The impact of traveling waves on HVDC protection

The development of High Voltage Direct Current (HVDC) protection technology is a necessary step in the development of high power Voltage Source Converter (VSC) transmission grids. Presently, only a few industry prototypes have been developed for VSC HVDC grid applications[1-3]. However, before any piece of equipment can be installed, it must be subject to testing to prove it is capable of working. These tests are based upon operational experience and/or theoretical analysis of the system it is to be placed in. To date, no VSC HVDC circuit breaker is in commercial operation. Developing knowledge around the testing of the circuit breaker is an important step on the road to HVDC grids. This paper discusses the impact of traveling wave phenomena on the testing of HVDC circuit breakers for VSC applications, derives theoretical calculations to describe the phenomena and compares this to PSCAD simulations of a VSC under DC side pole-to-pole faults.