Research On The Prediction Of Overload Relay Protection Characteristics Trend

Overload relay is an important element of low-voltage protection appliance. It ismainly used for overload protection of AC motor. According to its heat effect, it can bedivided into bimetal type, the fusible alloy type, induction magnetic type and electronictype and other types. The bimetal overload relay is widely used with ease of use andmultiple functions at home and abroad. But at present, there are still many faults at overloadrelay to make the motor burned. It brings huge economic losses to the national economy.With the continuous development of power industry and control system, the protectionperformance of overload relay is more important and the study on the trend has been a greatconcern in the industry. With the increasingly fierce competition of low-voltage electricalproducts at home and abroad, the research on the prediction of variation trend of overloadrelay protection performance becomes extremely important.In this paper, the characteristics of the overload relay are analyzed. The test method ofdata acquisition for the prediction of protection performance of overload relay is determined.Accordingly, the test data of acting time can be regarded as the typical non-stationarystochastic process. Therefore, based on grey theory, the grey model is established. By useof MATLAB, the corresponding program is written. The grey prediction with the originaltest data is finished. Because any model has its advantages and disadvantages, in order toimprove the prediction accuracy, the wavelet analysis and the grey prediction model arecombined. The test data is dealing in to remove interference by the wavelet method andthen the prediction is carried out by the grey prediction model. By comparison, the predictionaccuracy of the grey model based on the wavelet analysis is higher.