This dissertation analyzes the technical and economical impact of the integration of a high capacity distributed generation (DG) in a distribution system composed of two feeders, both with two cascaded step voltage regulators (SVRs). Distribution networks with the presence of high capacity DG may subject SVR to reverse active power flow scenarios, which, depending on the control modes “Active Bidirectional Flow up to Opposite Limit” and “Reverse Flow by Cogeneration”, result in abnormal situations that lead the SVR to lose its regulating capacity. As a consequence, consumers may be subjected to severe undervoltage or overvoltage. This phenomenon, in which the SVR loses its ability to control the desired bus voltage, is known in technical literature as the reverse power tap changer runaway condition. In addition, high capacity GDs, depending on their location in the distribution system, can cause critical overvoltages. Some actions can be taken to reduce or mitigate this effect, such as distribution system reconfiguration, adjusting the SVR setpoint, and modifying DG control mode. The economic assessment was accomplished for all studied operating scenarios, highlighting technical and financial impacts on the utility and customers.
|
