repair time or failover time.

基于上述过程，本发明所提及方法中可靠性计算的主要步骤是根据元件的可靠性参数计算出各类单一元件故障所造成负荷点的停电时间并建立系统的故障模式影响分析表(FMEA表)，进而计算各负荷点的年停电时间，最后计算出系统的可靠性指标，即平均供电可用度。Based on the above-mentioned process, the main step of reliability calculation in the method mentioned in the present invention is to calculate the outage time of the load point caused by various single component failures according to the reliability parameters of the components and to establish the failure mode impact analysis table (FMEA table) of the system ), and then calculate the annual outage time of each load point, and finally calculate the reliability index of the system, that is, the average power supply availability.

(2)配电系统供电能力计算(2) Calculation of power supply capacity of power distribution system

在满足可靠性约束的前提下，对馈线的负载率进行优化，优化的目标函数为系统的供电能力最大，基于可靠性的配电系统供电能力计算模型具体如下：Under the premise of satisfying the reliability constraints, the load rate of the feeder is optimized. The optimized objective function is the maximum power supply capacity of the system. The power supply capacity calculation model of the distribution system based on reliability is as follows:

$\mathrm{<span><span>max</span>max</span>}\mathrm{<span><span>p</span>p</span>}\mathrm{<span><span>s</span>the\; s</span>}\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\underset{\mathrm{<span><span>i</span>i</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>)</span>)</span>$

s.t.s.t.

$\left\{\begin{array}{c}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>\&Sigma;U</span>\&Sigma;U</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}{{\mathrm{<span><span>T\&Sigma;n</span>T\&Sigma;n</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}\\ {\mathrm{<span><span>U</span>u</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>r</span>r</span>}<span><span>\&Element;</span>\&Element;</span>{\mathrm{<span><span>I</span>I</span>}}_{\mathrm{<span><span>P</span>P</span>}}<span><span>(</span>(</span>\mathrm{<span><span>j</span>j</span>}<span><span>)</span>)</span>}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>p</span>p</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>t</span>t</span>}}_{\mathrm{<span><span>r</span>r</span>}\mathrm{<span><span>j</span>j</span>}}\\ \mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>\mathrm{<span><span>E</span>E.</span>}\\ {\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>q</span>q</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}\\ \mathrm{<span><span>0</span>0</span>}<span><span>\&le;</span>\&le;</span>{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>\&le;</span>\&le;</span>\mathrm{<span><span>1</span>1</span>}\\ \mathrm{<span><span>0</span>0</span>}<span><span>\&le;</span>\&le;</span>{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>\&le;</span>\&le;</span>\mathrm{<span><span>1</span>1</span>}\end{array}\right.<span><span>.</span>.</span>$

3)提出基于配电系统可靠性的中压配电网供电能力评估流程3) Propose a process for evaluating the power supply capacity of the medium-voltage distribution network based on the reliability of the distribution system

(1)系统可靠性分析：根据元件的故障率，分析单一元件故障所造成负荷点的停电时间，并依此建立系统的故障模式影响分析表FMEA表；(1) System reliability analysis: According to the failure rate of the components, analyze the outage time of the load point caused by the failure of a single component, and establish the FMEA table of the system failure mode impact analysis table accordingly;

(2)可靠性指标的求解：设定系统中馈线的初始负载率，并结合系统的故障模式影响分析表FMEA表计算系统中各负荷点的年停运时间，从而求解系统的平均供电可用度；(2) Solving the reliability index: set the initial load rate of the feeder in the system, and calculate the annual outage time of each load point in the system in combination with the failure mode impact analysis table FMEA table of the system, so as to solve the average power supply availability of the system ;

(3)约束条件校验：比较步骤2)中计算出的平均供电可用度ASAI指标与系统设置的可靠性目标E的大小关系，如果满足ASAI≥E关系，则计算在此情况下的初始供电能力；否则，优化系统中馈线的负载率后重新计算系统的平均供电可用度ASAI指标。(3) Constraint condition verification: compare the relationship between the average power supply availability ASAI index calculated in step 2) and the reliability target E set by the system, and if the ASAI≥E relationship is satisfied, then calculate the initial power supply in this case capacity; otherwise, recalculate the average power supply availability ASAI index of the system after optimizing the load rate of the feeder in the system.

(4)馈线负载率优化：利用遗传算法优化系统中馈线的负载率，并重复步骤(3)中的计算过程，每进行一次优化后都需要校验是否满足系统的可靠性目标E，若能够满足则进行供电能力的计算，否则淘汰当前的馈线负载率，继续进行优化，直到计算结果趋于稳定或计算达到相应的迭代次数为止。(4) Feeder load rate optimization: use the genetic algorithm to optimize the load rate of the feeder in the system, and repeat the calculation process in step (3). After each optimization, it is necessary to check whether the reliability target E of the system is met. If it is satisfied, calculate the power supply capacity; otherwise, eliminate the current feeder load rate and continue to optimize until the calculation result tends to be stable or the calculation reaches the corresponding number of iterations.

(5)系统供电能力分析：通过基于可靠性的配电系统供电能力计算模型，利用Matlab求解系统的最大供电能力。(5) System power supply capacity analysis: Through the calculation model of power distribution system power supply capacity based on reliability, Matlab is used to solve the maximum power supply capacity of the system.

下面给出最佳实例The best examples are given below

以某地区的实际配电网结构为算例，建立基于主变互联关系的联络模型，并按照N-1准则以及负荷约束将其扩展到馈线层面，对其网架结构的可靠性进行分析，并且在可靠性指标的约束条件下计算该网架结构下的最大供电能力。Taking the actual distribution network structure in a certain area as an example, a connection model based on the interconnection of main transformers is established, and it is extended to the feeder level according to the N-1 criterion and load constraints, and the reliability of its grid structure is analyzed. And the maximum power supply capacity under the grid structure is calculated under the constraints of the reliability index.

(1)网架结构可靠性的确定(1) Determination of the reliability of the grid structure

该地区的变互联关系的联络结构如图2所示，各变电站相关信息如表1所示，在进行可靠性计算的过程中重点考虑网架结构中单一元件的故障对于负荷点的影响，具体包括：主变故障、母线故障、配电变压器故障、断路器故障、线路故障和开关故障等，各类元件的可靠性参数如表2所示。The connection structure of the substation interconnection relationship in this area is shown in Figure 2, and the relevant information of each substation is shown in Table 1. In the process of reliability calculation, the influence of the failure of a single component in the grid structure on the load point is mainly considered. Including: main transformer failure, bus failure, distribution transformer failure, circuit breaker failure, line failure and switch failure, etc. The reliability parameters of various components are shown in Table 2.

表1算例中变电站配置情况表Table 1. Substation configuration table in the calculation example

表2系统中主要元件可靠性参数Table 2 Reliability parameters of main components in the system

元件elementλlambdarrr_pr_p母线busbar0.0010.00155－-馈线feeder0.0650.06555－-配电变压器distribution transformer0.0130.013－-55分段开关Segment switch0.0060.00655－-主变Main transformer0.010.01200200－-高压断路器High voltage circuit breaker0.0020.0025050－-低压断路器Low voltage circuit breaker0.0050.0052020－-

表2中，λ为各元件的平均故障率，单位为次/年，对于馈线为次/年˙km，对于主变为次/台˙年；r为平均修复时间、r_p为平均替换时间，单位均为小时。In Table 2, λ is the average failure rate of each component, the unit is times/year, for the feeder it is times/year ˙km, for the main transformer times/unit ˙year; r is the average repair time, r_p is the average replacement time , the unit is hour.

基于上述说明，算例的整体情况包括三个变电站、六台主变、28条馈线、352个负荷节点(11个工业负荷节点、62个商业负荷节点、279个居民负荷节点)、436个315kV的配电变压器。Based on the above description, the overall situation of the calculation example includes three substations, six main transformers, 28 feeders, 352 load nodes (11 industrial load nodes, 62 commercial load nodes, 279 residential load nodes), 436 315kV load nodes distribution transformers.

利用馈线分区法计算此配电系统网络的可靠性指标，得到此配电系统网络的平均供电可用度指标(ASAI)为0.9993。考虑到对于不同的地区，不同的负荷分布，对于配电系统的可靠性指标有着不同的要求。因此，再选取平均供电可用度指标(ASAI)从0.9900到0.9990作为约束条件，计算在此约束条件下配电系统的最大供电能力，计算结果如表3所示：The reliability index of the distribution system network is calculated by the feeder zoning method, and the average supply availability index (ASAI) of the distribution system network is obtained as 0.9993. Considering different regions and different load distributions, there are different requirements for the reliability index of the power distribution system. Therefore, the average power supply availability index (ASAI) from 0.9900 to 0.9990 is selected as the constraint condition, and the maximum power supply capacity of the power distribution system is calculated under this constraint condition. The calculation results are shown in Table 3:

表3可靠性目标与供电能力之间的关系分析Table 3 Analysis of the relationship between reliability objectives and power supply capacity

将上述结果绘制成曲线图以便更好的说明展示结果的趋势，曲线图如图3所示：Draw the above results into a graph to better illustrate the trend of the display results. The graph is shown in Figure 3:

根据上述结果可以分析得到：在一定的可靠性范围内，系统的最大供电能力维持不变；如果提高系统的可靠性指标即平均供电可用度，意味着系统中负荷的可转供裕度增加，而系统中所带的负荷量降低，造成供电能力下降。不同的可靠性指标约束可以得到不同的供电能力结果，因此，本发明中所使用的基于可靠性的约束条件是属于一种柔性约束条件，可以根据不同的可靠性需求调整不同的结果。在目前的电网建设中，网架结构已经相对成型，因此很难再从已有的网架结构中做出有效的拓展，因此本发明在已有网架结构的基础上通过柔性的约束条件，既能够满足生产运行中的要求，又可以释放供电潜力，在现实的配电网规划中更实用并具有一定的指导意义。According to the above results, it can be analyzed that within a certain reliability range, the maximum power supply capacity of the system remains unchanged; if the reliability index of the system, that is, the average power supply availability, is increased, it means that the load transferable margin in the system increases. And the load carried by the system decreases, resulting in a decrease in power supply capacity. Different reliability index constraints can obtain different power supply capability results. Therefore, the reliability-based constraint conditions used in the present invention belong to a kind of flexible constraint conditions, and different results can be adjusted according to different reliability requirements. In the current power grid construction, the grid structure has been relatively formed, so it is difficult to make effective expansion from the existing grid structure, so the present invention uses flexible constraints on the basis of the existing grid structure, It can not only meet the requirements of production and operation, but also release the potential of power supply. It is more practical and has certain guiding significance in the actual distribution network planning.

Claims (9)

Translated fromChinese

1.一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，包括如下步骤：1. A method for evaluating the power supply capacity of a medium-voltage distribution network based on distribution system reliability, characterized in that it comprises the steps:1)建立基于配电系统可靠性的中压配电网供电能力评估模型1) Establish a power supply capacity assessment model for medium-voltage distribution networks based on distribution system reliability以可靠性作为柔性约束条件构建配电系统供电能力模型，目标函数为满足系统可靠性要求下的配电网最大负荷供应能力，对于含有多个相互联络变电站的配电网而言，供电能力计算公式如下：The power supply capacity model of the distribution system is constructed with reliability as the flexible constraint condition. The objective function is to meet the maximum load supply capacity of the distribution network under the system reliability requirements. For a distribution network with multiple interconnected substations, the power supply capacity calculation The formula is as follows:$\mathrm{<span><span>max</span>max</span>}\mathrm{<span><span>p</span>p</span>}\mathrm{<span><span>s</span>the\; s</span>}\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\underset{\mathrm{<span><span>i</span>i</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>)</span>)</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$式中，psc为所计算配电系统的供电能力；R_i为第i台主变的额定容量；T_i为第i台主变的负载率；In the formula, psc is the power supply capacity of the calculated power distribution system; R_i is the rated capacity of the i-th main transformer; T_i is the load rate of the i-th main transformer;2)基于配电系统可靠性的中压配电网供电能力评估模型的求解方法2) The solution method of the power supply capacity evaluation model of the medium-voltage distribution network based on the reliability of the distribution system整个计算过程包含两个方面，一是配电系统可靠性的求解计算，并检验是否满足可靠性约束；二是配电系统供电能力计算；The whole calculation process includes two aspects, one is the solution calculation of the reliability of the distribution system, and check whether the reliability constraints are satisfied; the other is the calculation of the power supply capacity of the distribution system;3)提出基于配电系统可靠性的中压配电网供电能力评估流程。3) A power supply capability assessment process for medium-voltage distribution networks based on distribution system reliability is proposed.2.根据权利要求1所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，步骤1)所述的以可靠性作为柔性约束条件，是结合配电系统自身运行特点，有以下几个约束条件：2. A method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system according to claim 1, wherein in step 1), the reliability is used as a flexible constraint condition in combination with the power distribution system The operating characteristics of the system itself have the following constraints:(1)可靠性等式约束条件、(2)可靠性不等式约束条件、(3)负荷约束条件和(4)负载率约束条件。(1) Reliability equality constraints, (2) Reliability inequality constraints, (3) Load constraints and (4) Load rate constraints.3.根据权利要求2所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，所述的可靠性等式约束，是根据配电系统结构所得到的相应可靠性指标，在评估系统的供电能力时选取可靠性指标中的平均供电可用度ASAI作为等式约束，平均供电可用度的含义是指在规定的时间内用户经受的不停电小时数与用户要求的总供电小时数之比，具体的计算方法为：3. A method for evaluating the power supply capacity of a medium-voltage distribution network based on distribution system reliability according to claim 2, wherein the reliability equation constraint is obtained according to the structure of the distribution system Corresponding to the reliability index, when evaluating the power supply capacity of the system, the average power supply availability ASAI in the reliability index is selected as the equation constraint. The ratio of the total required hours of power supply, the specific calculation method is:式中，T为在规定时间内的需电小时数；U_j为负荷节点j的年停运时间；T_j为负荷节点j的用户数；N_j为负荷节点j的用户数。In the formula, T is the number of hours of electricity demand within the specified time; U_j is the annual outage time of load node j; T_j is the number of users of load node j; N_j is the number of users of load node j.4.根据权利要求2所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，所述的可靠性不等式约束条件，是根据不同配电系统结构对于可靠性的要求所设定的不同可靠性目标，具体表现形式为：4. A method for evaluating the power supply capacity of a medium-voltage distribution network based on distribution system reliability according to claim 2, wherein the reliability inequality constraints are based on different distribution system structures for reliable The different reliability goals set by the requirements of sex, the specific manifestations are:ASAI≥E(3)ASAI≥E(3)式中，E为结合配电系统运行基础所设定的可靠性目标。In the formula, E is the reliability target set in combination with the operation basis of the power distribution system.5.根据权利要求2所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，所述的负荷约束条件，是配电系统中各主变与所连接馈线之间的容量关系，具体表现形式为：5. A method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system according to claim 2, wherein the load constraint condition is that each main transformer in the distribution system and the connected The capacity relationship between feeders is expressed in the form of:${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>q</span>q</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}<span><span>)</span>)</span>$式中，R_iq表示与第i台主变相连的第q条馈线的额定容量；T_iq表示与第i台主变相连的第q条馈线的负载率。In the formula, R_iq represents the rated capacity of the qth feeder connected to the i-th main transformer; T_iq represents the load rate of the q-th feeder connected to the i-th main transformer.6.根据权利要求2所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，所述的负载率约束条件表示的是所述的每一台主变负载率T_i和每一条馈线负载率T_iq的取值范围，具体表现形式为：6. A method for evaluating the power supply capacity of a medium-voltage distribution network based on the reliability of the distribution system according to claim 2, wherein the load rate constraints represent that each of the main transformers The load rate T_i and the value range of each feeder load rate T_iq are expressed in the following forms:0≤T_i≤1(5)0≤T_i ≤1(5)0≤T_iq≤1(6)。0 ≤ T_iq ≤ 1 (6).7.根据权利要求1所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，步骤2)中所述的配电系统可靠性计算，是采用馈线分区的方法，并结合系统内各元件的可靠性参数计算系统的平均供电可用度ASAI，步骤1)的(1)中给出了平均供电可用度的计算方法，在具体计算的过程中负荷节点j的用户数N_j采用下式进行计算：7. A method for evaluating the power supply capacity of a medium-voltage distribution network based on distribution system reliability according to claim 1, wherein the distribution system reliability calculation described in step 2) is to use feeder partitions method, and combined with the reliability parameters of each component in the system to calculate the average power supply availability ASAI of the system, step 1) (1) gives the calculation method of the average power supply availability, in the specific calculation process load node j The number of users N_j is calculated using the following formula:N_j＝n_jT_j(7)N_j =n_j T_j (7)式中，n_j为负荷节点j所在馈线的负载能力达到100％时，负荷节点j的用户数；T_j为负荷节点j所在馈线的负载率；In the formula, n_j is the number of users of load node j when the load capacity of the feeder where load node j is located reaches 100%; T_j is the load rate of the feeder where load node j is located;故平均供电可用度又表示为：Therefore, the average power supply availability is expressed as:$\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>\&Sigma;U</span>\&Sigma;U</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}{{\mathrm{<span><span>T\&Sigma;n</span>T\&Sigma;n</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>8</span>8</span>}<span><span>)</span>)</span>$式中，负荷点j的年停运时间U_j在完全失去连通性时间下的可靠性评估中的计算方式为：In the formula, the calculation method of the annual outage time U_j of the load point j in the reliability evaluation under the time of complete loss of connectivity is:${\mathrm{<span><span>U</span>u</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>r</span>r</span>}<span><span>\&Element;</span>\&Element;</span>{\mathrm{<span><span>I</span>I</span>}}_{\mathrm{<span><span>P</span>P</span>}}<span><span>(</span>(</span>\mathrm{<span><span>j</span>j</span>}<span><span>)</span>)</span>}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>p</span>p</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>t</span>t</span>}}_{\mathrm{<span><span>r</span>r</span>}\mathrm{<span><span>j</span>j</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>9</span>9</span>}<span><span>)</span>)</span>$式中，I_P(j)集合中的元件r发生破坏性故障时将引起负荷点j的持续停电；p_r为元件r发生破坏性故障时对应动作的自动开关装置的可靠动作率；λ_r为元件r的平均年破坏性故障率；t_rj为元件r发生破坏性故障时造成负荷点节点j的停电时间，t_rj可能为故障修复时间或故障切换时间。In the formula, when the component r in the I_P(j) set has a destructive fault, it will cause a continuous power outage at the load point j; p_r is the reliable operation rate of the automatic switching device corresponding to the action when the component r has a destructive fault; λ_r is the average annual destructive failure rate of component r; t_rj is the power outage time of load point node j caused by destructive failure of component r, and t_rj may be the fault repair time or failover time.8.根据权利要求1所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，步骤2)中所述的配电系统供电能力计算，是在满足可靠性约束的前提下，对馈线的负载率进行优化，优化的目标函数为系统的供电能力最大，基于可靠性的配电系统供电能力计算模型具体如下：8. A method for evaluating power supply capacity of a medium-voltage distribution network based on distribution system reliability according to claim 1, wherein the power supply capacity calculation of the power distribution system described in step 2) is based on reliable Under the premise of linear constraints, the load rate of the feeder is optimized, and the optimized objective function is the maximum power supply capacity of the system. The power supply capacity calculation model of the distribution system based on reliability is as follows:$\mathrm{<span><span>max</span>max</span>}\mathrm{<span><span>p</span>p</span>}\mathrm{<span><span>s</span>the\; s</span>}\mathrm{<span><span>c</span>c</span>}<span><span>=</span>=</span>\underset{\mathrm{<span><span>i</span>i</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>)</span>)</span>$s.t.s.t.$\left\{\begin{array}{c}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>=</span>=</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>\frac{{\mathrm{<span><span>\&Sigma;U</span>\&Sigma;\; U</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>n</span>no</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}{{\mathrm{<span><span>T\&Sigma;n</span>T\&Sigma;n</span>}}_{\mathrm{<span><span>j</span>j</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}}\\ {\mathrm{<span><span>U</span>u</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>r</span>r</span>}<span><span>\&Element;</span>\&Element;</span>{\mathrm{<span><span>I</span>I</span>}}_{\mathrm{<span><span>P</span>P</span>}}<span><span>(</span>(</span>\mathrm{<span><span>j</span>j</span>}<span><span>)</span>)</span>}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>p</span>p</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>\&lambda;</span>\&lambda;</span>}}_{\mathrm{<span><span>r</span>r</span>}}{\mathrm{<span><span>t</span>t</span>}}_{\mathrm{<span><span>r</span>r</span>}\mathrm{<span><span>j</span>j</span>}}\\ \mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>A</span>A</span>}\mathrm{<span><span>I</span>I</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>\mathrm{<span><span>E</span>E.</span>}\\ {\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>=</span>=</span>\underset{\mathrm{<span><span>q</span>q</span>}}{<span><span>\&Sigma;</span>\&Sigma;</span>}{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>q</span>q</span>}}\\ \mathrm{<span><span>0</span>0</span>}<span><span>\&le;</span>\&le;</span>{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>i</span>i</span>}}<span><span>\&le;</span>\&le;</span>\mathrm{<span><span>1</span>1</span>}\\ \mathrm{<span><span>0</span>0</span>}<span><span>\&le;</span>\&le;</span>{\mathrm{<span><span>T</span>T</span>}}_{\mathrm{<span><span>j</span>j</span>}}<span><span>\&le;</span>\&le;</span>\mathrm{<span><span>1</span>1</span>}\end{array}\right.<span><span>.</span>.</span>$9.根据权利要求1所述的一种基于配电系统可靠性的中压配电网供电能力评估方法，其特征在于，步骤3)所述的基于配电系统可靠性的中压配电网供电能力评估流程，包括：9. A method for evaluating the power supply capacity of a medium-voltage distribution network based on distribution system reliability according to claim 1, wherein the medium-voltage distribution network based on distribution system reliability in step 3) Power supply capacity assessment process, including:(1)系统可靠性分析：根据元件的故障率，分析单一元件故障所造成负荷点的停电时间，并依此建立系统的故障模式影响分析表FMEA表；(1) System reliability analysis: According to the failure rate of the components, analyze the outage time of the load point caused by the failure of a single component, and establish the FMEA table of the system failure mode impact analysis table accordingly;(2)可靠性指标的求解：设定系统中馈线的初始负载率，并结合系统的故障模式影响分析表FMEA表计算系统中各负荷点的年停运时间，从而求解系统的平均供电可用度；(2) Solving the reliability index: set the initial load rate of the feeder in the system, and calculate the annual outage time of each load point in the system in combination with the failure mode impact analysis table FMEA table of the system, so as to solve the average power supply availability of the system ;(3)约束条件校验：比较步骤2)中计算出的平均供电可用度ASAI指标与系统设置的可靠性目标E的大小关系，如果满足ASAI≥E关系，则计算在此情况下的初始供电能力；否则，优化系统中馈线的负载率后重新计算系统的平均供电可用度ASAI指标。(3) Constraint condition verification: compare the relationship between the average power supply availability ASAI index calculated in step 2) and the reliability target E set by the system, and if the ASAI≥E relationship is satisfied, then calculate the initial power supply in this case capacity; otherwise, recalculate the average power supply availability ASAI index of the system after optimizing the load rate of the feeder in the system.(4)馈线负载率优化：利用遗传算法优化系统中馈线的负载率，并重复步骤(3)中的计算过程，每进行一次优化后都需要校验是否满足系统的可靠性目标E，若能够满足则进行供电能力的计算，否则淘汰当前的馈线负载率，继续进行优化，直到计算结果趋于稳定或计算达到相应的迭代次数为止。(4) Feeder load rate optimization: use the genetic algorithm to optimize the feeder load rate in the system, and repeat the calculation process in step (3). After each optimization, it is necessary to check whether the reliability target E of the system is met. If it is satisfied, calculate the power supply capacity; otherwise, eliminate the current feeder load rate and continue to optimize until the calculation result tends to be stable or the calculation reaches the corresponding number of iterations.(5)系统供电能力分析：通过基于可靠性的配电系统供电能力计算模型，利用Matlab求解系统的最大供电能力。(5) System power supply capacity analysis: Through the calculation model of power distribution system power supply capacity based on reliability, use Matlab to solve the maximum power supply capacity of the system.