Short-circuit protection system of energy-storage bidirectional converter

Abstract

Provided is a short-circuit protection system of an energy-storage bidirectional converter. The short-circuit protection system comprises an AC side short-circuit protection module and a DC side short-circuit protection module, the two modules are designed independently and integrated inside a PCS, modular design is adopted by both protection, the AC side short-circuit protection module mainly comprises a diode three-phase full-bridge rectifier module, a high-power thyristor and resistors, and the DC side short-circuit protection module is formed by a high-power thyristor and resistors. The AC side short-circuit protection module is connected with a power conversion unit of the PCS in parallel, a three-phase supply firstly passes through the diode three-phase full-bridge rectifier module, then after the positive pole of a DC voltage output by a common cathode of the diode three-phase full-bridge rectifier module passes through the high-power thyristor, firstly the positive pole of the DC voltage passes through the resistors and finally flows back to a common anode of the diode three-phase full-bridge rectifier module, and a short-circuit protection loop is formed. The DC side short-circuit protection module is connected on a DC bus capacitor in parallel, the positive pole of a DC bus voltage firstly passes through the high-power thyristor, and then flows back to a DC bus negative pole through an absorption resistor, and the short-circuit protection loop is formed.

Description

technical field [0001] The invention belongs to the field of energy storage systems, is applicable to various energy storage converters, and is used to realize the short-circuit protection design for the AC grid side and the load side. Background technique [0002] At present, energy storage bidirectional converters are relatively widely used in distribution network systems. The distribution network is mainly composed of overhead lines, cables, towers, distribution transformers, isolating switches, reactive power compensation capacitors, and some auxiliary facilities. , due to the characteristics of the network composition of the distribution network and the way of line connection, it is very easy to have single-phase short-circuit, phase-to-phase short-circuit and other faults, so it is very necessary for the energy storage bidirectional converter to have the function of short-circuit protection. [0003] The conventional short-circuit protection of the energy storage bidir...

AI Technical Summary

Problems solved by technology

However, these short-circuit protections are all mechanical protections. First of all, there will be a certain mechanical error in the magnetic tripping, and there will be a certain delay time in the mechanical action, and some can even reach tens of milliseconds, which may occur before the circuit breaker trips. , the short-circuit fault has been eliminated, and the PCS has returned to a normal state, which cannot fully guarantee the safe and stable operation of the PCS

Images