Based On Dsp + Mcu Motor Development Of Computer Protection Device

The present development conditions of various protective device and protection algorithm for asynchronous (electric) motor are analyzed in this paper. With the development of modem integrated circuit technology and microelectronic technology, the traditional automatic protection model for motors is out of date and should be revolutionized, focusing on the motor's safe and reliable function, taking advantage of special-purpose Digital Signal Processing(DSP) chips, and combining with the ordinary Micro-controller Unit(MCU) and the large screen Liquid Crystal Display(LCD), has designed a new motor relay protective equipment. This equipment is able to collect the signals of voltage, current, frequency, etc, to make protection algorithm with the sample data, to monitor the working conditions of the power network and the motor active status, to alarm or switch off the fault and record the data about the malfunction once there's any troubles.Discussed in this paper are the design of the software and hardware of motor relay protection system selection and realization of protection algorithm. IN the design scheme, In the course of hardware development, double Central Processing Unit(CPU) structure is adopted, an efficient, reliable hardware platform is established. In the design of software, a mixed programming method of C language ad Assembly language model designing are taken, thus improves the efficiency of development, being convenient for maintenance and updating. In the soft design of protection algorithm, Fast Fourier Transform(FFT) Algorithm and Root Mean Square Algorithm(RMS) are adopted to obtain parameters precisely and promptly to make a quick judgment about the malfunction by selecting the Symmetric Vector method.After designing and debugging the microcomputer relay protection system is capable of realizing various functions normally, and the performance has attained the expected requirements. The equipment has fast reaction, perfect protective function and better man-machine interface, simple operating methods and flexible arrangement scheme.