Excitation Regulator Based On Double Microprocessor Of 87c196cb: Its Research And Development

With the development of cybernetics and micro-electron technique, the technique of computer control has been popularized and applied gradually in hydro-power plants, while gaining good effect and accumulating a plenty of experience, the level of automation has been boosted largely in hydro-power plants, a lot types of excitation regulators based on microprocessor appear in excitation control of the generator. However, the microprocessor excitation regulators applied in power plants replace the general integration circuit with microcomputer only in closed loop control mostly. Its reliability, communication ability and interface can't meet the need of hydro-power plants.This paper researches and develops a type of double microprocessor-controlled excitation regulator with 87C196CB based on the present microprocessor-based excitation regulator applied in power plant. First, the whole structure and the working principle of the excitation system are introduced briefly. Second the specific design and realization ways of regulator's software and hardware based on 87C196CB are suggested. Lastly, the analysis and design of set's reliability is conducted.In communication, the use of the CAN serial communications controller of 87C196CB's and SJA1000 composes high reliability serial bus communications in order to ensure the reality of system's supervision and control reliably. In Alternating Current sampling, the adoption of high speed, synchronous and parallel A/D device ADS7864 avoids the phase error between voltage and current of the same phase which results from asynchronous sampling and low conversion speed of A/D device. In pulse forming, the utilization of the programmable logic device PLSI1032 makes the structure of theregulator's hardware become more compact and obtains higher reliability. In interface, the replacement of general keys with touch screen makes it convenient to set parameter, direct to operate and easy to maintain.The software adopts the C-196 with high efficiency, and combined with asm-196, so the code of program is simple and the processing time is short. The application of multi-interrupt brings much convenience to design program and makes the processing time of program meet the requirement of the fast excitation control system of generator's responding to signal.