Research On Distribution Network Single-phase Grounding Faulty Line Selection Device Based On Dsp

Single-phase grounding fault is the most common fault in small current grounding system. After single-phase grounding fault occured, quickly detecting and removing the faulty line is necessary to avoid enlarging the accident and ensure the security and stability of the distribution network. But the faulty line selection problem hasn’t been well solved in engineering.Based on a lot of studies on domestic and foreign existing faulty line selection methods, aimed at the disadvantage of’S injection’method that it can not adapt to the situation of high resistant grounding fault, an improved method based on utilizing the active power of injected signal is proposed in this thesis. A large number of experiments were done on the MATLAB/SIMULINK platform and the experiments’results proved the feasibility of the proposed method.A Faulty line selection device based on signal injection method and DSP controller was designed. The controller is one32bits fixed-point digital signal processor TMS320F2812produced by the TI Corporation. The device is mainly composed of DSP core board, signal injection module, signal collection module, man-machine interface module and other components. The software system of the device is designded by C language in the CCS3.3IDE and it includs PWM signal generation, A/D conversion, FFT operation, line judging and LCD display part etc. A low voltage distribution network analog model, which line voltage is380V, was built in laboratory. With this model, we have finished the debugging experiments of the faulty line selection device.