A multi-energy storage converter coordinated control method and system

Abstract

The application provides a multi-energy storage converter coordination control method and system. The method comprises the following steps: synchronously collecting power grid parameters of a PCC point through a unified collection module arranged at the PCC point; receiving and processing the power grid parameters to obtain standardized data for a power control algorithm; generating a global regulation instruction based on the standardized data and in combination with acquired power regulation information, wherein the power regulation information at least comprises operating state information of each PCS, and the operating state information of each PCS at least comprises one of an SOC state corresponding to each PCS, a current output power, an adjustable power margin and a health state; and synchronously issuing the global regulation instruction to each PCS through a real-time communication network module, so that each PCS performs power output according to the same instruction source. The method effectively eliminates regulation deviation and internal circulation caused by independent response of multiple PCSs, improves response synchronism and regulation accuracy of the energy storage system to the power grid, and realizes optimal configuration of energy storage resources.

Description

Technical Field

[0001] This application relates to the field of power system energy storage technology, specifically to a coordinated control method and system for multiple energy storage converters (PowerConversionSystem, PCS). Background Technology

[0002] With the integration of a high proportion of renewable energy sources, such as wind and solar power, into the power grid, the power system faces challenges such as reduced inertia and increased frequency and voltage fluctuations. Battery energy storage systems, due to their rapid and precise power regulation capabilities, have become key equipment for improving grid flexibility and stability. However, the traditional operation and control modes of energy storage power stations have significant shortcomings, limiting their effectiveness.

[0003] The current mainstream approach is for each PCS to independently sample the grid frequency and perform local primary frequency regulation. This method is prone to circulating currents within the energy storage system due to sampling calculation deviations and power command differences, and the response speed is slow. Summary of the Invention

[0004] This application aims to solve the technical problems of inconsistent power commands and slow response speed caused by PCS distributed sampling and independent calculation.

[0005] To solve the above-mentioned technical problems, the embodiments of this application are implemented through the following aspects.

[0006] Firstly, this application provides a coordinated control method for multiple energy storage converters, including: The power grid parameters of the PCC point are collected synchronously through a unified acquisition module set up at the common node PCC of the power grid. The power grid parameters include at least the power grid frequency and line voltage. The grid parameters are received and processed to obtain standardized data for the power control algorithm; Based on the standardized data and the acquired power regulation information, a global regulation command is generated. The power regulation information includes at least the operating status information of each energy storage converter PCS. The operating status information of each PCS includes at least one of the following: the battery state of charge (SOC), current output power, adjustable power margin, and health status of each PCS. The global adjustment command is synchronously sent to each PCS through the real-time communication network module, so that each PCS outputs power according to the same command source.

[0007] This application firstly uses a unified acquisition module located at a common node in the power grid for synchronous sampling, ensuring that all control commands originate from the same high-precision data source and eliminating internal circulating current problems caused by distributed sampling and calculation across multiple PCS. Secondly, a coordinated control module centrally processes and makes decisions on information across the entire network, enabling optimized calculations from a global perspective and laying the foundation for implementing advanced functions such as composite control and intelligent scheduling. Finally, a real-time communication network module synchronously distributes global commands to all PCS, ensuring millisecond-level precise coordination and high reliability at the execution level. This method constructs a new control paradigm for energy storage systems, moving from "distributed aggregation" to "unified coordination," and is an effective path to achieve rapid response, reduce circulating current, and enhance the grid's support capabilities.

[0008] Preferably, the unified acquisition module performs synchronous sampling at a frequency no less than N times that of the coordinated control module, and the measurement accuracy is no less than 0.5 level, to ensure that the input data of the control algorithm has sufficiently high accuracy and real-time performance.

[0009] Preferably, the global adjustment command includes a global active power adjustment command and a global reactive power adjustment command.

[0010] Furthermore, the method for generating the global active power regulation command includes: calculating the virtual inertial control output and the virtual droop control output in parallel based on the grid frequency in the standardized data. The output of the virtual inertial control is proportional to the grid frequency change rate, providing millisecond-level rapid transient power support and suppressing the frequency change rate; the output of the virtual droop control is proportional to the grid frequency deviation, providing steady-state power regulation and eliminating frequency deviation. The two outputs are superimposed to generate a composite global active power regulation command, thereby simultaneously optimizing the transient and steady-state frequency characteristics of the system.

[0011] Furthermore, the method for generating the global reactive power regulation command includes: generating reactive power compensation based on the grid line voltage in the standardized data using an adaptive voltage state function algorithm. This algorithm comprehensively considers voltage deviation, voltage deviation rate of change, and cumulative voltage change to achieve rapid sensing and error-free regulation of voltage dips, thereby generating the global reactive power regulation command.

[0012] Furthermore, the data processing procedure includes: filtering the power grid parameters to remove interference harmonics; performing integrity detection on the filtered power grid parameter data stream and using an interpolation algorithm to complete the identified missing or invalid data points to generate a continuous and complete control data sequence; and formatting the continuous and complete control data sequence according to a preset standard communication protocol data model to generate standardized data for unified calling and processing by various control algorithms within the coordinated control module, thereby improving system robustness.

[0013] Preferably, the real-time communication network module is an industrial Ethernet ring network based on EtherCAT. This network utilizes EtherCAT's "fly-read / fly-write" and hardware synchronization mechanisms to synchronously send global adjustment commands to all PCS with a deterministic delay of no more than 5 milliseconds, providing communication assurance for achieving millisecond-level coordinated control.

[0014] Preferably, the method further includes instruction priority scheduling: the coordination control module coordinates and dynamically optimizes the allocation of various types of power regulation instructions received based on the operating status information of each PCS, sets priorities, and forms the final global power regulation instructions.

[0015] Preferably, the method further includes dynamic switching of operating modes: based on standardized data and the operating status information of each PCS, the urgency of the power grid and the health status of the battery system are assessed, and the operating mode of the coordination control module is dynamically switched. The modes include at least: an emergency support mode aimed at providing maximum power support, an economic regulation mode aimed at optimizing operational economy, and a battery maintenance mode prioritizing extending battery life.

[0016] Secondly, this application provides a coordination control system for implementing the above method, comprising: A unified data acquisition module is set up at the PCC point to synchronously acquire the power grid parameters of the PCC point; The coordination control module, which is communicatively connected to the unified acquisition module, is used to receive and process the power grid parameters to obtain standardized data for the power control algorithm. The coordination control module is also used to generate a global adjustment command based on the standardized data and the acquired power adjustment information. The power adjustment information includes at least the operating status information of each PCS, and the operating status information of each PCS includes at least one of the following: the SOC status, current output power, adjustable power margin, and health status of each PCS. A real-time communication network module connects the coordination and control module with each PCS, and is used to synchronously send the global adjustment command to each PCS.

[0017] The technical advantages of this application are as follows: By constructing a closed-loop control architecture of "unified data collection, centralized decision-making, and synchronous data distribution," the problems of internal circulation and response lag caused by decentralized control in traditional energy storage systems can be solved.

[0018] 1. The unified acquisition module set up at the PCC point provides consistent power grid status awareness across the entire station, eliminating calculation deviations caused by independent sampling of each PCS, and solving the circulating current phenomenon caused by inconsistent frequency or power commands at the source; 2. The centralized processing of the coordination control module enables global optimization calculation of the grid status and the operating status of each PCS, providing a platform for implementing virtual inertial / droop composite control, adaptive reactive power regulation and multi-command priority scheduling, significantly improving the energy storage system's ability to quickly support grid frequency and voltage and its multi-objective coordination capabilities; 3. The EtherCAT-based real-time communication network ensures that global commands are synchronously delivered to all PCS with millisecond-level deterministic delay, thereby shortening the overall system response time. At the same time, the fiber optic ring network redundancy design significantly improves communication reliability. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a multi-energy storage converter coordinated control method provided in this application; Figure 2 This is a schematic diagram of the multi-energy storage converter coordinated control system provided in this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] The multi-energy storage converter coordinated control method and system provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0023] This method 100 is primarily executed by the coordination and control module—in other words, the decision-making, coordination, and instruction generation steps of the method can be implemented through software, hardware, or a combination of both, installed on the coordination and control module. In this embodiment, the coordination and control module is a centralized dedicated controller deployed locally at the energy storage power station, used to coordinate the collaborative operation of multiple energy storage converter PCSs. Figure 1 As shown, the method specifically includes the following steps.

[0024] S110: The power grid parameters of the PCC point are collected synchronously through the unified acquisition module set in the power grid common node PCC.

[0025] In this application, a unified acquisition module is deployed at the common grid node (PCC) of the energy storage power station. This module is an independent and dedicated high-precision synchronous measurement unit. Its sampling frequency is set to be no less than N times, such as twice, the control frequency of the coordinated control module, to ensure that the timeliness of the acquired data meets the real-time control requirements. The unified acquisition module adopts a three-phase electrical parameter acquisition unit with a measurement accuracy of no less than 0.5 class, such as 0.2 class, and integrates voltage transformers (PT) and incoming current transformers (CT) adapted to the voltage level of the PCC point. It directly and accurately acquires the grid parameters of the PCC point. The grid parameters include at least the grid frequency and line voltage, providing a reliable raw data foundation for subsequent data processing and the generation of global regulation commands.

[0026] The unified acquisition module establishes a time synchronization link with the coordination and control module through high-precision time synchronization protocols, such as the IEEE 1588PTP protocol and the IRIG-B code synchronization protocol, to ensure that the timestamps of the acquired data are consistent, thus laying the time benchmark for subsequent "same command source" control.

[0027] Data is continuously collected at a preset sampling frequency. After each sampling, a set of raw data packets is generated. The data packets contain a timestamp, real-time power grid frequency value, and effective value of power grid line voltage. The data packets are transmitted to the coordination and control module in real time via optical fiber or industrial network cable to ensure the real-time performance of data transmission.

[0028] S120: Receive and process the power grid parameters to obtain standardized data for the power control algorithm.

[0029] After receiving the raw power grid parameter data, the coordination control module performs standardization processing to obtain standardized data for the power control algorithm.

[0030] In one alternative approach, step S120 may include: S121: Filter the power grid parameters to remove interference harmonics.

[0031] To address grid-side harmonic interference in the grid parameters, such as harmonics generated by industrial loads and the operation of power electronic devices, a digital low-pass filtering algorithm adapted to power data is used to filter the original parameters. By setting a preset filtering threshold, the fundamental signals of the grid frequency and line voltage are retained, while high-frequency harmonic components are filtered out to avoid parameter distortion caused by harmonic interference. This ensures that the filtered grid parameters accurately reflect the actual grid status at the PCC (Power Grid Control Center) at the grid connection point.

[0032] S122: Perform integrity checks on the filtered power grid parameter data stream and use interpolation algorithms to complete the identified missing or invalid data points in order to generate a continuous and complete control data sequence.

[0033] Real-time integrity detection of the filtered power grid parameter data stream includes two aspects: first, detecting missing data points caused by instantaneous communication fluctuations and signal attenuation during data transmission; and second, identifying invalid data points caused by instantaneous faults in the acquisition module and interference signal intrusion, such as data that exceeds the reasonable range of the power grid's rated parameters.

[0034] For the detected missing or invalid data points, an interpolation algorithm adapted to the timing characteristics of power parameters is used to complete the data. Based on the valid data sequence before and after the fault data point, the complete value is calculated and filled into the data stream, and finally a continuous, complete and uninterrupted control data sequence is generated, so as to avoid the interruption of power control algorithm calculation and the deviation of command generation caused by missing or invalid data.

[0035] S123: The continuous and complete control data sequence is formatted and converted according to the preset standard communication protocol data model to generate standardized data for unified calling and processing by various control algorithms within the coordination control module.

[0036] The completed continuous control data sequence is formatted and converted according to a preset standard communication protocol data model. The preset standard communication protocol uses common power system standards, such as IEC61850 and DL / T860. During the conversion process, the data format, unit identifier, data frame structure, and field definition are unified, and the frequency and line voltage data are encapsulated into standardized data frames.

[0037] The converted standardized data can be directly called and processed by various power control algorithms within the coordination control module, such as the virtual inertia and virtual droop combination algorithm and the voltage state function-based algorithm, without the need for additional format adaptation. This eliminates data compatibility issues between different algorithms, improves instruction generation efficiency, and ensures the standardization of data transmission and processing, adapting to the communication needs of multi-module collaboration in energy storage systems.

[0038] S130: Based on standardized data and combined with the acquired power regulation information, a global regulation command is generated.

[0039] The power regulation information includes at least the operating status information of each PCS, and the operating status information of each PCS includes at least one of the following: the battery state of charge (SOC) corresponding to each PCS, the current output power, the adjustable power margin, and the health status.

[0040] In this step, the coordination control module receives data uploaded by the battery management system (BMS) corresponding to each PCS through an adapted bus protocol, such as CAN bus or RS485 bus, to obtain the state of charge (SOC) of the battery for each PCS; and receives the operating status information reported by each PCS itself through real-time industrial Ethernet protocols, such as EtherCAT protocol or Profinet protocol, including the current output power, adjustable power margin, and health status.

[0041] Then, based on the standardized data in step S120, combined with the acquired power regulation information, i.e. the operating status information of each PCS, a global regulation command is generated through a preset algorithm.

[0042] S140: Through the real-time communication network module, global adjustment commands are synchronously sent to each PCS so that each PCS can output power based on the same command source.

[0043] In this step, the real-time communication network module is an industrial Ethernet ring network based on EtherCAT. The coordination control module transmits the generated global adjustment commands to each PCS through this ring network. The deterministic delay of command transmission is no more than 5 milliseconds, ensuring that the time difference for all PCS to receive commands is kept within a very small range, guaranteeing that all PCS start adjustment synchronously based on the "same command source". After receiving the command, each PCS adjusts the state of the power output device through its internal power control loop, synchronously responding to the global adjustment command.

[0044] The aforementioned control method reduces measurement errors at the source by deploying independent, dedicated high-precision synchronous measurement units at the PCC point, paired with compatible PT and CT components, and combining high-precision time synchronization protocols with high sampling frequencies. This ensures consistent data acquisition time and timely compliance, providing high-quality raw data support for the control algorithm. Simultaneously, a three-step data processing strategy of "filtering-completion-formatting conversion" effectively filters out harmonic interference, completes data gaps, and achieves data format unification based on general power standards, eliminating algorithm compatibility barriers and improving command generation efficiency and accuracy. Relying on the EtherCAT industrial Ethernet ring network, commands are synchronously issued with a deterministic delay of no more than 5 milliseconds. This method ensures synchronized adjustment of all PCS (Power Control Systems) and allocates tasks as needed based on the PCS's SOC, power margin, and health status. This avoids equipment overload, eliminates internal circulating currents, and extends equipment lifespan. Furthermore, the method employs a multi-protocol adaptation strategy, making it compatible with commonly used hardware and communication architectures in energy storage systems. It eliminates the need for large-scale modifications to existing equipment, and the locally deployed centralized controller can flexibly adapt to different power plant scales with rapid response. The entire control process achieves closed-loop management, effectively improving the system's anti-interference capability. Through precise active and reactive power regulation, it can quickly suppress grid frequency and voltage fluctuations, improve the regional grid's frequency and voltage regulation level, facilitate source-grid-load coordinated interaction, and ensure the safe and stable operation of the power grid.

[0045] In one possible implementation, the global regulation command includes a global active power regulation command and a global reactive power regulation command, which correspond to the grid frequency regulation and voltage regulation requirements, respectively, so as to realize the precise support of the energy storage system for the grid.

[0046] Generating a global active power regulation command may include: calculating the virtual inertial control output and the virtual droop control output in parallel based on the grid frequency in standardized data, wherein the output of the virtual inertial control is proportional to the grid frequency change rate and is used to provide fast transient power support; the output of the virtual droop control is proportional to the grid frequency deviation and is used to provide steady-state power regulation; and superimposing the virtual inertial control output and the virtual droop control output to generate a global active power regulation command.

[0047] In this step, the coordination control module first extracts the standardized power grid frequency time series. It can identify the current frequency status in real time, including transient conditions with sudden frequency changes (such as a sudden drop in wind power / photovoltaic output causing a rapid drop in frequency) and steady-state conditions with stable frequency deviations (such as the frequency fluctuating slightly around the rated value), providing a basis for parameter adaptation of the two types of control outputs.

[0048] Virtual inertia control output: proportional to the rate of change of the grid frequency, as shown in the following formula: in, For virtual inertial control output power, This is an inertia coefficient, which can be dynamically adjusted according to the magnitude of the rate of change of frequency. When Exceeding the preset transient threshold, It automatically increases and quickly outputs the corresponding power, providing instantaneous transient power support, and quickly suppresses frequency surges to prevent the frequency from exceeding the safe operating boundary in a short period of time.

[0049] Virtual droop control output: proportional to the grid frequency deviation rate, as shown in the following formula: in, To control the output power using virtual droop control. This is the droop coefficient, which can be dynamically adjusted according to the frequency deviation range. The rated frequency of the power grid. This is the frequency deviation. After the frequency enters the steady-state deviation stage, The adaptive optimization continuously adjusts the output power to gradually reduce the frequency deviation and push the grid frequency back to the rated value, while avoiding frequency oscillations caused by over-adjustment.

[0050] Superposition and Instruction Optimization: The coordinated control module linearly superimposes the two types of control outputs obtained from parallel computation, introducing a superposition weighting coefficient. ( Adapts to the priority of transient and steady-state regulation under different operating conditions, under transient operating conditions Bias Under steady-state conditions, biased The initial global active power regulation command is generated, and the core formula is as follows: in, This sets the initial global active power regulation total power. Subsequently, based on the preset fault-tolerant mechanism, [the following is applied]: Verification is performed to eliminate outliers that exceed the total regulation capacity of the energy storage system, and finally, executable global active power regulation commands are determined, which take into account both rapid transient response and precise steady-state regulation, and ensure that the commands match the actual operating capacity of the energy storage system.

[0051] Generating a global active power regulation command may include: generating reactive power compensation based on grid line voltages in standardized data, using an adaptive voltage state function algorithm, and generating a global reactive power regulation command.

[0052] The coordinated control module calculates the grid line voltage amplitude based on the grid line voltage in the standardized data. Voltage change rate Accumulated voltage deviation d Data such as voltage drops, voltage spikes, voltage shifts, and voltage oscillations are used to determine the current voltage conditions in real time, providing input for adjusting the parameter weights of the adaptive algorithm.

[0053] The core formula for dynamically constructing a voltage state function model using grid line voltage-related parameters as input is as follows: in, To calculate the total reactive power compensation, The rated line voltage of the power grid. , , These are the adaptive weighting coefficients for voltage amplitude deviation, voltage change rate, and cumulative voltage deviation, respectively. This is a pre-defined segmented voltage state function. The algorithm can adaptively adjust the weighting coefficients according to changes in voltage conditions: under voltage sag conditions, it increases... Weighting prioritizes and rapidly outputs reactive power compensation; under conditions of continuous voltage deviation, amplification is applied. , Weighting ensures regulation accuracy; under voltage oscillation conditions, it reduces... Weights are assigned to avoid exacerbating oscillations. Weights are obtained through real-time calculations to adapt to the current voltage state. The total reactive power that the energy storage system needs to output or absorb should be clearly defined.

[0054] Based on calculations This generates an initial global reactive power regulation command, which includes core information such as total reactive power compensation and regulation response time. Subsequently, it combines preset voltage regulation constraints, including the PCS reactive power output upper limit. Grid voltage safety threshold range The initial instructions are validated and optimized to ensure... Furthermore, the adjusted voltage remains within a safe range, ultimately generating a global reactive power adjustment command that can be issued and executed.

[0055] Generate global active power regulation commands (including) and the power allocated to a single PCS) and global reactive power regulation commands (including After allocating power to each PCS, the coordination control module combines the power regulation information (SOC, adjustable power margin, health status, etc.) obtained from the BMS and PCS to decompose and allocate two types of instructions to each PCS: for PCS with high SOC and good health status, priority is given to allocating regulation tasks; for PCS with sub-health status, low SOC, or insufficient reactive power regulation margin, derated allocation is performed to avoid equipment overload operation.

[0056] After the instructions are assigned, the two types of instructions are synchronously sent to each PCS with a deterministic delay of no more than 5 milliseconds through the industrial network ring network based on EtherCAT. This ensures that all PCS execute active and reactive power regulation actions synchronously based on the same instruction source, thereby realizing the coordinated support of the energy storage system for the grid frequency and voltage.

[0057] In one possible implementation, the power regulation information may further include various types of power regulation commands. Based on this, and using standardized data combined with the acquired power regulation information, generating global regulation commands may further include: based on standardized data and according to the operating status information of each PCS, performing online coordination and dynamic optimization allocation of various types of power regulation commands to form global power regulation commands.

[0058] In this possible implementation, the coordination and control module receives various types of power regulation commands from external systems such as the regional power grid dispatch center, power trading platform, renewable energy plant control terminal, and power plant operation and maintenance platform via a dedicated dispatch communication link. These commands specifically cover four categories: First, power grid safety commands, including primary frequency regulation support commands allocated by the dispatch center based on the overall network frequency situation, dynamic voltage support commands issued for voltage fluctuations at the grid connection point, black start support commands activated after a power grid fault, and emergency power control commands under emergency fault conditions; Second, power market commands, including peak-valley price arbitrage commands issued by the power trading platform, peak shaving and valley filling commands pushed by the demand-side response platform, and paid frequency and voltage regulation commands from the ancillary service market; Third, renewable energy coordination commands, including photovoltaic / wind power output stabilization commands issued by renewable energy plants and renewable energy consumption commands issued by the dispatch center; Fourth, operation and maintenance management commands, including planned charging and discharging commands formulated by the power plant operation and maintenance platform and power-limited operation commands during power grid maintenance. The above instructions are all independent instructions issued by external systems based on the overall network control needs, market signals, or operation and maintenance plans. At the same time, the coordination and control module synchronously collects the battery charge status, adjustable power margin, and health status of each PCS, providing equipment capability basis for the coordinated allocation of multiple instructions.

[0059] The coordination and control module prioritizes instructions based on the safe and stable operation of the power grid. Power grid safety instructions are given the highest priority, followed by instructions related to new energy collaboration and the electricity market, while operation and maintenance management instructions are given the lowest priority. In actual control processes, when multiple types of external power regulation instructions are issued concurrently, and the total power demand exceeds the maximum regulation capacity of the energy storage system, or when there are conflicts in the execution time or power direction of different instructions, the coordination and control module combines standardized real-time power grid parameters to resolve conflicts online. For low-priority instructions, it reduces their load, staggers peak times, or partially executes them, prioritizing the full satisfaction of the power demand of high-priority instructions. After completing instruction priority determination and conflict resolution, the coordination control module performs dynamic optimization allocation based on the operating status information of each PCS. High-priority grid safety instructions are broken down into active and reactive power regulation sub-tasks and preferentially allocated to PCS with good health status, reasonable SOC, and sufficient regulation margin. For renewable energy coordination and power market instructions, balanced allocation is carried out based on the real-time grid absorption demand and power plant revenue targets. For operation and maintenance management instructions, they are only executed when there are no other control tasks in the system. Subsequently, all allocated sub-tasks are integrated to form a global regulation instruction that includes the active / reactive power target output values ​​of each PCS, execution time limits, and priority identifiers, ensuring that each PCS can clearly understand the execution order and task weight.

[0060] After generating global regulation commands, the coordination control module synchronously sends the commands to all PCSs with a deterministic delay of no more than 5 milliseconds through an industrial Ethernet ring network based on EtherCAT. Upon receiving the commands, each PCS executes the regulation tasks in an orderly manner according to the priority identifier in the commands. For example, when the power grid dispatch center simultaneously issues dynamic voltage support commands and peak-valley electricity price active power dispatch commands, each PCS will prioritize outputting reactive power to support the grid voltage. Once the voltage recovers to the safe operating range and the system still has remaining regulation margin, it will then execute active power regulation to respond to the peak-valley electricity price dispatch demand. This effectively ensures the safe and stable operation of the power grid, takes into account the consumption of new energy sources and the economic benefits of power plants, and avoids PCS overload operation, significantly improving the energy storage system's response capability to the multi-scenario regulation needs of the power grid.

[0061] In one possible implementation, before generating the global power regulation command, the process may include: assessing the grid emergency state and battery system health state based on standardized data and the operating status information of each PCS; and dynamically switching the operation control mode of the coordination control module according to the assessment results. The operation control mode includes at least: an emergency support mode aimed at providing maximum power support, an economic regulation mode aimed at optimizing operational economy, and a battery maintenance mode that prioritizes extending battery life.

[0062] In this possible implementation, after the coordination control module completes the standardization of grid parameters, it does not directly generate a global power regulation command. Instead, it first synchronously collects the operating status information of each PCS, including SOC, battery health status SOH, charge / discharge temperature rise rate, and adjustable power margin. Combined with the standardized grid parameters, it conducts a dual-state assessment. The grid emergency state assessment can set a frequency deviation threshold of ±0.2Hz and a voltage descent / surge threshold of ±10% of the rated voltage. When the grid frequency deviation in the standardized data exceeds the threshold or the voltage change rate is ≥0.5kV / s, it is determined to be a grid emergency state. The battery system health status assessment is based on real-time data uploaded by the BMS. When the SOC is below 20% or above 85%, the temperature rise rate exceeds 3℃ / min, or the SOH is below 80%, it is determined to be a battery health warning state.

[0063] Based on the dual evaluation results, the coordination control module dynamically switches between operating control modes. The triggering conditions and control logic of the three modes are as follows: When the grid is determined to be in an emergency state, it automatically switches to the emergency support mode, with the core objective of providing maximum power support. At this time, the coordination control module will prioritize the use of all adjustable power margins of the energy storage system, weaken the constraints of battery cycle loss, and ensure rapid response to emergency adjustment needs such as primary frequency regulation and dynamic reactive power support. When the grid is in a stable state, i.e., the frequency and voltage are within the safe threshold and the battery is in good health, it switches to the economic regulation mode, with the goal of optimizing operational economy. It prioritizes responding to revenue-oriented adjustment needs such as peak-valley electricity price arbitrage and ancillary service markets, and maximizes the operating revenue of the power station by accurately allocating charging and discharging power. When the battery is determined to be in a battery health warning state and the grid has no emergency adjustment needs, it switches to the battery maintenance mode, with the priority objective of extending battery life. At this time, it will limit the charging and discharging power of the PCS, reduce the charging and discharging frequency, avoid deep charging and discharging or overload operation of the battery, and optimize the power allocation strategy, prioritizing the scheduling of PCS in good health to perform light adjustment tasks.

[0064] After switching between the three modes, the coordination control module generates global power regulation commands under the target constraints of the corresponding mode, combined with power regulation information: In emergency support mode, power grid safety commands are forcibly prioritized to the highest level, ensuring sufficient allocation of emergency regulation power even if it exceeds the execution requirements of some economic commands; in economic regulation mode, resources are optimized for allocation according to the logic of "market commands take precedence over maintenance commands," improving the execution efficiency of revenue-generating commands such as peak-valley arbitrage and ancillary services; in battery maintenance mode, all regulation commands are derated to ensure that the total regulation power does not exceed the battery's safe operating boundary, while avoiding long-term high-load operation of a single PCS. The generated global power regulation commands are synchronously sent to each PCS through an EtherCAT-based industrial Ethernet ring network with a delay of no more than 5 milliseconds, ensuring seamless connection between mode switching and command execution.

[0065] Actual operation scenario verification shows that when the grid experiences a sudden voltage drop (voltage momentarily drops by 15% of the rated value), the coordination and control module determines it to be a grid emergency state, quickly switches to emergency support mode, dispatches each PCS to output sufficient reactive power within 1 second, and restores the grid connection point voltage to a safe range within 3 seconds, meeting the national standard response requirements for dynamic voltage support. When the grid state is stable and the battery SOC is in the healthy range of 50%, the system automatically switches to economic regulation mode, prioritizing response to peak-valley electricity price arbitrage commands, charging at full power during off-peak hours and discharging at full power during peak hours, increasing the average daily revenue of the power station by about 8%. When the SOC of some PCS batteries drops to 18% and triggers a health warning, the system switches to battery maintenance mode, reducing the regulation power of those PCS to 25% of the rated value, while evenly distributing the regulation tasks to other healthy PCS, ensuring both the basic regulation needs of the grid and avoiding excessive battery wear.

[0066] The above-mentioned closed-loop logic of "state assessment - mode switching - instruction optimization" achieves a dynamic balance between grid security, operational economy and battery life, thereby improving the overall operational performance and scenario adaptability of the energy storage system.

[0067] Based on the multi-energy storage converter coordinated control method described above, this application discloses a multi-energy storage converter coordinated control system 200, as follows: Figure 2 As shown, the device 200 mainly includes: A unified data acquisition module 210 is set at the PCC point to synchronously acquire the power grid parameters of the PCC point. The coordination control module 220 is communicatively connected to the unified acquisition module and is used to receive and process the power grid parameters to obtain standardized data for the power control algorithm. The coordination control module is also used to generate a global adjustment command based on the standardized data and the acquired power adjustment information. The power adjustment information includes at least the operating status information of each PCS, and the operating status information of each PCS includes at least one of the following: the SOC, current output power, adjustable power margin, and health status of each PCS. The real-time communication network module 230 connects the coordination control module with each PCS and is used to synchronously send the global adjustment command to each PCS.

[0068] In one possible implementation, the unified acquisition module performs synchronous sampling at a frequency no less than N times that of the coordination control module, and the measurement accuracy is no less than 0.5 level.

[0069] In one possible implementation, the global adjustment command includes a global active power adjustment command and a global reactive power adjustment command.

[0070] In one possible implementation, the coordination control module 220 is further configured to calculate, in parallel, a virtual inertial control output and a virtual droop control output based on the grid frequency in the standardized data; wherein the output of the virtual inertial control is proportional to the grid frequency change rate and is used to provide fast transient power support; the output of the virtual droop control is proportional to the grid frequency deviation and is used to provide steady-state power regulation; the virtual inertial control output and the virtual droop control output are superimposed to generate the global active power regulation command.

[0071] In one possible implementation, the coordination control module 220 is further configured to generate reactive power compensation based on the grid line voltage in the standardized data using an adaptive voltage state function algorithm, and generate the global reactive power adjustment command.

[0072] In one possible implementation, the coordination control module 220 is further configured to filter the power grid parameters to remove interference harmonics; perform integrity detection on the filtered power grid parameter data stream, and use an interpolation algorithm to complete the identified missing or invalid data points to generate a continuous and complete control data sequence; and format and convert the continuous and complete control data sequence according to a preset standard communication protocol data model to generate standardized data for unified calling and processing by various control algorithms within the coordination control module.

[0073] In one possible implementation, the real-time communication network module is an EtherCAT-based industrial Ethernet ring network, used to synchronously send the global active power adjustment command and / or global reactive power adjustment command to all PCS with a deterministic delay of no more than 5 milliseconds.

[0074] In one possible implementation, the power regulation information further includes: various types of power regulation commands; the coordination control module 220 is also used to coordinate and dynamically optimize the allocation of the various types of power regulation commands online based on the standardized data and the operating status information of each PCS, so as to form the global power regulation command.

[0075] In one possible implementation, the coordination control module 220 is further configured to assess the grid emergency state and battery system health state based on the standardized data and the operating status information of each PCS; and to dynamically switch the operation control mode of the coordination control module according to the assessment results; wherein the operation control mode includes at least: an emergency support mode aimed at providing maximum power support, an economic regulation mode aimed at optimizing operating economy, and a battery maintenance mode that prioritizes extending battery life.

[0076] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A coordinated control method for multiple energy storage converters, characterized in that, include: The power grid parameters of the PCC point are collected synchronously through a unified acquisition module set up at the common node PCC of the power grid. The power grid parameters include at least the power grid frequency and line voltage. The grid parameters are received and processed to obtain standardized data for the power control algorithm; Based on the standardized data and the acquired power regulation information, a global regulation command is generated. The power regulation information includes at least the operating status information of each energy storage converter PCS. The operating status information of each PCS includes at least one of the following: the battery state of charge (SOC), current output power, adjustable power margin, and health status of each PCS. The global adjustment command is synchronously sent to each PCS through the real-time communication network module, so that each PCS outputs power according to the same command source.

2. The control method according to claim 1, characterized in that, The unified acquisition module performs synchronous sampling at a frequency no less than N times that of the coordination control module, and the measurement accuracy is no less than 0.5 level.

3. The control method according to claim 1, characterized in that, The global adjustment commands include global active power adjustment commands and global reactive power adjustment commands.

4. The control method according to claim 3, characterized in that, Generating the global active power regulation command includes: Based on the grid frequency in the standardized data, the virtual inertial control output and the virtual droop control output are calculated in parallel; wherein, the output of the virtual inertial control is proportional to the grid frequency change rate and is used to provide fast transient power support; the output of the virtual droop control is proportional to the grid frequency deviation and is used to provide steady-state power regulation. The virtual inertial control output and the virtual droop control output are superimposed to generate the global active power adjustment command.

5. The control method according to claim 3, characterized in that, Generating the global reactive power regulation command includes: Based on the grid line voltage in the standardized data, an adaptive voltage state function algorithm is used to generate reactive power compensation, and then the global reactive power adjustment command is generated.

6. The control method according to claim 1, characterized in that, The process of receiving and processing the grid parameters to obtain standardized data for power control algorithm calculations includes: The power grid parameters are filtered to remove interference harmonics; The filtered power grid parameter data stream is subjected to integrity detection, and the identified missing or invalid data points are filled in using an interpolation algorithm to generate a continuous and complete control data sequence. The continuous and complete control data sequence is formatted and converted according to a preset standard communication protocol data model to generate standardized data that can be uniformly called and processed by various control algorithms within the coordination control module.

7. The control method according to claim 1, characterized in that, The real-time communication network module is an EtherCAT-based industrial Ethernet ring network, used to synchronously send the global active power adjustment command and / or global reactive power adjustment command to all PCS with a deterministic delay of no more than 5 milliseconds.

8. The control method according to claim 1, characterized in that, The power regulation information also includes: various types of power regulation commands; the generation of global regulation commands based on the standardized data and the acquired power regulation information includes: Based on the standardized data and according to the operating status information of each PCS, the various types of power regulation commands are coordinated and dynamically optimized online to form the global power regulation command.

9. The control method according to claim 1, characterized in that, Before generating the global power regulation command, the following is also included: Based on the standardized data and the operating status information of each PCS, assess the power grid emergency state and the battery system health status. Based on the evaluation results, the coordination control module dynamically switches its operating control mode; The operation control modes include at least: an emergency support mode aimed at providing maximum power support, an economic adjustment mode aimed at optimizing operational economy, and a battery maintenance mode that prioritizes extending battery life.

10. A multi-energy storage converter coordinated control system, used to implement the control method as described in any one of claims 1 to 9, characterized in that, include: A unified data acquisition module is set up at the PCC point to synchronously acquire the power grid parameters of the PCC point; The coordination control module, which is communicatively connected to the unified acquisition module, is used to receive and process the power grid parameters to obtain standardized data for the power control algorithm. The coordination control module is also used to generate a global adjustment command based on the standardized data and the acquired power adjustment information. The power adjustment information includes at least the operating status information of each PCS, and the operating status information of each PCS includes at least one of the following: the SOC status, current output power, adjustable power margin, and health status of each PCS. A real-time communication network module connects the coordination and control module with each PCS, and is used to synchronously send the global adjustment command to each PCS.

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