Abstract – Coordination of HVDC and STATCOM to Enhance Inverter Fault Recovery

One of key performance indicators for a line commutated converter (LCC) HVDC is inverter recovery performance after an AC disturbance and avoidance of commutation failure. From the overall system perspective, a commutation failure is extremely disruptive as there is momentary power transfer loss which could potentially result in system instabilities for a weak system. Moreover, the rapid increase in the direct current during the commutation failure results in additional stresses on the thyristor valves.

In an attempt to reduce the probability of commutation failure, a commutation failure prevention function is usually added to the HVDC system controls. In this presentation, the use of STATCOM controls to supplement this functionality will be described. A brief overview of the commutation failure phenomenon will be followed by description of the STATCOM controls, PSCAD modeling of the controls and simulation results.