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CN-122026569-A - High-power energy storage emergency power supply discharge control system

CN122026569ACN 122026569 ACN122026569 ACN 122026569ACN-122026569-A

Abstract

The invention relates to the technical field of energy storage power supply discharge control and discloses a high-power energy storage emergency power supply discharge control system which comprises a monitoring unit, a total current monitoring unit and a central discharge controller, wherein the central discharge controller is used for maintaining connection of a battery cluster and instructing a load to reduce power when the voltage of a battery core reaches an early warning threshold value, the controller is also used for monitoring the total current to check load response, if the response fails, a switching strategy is used for switching off the battery cluster, the conflict between the cutting-off action of a battery management system and the stability of a system bus is solved, the failure mode is changed from instantaneous breakdown to smooth dimension reduction, and the effectiveness of a control loop in failure is ensured.

Inventors

  • ZHONG XUHANG

Assignees

  • 东方醒狮储能电池有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. The utility model provides a high-power energy storage emergency power supply discharge control system, is applied to the emergency power supply that includes N parallelly connected battery cluster and controllable power load, its characterized in that, the system includes monitoring unit, total current monitoring unit, central discharge controller: The monitoring unit is used for monitoring the real-time voltage and the real-time temperature of the battery cells in each of the N parallel battery clusters; the total current monitoring unit is used for monitoring the total output current of the system of the emergency power supply; The central discharge controller is connected with the monitoring unit, the total current monitoring unit and the controllable power load through the communication interface and is used for: Step a, responding to emergency discharge start, and instructing a controllable power load to operate at an initial power quota; Step b, continuously receiving real-time voltage and real-time temperature when the controllable power load operates; step c, when at least one real-time voltage is monitored to reach a preset early warning lowering threshold for the first time, and the real-time temperature is lower than a preset temperature safety overrule threshold; step (d), step (i) is carried out to maintain the discharge connection of all N parallel battery clusters to replace the disconnection of the battery clusters reaching the early warning and lowering threshold value, and step (ii) is carried out to send a power lowering instruction to the controllable power load so as to lower the running power of the controllable power load to a lowered power quota; And e, after the power regulating and reducing instruction is sent, the method is further used for monitoring whether the total output current of the system is expected to be reduced corresponding to the power regulating and reducing instruction in a preset response confirmation window period or not in step e1, and switching the control strategy and then instructing to disconnect the battery cluster reaching the early warning regulating and reducing threshold value if the total output current of the system is monitored to be not expected to be reduced in step e 2.
  2. 2. The system of claim 1, wherein the central discharge controller is further configured to repeatedly send a power-down command to the controllable power load to further reduce the operating power of the controllable power load to a lower power-down rating if the real-time voltage is detected to reach the pre-warning-down threshold again after the controllable power load is operated at the post-down power-down rating.
  3. 3. The high-power energy-storage emergency power supply discharge control system according to claim 1, wherein the central discharge controller is further used for acquiring real-time temperature corresponding to a battery cell reaching an early warning and lowering threshold value before performing the step d, acquiring average temperature of N parallel battery clusters as a temperature reference, judging whether the real-time temperature is lower than a reasonable temperature raising threshold value determined by the sum of the temperature reference and a preset temperature raising margin, performing the step d only when the real-time temperature is not lower than the reasonable temperature raising threshold value, and inhibiting the step d when the real-time temperature is lower than the reasonable temperature raising threshold value.
  4. 4. The high-power energy-storage emergency power supply discharge control system according to claim 1, wherein the central discharge controller is further configured to obtain SOH information of a health state of each of the N parallel battery clusters before emergency discharge is started, set different early warning lowering thresholds for different SOH information clusters of the N parallel battery clusters based on the SOH information, respectively, and wherein the step c specifically includes triggering the step d when it is detected that a real-time voltage of a certain battery cluster reaches a corresponding different early warning lowering threshold for the first time and that a real-time temperature is lower than a preset temperature safety overrule threshold.
  5. 5. The system of claim 4, wherein the central discharge controller is configured to control the discharge of the emergency power source based on SOH information by Is to set the relation of (a) Different early warning drop thresholds of each battery cluster Wherein Is a preset reference threshold value, and the reference threshold value is set, Is the first SOH information of the state of health of the individual battery clusters, Is a preset drop coefficient.
  6. 6. The system of claim 1, wherein the central discharge controller is further configured to immediately instruct disconnection of the corresponding battery cluster if the real-time voltage is monitored to be lower than a preset voltage safety rejection threshold at any time of the emergency discharge, and to immediately instruct disconnection of the corresponding battery cluster if the real-time temperature is monitored to be higher than the preset temperature safety rejection threshold at any time of the emergency discharge.
  7. 7. The system of claim 1, wherein the predetermined response confirmation window period is a fixed time window, and the time window is set to a value greater than a communication delay between the central discharge controller and the controllable power load and less than a time when the voltage of the battery cluster reaching the pre-warning drop threshold drops to a predetermined safety rejection threshold at the power.
  8. 8. The high power energy storage emergency power supply discharge control system of claim 1, wherein the early warning drop threshold is disposed at an end of a voltage plateau region of the battery cell.
  9. 9. The high power energy storage emergency power supply discharge control system of claim 1, wherein the expected drop includes a drop in total output current of the system, and the magnitude of the drop reaches a current reference value, the current reference value being determined based on a derated power rating in the power derating command.
  10. 10. The high power energy storage emergency power supply discharge control system of claim 1, wherein the N parallel battery clusters are lithium ion battery clusters.

Description

High-power energy storage emergency power supply discharge control system Technical Field The invention relates to a high-power energy storage emergency power supply discharge control system, and belongs to the technical field of energy storage power supply discharge control. Background The scheme of adopting lithium ion batteries in a high-power energy storage system is widely applied at present, a Battery Management System (BMS) is configured to be standard configuration for guaranteeing the operation of the battery management system, the main functions of the system are to monitor the state of a battery core in the system and conduct protection actions when the battery core touches a protection threshold value, inconsistency among lithium ion battery cores (especially under a high-current working condition) due to differences of internal resistance, capacity, polarization characteristics and the like is an objectively existing physical characteristic, the inconsistency leads to the fact that in a system formed by parallel battery clusters, the weakest battery core always exists before other battery cores touch a preset discharge cut-off voltage threshold value of the Battery Management System (BMS), however, under the specific working condition of high-power emergency discharge, the conventional protection actions of the BMS can cause a systematic failure conduction chain, when the weakest battery core in a certain parallel cluster touches the cut-off threshold value, the BMS standard actions are to cut off the battery core so as to protect the battery core, the current borne by the cluster is instantaneously and evenly distributed to N-1 parallel battery clusters, and the situation that for the high-power emergency discharge reaches the maximum current, the system immediately drops down, and the instantaneous load is caused by the fact that the instantaneous voltage drops down level of the system is gradually and the corresponding to the maximum current is suddenly drops. In view of this problem, conventional improved paths, such as those attempting to screen cells with higher consistency or to increase system redundancy, the former being limited by electrochemical principles and costs, the latter being unable to avoid the physical process of bus voltage impact caused by the cutting of the weakest cluster, expose the inherent contradiction of the fundamental nature, that is, in the prior art framework, the cutting action performed to protect individual cells becomes a direct cause of system-level instability, and that is, the control logic sacrificing system stability for protecting individuals is also embodied in the existing emergency power supply patents, and the focus is on switching and energy storage of the power supply, rather than system robustness under high-power discharge conditions, for example, the chinese patent of the grant bulletin CN104269904B discloses a high-power mobile low-valley-power storage emergency power supply house. Therefore, how to design a new discharge control system can solve the problem of the invalid conductive chain on the premise of not depending on the absolute consistency or excessive redundancy of the battery cells, not only can the safety boundary information of the battery cells be utilized, but also the instant impact of the cutting action on the system bus voltage can be avoided, and the invention is the technical problem to be solved. Disclosure of Invention The invention provides a high-power energy storage emergency power supply discharge control system, which mainly aims to solve the problems that the conflict exists between the cell protection action and the system-level power supply stabilizing target of the traditional battery management system, and the bus voltage drop and the interlocking failure are easy to cause. In order to achieve the above purpose, the invention provides a high-power energy storage emergency power supply discharge control system, which is applied to an emergency power supply comprising N parallel battery clusters and a controllable power load, wherein the system comprises a monitoring unit, a total current monitoring unit and a central discharge controller: The monitoring unit is used for monitoring the real-time voltage and the real-time temperature of at least one electric core in each of the N parallel battery clusters; the total current monitoring unit is used for monitoring the total output current of the system of the emergency power supply; The central discharge controller is connected with the monitoring unit, the total current monitoring unit and the controllable power load through the communication interface and is used for: Step a, responding to emergency discharge start, and instructing a controllable power load to operate at an initial power quota; Step b, continuously receiving real-time voltage and real-time temperature when the controllable power load operates; step c, when at least one real-time voltage is monito