Research On Power Health Detection Technique Of Power Distribution System

Power distribution system have the closest contact with power consumers and units,also the most vulnerable part of the power system.In case of power failure of distribution system,social productivity will be affected,and even fire and casualties will be caused,so the issue of power health in distribution system is more and more important.It will be of great significance if we can conduct physical examination on power supply of distribution system,just like we do it with human body.And judge the power supply's health condition by the indexes on the test sheet,then decide whether fix or change corresponding devices or not.The distribution system is mainly composed of transformer,distribution cabinet,switchgear,distribution line and various loads.The health of power supply in distribution system is closely related to the health of these equipment.The health status of these equipment can be used as the evaluation index of power supply health in distribution system.The bad contact of switchgear,the damage of distribution line insulation and the aging of motor type load winding are all its unhealthy manifestations.These faults are all in the form of fault arc in the circuit.The biggest enemy that affects the healthy operation of high-voltage distribution cabinet and transformer is the partial discharge inside.Therefore,this article takes the detection of these two faults as the research focus,and is also the two core detection indicators of the entire power distribution system power health,in order to evaluate the power health of the power distribution system.The detection method of low-voltage series fault arc proposed in this paper is mainly based on the fact that the distortion of the current waveform will lead to the obvious difference between the equivalent "area" of the fault arc and the normal current waveform,and the fusion judgment is carried out in combination with the slope change of the current waveform and the generation of the flat shoulder.Although the traditional judgment method based on the number of fault current waveforms simplifies the judgment process,its physical meaning is ambiguous.Therefore,based on the theory of instantaneous reactive power,this paper decomposes the nonsinusoidal current signal of fault arc,calculates the active power when fault arc occurs,and then obtains the energy when fault arc occurs,finally proposes a method to judge fault arc according to whether the magnitude of arc energy can ignite surrounding combustibles.When partial discharge occurs in high-voltage distribution cabinet,it will be accompanied by sound wave.In this paper,according to the double detection system of sound wave and ultrasonic wave,we can accurately judge the generation of different types of partial discharge.Through the design of embedded hardware for fault arc and partial discharge detection and the implementation of the above detection method with embedded software,the experimental results verify the feasibility of the above detection algorithm.Finally,according to the detection of the core indicators of power supply health in the distribution system,the corresponding scoring and evaluation system is expected,which will be more intuitive to judge the health condition.