CN104360285B - A kind of battery capacity modification method based on improved ampere-hour integration method - Google Patents

Abstract

Translated fromChinese

本发明公开了一种基于改进的安时积分法的电池容量修正方法，步骤如下：电池组车载运行；利用安时积分法计算SOC；判断电池电量是否过低；判断最低电池电压V_min是否低于容量修正模式门槛电压V_mdy；进入容量修正模式；进行容量修正，然后退出容量修正模式；电池充电，计算SOC；判断电池组最高电压V_max是否大于充电截止电压V_h；充电结束，保存此次充电过程累积的电池容量Q，并替代之前的电池容量Q_n，同时修改当前的电池容量值为Q，修改SOC值。本发明在电池进行充电的末期，对电池的SOC值和存储的电量值进行校正，使得每次充电完成能得到准确的SOC初始值，同时电池放电末期可以选择进入电池容量校准模式，来校准当前电池的容量，从而消除电池老化带来的计算误差。

The invention discloses a battery capacity correction method based on the improved ampere-hour integral method, the steps are as follows: the battery pack is operated on a vehicle; the SOC is calculated by using the ampere-hour integral method; judging whether the battery power is too low; judging whether the minimum battery voltage V_min is low In the capacity correction mode threshold voltage V_mdy ; enter the capacity correction mode; perform capacity correction, then exit the capacity correction mode; charge the battery, calculate the SOC; judge whether the maximum voltage V_max of the battery pack is greater than the charge cut-off voltage V_h ; The battery capacity Q accumulated in the second charging process is replaced by the previous battery capacity Q_n , and the current battery capacity value is modified to Q, and the SOC value is modified. The present invention corrects the SOC value and the stored power value of the battery at the end of battery charging, so that an accurate SOC initial value can be obtained each time the battery is charged, and at the same time, the battery can choose to enter the battery capacity calibration mode at the end of battery discharge to calibrate the current The capacity of the battery, thereby eliminating the calculation error caused by battery aging.

Description

Translated fromChinese

一种基于改进的安时积分法的电池容量修正方法A battery capacity correction method based on the improved ampere-hour integration method

技术领域technical field

本发明涉及一种基于改进的安时积分法的电池容量修正方法。The invention relates to a battery capacity correction method based on an improved ampere-hour integration method.

背景技术Background technique

电池剩余电量又称电池荷电状态(State of Charge，SOC)是表示电池当前可供用电设备使用的电量多少的参数之一，SOC可以为电动汽车整车的能量管理策略提供重要依据。准确估算电池剩余电量可以在电池使用时使SOC维持在合理的范围内，防止出现过充或者过放对电池造成损伤，为合理利用电池，延长电池使用寿命，降低电池使用成本提供了重要依据。准确估算SOC值是电池管理系统的重要任务之一。The remaining power of the battery, also known as the State of Charge (SOC), is one of the parameters indicating how much power the battery can currently use for electrical equipment. The SOC can provide an important basis for the energy management strategy of the electric vehicle. Accurately estimating the remaining power of the battery can maintain the SOC within a reasonable range when the battery is in use, prevent overcharge or overdischarge from causing damage to the battery, and provide an important basis for rational use of the battery, prolonging the service life of the battery, and reducing the cost of battery use. Accurately estimating the SOC value is one of the important tasks of the battery management system.

目前国内外对电池SOC估算已做了大量研究。实际产品应用中由于电池管理系统硬件实现的限制，常用的方法是开路电压和安时积分相结合的方法，此外还有卡尔曼滤波法和神经网络法。At present, a lot of research has been done on battery SOC estimation at home and abroad. Due to the limitations of the hardware implementation of the battery management system in actual product applications, the commonly used method is the combination of open circuit voltage and ampere-hour integration, in addition to Kalman filter method and neural network method.

卡尔曼滤波，神经网络：运算量大，硬件受限，算法本身不成熟，未得到大量实际应用。Kalman filter, neural network: large amount of calculation, limited hardware, immature algorithm itself, and has not been widely used in practice.

开路电压法：该方法需要对电池进行长时间的静置并且需要电池的ocv曲线有较大斜率，但是，磷酸铁锂电池具有较平坦的充放电曲线，所以该方法不适用于磷酸铁锂电池的soc估算。Open circuit voltage method: This method requires the battery to stand for a long time and the ocv curve of the battery has a large slope. However, lithium iron phosphate batteries have a flat charge and discharge curve, so this method is not suitable for lithium iron phosphate batteries The soc estimate.

安时积分法：该方法是对电流进行对时间的积分来计算输入和输出电池的能量，通过与额定容量的比值确定soc的值。该方法的缺点是，初始soc值的确定必须准确，否则会有很大的误差，随着时间的延长，会有较大的累积误差，并且当电池使用较长时间后会出现老化，安时积分法的计算精度也会下降。Ah-hour integration method: This method is to calculate the energy of the input and output batteries by integrating the current with respect to time, and determine the value of SOC by the ratio to the rated capacity. The disadvantage of this method is that the determination of the initial SOC value must be accurate, otherwise there will be a large error, and as time goes on, there will be a large cumulative error, and when the battery is used for a long time, it will age, and the AH The calculation accuracy of the integral method will also decrease.

中国发明专利(专利号：201410074003，专利名称：锂离子电池在充电过程中的SOC在线检测与修正方法)，该专利通过测试不同放电倍率下的SOC-V曲线以及电压差值，得到3rd-SOC关系，在计算soc时通过电池电压对SOC进行修正。但是这种方法的不当之处：Chinese invention patent (patent number: 201410074003, patent name: SOC online detection and correction method of lithium-ion battery during charging), the patent obtains 3rd-SOC by testing the SOC-V curve and voltage difference under different discharge rates Relationship, the SOC is corrected by the battery voltage when calculating the SOC. But the inappropriateness of this approach:

(1)锂电池，特别是磷酸铁锂电池的放电曲线，线性度很差，电池容量在90％到20％之间的电压差只有200mV，这样对电压采样精度有较高要求，且容易造成计算误差；(1) The discharge curve of lithium batteries, especially lithium iron phosphate batteries, has poor linearity, and the voltage difference between 90% and 20% of the battery capacity is only 200mV, which has high requirements for voltage sampling accuracy and is easy to cause Calculation error;

(2)各个厂家的电池性能不一致性较大，且同一电池在长时间使用后的性能也会发生较大变化，这样就造成适应不同厂家的电池时的需要大量的测试工作，并且不能解决电池老化后soc计算精度降低的问题。(2) The battery performance of various manufacturers is inconsistent, and the performance of the same battery will change greatly after long-term use, which requires a lot of testing work when adapting to batteries from different manufacturers, and cannot solve the problem of battery failure. The problem that the accuracy of soc calculation decreases after aging.

中国发明专利(专利号：201110165914X，专利名称：蓄电池剩余容量及健康状况预测方法)，虽然也是纠正电池老化对电量预测的影响，但是该专利存在两处缺陷：Chinese invention patent (patent number: 201110165914X, patent name: battery remaining capacity and health status prediction method), although it also corrects the impact of battery aging on power prediction, there are two defects in this patent:

(1)计算老化电池容量的方法是该方法通过当前电池电压V1确定公式中的SOC值，当前电压V1不是经过静置之后的电压，不适用与开路电压发确定SOC，所以这种计算方法精度会收影响；(1) The method to calculate the aging battery capacity is This method determines the SOC value in the formula through the current battery voltage V1. The current voltage V1 is not the voltage after standing still, and it is not applicable to determine the SOC with the open circuit voltage, so the accuracy of this calculation method will be affected;

(2)专利中使用的开路电压法与安时积分发相结合的方法适用于电压线性度较好的铅酸电池，但是不适用与锂电池。(2) The open-circuit voltage method combined with the ampere-hour integration method used in the patent is suitable for lead-acid batteries with good voltage linearity, but not for lithium batteries.

中国发明专利(专利号：2013107193759，专利名称：一种基于卡尔曼滤波的自校正电池SOC估算方法)，这个专利可以解决安时积分法在长时间运行之后会产生累积误差的问题，但是不能解决电池老化造成容量变化对SOC计算的影响。Chinese invention patent (patent number: 2013107193759, patent name: a self-correcting battery SOC estimation method based on Kalman filter), this patent can solve the problem that the ampere-hour integration method will produce cumulative errors after long-term operation, but it cannot solve the problem The influence of capacity change caused by battery aging on SOC calculation.

发明内容Contents of the invention

本发明的目的就是为了解决上述问题，提供一种基于改进的安时积分法的电池容量修正方法，它具有针对安时积分法的缺点，本发明在电池进行充电的末期，对电池的SOC值和存储的电量值进行校正，使得每次充电完成能得到准确的SOC初始值，同时电池放电末期可以选择进入电池容量校准模式，来校准当前电池的容量，从而消除电池老化带来的计算误差的优点。The purpose of the present invention is to solve the above problems, to provide a battery capacity correction method based on the improved ampere-hour integration method, which has the disadvantages of the ampere-hour integration method. Correct the stored power value so that an accurate initial SOC value can be obtained each time the battery is charged. At the same time, at the end of battery discharge, you can choose to enter the battery capacity calibration mode to calibrate the current battery capacity, thereby eliminating the calculation error caused by battery aging. advantage.

为了实现上述目的，本发明采用如下技术方案：In order to achieve the above object, the present invention adopts the following technical solutions:

一种基于改进的安时积分法的电池容量修正方法，包括如下步骤：A battery capacity correction method based on the improved ampere-hour integration method, comprising the steps of:

步骤(1)：电池组车载运行；Step (1): The battery pack runs on the vehicle;

步骤(2)：实时获取电池组的单体电池电压V_i、最高电池电压V_max、最低电池电压V_min、充放电电流I；利用安时积分法计算SOC；Step (2): Obtain the single battery voltage V_i , the highest battery voltage V_max , the lowest battery voltage V_min , and the charging and discharging current I of the battery pack in real time; use the ampere-hour integral method to calculate the SOC;

步骤(3)：判断电池电量是否过低，如果是就进入步骤(4)；如果否就返回步骤(2)；Step (3): Determine whether the battery power is too low, if yes, enter step (4); if not, return to step (2);

步骤(4)：判断最低电池电压V_min是否低于容量修正模式门槛电压V_mdy，如果是就进入步骤(5)；如果否就进入步骤(6)；Step (4): Judging whether the minimum battery voltage V_min is lower than the capacity correction mode threshold voltage V_mdy , if yes, proceed to step (5); if not, proceed to step (6);

步骤(5)：进入容量修正模式；进行容量修正，然后退出容量修正模式；进入步骤(7)；Step (5): Enter capacity correction mode; carry out capacity correction, then exit capacity correction mode; enter step (7);

步骤(6)：电池充电，计算SOC；进入步骤(7)；Step (6): battery charging, calculate SOC; enter step (7);

步骤(7)：判断电池组最高电压V_max是否大于充电截止电压V_h，如果大于就进入步骤(8)；否则返回步骤(6)；Step (7): Judging whether the maximum voltage V_max of the battery pack is greater than the charge cut-off voltage V_h , if it is greater, proceed to step (8); otherwise, return to step (6);

步骤(8)：充电结束，保存此次充电过程累积的电池容量Q，并替代之前的电池容量Q_n，同时修改当前的电池容量值为Q，修改SOC值。Step (8): At the end of charging, save the battery capacity Q accumulated in this charging process, and replace the previous battery capacity Q_n , and modify the current battery capacity value Q, and modify the SOC value.

所述步骤(5)的步骤包括：The step of described step (5) comprises:

步骤(5-1)：进入容量修正模式；清空电池容量计算变量；Step (5-1): enter the capacity correction mode; clear the battery capacity calculation variables;

步骤(5-2)：电池充电，进行SOC的积分计算；Step (5-2): charging the battery, and performing integral calculation of SOC;

步骤(5-3)：判断是否满足容量修正条件，如果是就进入步骤(5-4)；如果否就进入步骤(5-6)；Step (5-3): Judging whether the capacity correction condition is satisfied, if yes, proceed to step (5-4); if not, proceed to step (5-6);

步骤(5-4)：判断电池组最高电压V_max是否大于充电截止电压V_h，如果大于就进入步骤(5-5)；否则返回步骤(5-2)；Step (5-4): Judging whether the maximum voltage V_max of the battery pack is greater than the charge cut-off voltage V_h , if so, enter step (5-5); otherwise, return to step (5-2);

步骤(5-5)：电池充电结束，修改SOC值，修改电池容量Q_n；进入步骤(1)；Step (5-5): After the battery charging is completed, modify the SOC value and modify the battery capacity Q_n ; enter step (1);

步骤(5-6)：退出容量修正模式，进入步骤(7)。Step (5-6): Exit the capacity correction mode and enter step (7).

所述容量修正模式是指通过手动进入或者自动捕捉到的一个状态，在这个状态内进行步骤(5)操作，出现放电状态或者V_max>V_h时，自动退出该模式。The capacity correction mode refers to a state that is manually entered or automatically captured. In this state, the operation of step (5) is performed, and when a discharge state occurs or V_max >V_h , the mode is automatically exited.

所述步骤(5-2)中进行SOC的积分计算的公式为：The formula for the integral calculation of SOC in the step (5-2) is:

其中，SOC的参数含义是当前电池SOC值，SOC₀的参数含义是初始SOC值，t的参数含义是时间，累积电池容量临时变量Q。Among them, the parameter meaning of SOC is the current battery SOC value, the parameter meaning of SOC₀ is the initial SOC value, the parameter meaning of t is time, and the temporary variable Q of accumulated battery capacity.

本发明的有益效果：Beneficial effects of the present invention:

1.本发明在电池进行充电的末期，对电池的SOC值和存储的电量值进行校正，使得每次充电完成能得到准确的SOC初始值，同时电池放电末期可以选择进入电池容量校准模式，来校准当前电池的容量，从而消除电池老化带来的计算误差的优点。1. The present invention corrects the SOC value and the stored power value of the battery at the end of battery charging, so that an accurate initial SOC value can be obtained after each charge is completed, and at the same time, the battery can choose to enter the battery capacity calibration mode at the end of battery discharge. The advantage of calibrating the capacity of the current battery, thereby eliminating the calculation error caused by battery aging.

2本发明用于解决电动大巴车，在换电模式应用下，磷酸铁锂电池组SOC计算精度的提高；2. The present invention is used to solve the problem of improving the calculation accuracy of the SOC of the lithium iron phosphate battery pack under the application of the battery replacement mode of the electric bus;

3易于实现，充分利用换电模式电动大巴的运行特点进行安时积分法的校准和修正，来提高SOC估算的精度；3. It is easy to implement, making full use of the operating characteristics of the electric bus in the battery swap mode to calibrate and correct the ampere-hour integral method to improve the accuracy of SOC estimation;

4每个电池充放电循环进行初始SOC值标定，消除一个循环内的累积误差，不会产生长时间的累积误差；4 The initial SOC value is calibrated for each battery charge and discharge cycle, eliminating the cumulative error within a cycle, and will not produce long-term cumulative errors;

5可以自动跟踪电池的健康状况并修正当前电池的容量，通过修正安时积分法公式里的分母，消除电池老化带来的计算误差。5. It can automatically track the health status of the battery and correct the current battery capacity. By correcting the denominator in the formula of the ampere-hour integral method, the calculation error caused by battery aging can be eliminated.

6.本发明方法也可以避免累积误差的产生，并且更易于工程实现。6. The method of the present invention can also avoid the generation of cumulative errors, and is easier to implement in engineering.

7.以一个充放电循环为单位来计算和校准电池能量值和soc值，避免产生长时间的误差累积7. Calculate and calibrate the battery energy value and SOC value based on one charge and discharge cycle to avoid long-term error accumulation

8.自动电池容量计算，并对soc计算公式进行修正，消除电池老化带来的计算误差。8. Automatic battery capacity calculation and correction of the SOC calculation formula to eliminate calculation errors caused by battery aging.

附图说明Description of drawings

图1为本发明的方法流程图。Fig. 1 is a flow chart of the method of the present invention.

具体实施方式detailed description

下面结合附图与实施例对本发明作进一步说明。The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

如图1所示，一种基于改进的安时积分法的电池容量修正方法，包括如下步骤：As shown in Figure 1, a battery capacity correction method based on the improved ampere-hour integration method includes the following steps:

步骤(1)：电池组车载运行；Step (1): The battery pack runs on the vehicle;

步骤(2)：实时获取电池组的单体电池电压V_i、最高电池电压V_max、最低电池电压V_min、充放电电流I；利用安时积分法计算SOC；Step (2): Obtain the single battery voltage V_i , the highest battery voltage V_max , the lowest battery voltage V_min , and the charging and discharging current I of the battery pack in real time; use the ampere-hour integral method to calculate the SOC;

步骤(3)：判断电池电量是否过低，如果是就进入步骤(4)；如果否就返回步骤(2)；Step (3): Determine whether the battery power is too low, if yes, enter step (4); if not, return to step (2);

步骤(4)：判断最低电池电压V_min是否低于容量修正模式门槛电压V_mdy，如果是就进入步骤(5)；如果否就进入步骤(6)；Step (4): Judging whether the minimum battery voltage V_min is lower than the capacity correction mode threshold voltage V_mdy , if yes, proceed to step (5); if not, proceed to step (6);

步骤(5)：进入容量修正模式；进行容量修正，然后退出容量修正模式；进入步骤(7)；Step (5): Enter capacity correction mode; carry out capacity correction, then exit capacity correction mode; enter step (7);

步骤(6)：电池充电，计算SOC；进入步骤(7)；Step (6): battery charging, calculate SOC; enter step (7);

步骤(7)：判断电池组最高电压V_max是否大于充电截止电压V_h，如果大于就进入步骤(8)；否则返回步骤(6)；Step (7): Judging whether the maximum voltage V_max of the battery pack is greater than the charge cut-off voltage V_h , if it is greater, proceed to step (8); otherwise, return to step (6);

步骤(8)：充电结束，保存此次充电过程累积的电池容量Q，并替代之前的电池容量Q_n，同时修改当前的电池容量值为Q，修改SOC值。Step (8): At the end of charging, save the battery capacity Q accumulated in this charging process, and replace the previous battery capacity Q_n , and modify the current battery capacity value Q, and modify the SOC value.

所述步骤(5)的步骤包括：The step of described step (5) comprises:

步骤(5-1)：进入容量修正模式；清空电池容量计算变量；Step (5-1): enter the capacity correction mode; clear the battery capacity calculation variables;

步骤(5-2)：电池充电，进行SOC的积分计算；其中SOC的参数含义是当前电池SOC值，SOC₀的参数含义是初始SOC值，t的参数含义是时间，累积电池容量临时变量Q；Step (5-2): battery charging, Carry out the integral calculation of SOC; the parameter meaning of SOC is the current battery SOC value, the parameter meaning of SOC₀ is the initial SOC value, the parameter meaning of t is time, and the temporary variable Q of accumulated battery capacity;

步骤(5-3)：判断是否满足容量修正条件，如果是就进入步骤(5-4)；如果否就进入步骤(5-6)；Step (5-3): Judging whether the capacity correction condition is satisfied, if yes, proceed to step (5-4); if not, proceed to step (5-6);

步骤(5-4)：判断电池组最高电压V_max是否大于充电截止电压V_h，如果大于就进入步骤(5-5)；否则返回步骤(5-2)；Step (5-4): Judging whether the maximum voltage V_max of the battery pack is greater than the charge cut-off voltage V_h , if so, enter step (5-5); otherwise, return to step (5-2);

步骤(5-5)：电池充电结束，修改SOC值，修改电池容量Q_n；进入步骤(1)；Step (5-5): After the battery charging is completed, modify the SOC value and modify the battery capacity Q_n ; enter step (1);

步骤(5-6)：退出容量修正模式，进入步骤(7)。Step (5-6): Exit the capacity correction mode and enter step (7).

所述容量修正模式是指通过手动进入或者自动捕捉到的一个状态，在这个状态内进行步骤(5)操作，出现放电状态或者V_max>V_h时，自动退出该模式。The capacity correction mode refers to a state that is manually entered or automatically captured. In this state, the operation of step (5) is performed, and when a discharge state occurs or V_max >V_h , the mode is automatically exited.

上述虽然结合附图对本发明的具体实施方式进行了描述，但并非对本发明保护范围的限制，所属领域技术人员应该明白，在本发明的技术方案的基础上，本领域技术人员不需要付出创造性劳动即可做出的各种修改或变形仍在本发明的保护范围以内。Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (4)

1. a kind of battery capacity modification method based on improved ampere-hour integration method, is characterized in that, comprise the steps：

Step (1)：Set of cells on-board running；

Step (2)：Obtain the monomer battery voltage V of set of cells in real time_i, highest cell voltage V_max, minimum cell voltage V_min, fillDischarge current I；Calculate SOC using ampere-hour integration method；

Step (3)：Judge whether battery electric quantity is too low, if being put into step (4)；It is returned to step (2) if not；

Step (4)：Judge minimum cell voltage V_minWhether it is less than cubage correction pattern threshold voltage V_mdy, if being put into walkingSuddenly (5)；It is put into step (6) if not；

Step (5)：Enter cubage correction pattern；Carry out cubage correction, be then log out cubage correction pattern；Enter step (7)；

Step (6)：Battery charges, and calculates SOC；Enter step (7)；

Step (7)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than being put into step (8)；Otherwise return to step (6)；

Step (8)：Charging terminates, and preserves battery capacity Q of this charging process accumulation, and instead front battery capacity Q_n, withThe current battery capacity value of Shi Xiugai is Q, changes SOC value.

2. a kind of battery capacity modification method based on improved ampere-hour integration method as claimed in claim 1, is characterized in that, instituteThe step stating step (5) includes：

Step (5-1)：Enter cubage correction pattern；Empty battery capacity and calculate variable；

Step (5-2)：Battery charges, and carries out the integral and calculating of SOC；

Step (5-3)：Judge whether to meet cubage correction condition, if being put into step (5-4)；It is put into step if not(5-6)；

Step (5-4)：Judge set of cells ceiling voltage V_maxWhether it is more than charge cutoff voltage V_h, if greater than being put into step(5-5)；Otherwise return to step (5-2)；

Step (5-5)：Battery charges and terminates, and changes SOC value, changes battery capacity Q_n；Enter step (1)；

Step (5-6)：Exit cubage correction pattern, enter step (7).

3. a kind of battery capacity modification method based on improved ampere-hour integration method as claimed in claim 1, is characterized in that, instituteState the state that cubage correction pattern refers to manually enter or automatically capture, carry out step in this state(5) operate, discharge condition or V occur_max>V_hWhen, automatically exit from this pattern.

4. a kind of battery capacity modification method based on improved ampere-hour integration method as claimed in claim 2, is characterized in that, instituteThe formula stating the integral and calculating carrying out SOC in step (5-2) is：

$SOC={\mathrm{SOC}}_0+\frac{1}{Q}{\∫}_0^{t}Idt$

Wherein, the meaning of parameters of SOC is present battery SOC value, SOC₀Meaning of parameters be initial SOC value, the meaning of parameters of t isTime, Q is accumulation battery capacity temporary variable.