Novel two-stage bidirectional energy storage converter control system and control method thereof

Abstract

The invention discloses a novel two-stage bidirectional energy storage converter control system and a control method thereof. An energy storage converter main circuit mainly comprises a three-phase voltage type PWM (Pulse Width Modulation) rectifier, a novel half bridge three-level push-pull bidirectional DC-DC converter, a charging-discharging buffer interface circuit for limiting battery charging current, and a battery pack module. A control system circuit mainly comprises a voltage and current sensor, a driving circuit, a protection circuit, a main controller, an SOC (State of Charge) detection module, a radiator, a buzzer, a man-machine interface, a communication interface circuit and a system auxiliary power supply. The alternating-current micro-grid power or voltage and the states of charge of energy storage batteries can be detected in real time, so that the running modes of each generating set and the energy storage converter in a micro-grid system are controlled flexibly, and the effects of 'filling peaks and clipping valleys' in a power system, smoothening power in a wind-solar hybrid micro-grid system and the like are achieved. Moreover, the control system has the advantages of high power density, small size, high efficiency, low harmonic content, high reliability, high self-control degree and the like.

Description

technical field [0001] The invention belongs to the application field of power electronic power converters, and relates to an energy storage converter, in particular to a two-stage bidirectional energy storage converter used to maintain stable operation of a micro-grid. Background technique [0002] It is a micro-electrical network system composed of distributed generation (Distributed Generations, DGS), energy storage device, energy conversion device, related load and monitoring equipment, and protection device, and can realize the autonomous functions of self-control, protection and management, and at the same time It also has the ability of grid-connected operation and island operation. With the rapid development of distributed power generation technology, microgrid and smart grid, the role of energy storage system is becoming more and more important. Among them, the bidirectional energy storage converter realizes the bidirectional energy transfer between the DC energy st...

AI Technical Summary

Problems solved by technology

This type of energy storage converter is complex to operate, low in automation, prone to failure, and low in reliability. When working, the current waveform on the AC side is severely distorted, the power factor is low, and the power grid is seriously polluted.

The battery capacity configuration of the single-stage energy storage converter lacks flexibility, the working voltage range of the battery is small, and the current sharing characteristics of the battery pack are not good

Images