Convertible static transmission controller (CSTC) system model validation by controller hardware-in-the-loop-simulation

Convertible Static Transmission Controller (CSTC) is a versatile power electronic system which is installed across a transmission transformer. The proposed solution provides several integration options with multiple operational modes. The CSTC can be used to control the power flow in a meshed transmission grid or to extend the life time of existing transformers by partially bypassing and conditioning the substation throughput power. From the supervisory control point of view, a control algorithm is required to set the reference values of active and reactive power flow of the CSTC converters based on the desired operating points for the transformer and the grid active and reactive power flows. In this paper, a generalized algebraic model of the CSTC in three different modes of operation is derived. The proposed algebraic model presents the behavior of transformer power flow with respect to various operating points of the CSTC. Therefore, the P-Q transformer operating range can be obtained. To verify the control structure and algorithm of the CSTC as a transmission asset, an ultra-high fidelity Controller Hardware-in-the-Loop (CHIL) experimentation will be explained and comparative results will be presented.