Research And Implementation Of Fault Recording And Analyzing System Of Generator-Transformer Unit

Being one of the important source equipments, the generator will affect the operations of power system and power quality when faults and exceptions occur. Considering the insulation problem, unit groups'connections have been adopted as main electrical connection in power plants, namely Generator-Transformer Unit (GTU). When faults occur, the whole system will oscillate, which will bring tremendous economical and social influences. Therefore, the diagnosis and recovery of GTU have significant influences on the security and reliability of power system.Based on framework and working flow of the existing fault recorders for GTU, the thesis analyzes some defects, such as low sampling rate, poor reliability, low real-time ability and so on. According to DL/T 873-2004 Specification of Microprocessor-based Generator-Transformer Unit Dynamic Recorder, a new kind of fault recording and analyzing system of GTU is proposed based on NI CompaceRIO series programmable automation controller, local networks communication technology and NI Lab VIEW virtual instrument technology.The structure of Server/Client has been adopted in the system. The top layer is composed of a storage station in the monitoring center. The lower layer is composed of monitoring stations on site. The system have following features:the monitoring station adopts virtual instrument technology in the software and NI CompaceRIO series programmable automation controller (PAC) on the hardware. The monitoring station is charges of data collection, fault analysis, data files formation, data files storage and data files transmission independently. The storage station plays a role of information processing center. The hardware design, main detection algorithms and software realization of the system have been introduced detailedly in the thesis. Firstly, high performance data acquisition card is adopted in the hardware design. Secondly, an improved frequency tracking algorithm is presented in the monitoring of the electric quantity, which could predigest calculation formula and improve real-time performance of the system greatly when detection precision is guaranteed. Finally. functions of fault analysis and generator test are added to software design.The system test in lab and on field shows that the recording performance has been improved greatly, such as data precision, computational complexity, recorded data capacity and redundancy character.