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CN-121984307-A - Temperature equalization control method and system for series-type energy storage converter

CN121984307ACN 121984307 ACN121984307 ACN 121984307ACN-121984307-A

Abstract

The invention relates to a temperature equalization control method and a system for a series-type energy storage converter, wherein the method comprises the steps of collecting the operation temperature of each power module; judging whether the series-connected energy storage converters need to perform temperature balance control based on the temperature and the temperature difference of each power module, constructing a temperature weight factor based on the temperature of each power module when the series-connected energy storage converters need to perform temperature balance control, distributing the power of each power module based on the temperature weight factor, acquiring parameters such as the temperature state of each converter module in real time, calculating an optimal power distribution scheme of the PCS module based on multiple targets, generating and issuing a power command according to the scheme, further adjusting the temperature of the PCS module, dynamically distributing the power through the weight factor, embedding thermal management into a power control closed loop, and realizing temperature balance, overheat protection and total power tracking simultaneously.

Inventors

  • WANG QIANG
  • LEI YUZHU
  • MENG SHUN
  • MENG QINGGUO
  • ZHANG CHEN
  • CAI CHENG
  • PENG HAO
  • YE HAO
  • ZHU LEI
  • ZHANG ZHANFEI

Assignees

  • 中能建储能科技(武汉)有限公司

Dates

Publication Date
20260505
Application Date
20251224

Claims (10)

  1. 1. The temperature equalization control method for the series-type energy storage converter is characterized by comprising the following steps of: step 1, collecting the operation temperature of each power module; step 2, judging whether the series-connected energy storage converters need to perform temperature balance control or not based on the temperature and the temperature difference of each power module; and 3, when the temperature balance control is required by the series-type energy storage converters, constructing temperature weight factors based on the temperatures of the power modules, and distributing the power of the power modules based on the temperature weight factors.
  2. 2. The method of claim 1, wherein the determining whether the temperature equalization control is required for the series-connected energy storage converters based on the temperatures of the power modules in the step 2 comprises: And when judging that the temperature of any power module is larger than a set threshold value, judging that the series-type energy storage converters need to be subjected to temperature balance control.
  3. 3. The temperature equalization control method according to claim 1, wherein the step 2 of determining whether the series-connected energy storage converters need to perform temperature equalization control based on the temperatures of the power modules comprises: and when judging that the temperature difference between the highest temperature and the lowest temperature in each power module is larger than a set threshold value, judging that the series-type energy storage converters need to be subjected to temperature balance control.
  4. 4. The method of claim 1, wherein step 2 further comprises calculating a standard deviation and an average temperature of the power modules, and determining that the series-connected energy storage converters need to perform temperature equalization control when the standard deviation or the average temperature is greater than a set threshold.
  5. 5. The temperature equalization control method of claim 1, wherein the step of allocating power of each of the power modules in the step 3 comprises: The real-time temperatures of the power modules are ordered, and the output power of the power module with higher control temperature is smaller.
  6. 6. The temperature equalization control method of claim 1, wherein the step 3 of allocating power of each of the power modules based on the temperature weight factor comprises: step 301, calculating a temperature weight factor as: wi=(T_max-T_i+ )/(∑(T_max-T_j+ )),j=1, 2, ..., N; wherein wi is the temperature weight factor of the ith power module, T_max is the highest value of the temperatures of the respective power modules, T_i and T_j are the temperatures of the ith and jth power modules, respectively, A set zero amount for control; step 302, defining the initial allocation coefficient of the ith power module as: K i '=1/(N (1-βwi)); step 303, performing normalization processing on the initial distribution coefficient to obtain a distribution coefficient which is: Ki= K i '/∑（K i '); step 304, determining that the power allocated by the ith power module is: P_i=Ki P_total; wherein, P_total is the total output power of the converter.
  7. 7. The temperature equalization control method of claim 1, wherein said step 3 further comprises: setting a temperature threshold t_l < t_m < t_h, for the temperature t_i of any i-th power module: When T_i is judged to be less than T_l, the heat radiating unit of the ith power module is closed; When T_l is less than or equal to T_i < T_m, controlling a heat radiating unit of the ith power module to run at a low speed; When T_m is less than or equal to T_i < T_h, controlling a heat radiating unit of the ith power module to run at a medium speed; When the T_i is more than or equal to T_h, controlling a heat radiating unit of the ith power module to run at a high speed; And when the system temperature T_max exceeds the system level set value T_max_set, the operation temperature balance control strategy is exited, and the system derating strategy is executed.
  8. 8. The temperature equalization control system of the series-connected energy storage converter is characterized by comprising a data acquisition unit, a state evaluation unit, a calculation decision unit and a power distribution unit; The data acquisition unit is used for acquiring the operation temperature of each power module; the state evaluation unit is used for calculating whether the temperature and the temperature difference of each power module exceed set thresholds; the calculation decision unit is used for judging whether the series-connected energy storage converters need to perform temperature balance control or not based on the temperature and the temperature difference of each power module; And the state evaluation unit is used for constructing a temperature weight factor based on the temperature of each power module when the series-type energy storage converter is judged to need to perform temperature balance control, and distributing the power of each power module based on the temperature weight factor.
  9. 9. An electronic device, comprising a memory and a processor, wherein the processor is configured to implement the method for controlling temperature equalization of a string energy storage converter according to any one of claims 1 to 7 when executing a computer management program stored in the memory.
  10. 10. A computer-readable storage medium, having stored thereon a computer-management-class program which, when executed by a processor, implements the steps of the temperature equalization control method of a string-type energy storage converter as claimed in any one of claims 1 to 7.

Description

Temperature equalization control method and system for series-type energy storage converter Technical Field The invention relates to the technical field of energy storage converters, in particular to a temperature equalization control method and a temperature equalization control system for a series-type energy storage converter. Background The group string type energy storage converter is used as core power conversion equipment of the battery energy storage system, and the multi-module parallel structure of the group string type energy storage converter improves the capacity of the system and brings about obvious difference of temperature distribution. In long-term operation, temperature gradients are very easy to generate among the modules due to the difference of the positions of the power modules, the heat dissipation conditions and the load current. The temperature unbalance not only accelerates the ageing of electronic components and reduces the overall efficiency of the system, but also can trigger a protection shutdown mechanism due to local overheating, thereby seriously affecting the reliability and the service life of the energy storage system. The current industry generally adopts a global fan speed regulation strategy based on an average temperature or a highest temperature threshold, and the method is simple and easy, but cannot accurately control the temperature of the local overheating module. The adoption of the full system forced heat dissipation to cope with the hottest spot temperature causes excessive consumption of cooling resources in the low temperature module area. Meanwhile, the service life difference of components is enlarged due to temperature non-uniformity, and the average failure-free time of the whole system is reduced. Disclosure of Invention Aiming at the technical problems existing in the prior art, the invention provides a temperature equalization control method of a group string energy storage converter, and provides a control strategy capable of realizing active equalization of the temperatures of multiple power modules of the group string energy storage converter, thereby fundamentally solving the problems of reduced system reliability, low heat dissipation efficiency, poor equipment adaptability, inconsistent service lives of key devices and the like caused by uneven heat distribution. According to a first aspect of the present invention, there is provided a temperature equalization control method for a string energy storage converter, including: step 1, collecting the operation temperature of each power module; step 2, judging whether the series-connected energy storage converters need to perform temperature balance control or not based on the temperature and the temperature difference of each power module; and 3, when the temperature balance control is required by the series-type energy storage converters, constructing temperature weight factors based on the temperatures of the power modules, and distributing the power of the power modules based on the temperature weight factors. On the basis of the technical scheme, the invention can also make the following improvements. Optionally, the determining, in step 2, whether the series-connected energy storage converters need to perform temperature equalization control based on the temperatures of the power modules includes: And when judging that the temperature of any power module is larger than a set threshold value, judging that the series-type energy storage converters need to be subjected to temperature balance control. Optionally, the determining, in step 2, whether the series-connected energy storage converters need to perform temperature equalization control based on the temperatures of the power modules includes: and when judging that the temperature difference between the highest temperature and the lowest temperature in each power module is larger than a set threshold value, judging that the series-type energy storage converters need to be subjected to temperature balance control. Optionally, the step 2 further includes calculating a standard deviation and an average temperature of the temperature of each power module, and determining that the series-type energy storage converters need to perform temperature balance control when the standard deviation or the average temperature of the temperature is determined to be greater than a set threshold. Optionally, the process of allocating power of each power module in step 3 includes: The real-time temperatures of the power modules are ordered, and the output power of the power module with higher control temperature is smaller. Optionally, the step 3 of allocating power of each power module based on the temperature weight factor includes: step 301, calculating a temperature weight factor as: wi=(T_max-T_i+)/(∑(T_max-T_j+)) (j=1, 2, ..., N); wherein wi is the temperature weight factor of the ith power module, T_max is the highest value of the temperatures of the resp