Smart Transformer Based Loop Power Controller in Radial Power Distribution Grid

摘要

In electric distribution grid, increased penetration of renewable energy sources (RES) and electric vehicles (EV) will create several challenging issues such as voltage limits violation in the feeder, line congestion, transformer overloading, etc. These issues could be mitigated using a loop power controller (LPC), by looping the radial distribution system. The LPC is realized either using a back-to-back power converter or with a combination of tap changer and phase shifter transformers. This paper introduces smart transformer (ST), an alternative of line frequency transformer (LFT), to additionally achieve the features of conventional LPC. The ST can achieve operational features of the conventional LPC with effective control and communication functionalities. The ST controls the active and reactive power flow in the radial distribution feeders to achieve voltage regulation in the feeder, loading balancing in the feeders, prevents LFT overloading, etc. Moreover, DC links of the ST also provide an opportunity to integrate energy storage and it allows the ST in the proposed configuration to support the grid during the peak load demand. These advantages of ST in a two feeder radial grid are validated through PSCAD based simulation studies.