A black start method and application of a cascaded energy storage system with self-balancing capability

Abstract

The present invention provides a black start method and application of a cascaded energy storage system with self-balancing capability. According to the given start time deltaT of the black start, the output three-phase AC voltage of the cascade energy storage system at the current moment is obtained through the black start command calculation module. The given value of the given value is obtained by the voltage-current double-loop vector control module to obtain the modulation voltage of each link power conversion unit of each phase of abc, and then superimposed with the balanced control voltage component of each link power conversion unit output by the balance control module to obtain each The total modulation voltage of the power conversion units of each chain link in a phase is obtained by the carrier phase-shifted sinusoidal pulse width modulation algorithm module to obtain the pulse driving signals of each power device of the power conversion unit of each series link in each phase. The black start method and application of the cascaded energy storage system with self-balancing capability provided by the present invention can realize the high self-balancing control of the cascaded energy storage system, high-voltage direct-mounted high-efficiency and fast start-up, high power quality, and convenient blackout for centralized scheduling. Startup purpose.

Description

technical field [0001] The invention relates to the technical field of power system black start methods, in particular to a black start method and application of a cascaded energy storage system with self-balancing capability. Background technique [0002] The traditional power grid black start generally uses fuel oil units and hydroelectric units as the black start power supply, and starts the thermal power units and the main power grid first, and then gradually restores the distribution network, and the entire power grid is restored from top to bottom according to the voltage level. Due to the rapid development of energy storage at present, after the entire power grid is out of power, if the energy storage system widely distributed in the distribution network can be used at the same time to quickly restore important loads and thermal power units in the distribution network, it will effectively speed up the recovery process of the distribution network and It can accelerate ...

AI Technical Summary

Problems solved by technology

[0004] In the traditional power system, there are the following requirements for the selection of the black start power supply: the position of the black start power supply in the power grid must be close to the large unit, the start path is short, the voltage level change is small (the number of Near the center, fast starting speed, strong load capacity, voltage and frequency adjustment function, long power supply time

[0005] Therefore, the parallel connection of multiple distributed low-voltage energy storage converters to boost the 10 / 35kV distribution network system not only increases the step-up link of power frequency transformers, but also the speed of black start is limited by the parallel connection of multiple distributed low-voltage energy storage converters. The communication coordination time between low-voltage parallel energy storage converters is relatively slow, and it is urgent to provide a high-rated charging and discharging power, less voltage level changes (the number of transformers passed through), fast starting speed, and load-carrying capacity. Strong energy storage system with voltage and frequency adjustment function and long power supply time is used as the main power supply to improve the black start capability of the power distribution system

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