CN103414186B - Based on the distributed-type frequency modulation of inverter under microgrid off-network pattern - Google Patents

Abstract

Translated fromChinese

本发明公开了一种微网离网模式下利用发电和储能系统逆变器分布式调频方法，当微网处于离网模式时，微网中各个发电系统和储能系统的逆变器的输出功率随系统频率变化而变化，从而保证离网运行的微网系统的频率偏差在可接受的范围内。本发明能够利用微电网中现有的发电和储能系统的逆变器在微网频率发生偏移的时候调节输出功率稳定微网频率，节约微电网中用于稳定系统频率设备的投资。

The invention discloses a distributed frequency modulation method using inverters of power generation and energy storage systems in the off-grid mode of the microgrid. The output power changes with the system frequency, so as to ensure that the frequency deviation of the off-grid microgrid system is within an acceptable range. The present invention can utilize the inverter of the existing power generation and energy storage system in the micro-grid to adjust the output power to stabilize the frequency of the micro-grid when the frequency of the micro-grid deviates, saving the investment in the equipment used to stabilize the system frequency in the micro-grid.

Description

Translated fromChinese

微网离网模式下基于逆变器的分布式调频方法Distributed frequency regulation method based on inverter in microgrid off-grid mode

技术领域technical field

本发明属于微网逆变器技术领域，尤其涉及离网运行时的调频方法。The invention belongs to the technical field of micro-grid inverters, and in particular relates to a frequency modulation method during off-grid operation.

背景技术Background technique

目前，微电网正在得到关注。微电网有并网和离网两种模式。在离网模式下，微电网与主网断开。由于微电网转动惯量比较小，因而此时频率控制就成为重要的问题。由于微电网中存在不少发电系统和储能系统，它们的并网逆变器可以在微电网频率发生偏差时调节输出功率，从而稳定系统的频率，并节约了微电网中用来稳定频率的设备投资。Currently, microgrids are gaining attention. There are two modes of microgrids: grid-connected and off-grid. In off-grid mode, the microgrid is disconnected from the main grid. Since the moment of inertia of the microgrid is relatively small, frequency control becomes an important issue at this time. Since there are many power generation systems and energy storage systems in the microgrid, their grid-connected inverters can adjust the output power when the frequency of the microgrid deviates, thereby stabilizing the frequency of the system and saving the energy used to stabilize the frequency in the microgrid. equipment investment.

发明内容Contents of the invention

发明目的：针对上述现有存在的问题和不足，本发明提供了提出一种微网离网模式下利用发电和储能系统逆变器分布式调频方法，稳定系统频率。Purpose of the invention: Aiming at the above existing problems and deficiencies, the present invention provides a distributed frequency modulation method using inverters of power generation and energy storage systems in the microgrid off-grid mode to stabilize the system frequency.

技术方案：为实现上述发明目的，本发明采用以下技术方案：一种微网离网模式下基于逆变器的分布式调频方法，当微网处于离网模式时，微网中各个发电系统和储能系统的逆变器的输出功率随系统频率变化而变化，该变化规律如下：从而保证离网运行的微网系统的频率偏差在可接受范围内；Technical solution: In order to achieve the purpose of the above invention, the present invention adopts the following technical solution: a distributed frequency regulation method based on inverters in the off-grid mode of the microgrid. When the microgrid is in the off-grid mode, each power generation system in the microgrid and The output power of the inverter of the energy storage system changes with the system frequency, and the change rule is as follows: so as to ensure that the frequency deviation of the off-grid microgrid system is within an acceptable range;

当微电网处于离网运行状态时，微网中各个发电系统的逆变器控制模式切换到带死区的下垂控制模式，逆变器的有功输出和频率的偏差变化如公式（1）所示：When the microgrid is in off-grid operation state, the inverter control mode of each power generation system in the microgrid is switched to the droop control mode with dead zone, and the deviation of the active output and frequency of the inverter is shown in formula (1) :

$\mathrm{<span><span>P</span>P</span>}<span><span>=</span>=</span>\left\{\begin{array}{c}\mathrm{<span><span>0</span>0</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>\&Delta;f</span>\&Delta;f</span>}<span><span>></span>></span>\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span>></span>></span>\mathrm{<span><span>0</span>0</span>}<span><span>)</span>)</span>\\ \mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;</span>K\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span><</span><</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span><</span><</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\\ {\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\end{array}\right.<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

其中，P为各个发电系统的逆变器的输出功率，K是输出功率和系统频率偏差之间的比例系统，Δf表示系统的频率偏差，Δf_th表示频率死区的截止值；所述频率死区是因为系统的频率通常会发生微小波动，这些波动在系统的允许范围内，逆变器没有必要为此频繁调整输出功率；P_max表示发电系统输出功率的最大值；Among them, P is the output power of the inverter of each power generation system, K is the proportional system between the output power and the system frequency deviation, Δf represents the frequency deviation of the system, and Δf_th represents the cut-off value of the frequency dead zone; the frequency dead zone The reason is that the frequency of the system usually fluctuates slightly, these fluctuations are within the allowable range of the system, and the inverter does not need to adjust the output power frequently; P_max indicates the maximum output power of the power generation system;

当微电网处于离网运行状态时，微网中各个储能系统的逆变器控制模式切换到改进型带死区的下垂控制模式，逆变器的有功输出和频率的偏差变化如公式（2）所示：When the microgrid is in off-grid operation state, the inverter control mode of each energy storage system in the microgrid is switched to the improved droop control mode with dead zone, and the deviation of the active output and frequency of the inverter changes as shown in the formula (2 ) as shown in:

$\mathrm{<span><span>P</span>P</span>}<span><span>=</span>=</span>\left\{\begin{array}{c}\mathrm{<span><span>0</span>0</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>\&Delta;f</span>\&Delta;\; f</span>}<span><span>></span>></span>\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span>></span>></span>\mathrm{<span><span>0</span>0</span>}<span><span>)</span>)</span>\\ \mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;</span>K\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span><</span><</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span><</span><</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\\ {\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\end{array}\right.$

$\mathrm{<span><span>K</span>K</span>}<span><span>=</span>=</span>{\mathrm{<span><span>K</span>K</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>\{</span>\{</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>{<span><span>(</span>(</span>\frac{\mathrm{<span><span>SOC</span>SOC</span>}<span><span>-</span>-</span>{\mathrm{<span><span>SOC</span>SOC</span>}}_{\mathrm{<span><span>low</span>low</span>}<span><span>(</span>(</span>\mathrm{<span><span>high</span>high</span>}<span><span>)</span>)</span>}}{{\mathrm{<span><span>SOC</span>SOC</span>}}_{\mathrm{<span><span>max</span>max</span>}<span><span>(</span>(</span>\mathrm{<span><span>min</span>min</span>}<span><span>)</span>)</span>}<span><span>-</span>-</span>{\mathrm{<span><span>SOC</span>SOC</span>}}_{\mathrm{<span><span>low</span>low</span>}<span><span>(</span>(</span>\mathrm{<span><span>high</span>high</span>}<span><span>)</span>)</span>}}<span><span>)</span>)</span>}^{\mathrm{<span><span>n</span>no</span>}}<span><span>\}</span>\}</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>2</span>2</span>}<span><span>)</span>)</span>$

其中，P是各个储能系统的逆变器的输出功率，K是输出功率和系统频率偏差之间的比例系统；Δf表示系统的频率偏差，Δf_th表示频率死区的截止值；所述改进型带死区是因为系统的频率通常会发生微小波动，这些波动在系统的允许范围内，逆变器没有必要为此频繁调整输出功率；P_max表示储能系统输出功率的最大值；K_max表示输出功率和系统频率偏差之间的比例系统的最大值SOC_max和SOC_min分别表示逆变器储能的SOC最大和最小值，SOC_low和SOC_high表示逆变器在调整时储能允许的SOC最大和最小值；n取2。Among them, P is the output power of the inverter of each energy storage system, K is the proportional system between the output power and the system frequency deviation; Δf represents the frequency deviation of the system, Δf_th represents the cut-off value of the frequency dead zone; the improved The type has a dead zone because the frequency of the system usually fluctuates slightly, and these fluctuations are within the allowable range of the system, and the inverter does not need to adjust the output power frequently; P_max indicates the maximum output power of the energy storage system; K_max Indicates the ratio between the output power and the system frequency deviation. The maximum SOC_max and SOC_min of the system indicate the maximum and minimum SOC values of the inverter energy storage, respectively. SOC_low and SOC_high indicate the allowable energy storage of the inverter during adjustment. SOC maximum and minimum; n takes 2.

作为优选，公式（1）中K选取为200；Δf_th选取0.1Hz。As a preference, K in formula (1) is selected as 200; Δf_th is selected as 0.1 Hz.

作为优选，公式（2）中K选取为200；SOC_max和SOC_min分别取为10%和90%；SOC_low和SOC_high取为20%和80%。As a preference, K in the formula (2) is selected as 200; SOC_max and SOC_min are respectively selected as 10% and 90%; SOC_low and SOC_high are selected as 20% and 80%.

有益效果：与现有技术相比，本发明具有以下优点：首先能够利用微电网中现有的发电和储能系统的逆变器在微网频率发生偏移的时候调节输出功率，有助于稳定微网频率，节约微电网中用于稳定系统频率设备的投资；第二，考虑了储能系统SOC的约束，能够根据不同的SOC状态调整逆变器的输出功率幅值，在满足储能系统SOC约束的情况下调节系统频率。第三，新型设计的逆变器控制策略不需要增加新的控制装置，可以在原有的设备上完成。Beneficial effects: Compared with the prior art, the present invention has the following advantages: firstly, the inverter of the existing power generation and energy storage system in the microgrid can be used to adjust the output power when the frequency of the microgrid deviates, which helps Stabilize the frequency of the microgrid and save the investment in the equipment used to stabilize the system frequency in the microgrid; secondly, considering the constraints of the SOC of the energy storage system, the output power amplitude of the inverter can be adjusted according to different SOC states to meet the energy storage requirements. Adjust system frequency in case of system SOC constraints. Third, the newly designed inverter control strategy does not need to add new control devices, and can be completed on the original equipment.

附图说明Description of drawings

图1为本发明所述微网离网模式下利用发电和储能系统逆变器分布式调频方法的工作原理示意图。Fig. 1 is a schematic diagram of the working principle of the distributed frequency regulation method using the inverter of the power generation and energy storage system in the off-grid mode of the microgrid according to the present invention.

具体实施方式detailed description

下面结合附图和具体实施例，进一步阐明本发明，应理解这些实施例仅用于说明本发明而不用于限制本发明的范围，在阅读了本发明之后，本领域技术人员对本发明的各种等价形式的修改均落于本申请所附权利要求所限定的范围。Below in conjunction with accompanying drawing and specific embodiment, further illustrate the present invention, should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various aspects of the present invention Modifications in equivalent forms all fall within the scope defined by the appended claims of this application.

本发明微网离网模式下利用发电和储能系统逆变器分布式调频方法，具体为：当微网处于离网模式时，微网中各个发电系统和储能系统的逆变器的输出功率随系统频率变化而变化，从而保证离网运行的微网系统的频率偏差在可接受的范围内。其中，所述微网中发电系统的逆变器采用带死区的下垂控制；所述微网中储能系统的逆变器采用改进型带死区的下垂控制，输出功率和频率偏差的比例系数和储能系统的SOC状态有关。In the microgrid off-grid mode of the present invention, the distributed frequency modulation method using the inverter of the power generation and energy storage system is specifically: when the microgrid is in the off-grid mode, the output of the inverters of each power generation system and energy storage system in the microgrid The power varies with the system frequency, so as to ensure that the frequency deviation of the off-grid microgrid system is within an acceptable range. Wherein, the inverter of the power generation system in the microgrid adopts droop control with a dead zone; the inverter of the energy storage system in the microgrid adopts an improved droop control with a dead zone, and the ratio of the output power to the frequency deviation is The coefficient is related to the SOC state of the energy storage system.

当微电网处于离网运行状态时，微网中各个发电系统的逆变器控制模式切换到带死区的下垂控制模式，逆变器的有功输出和频率的偏差变化如下公式所示：When the microgrid is in off-grid operation state, the inverter control mode of each power generation system in the microgrid is switched to the droop control mode with dead zone, and the deviation of the active output and frequency of the inverter is shown in the following formula:

$\mathrm{<span><span>P</span>P</span>}<span><span>=</span>=</span>\left\{\begin{array}{c}\mathrm{<span><span>0</span>0</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>\&Delta;f</span>\&Delta;\; f</span>}<span><span>></span>></span>\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span>></span>></span>\mathrm{<span><span>0</span>0</span>}<span><span>)</span>)</span>\\ \mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;</span>K\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span><</span><</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span><</span><</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\\ {\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\end{array}\right.$

其中，P是各个发电系统的逆变器的输出功率，K是输出功率和系统频率偏差之间的比例系统，通常可以选取为200，而Δf表示系统的频率偏差，Δf_th表示频率死区的截止值。设定死区是因为系统的频率通常会发生微小波动，这些波动在系统的允许范围内，逆变器没有必要为此频繁调整输出功率。Δf_th可选取0.1Hz。P_max表示发电系统输出功率的最大值。Among them, P is the output power of the inverter of each power generation system, K is the proportional system between the output power and the system frequency deviation, which can usually be selected as 200, and Δf represents the frequency deviation of the system, and Δf_th represents the frequency dead zone cutoff value. The dead zone is set because the frequency of the system usually fluctuates slightly, and these fluctuations are within the allowable range of the system, and the inverter does not need to adjust the output power frequently for this. Δf_th can be selected as 0.1Hz. P_max represents the maximum output power of the power generation system.

当微电网处于离网运行状态时，微网中各个储能系统的逆变器控制模式切换到改进型带死区的下垂控制模式，逆变器的有功输出和频率的偏差变化如下公式所示：When the microgrid is in off-grid operation state, the inverter control mode of each energy storage system in the microgrid is switched to the improved droop control mode with dead zone, and the deviation of the active output and frequency of the inverter is shown in the following formula :

$\mathrm{<span><span>P</span>P</span>}<span><span>=</span>=</span>\left\{\begin{array}{c}\mathrm{<span><span>0</span>0</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>\&Delta;f</span>\&Delta;f</span>}<span><span>></span>></span>\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span>></span>></span>\mathrm{<span><span>0</span>0</span>}<span><span>)</span>)</span>\\ \mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;</span>K\&Delta;</span>}{\mathrm{<span><span>f</span>f</span>}}_{\mathrm{<span><span>th</span>the\; th</span>}}<span><span><</span><</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span><</span><</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\\ {\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>,</span>,</span><span><span>(</span>(</span>\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>)</span>)</span>\end{array}\right.$

其中$K=K_{\max }\{1-{\left(\frac{\mathrm{SOC}-{\mathrm{SOC}}_{\mathrm{low}\left(\mathrm{high}\right)}}{{\mathrm{SOC}}_{\max \left(\min \right)}-{\mathrm{SOC}}_{\mathrm{low}\left(\mathrm{high}\right)}}\right)}^n\}$in$K=K_{\max }\{1-{\left(\frac{\mathrm{SOC}-{\mathrm{SOC}}_{\mathrm{low}\left(\mathrm{high}\right)}}{{\mathrm{SOC}}_{\max \left(\min \right)}-{\mathrm{SOC}}_{\mathrm{low}\left(\mathrm{high}\right)}}\right)}^{\mathrm{no}}\}$

其中，P是各个储能系统的逆变器的输出功率，K是输出功率和系统频率偏差之间的比例系统，通常可以选取为200，而Δf表示系统的频率偏差，Δf_th表示频率死区的截止值。设定死区是因为系统的频率通常会发生微小波动，这些波动在系统的允许范围内，逆变器没有必要为此频繁调整输出功率。Δf_th可选取0.1Hz。P_max表示储能系统输出功率的最大值。K_max表示输出功率和系统频率偏差之间的比例系统的最大值，可以取为200.SOC_max和SOC_min表示逆变器储能的SOC最大和最小值，分别取为10%和90%，SOC_low和SOC_high表示逆变器在调整时储能允许的SOC最大和最小值，可取为为20%和80%。n通常可取为2。Among them, P is the output power of the inverter of each energy storage system, K is the proportional system between the output power and the system frequency deviation, which can usually be selected as 200, and Δf represents the frequency deviation of the system, and Δf_th represents the frequency dead zone cutoff value. The dead zone is set because the frequency of the system usually fluctuates slightly, and these fluctuations are within the allowable range of the system, and the inverter does not need to adjust the output power frequently for this. Δf_th can be selected as 0.1Hz. P_max represents the maximum output power of the energy storage system. K_max represents the maximum value of the proportional system between output power and system frequency deviation, which can be taken as 200. SOC_max and SOC_min represent the maximum and minimum SOC values of inverter energy storage, which are taken as 10% and 90% respectively. SOC_low and SOC_high represent the maximum and minimum SOC values allowed by the energy storage of the inverter during adjustment, which can be taken as 20% and 80%. n can usually be taken as 2.

Claims (3)

Translated fromChinese

1.微网离网模式下利用发电和储能系统逆变器分布式调频方法，其特征在于：当微网处于离网模式时，微网中各个发电系统和储能系统的逆变器的输出功率随系统频率变化而变化，从而保证离网运行的微网系统的频率偏差在可接受的范围内；1. In the off-grid mode of the microgrid, the distributed frequency regulation method of the inverters of the power generation and energy storage systems is used. The output power changes with the system frequency, so as to ensure that the frequency deviation of the off-grid microgrid system is within an acceptable range;当微电网处于离网运行状态时，微网中各个发电系统的逆变器控制模式切换到带死区的下垂控制模式，逆变器的有功输出和频率的偏差变化如下公式(1)所示：When the microgrid is in the off-grid operation state, the inverter control mode of each power generation system in the microgrid is switched to the droop control mode with dead zone, and the deviation of the active output and frequency of the inverter is shown in the following formula (1): :${\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>g</span>g</span>}}<span><span>=</span>=</span>\left\{\begin{array}{cc}\mathrm{<span><span>0</span>0</span>}<span><span>,</span>,</span>& \mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span>></span>></span>{\mathrm{<span><span>\&Delta;f</span>\&Delta;\; f</span>}}_{\mathrm{<span><span>t</span>t</span>}\mathrm{<span><span>h</span>h</span>}}<span><span>></span>></span>\mathrm{<span><span>0</span>0</span>}\\ \mathrm{<span><span>K</span>K</span>}<span><span>(</span>(</span>\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span>-</span>-</span>{\mathrm{<span><span>\&Delta;f</span>\&Delta;\; f</span>}}_{\mathrm{<span><span>t</span>t</span>}\mathrm{<span><span>h</span>h</span>}}<span><span>)</span>)</span><span><span>,</span>,</span>& {\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}}_{\mathrm{<span><span>t</span>t</span>}\mathrm{<span><span>h</span>h</span>}}<span><span><</span><</span>\mathrm{<span><span>K</span>K</span>}\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span><</span><</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>g</span>g</span>}<span><span>,</span>,</span>\mathrm{<span><span>max</span>max</span>}}\\ {\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>g</span>g</span>}<span><span>,</span>,</span>\mathrm{<span><span>max</span>max</span>}}<span><span>,</span>,</span>& \mathrm{<span><span>K</span>K</span>}\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>g</span>g</span>}<span><span>,</span>,</span>\mathrm{<span><span>max</span>max</span>}}\end{array}\right.<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>$其中，P_g是各个发电系统的逆变器的输出功率，K是输出功率和系统频率偏差之间的比例系统，Δf表示系统的频率偏差，Δf_th表示频率死区的截止值；所述频率死区是因为系统的频率通常会发生微小波动，这些波动在系统的允许范围内，逆变器没有必要为此频繁调整输出功率；P_g,max表示发电系统输出功率的最大值；Among them, P_g is the output power of the inverter of each power generation system, K is the proportional system between the output power and the system frequency deviation, Δf represents the frequency deviation of the system, Δf_th represents the cut-off value of the frequency dead zone; the frequency The dead zone is because the frequency of the system usually fluctuates slightly, and these fluctuations are within the allowable range of the system, and the inverter does not need to frequently adjust the output power for this; P_g,max represents the maximum output power of the power generation system;当微电网处于离网运行状态时，微网中各个储能系统的逆变器控制模式切换到改进型带死区的下垂控制模式，逆变器的有功输出和频率的偏差变化如下公式(2)所示：When the microgrid is in the off-grid operation state, the inverter control mode of each energy storage system in the microgrid is switched to the improved droop control mode with dead zone, and the deviation of the active output and frequency of the inverter changes as follows: (2 ) as shown:${\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>s</span>the\; s</span>}}<span><span>=</span>=</span>\left\{\begin{array}{cc}\mathrm{<span><span>0</span>0</span>}<span><span>,</span>,</span>& \mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span>></span>></span>{\mathrm{<span><span>\&Delta;f</span>\&Delta;\; f</span>}}_{\mathrm{<span><span>t</span>t</span>}\mathrm{<span><span>h</span>h</span>}}<span><span>></span>></span>\mathrm{<span><span>0</span>0</span>}\\ \mathrm{<span><span>K</span>K</span>}\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span>,</span>,</span>& {\mathrm{<span><span>K\&Delta;f</span>K\&Delta;f</span>}}_{\mathrm{<span><span>t</span>t</span>}\mathrm{<span><span>h</span>h</span>}}<span><span><</span><</span>\mathrm{<span><span>K</span>K</span>}\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span><</span><</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>s</span>the\; s</span>}<span><span>,</span>,</span>\mathrm{<span><span>max</span>max</span>}}\\ {\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>s</span>the\; s</span>}<span><span>,</span>,</span>\mathrm{<span><span>max</span>max</span>}}<span><span>,</span>,</span>& \mathrm{<span><span>K</span>K</span>}\mathrm{<span><span>\&Delta;</span>\&Delta;</span>}\mathrm{<span><span>f</span>f</span>}<span><span>\&GreaterEqual;</span>\&Greater\; Equal;</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>s</span>the\; s</span>}<span><span>,</span>,</span>\mathrm{<span><span>max</span>max</span>}}\end{array}\right.$$\mathrm{<span><span>K</span>K</span>}<span><span>=</span>=</span>{\mathrm{<span><span>K</span>K</span>}}_{\mathrm{<span><span>max</span>max</span>}}<span><span>\{</span>\{</span>\mathrm{<span><span>1</span>1</span>}<span><span>-</span>-</span>{<span><span>(</span>(</span>\frac{\mathrm{<span><span>S</span>S</span>}\mathrm{<span><span>O</span>o</span>}\mathrm{<span><span>C</span>C</span>}<span><span>-</span>-</span>{\mathrm{<span><span>SOC</span>SOC</span>}}_{\mathrm{<span><span>l</span>l</span>}\mathrm{<span><span>o</span>o</span>}\mathrm{<span><span>w</span>w</span>}<span><span>(</span>(</span>\mathrm{<span><span>h</span>h</span>}\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>g</span>g</span>}\mathrm{<span><span>h</span>h</span>}<span><span>)</span>)</span>}}{{\mathrm{<span><span>SOC</span>SOC</span>}}_{\mathrm{<span><span>max</span>max</span>}<span><span>(</span>(</span>\mathrm{<span><span>min</span>min</span>}<span><span>)</span>)</span>}<span><span>-</span>-</span>{\mathrm{<span><span>SOC</span>SOC</span>}}_{\mathrm{<span><span>l</span>l</span>}\mathrm{<span><span>o</span>o</span>}\mathrm{<span><span>w</span>w</span>}<span><span>(</span>(</span>\mathrm{<span><span>h</span>h</span>}\mathrm{<span><span>i</span>i</span>}\mathrm{<span><span>g</span>g</span>}\mathrm{<span><span>h</span>h</span>}<span><span>)</span>)</span>}}<span><span>)</span>)</span>}^{\mathrm{<span><span>n</span>no</span>}}<span><span>\}</span>\}</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>2</span>2</span>}<span><span>)</span>)</span>$其中，P_s是各个储能系统的逆变器的输出功率，K是输出功率和系统频率偏差之间的比例系统，Δf表示系统的频率偏差，Δf_th表示频率死区的截止值；所述改进型带死区是因为系统的频率通常会发生微小波动，这些波动在系统的允许范围内，逆变器没有必要为此频繁调整输出功率；P_s,max表示储能系统输出功率的最大值；K_max表示输出功率和系统频率偏差之间的比例系统的最大值，SOC_max和SOC_min分别表示逆变器储能的SOC最大和最小值，SOC_low和SOC_high表示逆变器在调整时储能允许的SOC最大和最小值，n取为2。Among them, P_s is the output power of the inverter of each energy storage system, K is the proportional system between the output power and the system frequency deviation, Δf represents the frequency deviation of the system, Δf_th represents the cut-off value of the frequency dead zone; the The improved type has a dead zone because the frequency of the system usually fluctuates slightly, and these fluctuations are within the allowable range of the system, and the inverter does not need to frequently adjust the output power for this; P_s,max represents the maximum output power of the energy storage system ; K_max indicates the maximum value of the proportional system between the output power and the system frequency deviation, SOC_max and SOC_min indicate the maximum and minimum SOC values of the inverter energy storage respectively, SOC_low and SOC_high indicate the inverter is adjusting The maximum and minimum values of SOC allowed by the energy storage, n is taken as 2.2.根据权利要求1所述微网离网模式下利用发电和储能系统逆变器分布式调频方法，其特征在于：公式(1)中K选取为200；Δf_th选取0.1Hz。2. According to claim 1, the distributed frequency regulation method using inverters of power generation and energy storage systems in the off-grid mode of the microgrid is characterized in that: K in the formula (1) is selected as 200; Δf_th is selected as 0.1 Hz.3.根据权利要求1所述微网离网模式下利用发电和储能系统逆变器分布式调频方法，其特征在于：公式(2)中K选取为200；SOC_max和SOC_min分别取为10％和90％；SOC_low和SOC_high分别取为20％和80％。3. According to claim 1, the distributed frequency modulation method utilizing power generation and energy storage system inverters in the off-grid mode of the microgrid is characterized in that: K is selected as 200 in the formula (2); SOC_max and SOC_min are respectively taken as 10% and 90%; SOC_low and SOC_high are taken as 20% and 80% respectively.