Dynamic voltage control of a smart distribution transformer

With the increased penetration of distributed generation, maintaining voltages across distribution networks within statutory limits becomes challenging. To maintain the voltage within statutory limits with the variability of the distributed generation, a dynamic voltage control (DVC) mechanism should be implemented. Such voltage control also facilitates load control especially at peak load periods as the demand depends on the load busbar voltages to some extent. An electronically controlled series compensator based on smart distribution transformer was investigated to achieve the DVC in the low voltage distribution system. The controller design and the operation of the three-phase series compensator and its control are discussed. The proposed topology and control strategies are evaluated on a typical distribution network. From simulations, it was found that the smart distribution transformer can be controlled with less than two cycle response to obtain performance similar to a conventional transformer. Further, the DVC enhances the loadability of the smart distribution transformer.