Investigation of black start capability of LCC HVDC system with controllable capacitors

It is generally accepted that it is not easy to black start a passive AC network using traditional Line-CommutatedConverter (LCC) based High-Voltage-Direct-Current (HVDC) systems. This paper investigates the possibility of supplying active power to a passive network using the LCC HVDC system with controllable capacitors. The aims are 1) to achieve reliable black start of a dead AC network without additional synchronous compensators; 2) to achieve local control of inverter AC bus voltage during and after black start process; 3) to mitigate the problem of commutation failure especially when more resistive loads are picked up at inverter AC system. Operating principles and characteristics of the LCC HVDC system with controllable capacitors will be presented followed by its application to black start scenario. Then the associated black start sequence will be proposed with verifications by simulation results from Real Time Digital Simulator (RTDS).