Method and system for monitoring hidden faults of power grid power supply equipment

Abstract

The invention relates to a method and system for monitoring hidden faults of power grid power supply equipment. According to the invention, the method comprises the steps: defining virtual nodes comprising a plurality of power supply devices, calculating true virtual value electric energy flowing into the virtual nodes and true virtual value electric energy flowing out of the virtual nodes within0.1 s in real time with 0.1 s as a period, and marking accurate time marks; continuously calculating the power losses occurring in the virtual nodes within a time window of a plurality of periodic scales; and finally, judging whether the internal equipment of the virtual node has a hidden fault or not through a virtual resistance method, a similar virtual node loss comparison method and a historical loss comparison method. The system based on the method comprises a true virtual value electric energy synchronous measurement device and a power supply equipment hidden fault monitoring station domain main station, and is suitable for monitoring power supply equipment non-control loop faults.

Description

technical field [0001] The invention belongs to the technical field of grid fault diagnosis, and in particular relates to a method and system for monitoring hidden faults of power supply equipment. Background technique [0002] The power grid relies on a large number of power supply equipment such as lines, switches, transformers, capacitors, and frequency converters to complete the transmission of electric energy from power generation equipment to electrical equipment. The power supply equipment itself or its interconnected joints, contacts and insulation may often have poor contact, discharge or non-metallic short circuit problems, resulting in heat generation, which may eventually cause fire or explosion, seriously affecting the safety of power transmission. This is especially common in low voltage power supply systems of 400V or 6kV. For example: Poor contact occurred at the inlet line of the 400V switch cabinet drawer in a chemical enterprise, which caused heat generat...

AI Technical Summary

Problems solved by technology

[0004] Existing fault monitoring methods for power supply equipment have various shortcomings that limit their wide application

For example, the ultrasonic monitoring method relies on external signals and is difficult to apply in real time. The traveling wave analysis method is not suitable for short lines or equipment. The electromagnetic coupling method for testing partial discharge needs to install a built-in partial discharge sensor, which is difficult to adopt in existing equipment. Wavelet analysis method and neural network method It is greatly affected by the type of fault point and interference type

Therefore, there is no perfect monitoring method for hidden faults of power supply equipment for a wide range of fault types.

[0005] In addition, it should be pointed out that temperature rise is also a common feature of power supply equipment failure, but the measurement sensitivity of temperature rise is much lower than the measurement of transmission power loss, which is not conducive to early detection of faults

In addition, the abnormal temperature can be detected in time only when the temperature sensor is installed near the fault point. However, the fault point is often difficult to predict, or there are too many sensors to install a large number of sensors.

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