Real-Time Simulation of Voltage Source Converters Based on Time Average Method

When a real-time digital simulator, emulating a switched circuit such as a voltage source converter, is interfaced with a digital controller, the controller's firing signals may not be in synchronism with the simulation time step. Several methods to minimize the resulting inaccuracies have been proposed in the past. However, some of these approaches introduce unnecessary delays and/or generate artificial harmonics. A method based on time averaging is presented. The algorithm is shown to be fast, easy to implement in a programmable logic device, and highly accurate. The method is applied in a hardware-in-the-loop simulation, and the simulation results are compared with experimental results.