Electromagnetic Interference Analysis in HV Substation Due to a Static Var Compensator Device

Static var compensator (SVC) devices have been extensively utilized in modern substations to achieve high flexibility and wide tolerance to load variation. However, due to frequent switching of the thyristors in a static var compensator, large amounts of electromagnetic interference (EMI) are being generated, which may cause malfunction of the SVC or unaccepted response of victim devices positioned nearby. In this paper, an advanced acquisition system was established to implement onsite measurements in order to obtain the EMI data. A digital calibration technique for the antenna was applied to trace back the actual electromagnetic emissions. The radiated and conducted EMI data are comparatively analyzed to present detailed and useful information of the EMI levels. According to the configuration of an SVC and the dynamic performance of the random load, an equivalent model was established to simulate and predict the conducted EMI levels. Based on onsite measurements as well as theoretical analysis, pertinent immunity measures were put forward to reduce coupling impacts on the electronic units of the secondary side.