Power distribution network failure data self-synchronizing method based on instantaneous amplitude change

Abstract

The invention discloses a power distribution network failure data self-synchronizing method based on instantaneous amplitude change. According to the power distribution network failure data self-synchronizing method, the instantaneous amplitude of the failure current is calculated by use of the instantaneous sampled values of three-phase currents at the same moment, failure synchronization is realized according to the characteristic that the instantaneous amplitude of the currents after a failure changes suddenly, and whether the failure exists is determined according to whether the magnitude of the sudden change of two cycle current instantaneous amplitudes before and after the failure exceeds a certain threshold; the power distribution network failure data self-synchronizing method has the characteristics of high sensitivity and high speed, and is capable of effectively overcoming the defects of an existing fault detection method, such as slow start, high failure moment detection error and poor self-synchronizing effect in case of failures occurring near a current zero-crossing point; without increasing the construction cost, the clock synchronization accuracy is improved to meet the requirements of the line longitudinal differential protection of the power distribution network.

Description

technical field [0001] The invention belongs to the field of power system automation, and in particular relates to a self-synchronization method for distribution network fault data based on instantaneous amplitude changes. Background technique [0002] The increase in the reliability of power supply for important loads has promoted the application of closed-loop networks in distribution networks. On the other hand, the development of the active distribution network, especially the massive access of distributed power sources, has changed the characteristics of the single-radiation network structure of the traditional distribution network. Uncertainty causes the traditional three-stage current protection to malfunction or refuse to operate. The longitudinal current differential protection can effectively use the information in the fault zone, and is the most effective protection method. [0003] The emergence of the above problems has promoted the application of the longitud...

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Problems solved by technology

[0006] In order to solve the above problems, the present invention proposes a distribution network fault data self-synchronization method based on instantaneous amplitude changes. Self-synchronization of fault data based on the characteristics of instantaneous current amplitude mutation, which effectively overcomes the problems of slow start-up, large detection error at fault time, and poor self-synchronization effect when the current fault self-synchronization technology fails near the zero-crossing point of the current

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