The Development Of Supervision Subsystem For 500kV Shunt Reactor Protection Device

As an important electrical equipment in Ultra High Voltage (UHV) power system, a shunt reactor can provide inductive reactance to compensate for the effects of high charging current of long transmission lines, restrain the power frequency over-voltage. So the safe operation and stability of shunt reactors play an important role in the safety and stability of the whole electric power system. However, the fault rate of shunt reactors is relatively high while the existing protection devices have shortcomings such as low sensitivity and unsatisfactory integrative performance. On the other hand, for the enhancement of protection subsystem and the trend of applying information technology to microprocessor-based protection, it brings higher requirements for supervision subsystem.Therefore, it is of great necessity and significance to develop more advanced protection device for UHV line shunt reactor.This paper first summarizes the existing application of UHV line shunt reactor in power systems as well as the present situation and future development of microprocessor-based reactor protection. Then it gives a detailed explanation to the major designing principles and technical characteristic of the system, so as to its integrated configuration. According to the fault types of UHV line shunt reactor, the protective principles scheme is analyzed detailedly.As an important part of the device, supervision subsystem is in charge of supervising the entire equipment and managing the man-machine interface. On the other hand, the subsystem is a bridge of communicating with outer terminal or protection subsystem. Referring to the application request of the device and the hardware characteristic of supervision subsystem, this paper explains in great details the function design and software structure of the subsystem. AT91RM9200 adopted in the device is a high-powered microprocessor, which has excellent expansibility and external resources. For the flexible scheme and integrity of software function, the subsystem can be applied in different situations of field operation.Software design about supervision module and communication module is one of the central works in this paper. By the mode of a classification menu, modularized programming is adopted in the supervision module according to the function of the menu. The paper minutely illuminates the realizing methods of interface displaying, menu operating and keyboard controlling. Referring to the request of software function, five inner transmission projects are designed. From the receiving and the sending patterns, the paper explains the programming means of communication module and analyzes the inter communication protocol, which has several virtues such as reasonable framework, high reliability, excellent expansibility.The protection device for UHV line shunt reactor has been verified by static simulation experiment and dynamic simulation experiment. The experiment results, which are given in the paper, manifest that capability of equipment has come up to prospective destination and it can meet the demands of actual application.