Upgrading of the Vyborg Converter Substation: Analysis of Lightning Impulse Voltage Withstand Capability

The basic design of the high-voltage thyristor valve developed for the Vyborg converter substation is described. The parameters of the design impulse voltage across the valve and the model of the converter bridge valve assembly are justified. It is established that when subject to a design lightning impulse voltage, the designed valve ensures safe operation in terms of the voltage amplitude and voltage rise rate in the thyristors. It is shown that the difference between the detailed and simplified model does not exceed 3%.