Integrated Control Method for the Active Superconducting Current Controller

The active superconducting current controller (SCC) adopts the principle of series voltage compensation, which can be utilized to control the system currents and limit the fault currents effectively during fault conditions. It consists of a series transformer, an ac/dc bidirectional converter, and an energy storage unit. To avoid the issue of iron-core saturation, air-core HTS transformer is used. Considering the transient stability enhancement and the fault current limiting comprehensively, the energy-function-based integrated control strategy for SCC is designed. Furthermore, to improve the damping effect of the SCC, the variable coefficient method is adopted in the energy function to control the output voltage of the SCC. Simulation tests are performed to evaluate the performance of the proposed energy-function-based control method.