Development of a control strategy for mini CHP plants for an active voltage management in low voltage networks

The increasing number of Distributed Generation Units (DGs) in distribution grids is challenging the way electrical systems are designed and operated. For traditional power systems, Low Voltage (LV) networks play a passive role in voltage regulation, but when DGs are present the LV network may play an active role in voltage control. In this paper, a voltage control strategy using mini Combined Heat and Power (mCHP) is proposed. For this aim, the electrical and thermal dynamics of a mCHP plant are considered, a voltage controller is designed and a voltage control mode is developed, which prolongs the regulation action of the mCHP unit using heat storage. Simulations are conducted considering thermal and electrical demand of a typical multi-family house in the climate region of North Rhine-Westphalia, Germany. Aspects of resulting voltage and thermal profiles, compared to a traditional heat lead mode, are discussed for an exemplary day.