Voltage Source Converter (VSC) based schemes require small timesteps to properly represent high frequency switching and circuit dynamics. To efficiently include such schemes in larger scale simulations RTDS Technologies has developed the small timestep VSC subnetwork technique.
The VSC subnetworks operate with timesteps in the range of 1-4µs and can be interfaced to large scale simulations operating with timesteps in the order of 50µs. A key feature of VSC subnetworks is that the circuit and valve topology is user configurable. Two- and three-level converters can be freely configured to provide crow-bar circuits, etc. for PWM switching <2kHz. A fixed topology two-level converter is also available for operation at PWM switching frequencies in the range of 10kHz.
Multiple VSC subnetworks can be linked together by traveling wave transmission lines or cables to create entire sytems running with timesteps <4µs.