Transformer Management System for Energy Control of Customer Demand Response and PV Systems

This paper proposes an innovative transformer management system (TMS) for energy control of customer loads and photovoltaic (PV) systems to solve the problems of transformer overloading and over voltage due to power injection by PV renewable energy. The operation status of distribution transformers is monitored by transformer terminal unit (TTU) and reported to the control master station via the hybrid communication system. The demand response of customer load control is activated to reduce the loading level of transformers for mitigation of overloading problem. For the residential customers with installation of roof top PV system, the TTU is applied to perform the power factor control of smart inverter to prevent the over voltage problem. The hybrid communication system consisting of power line carrier, radio frequency and optical fiber is used to provide two-way communication for data collection and controls of customer loads and PV system. According to the field testing of the proposed TMS in Taipower, the adaptive energy control of customer loads according to the over loading level of distribution transformer is executed to support the demand response for peak load shaving effectively. The over voltage problem due to PV power injection has also been solved by TTU for control of PV smart inverters to perform the proper reactive power compensation.