Method for implementing adaptive zero sequence current network protection

Abstract

The invention discloses a method for implementing adaptive zero sequence current network protection. The method is characterized by comprising two main steps of grounding transformer zero sequence protection and feeder zero sequence protection. An action fixed value is adaptively adjusted according to the characteristic of a multi-loop grounding failure, so that the reliability of the feeder zero sequence current protection action is guaranteed to the maximum extent, and mis-operation of zero sequence current protection for a grounding transformer serving as a standby is avoided; and therefore, effective protection can be provided for various grounding failures of a power system.

Description

technical field [0001] The invention belongs to a protection method for a grounding fault in a power system, and in particular relates to a method for realizing the self-adaptive zero-sequence current network protection of the power system. Background technique [0002] Zero-sequence current protection has the advantages of simple principle and few required components. Therefore, zero-sequence current protection, as the main protection for various ground short-circuit faults, is widely used in medium-voltage power grids with voltage levels of 35kV and below in my country. The setting value of the traditional zero-sequence current protection is obtained through off-line calculation based on the characteristics of the single-circuit ground fault of the system, and remains unchanged during operation. However, with the continuous development of modern power supply and distribution networks, the types of feeder ground faults are becoming more and more complex. When a ground fau...

AI Technical Summary

Problems solved by technology

However, with the continuous development of modern power supply and distribution networks, there are more and more types of feeder ground faults, and they are becoming more and more complex.

When a ground fault occurs on a multi-circuit line, the distribution characteristics of the zero-sequence current will be greatly changed, which will affect the reliability of the zero-sequence current protection action; the multi-point fault with time difference will make the grounding as a backup change the zero-sequence current protection One of the main causes of malfunction

For the fixed operating value method adopted by the existing zero-sequence current protection, any adjustment is difficult to fundamentally solve the impact caused by complex ground faults, so it must be improved from the protection principle and strategy

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