Current transformer parallel operation switching control device and switching control method

Abstract

The invention discloses a current transformer parallel operation switching control device and a switching control method. The current transformer parallel operation switching control device comprises a processor, two voltage sampling circuits, two current sampling circuits, an input circuit, a PWM (pulse width modulation) rectifier, a PWM inverter and an output circuit. Compared with other frequency converter operation protection products, the current transformer parallel operation switching control device can realize effective current-limiting protection in a frequency converter parallel system, is high in response speed, and can resist transient and non-transient short-circuit impact, and ring current in parallel operation can be effectively suppressed. The current transformer parallel operation switching control device and the switching control method have the advantages that the method is high in reliability and can effectively guarantee that current transformers keep outputting limited current in failure periods, the current transformers can be effectively protected, good voltage and current waveforms can be outputted, and the power supply continuity is maintained.

Description

technical field [0001] The invention relates to a converter, in particular to a converter switching control device for parallel operation and a switching control method thereof. Background technique [0002] The demand for converter capacity of shore power station is constantly increasing, and the requirements for its performance and reliability are getting higher and higher. The capacity of a single converter is generally up to 500kVA, while the shore power demand has reached the megawatt level. In order to expand the capacity of the converter, using multiple converters to run in parallel is the most reliable method so far. However, the overload capacity of the power components (GTO, IGBT, IPM, etc.) in the converter is poor, and the overcurrent detection circuit of the protection component is very sensitive. The existing products often cause the converter to stop due to the impact of the impact current. Ship electrical loads include high-power and strong impact loads suc...

AI Technical Summary

Problems solved by technology

These technologies should mainly be used in the protection module of a single converter or a low-power converter. When applied to a parallel system together with the converter, the impact resistance is poor, and it is prone to slow response and delay due to recovery time. The difference causes a large circulating current between the converters

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