Active power control method for MW-level battery energy storage system based on battery charge state

Abstract

The invention discloses an active power control method for a MW-level battery energy storage system based on the battery charge state. The method comprises that voltages and currents of a common bus are collected, and the active power, reactive power and voltage amplitude are calculated; a given voltage amplitude is obtained by sagging control of the active power based on the battery charge state; and a voltage difference between the given voltage amplitude and the practically measured voltage amplitude is processed by a proportion-integration regulator to obtain the modulation ratio of a PWM generator, and the PWM generator generates a switch drive signal to control the switching state of a power conversion system, and further to realize effective control for the active power output of the MW-level battery energy storage system. Thus, the MW-level battery energy storage system can effectively distribute the load active power and control output of the active power, the voltage amplitude and frequency of the common bus are stabilized around the rated values, and the charge states of modularized battery energy-storage subsystems of the MW-level battery energy storage system are controlled in an equalized manner.

Description

technical field [0001] The invention belongs to the technical field of control of a MW-level battery energy storage system in a smart grid, and relates to a method for controlling the active power of a MW-level battery energy storage system based on the state of charge of a battery. Background technique [0002] The development and utilization of distributed power sources such as wind energy and solar energy provide an effective way to solve the current energy crisis and environmental degradation faced by countries around the world. Restricting its access to large power grids and large-scale applications. The battery energy storage system can effectively solve the impact on the grid when these distributed power sources are connected to the grid, and can provide active power and reactive power support for the grid to achieve stable control of the system voltage amplitude and frequency. At the same time, due to the development scale of distributed power sources such as wind p...

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Problems solved by technology

[0004] The problem to be solved by the present invention is to provide a method for controlling the active power of a MW-level battery energy storage system based on the state of charge of the battery, and to solve the problem of active power control of a MW-level battery energy storage system formed by parallel connection of N modular battery energy storage subsystems. Due to the unreasonable distribution of load active power and system instability caused by the inconsistent state of charge of the battery, the purpose of effectively distributing the load active power, maintaining the voltage amplitude and frequency of the common bus is stable, and realizing the energy storage of each modular battery. Balance control of battery state of charge between systems

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