Microgrid energy storage PCS control system and method

Abstract

The invention discloses a microgrid energy storage PCS control system and method. An input end of a three-phase bridge inverter circuit is connected to a storage battery through a direct current EMI filter circuit, and an output end is connected to a three-phase power grid through an LCL filter circuit; a current sensors and a voltage sensor are separately disposed on a three phase line of the output end of the three-phase bridge inverter circuit, and output ends of current transformers and the voltage sensor are separately connected to a control module; the control module receives an externalthree-phase command signal, and according to the received command signals corresponding to each of phases, and a voltage or a current feedback value input by a corresponding phase voltage sensor andcurrent sensor, turn-on or turn-off of each of switching devices in the three-phase bridge inverter circuit is controlled. The control module of the system and the method can achieve phase splitting control of microgrid energy storage, and the power control precision can be improved.

Description

technical field [0001] The invention relates to the technical field of microgrid energy storage control, in particular to a microgrid energy storage PCS control system and method. Background technique [0002] Compared with the traditional large power grid, distributed power generation has the characteristics of green and pollution-free, flexible installation location, high energy utilization rate, and reduced transmission loss energy of long lines. However, its own problems are gradually exposed, such as distributed power supply control is difficult, unstable, and costly. With the development of power electronics technology and modern control, a microgrid has emerged, which is composed of micro-sources, loads, control equipment, and energy storage equipment to form a controllable unit that provides electricity or heat to users. Compared with the large power grid, the micro-grid is closer to the load, without the need to build ultra-high voltage and long-distance power grid...

AI Technical Summary

Problems solved by technology

The user cannot independently set the output power parameters of each phase, and the power control parameters have not achieved decoupling control

[0006] 2. The power control accuracy is low

The control algorithm of the PCS control unit is difficult to meet the requirements of stability and high precision at the same time

The PI controller has strong stability but has the disadvantage of low control gain in the high frequency band; the proportional resonant controller (PR) has a very large gain at the fundamental frequency, and the low frequency band will cause inter-harmonic problems due to the fluctuation of the grid frequency, so It is difficult to use in the low frequency band, the quasi-proportional resonant controller will enlarge the cut-off frequency bandwidth of the PR controller, and the effect is poor in the high frequency band, and the parallel use of the proportional resonant controller (PR) and the quasi-proportional resonant controller can theoretically be realized The perfect effect of low gain in the low frequency band and high gain in the high frequency band, but it will sacrifice the phase angle margin of the control system, making it difficult to ensure the stability of the control system

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