Comprehensive Protection Of Motor Based On PROFIBUS Communication

Motor is the most widely used dynamice quipment in all fields, whose method of protection has been payed closely attention for many years all over the world. Nowadays, as the fast development of the technology of computer and control theory, a new method of computer comprehensive motor protection has appeared, which has more powerful logic analosis character and function compared with the former motor protection. At the same time, these new motor protections can record and analyse the faults. Further more, they can be connected by a network, for the purpose of being easily contolled. And, this dirction of development has been the major direction of this relm. This paper begins the study of comprehensive motor protection based on this background.At first, this paper use the theory of Symmetrical components method analyse varieties of symmetrical and asymmetrical faults of motor, and adopt the measuring method of negative and zero sequence. Especially study deeply in the overload protection. The protection system can deal with the following motor faults: heavy over-current, over/under-voltage, over-current, current unbalance protection, repeated startings, earth fault and so on. After analyse several protection algorithms, this paper adopt a new fast algorithms which is developed from half wave Fourieri algorithms and Mann-Morrison algorithms, and which ensure the reliability and real time of the comprehensive motor protection system.This comprehensive motor protection system uses 80C196KS 16bits MCU as its CPU,making full use of it's powerful capture function to outside event and strong ability of treatment to signal to design a new type of motor protective device. This comprehensive motor protection system construct a PROFIBUS station using PROFIBUS protocol chip SPC3 and 89C52. Using the technology of PROFIBUS bus to build a communication network,making it from the traditional protective device changed to a new type of intelligent motor remote unit which having the function of measurement,control,fault diagnosis and communication.In the process of the software and hardware design of the protection system, manifold self-checked error ways and anti-jamming measures are adopted to enhance reliability and stability of the control network system running at the spot.After the whole design of the protection system are completed, the single and...