Study And Design Of The Intellectual Asynchronous Motor Protection Based On DSP

This paper combines with the actual project of the NARI Automatic control Ltd. and researches the asynchronous motor protection. We bring forward a new method for digital asynchronous motor protector, which is based on the DSP hardware platform. This microcomputer protector for the asynchronous motor uses the DSP56F807 which is the series of the Motorola's DSP56800 as its kernel processor. The chipset not only has single chip's great steering capability but also has digital signal processor's arithmetic capability. It also has reasonable price and high performance.On the base of analyzing various fault of the motor by symmetrical component method. Dividing motor fault into two kinds: symmetrical breakdown and asymmetric failure and making use of the features and differences of positive sequence, negative sequence, zero sequence fault components to provide a reliable protection for motor devices.Using the method of tri-sampling, Fourier algorithm of full cycle and the algorithm of root-mean-square. It will meet the requirements of not only anti-disturbance but also quantity testing if the Fu's algorithm of full cycle is adopted and the expected effect is reached when we adopted this method in the designed device.Analyzing the method of denoising signal based on wavelet transform. By means of simulation, it shoes that wavelet analysis with local feature well in the time-frequency domain is very effective in fault diagnosis.In addition, to insure the asynchronous motor protection equipment work reliably, the system considers the ability of anti-jamming from software and hardware.