Converter transformer tap switch vibration-electromagnetic wave combined online monitoring method

Abstract

The invention provides a converter transformer tap switch vibration-electromagnetic wave combined online monitoring method. The vibration signal of the top part of a tap switch is acquired, and an electromagnetic wave signal excited by the breaking arc is acquired; the acquired vibration signal and the electromagnetic wave signal are denoised; the threshold of the wavelet coefficient when the electromagnetic wave signal is analyzed is determined by using the electromagnetic wave signal in case of normal action of the tap switch; the threshold of the wavelet coefficient when the vibration signal is analyzed is determined by using the vibration signal in case of normal action of the tap switch; the tap switch contact action time and the wavelet coefficient are determined by using the electromagnetic wave signal in case of action of the tap switch to be detected; the action time and the wavelet coefficient of each phase of the tap switch are determined by using the vibration signal in case of action of the tap switch to be detected; and the operation state of the tap switch to be detected is analyzed according to the contact action time and the wavelet coefficient. The problem that the converter transformer tap switch action event is difficult to be accurately associated by purely using the vibration signal can be effectively solved so that the operation state of the converter transformer tap switch can be accurately monitored and stable operation of the DC power transmission system can be guaranteed.

Description

technical field [0001] The invention belongs to the technical field of on-line monitoring of electrical equipment, and in particular relates to a vibration-electromagnetic wave combined on-line monitoring method of a converter transformer tap changer. Background technique [0002] The converter transformer is the core equipment of the interface between the converter and the inverter in the DC transmission project, and its operating status is directly related to the safe and reliable operation of the entire power grid. The tap changer is a device that maintains a constant DC voltage on the valve side and compensates voltage fluctuations by changing the turns ratio of the winding during the operation of the converter transformer. Its safe operation is the key to the reliable operation of the converter transformer. Compared with the AC transformer tap-changer, the converter tap-changer has a larger voltage regulation range, smaller gear span, and the switching current steepness...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a combined on-line monitoring method for converter tap changer vibration-electromagnetic waves, aiming to solve the problem that it is difficult to accurately correlate the action events of converter converter tap changers using only vibration signals

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