Hardware model of a Dynamic Power Flow Controller

The opening of the electricity markets and the increased utilization of renewable energies lead to highly unpredictable and volatile power flows in the transmission grids. Enforcing the grid by constructing new transmission lines is only possible on the long term due to complicated approval procedures and local public resistance. By implementing power flow controlling devices, it is possible to increase transmission capacity in the short and medium term. Phase Shifting Transformers (PST) are state of the art for power flow control. Fast control devices which perform control actions within milliseconds (like Thyristor Controlled Series Compensation or High Voltage Direct Current Back to Back stations) are available but very expensive. The topic of this paper is a hybrid device called Dynamic Power Flow Controller (DPFC). This device consists of a conventional PST combined with thyristor switched reactances. The thyristor switched devices are able to provide fast control actions while conventional PST offer a large control range for comparatively low costs. In this paper, we present a hardware model of a DPFC which has been developed at TU Dortmund University. This hardware model is downscaled by a factor of 1000 to a nominal phase-to-phase voltage of 380 V. We present measurement results of control actions in a realistic test environment. The DPFC model will be used to investigate practical issues related to the implementation and control on a real system. Furthermore, we plan to use the DPFC for educational purposes.