CN-122001047-A - Power distribution method for energy storage system

CN122001047ACN 122001047 ACN122001047 ACN 122001047ACN-122001047-A

Abstract

The invention relates to the technical field of new energy power generation, in particular to a power distribution method of an energy storage system, which comprises the following steps of S1, communicating with an energy storage system comprising but not limited to a BMS and a PCS through a communication module, wherein the communication mode comprises but not limited to Ethernet and CAN, and is used for data transmission among all controllers, S2, acquiring key information of a battery subsystem and an inverter system in real time based on the communication module by utilizing an acquisition module, and fully considering the characteristics of a lithium iron phosphate battery when the power distribution is carried out in the charging and discharging process, combining two influencing factors of SOC and voltage to carry out comprehensive weighting influencing factors, adapting to the energy storage system comprising but not limited to the lithium iron phosphate battery core in the voltage platform period, dynamically adjusting the charging and discharging power among all battery subsystems based on the characteristics of the lithium iron phosphate battery subsystem, enabling the electric quantity among all the subsystems to be balanced, enabling the consistency to be better, enabling the charging and discharging time to be controllable to be shortest, and improving the overall utilization rate and efficiency of energy storage.

Inventors

WANG GUANGMING
LIU MINGYUAN
LI XUYING
WANG HAILONG
LI WENPENG
GUO FUQIANG
QIAN HAO

Assignees

北京海博思创科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (10)

1. The power distribution method of the energy storage system is characterized by comprising the following steps of: S1, communicating with a BMS (battery management system) and a PCS (personal communication system) through a communication module, wherein the communication mode comprises an Ethernet and a CAN (controller area network) and is used for carrying out data transmission between controllers; s2, acquiring key information of a battery subsystem and an inverter system in real time based on the communication module by utilizing an acquisition module; s3, comprehensively weighting according to the key information by judging the voltage platform period to obtain influence factors of all influence factors; s4, respectively obtaining power distribution coefficients of all subsystems in the platform period based on a two-eight rule according to the influence factors, and combining the sum of SOPs of all subsystems to obtain final power distribution values of all subsystems; S5, comparing the finally obtained power distribution value with the SOP value of the corresponding subsystem, wherein the distributed power value cannot be larger than the SOP value of the subsystem.
2. The method of claim 1, wherein in step S1, the communication module is used to communicate with the BMS and the PCS, and the communication manner includes but is not limited to ethernet and CAN, and the method for data transmission between the controllers is as follows: The BMS and PCS nodes are scanned through the communication module, a communication channel is established through a handshake protocol, the communication module collects state data from each node at regular time, meanwhile, consistency check is carried out on the BMS-PCS data, under any one of two conditions of communication interruption or packet loss, data reconstruction is carried out through an interpolation and prediction mechanism, data transmission passes through hash abstract check, retransmission times expectation is calculated when a retransmission request is obtained, and the expression is as follows: , in the formula, Representing random variables Is used as a reference to the desired value of (a), Representing slave To an infinite number of summation symbols, Representing the probability of failure of each attempt, Representation of The probability of failure of the secondary pair, Represent the first Probability of secondary success, success probability = The probability of failure is determined by the probability of failure, Is shown in the first The probability of success of the secondary times the number of trials For the purpose of calculating the desired value, Indicating the average number of attempts required before success.
3. The method for distributing power to an energy storage system according to claim 2, wherein in step S2, based on the communication module, the method for acquiring key information of the battery subsystem and the inverter system in real time by using the acquisition module is as follows: the key information includes, but is not limited to, information of each subsystem SOC, highest single voltage, lowest single voltage, subsystem SOP, current actual power and rated power of an inverter, the asynchronous multiplexing mechanism is utilized to realize concurrent acquisition, the battery SOC cannot be directly measured, then calculation of the SOC is based on actual capacity, online calculation is carried out by adopting extended Kalman filtering, and the expression is as follows: , in the formula, Is shown at the moment Is used to determine the state vector of (1), Indicating at the next moment Is used to determine the state vector of (1), Is a state transfer function representing the current state And input How to jointly determine the next state, Is shown at the moment Is used for controlling the input control quantity of the system, Is the noise of the process and, Is shown at the moment Is used to determine the observed quantity/output vector of (c), Is an observation function that represents how to slave the state vector Obtain output , Is the measurement noise.
4. The method for distributing power to an energy storage system according to claim 3, wherein in step S2, based on the communication module, the method for acquiring key information of the battery subsystem and the inverter system in real time by using the acquisition module is as follows: The subsystem SOP is obtained through a partial differential prediction model, and the expression is as follows: , in the formula, Represent the first SOP of subsystem with respect to time Is used for the rate of change of (a), Represent the first The sustainable output power of the subsystem is chosen, Is a constant coefficient representing the coefficient of influence of the voltage spatial variation on the SOP drop, the preceding plus minus sign representing that the influence is inhibitory, Represent the first The subsystem is in a spatial position The second partial derivative of the voltage distribution over, Represent the first Subsystem at time A function of the voltage at the time instant, The coordinates of the spatial location are represented, Is a constant coefficient, a positive value, indicates the degree of influence of temperature change on SOP, Represent the first The partial derivative of the temperature of the subsystem with respect to time, Represent the first Subsystem at time The temperature at that time, the subsystem represents the smallest unit that can be power controlled, and is not limited to the amount of electricity and the manner in which the batteries are grouped.
5. The method for distributing power to an energy storage system according to claim 4, wherein in step S3, by determining a voltage platform period and then performing comprehensive weighting according to the key information, the method for obtaining the influence factors of each influence factor is as follows: The judging voltage stage is carried out by utilizing characteristic curves of lithium iron phosphate batteries, and characteristic data obtained by testing in a battery laboratory are judged to be in the voltage stage when any threshold value of SOC epsilon [20%,90% ] or voltage epsilon [3.08V,3.48V ] is met, the threshold value is not limited to be a fixed value, the threshold value is any value of inflection points of the voltage stage, and in the voltage stage, the weighting formula of SOC factors is as follows: , in the formula, Is the first SOC weights for subsystems Indicating the effect of its remaining capacity on the discharge priority, Represent the first The current state of charge of the individual subsystems, Representing all Of subsystems The sum of the values is used for the normalization, Is the sum index variable and, The system is the total number of subsystems, the constraint condition is that the SOC of any subsystem is more than 20% and less than 90%, and when discharging, the weight assignment formula of the SOC factor is as follows: , in the formula, Representing all The sum of the SOC values of the subsystems is used for normalization, and the constraint condition is that the SOC of any subsystem is more than 20% and less than 90%.
6. The method for power distribution of energy storage system according to claim 5, wherein in step S3, the method for obtaining the influence factors of each influence factor by determining the voltage plateau and then comprehensively weighting according to the key information is as follows: During charging, the highest monomer voltage weighting formula is as follows: , in the formula, Represent the first Voltage influencing factor weighting of individual subsystems , Represent the first The highest voltage of the unit cells in the subsystem, Represent the first The highest voltage of the single battery in the subsystem relative to the charge reference voltage The difference in mV is that, Representing all Highest voltage in subsystem The sum of the differences in mV is used for normalization, Is the sum index variable and, Is the total number of subsystems that are to be included, Indicating only when the first The highest voltage of the subsystem exceeds 3480mV and participates in the calculation of the formula, the constraint condition is that the voltage of any subsystem is more than 3.48V, and the weighting formula of the lowest monomer voltage is as follows when discharging: , in the formula, Represent the first The lowest voltage of the unit cells in the subsystem, Represent the first The difference in the lowest voltage of the unit cells in the subsystem relative to the discharge reference voltage 2800mV, Representing all The sum of the difference between the lowest voltage in the subsystem and 2800mV is used for normalization, Indicating only when the first When the lowest voltage of the subsystem is less than 3080 mV, the subsystem participates in the calculation of the assigned weight, and the constraint condition is that the voltage of any subsystem is less than 3.08V.
7. The method for power distribution of energy storage system according to claim 6, wherein in step S4, based on the two-eight rule, the power distribution coefficients of each subsystem are obtained respectively in the platform stage and the platform stage, and the sum of the subsystems SOP is combined to obtain the final power distribution value of each subsystem, which comprises the following steps: and based on a two-eight rule, the power distribution coefficients of the subsystems are averaged after the SOC influence factor is multiplied by 0.8 and the voltage influence factor is multiplied by 0.2 in the voltage platform period, so that the final power distribution coefficient in the voltage platform period is obtained, and the expression is as follows: , in the formula, Represent the first The power distribution coefficient of the subsystem is determined, Is the first SOC weights for subsystems Indicating the effect of its remaining capacity on the discharge priority, Represent the first Voltage influencing factor weighting of individual subsystems And (3) during the period outside the voltage platform, multiplying the SOC influence factor by 0.2 and the voltage influence factor by 0.8, and then averaging to obtain a final power distribution coefficient outside the voltage platform, wherein the expression is as follows: , in the formula, Is to assign a weight factor representing the weight ratio of 80% to 20% in the two-eight rule, Representing the overall weighted result and then averaging the results, Indicating that the weighted sum in brackets is an integer.
8. The method for power distribution of energy storage system according to claim 7, wherein in step S4, based on the two-eight rule, the power distribution coefficients of each subsystem are obtained respectively in the platform stage and the platform stage, and the sum of the subsystems SOP is combined to obtain the final power distribution value of each subsystem, which comprises the following steps: Combining the product of the sum of the SOPs of the subsystems and the power distribution coefficient of each subsystem to obtain the final power distribution value of each subsystem, and the expression: , in the formula, The representation represents the sum of all subsystems SOP, Representation pair To the point of Is added up with all the subsystems of the system, Represent the first The SOP of the subsystem is selected, Represent the first The power distribution coefficient of the subsystem is determined, Represent the first The final power allocation value of the subsystem is, Representing the SOP sum of all subsystems, Representing from subsystem 1 to subsystem 1 SOP summation of subsystems.
9. The method for distributing power to an energy storage system according to claim 8, wherein in step S5, the method for distributing power value not larger than SOP value of the corresponding subsystem according to the finally obtained power distribution value is as follows: after eliminating the subsystem which limits work due to fault, defining an indication function as a normal working subsystem set, updating all distributed power and SOP limit matrix, and calculating the proportion of the subsystem exceeding the maximum SOP value, wherein the proportion of excess power is defined as follows: , in the formula, Representation subsystem Is used for the distribution of the overrun proportion, Representation subsystem Is a preliminary calculated power allocation value of (a), Representation subsystem Is used for the SOP value of (2), Indicating that the calculated deviation value exceeds SOP when the ratio of the calculated deviation value to SOP is greater than 0, and indicates that the calculated deviation value is still a margin when the calculated deviation value is less than 0, Representation of all Subsystems in a collection Is suitable for use in the present invention, The subsystem set currently participating in power distribution does not comprise abnormal and offline subsystems, when the 2 nd subsystem exceeds 1%, unified scaling correction is triggered for all subsystems, the power distributed by all subsystems is multiplied by 0.99, and power scaling and re-constraint are performed for all subsystems.
10. The method for distributing power to an energy storage system according to claim 8, wherein in step S5, the method for distributing power value not larger than SOP value of the corresponding subsystem according to the finally obtained power distribution value is as follows: Defining a smoothing factor by adopting a nonlinear buffer mechanism, controlling and improving responsiveness by using a piecewise correction function, and constructing a total power balance state by a regularized power adjustment model, wherein the expression is as follows: , in the formula, Meaning that it is minimized, Representation subsystem Is used to determine the corrected power allocation value of (c), Representation subsystem Is a preliminary calculated power allocation value of (a), Indicating all operating subsystems A set of numbers that are to be associated with a particular set of numbers, Representing the square error between the correction value and the initial value, Representing numbering of all subsystems The accumulation is performed and the data is stored, Representation subsystem Is used to determine the SOP limit value of (2), Representing all subsystems The sum of the power allocations after the correction, Representing all subsystems Sum of the preliminary allocated total powers.

Description

Power distribution method for energy storage system Technical Field The invention relates to the technical field of new energy power generation, in particular to a power distribution method of an energy storage system. Background With the increasing prominence of the problem of power grid stability caused by the rapid development and grid connection of the new energy power generation field, the power distribution of the energy storage system becomes a research hot spot. In order to improve energy storage efficiency and system stability and extend the service life of energy storage systems, practitioners have proposed various power distribution methods. The method comprises the steps of carrying out power distribution according to the current energy storage parameters and rated parameters of the energy storage subsystem and the total power demand of the energy storage subsystem, and adjusting the power distribution share in real time according to the temperature extreme value, the state of charge and the like of the battery cluster. In addition, the power distribution method of the hybrid energy storage system is also widely focused, and the overcharge or overdischarge phenomenon of the energy storage element is avoided and the system stability is improved by carrying out power distribution according to the charge states of the energy storage element such as a battery, a capacitor and the like and a preset distribution principle. The patent publication number CN118630840A, which records in the specification that the embodiment of the invention discloses a power distribution method, electronic equipment and an energy storage system, wherein the power distribution method is applied to a main battery monitoring unit in the energy storage system and comprises the steps of receiving power to be distributed issued by an energy management system; the method comprises the steps of obtaining first electric energy parameters of all energy storage cabinets in an energy storage system, generating first allocation instructions corresponding to the energy storage cabinets according to power to be allocated and the first electric energy parameters, and carrying out power scheduling on the corresponding energy storage cabinets according to the first allocation instructions. According to the embodiment of the invention, the main battery monitoring unit in the main energy storage cabinet generates corresponding power distribution instructions to be sent to the corresponding energy storage cabinets by acquiring the first electric energy parameters of each energy storage cabinet, so that fine power scheduling is realized, the energy storage system meets the power scheduling requirement ", the influence of the SOC precision deviation on power distribution is not considered in the technology, and when the SOC has estimation deviation, the power distribution based on the SOC can have the situation of power distribution errors. Patent publication No. CN119134609a, which states that the present application provides a power distribution method, a computer device, and a computer-readable storage medium. The power distribution method comprises the steps of obtaining first downlink power corresponding to each first battery cluster in an energy storage system, controlling the corresponding first battery clusters to conduct pre-charge and discharge based on the first downlink power, obtaining pre-charge and discharge parameter data corresponding to each first battery cluster, adjusting the first downlink power to obtain adjusted target downlink power if the pre-charge and discharge parameter data are abnormal, and controlling the corresponding first battery clusters to conduct charge and discharge based on the target downlink power. In summary, developing a power distribution method of an energy storage system is still a key problem to be solved in the technical field of new energy power generation. Disclosure of Invention The invention aims to solve the problem that in the prior art, the influence of the precision deviation of the SOC on the power distribution is not considered, and when the estimation deviation exists in the SOC, the power distribution based on the SOC can cause power distribution errors. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a power distribution method of an energy storage system, which comprises the following steps: S1, communicating with a BMS (battery management system) and a PCS (personal communication system) through a communication module, wherein the communication mode comprises an Ethernet and a CAN (controller area network) and is used for carrying out data transmission between controllers; s2, acquiring key information of a battery subsystem and an inverter system in real time based on the communication module by utilizing an acquisition module; s3, comprehensively weighting according to the key information by judging th