Research Of New Transformer And Capacitor Protection Devices Integrated With Measurement, Control For High-Voltage Switch Cabinet

This paper summarizes the evolvement and actuality of transformer protection and capacitor protection, basing on which an idea is raised for developing a series of new protection devices integrated with measurement, control, to satisfy occasion's requirement of factories, power plant and 110kV substation, which can install in high-voltage switch cabinet. And key technology problem is analyzed deeply. At first, the paper systematically expounds ensemble design project,design principles and function requirements of new protection system, and advances protection function project of transformer protection and capacitor protection devices. Four sets of transformer protection project are advanced basing on occasion's application of transformer protection in power system, which differ in in-out and protection function. Then, the paper introduces the system's hardware design and software design. Super performance, general-purpose, economical, anti-jamming, expansibility are considered for hardware design. The system chooses DSP as it's CPU, and using mode of DSP+CPLD to simplify hardware design. For satisfying measurement function, software design use special software framework. The software is organized by programming modules to simplify software design and improve expansibility. All kinds of protection principle are realized by the format of protection logical function, and protection logical functions are designed basing on the thought of protection logical framework. Aimed at the second harmonic restrain scheme which is commonly used in power system, the paper lists its disadvantages discovered in actual and studies the new harmonic restrain method called "improved second harmonic restrain". The theory basis, implement method, simulation result and performance analysis of the new theory are roundly stated .in addition. The method needs deeper simulation and dynamic experiment to test. The application of new protection devices integrated with measurement, control will be beneficial to decrease consumption of development and maintenance, and improve security and dependability of equipment running.