Investigation Of The Device For Fault Location Of The Over-head Transmission Line Using Two-terminal Asynchronous Data

When faults occur in the transmission line, locating the fault accurately and timely is propitious to eliminate the fault and resupply power. The exact fault location of the transmission line is fundamental to ensure a proper operation of the system. The main contributions to the investigation of the device for fault location are as follows: A set of device for fault location of the transmission line is developed, which consists of the signal sensor and the data acquisition system. The data acquisition and calculation are controlled by industrial controlling computer. Various algorithms are discussed completely in this paper. A new algorithm of two-terminal fault location using asynchronous data at both ends is used in the device, which use the data pre-fault to remove the angular difference caused by the asynchrony of the two terminals. In order to satisfy some requirement, the device can locate the fault using single-terminal data. Lots of simulation results show that the algorithms used in this device can locate the fault site precisely. Some protective algorithms are discussed in this paper. Most of device for fault location use single algorithm in both record star-up and the extraction of fundamental frequency component in location. This way has been improved in this paper. Whole-cycle Fourier differential algorithm is adopted in record start-up to satisfy the Real-time requirement. The least squares method is applied to extract the fundamental frequency component in location which has low computing speed but high precision. The software of the device is developed using Delphi 5.0 environment, which can control the data acquisition, monitor signals and show the Real-time waveform. The software start recording data in fault and calculate the fault site then, which has built database and make the device a rounded system.