The Development Of Microprocessor-Based Protection For Large Generators Of Three Gorges Plant

Three Gorges power plant is one of the world's largest power plant. The righ bank plant will use China's self-designed and produced 700,000 kilowatts Hydrogenerator for the first time,at the same time, will use the ptrotection devices independently developed in the domestic.It's a new challenge to develop the protection devices.Papers according to the equipment operating experience had been put into used by left bank of the Three Gorges Power Plant, and the new results of microprecess-based protection of the large generator at home and abroad, work out a new protection device technology overall program for the right bank of the Three Gorges power plant generator. The program for the protection of large generators for the Three Gorges power plant further improved and optimized for the used program.Papers research on the generator differential protection, integrated use of sampling differential and phase differential and the same time adopt 2-out of-3-logic of differential protection. At present, the principle used by Three Gorges Left Bank is ABB and SIMENZES differential protection principle.Based on the comparative analysis of the principles, optimization of differential protection is proposed. The program improved the device's sensitivity, speed, also enhance the ability of anti-jamming devices, anti - TA break, Anti - TA saturation capacity.Paper research a new type protection of the rotor point grounding. The principle of the protection is discribed, and a detailed analysis of the circuit is explained.This paper presents the design of the hardware device, a high-speed DSP process applications to improve device performance. Analysis of the papers focus on internal communications, through the discussion of the limitations of serial communication, CAN is used in protection devices. In addition to the papers also explain software design of the devices. The way based on modular design enhance the reliability of protection, portability and scalability.At present, the protection device has been successfully developed by Huazhong University of Science and Technology,and successfully finished the dynamic simulation tests of the Electric Power Research Institute.