MEASUREMENT OF THE FREQUENCY-DEPENDENT IMPEDANCE OF MAJOR STATION EQUIPMENT

High voltage direct current (HVDC) converter stations generate radio frequency (RF) electromagnetic (EM) noise due to valve firing. The noise propagates into the AC and DC switch-yards and along their corresponding transmission lines. This noise can affect the performance of adjacent communication, control and computer equipment, and can interfere with carrier system operation. Therefore, it is important to measure, predict, and mitigate the EM noise and interference. Information related to major station equipment impedance values in a broad frequency range is important for EM noise calculations. All power system components, including major station equipment, can be characterized as frequency dependent impedances. Measurements on equipment are necessary for the purpose of determining these impedance characteristics. The paper describes the instrumentation, improved measurement procedures, a systematic measurement program, and equipment representation concepts. All these have been developed and applied successfully in practice in the course of a project sponsored by the Electric Power Research Institute (EPRI). Transformer related examples are illustrate the more relevant features of the paper. Station equipment performance, station equipment measurements, frequency dependent impedance transformer representation. © 1989 IEEE