A zero-sequence current compensation method and device

Abstract

The present invention provides a zero-sequence current compensation method and device. The method includes: obtaining the zero-sequence current of a Z-type transformer; The rules determine the compensation zero-sequence current of the Z-type transformer and the compensation zero-sequence current of the static var generator; send the first zero-sequence current compensation command to the Z-type transformer, and send the second zero-sequence current compensation command to the The static var generator to achieve zero-sequence current compensation; wherein, the first zero-sequence current compensation command carries the compensation zero-sequence current of the Z-type transformer, and the second zero-sequence current compensation command carries the static zero-sequence current compensation command The compensation zero-sequence current of the power generator. The device is used to perform the above method. The zero-sequence current compensation method and device provided by the embodiments of the present invention can effectively prevent the Z-type transformer from overcurrent, and at the same time improve the compensation capacity of the zero-sequence current.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a zero-sequence current compensation method and device. Background technique [0002] As the most widely used form of energy today, electricity is a prerequisite for the development of various industries. With the development of various high-tech industries and the advancement of power reform, the power supply must not only keep up with the growing demand for power capacity, but also be able to Meet the increasingly high power quality requirements. [0003] At present, power quality problems are mainly reflected in reactive power compensation, harmonic control and three-phase imbalance. Most of the users are at the end of the distribution network, and most of them are single-phase loads. Since the three-phase loads change randomly and are usually unbalanced, three-phase unbalanced currents are generated, resulting in unbalanced three-phase voltages, thereby increasing ...

AI Technical Summary

Problems solved by technology

However, the zero-sequence current compensation capability of SVG is affected by power electronic devices and DC side capacitors, and the control algorithm is complex and the cost is high; the zero-sequence current compensated by the Z-type transformer depends on the magnitude of the load zero-sequence current, when the load zero-sequence When the current is too large, it is easy to cause the Z-type transformer to over-current or even be damaged.

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