Breaker Intelligent Release

The low-voltage frame circuit breaker is one of the main switches in the low-voltage power distribution network, It can electric apparatus put through and disconnect not only normal load current and overload current but also short current. It is mainly used in the not frequently operated low-voltage power distribution line or cubicle switchboard and served as power switch, and protect circuit, electric equipment, etc, When they take place overcurrent, overload, shorting out, loss of phase, leaking electricity, etc, it can cut off the circuit automatically, so it is used widely. The intelligence trip relay is a protector of the frame breaker, and is a key control device of the circuit breaker too. with the development at full speed of electric and electronic technology, microelectric technique, computer technology and communication technology, the protector of the circuit breaker has already been lead by traditional electromagnetism release to develop into a electronic release which adopts the integrated circuit, until presenting the intelligence trip relay with high performance microprocessor at present. The intelligence trip relay of new generation adopts the module structural design, incorporate functions, such as measurement,monitoring,controlling, communication, protecting, etc. into an organic whole, widely used in the low-voltage system.To satisfy the demand of selective protection of low-voltage power network and increasing the competition of new product, it is very important to design the intelligence trip relay with full protection ability and acceptable price. In this article, some practical problems for this design are contained, which start from the design of hardware and software. Firstly, the realizable ways of signal detection and sample,power circuit and the application of low-consumption model of M16C62 are discussed, by which the required function of current protection and voltage protection can be realized. Secondly, different protection algorithm based on micro-computer are discussed in this article, and from the virtues and defects of Fourier algorithm, an improved algorithm is put forward, and the importance of the improved algorithm is displaced. this text we optimize protection algorithm, overcome the shortcoming that is tripping slowly of congener product, have well solved the contradiction of tripping between sensitivity and accuracy.Among this subject, this intellectual trip relay regards M16C62LFGP which Renesas Company produces as the key processor on the hardware, it is mainly deal with trouble protection in circuit breaker and gathering data in real time. Hardware adopts standardized module design method, hardware circuit choose standardization, module typical circuit of structure as much as possible, in order to expand. The software adopts the module design method, the software programming is given, and the emphasis is the realization of FFT.For reliable running in the atrocious circumstance, the EMC design of intelligent release was discussed. As some measures of hardware and software are used in the system, the stability and reliability of release are achieved.