Analysis on electromagnetic compatibility immunity indexes for secondary systems of substation

The electromagnetic environment of substation threats the safe operation of secondary systems in substation, the electromagnetic compatibility (EMC) immunity test of secondary system in substation with strong electromagnetic environment is very important. According to the experimental and analysis results of electromagnetic environment parameters in substation in literatures, this paper summarized the characteristic values of electromagnetic environment parameters in substation, and proposed the recommended values for the electromagnetic environment parameters of substation, including power frequency electrical and magnetic fields, 1-3 s short-time magnetic field, lightning transient magnetic field, switching transient electric and magnetic fields, lightning interference voltage, switching interference voltage, short-circuit interference voltage, transient and power frequency ground potential rises. By analyzing the general demand to the EMC immunity of secondary system, the requirement to the EMC immunity test of secondary system in substation is proposed. The main characteristic parameters for the EMC immunity test of secondary systems in different locations of substation are also discussed, the test items, which should be added, are also listed, these test items and requirements are more suitable to the actual electromagnetic environments of substations.