Three-stage Solid State Transformer modeling through real time digital simulation with Controller Hardware-in-the-loop

The Solid State Transformer (SST) is one of the key elements in Smart Grid. Building as many hardware and multiplying SST devices is expensive and time consuming in addition to a needed lab space and safety measures. This paper constructs the three-stage SST switching model through real time digital simulator (RTDS) with Controller Hardware-in-the-loop. The models of SST rectifier and inverter stage are built on the RTDS using small time-step simulation. The controller hardware-in-the-loop technology is adopted for DC/DC converter stage modeling. The developed model is verified by comparing with the simulation results in MATLAB/PLECS. The simulation results show that, RTDS can not only accurately implement and validate the SST switching model, but also provide more detailed information about state variables in real time.