Impact of Dg and Voltage Regulator Interaction on Distribution System Voltage Regulation

Load currents through the power and distribution transformer and line impedances cause voltage drops, which reduce voltage magnitude at the loads. Voltage magnitudes at service locations must be maintained within specified ranges. This is accomplished in both fixed designs of the system (e.g., conductor selection, substation and distribution transformer tap settings, fixed capacitor banks) and by voltage control equipment such as automatic load tap changers, step-type voltage regulators (SVR), and switched capacitors. The fixed design of the feeder is based on the assumption that loading profiles generally follow a predictable pattern, with current on the feeder monotonically decreasing with increasing distance from the substation. SVR controls continuously monitor voltages and load currents to adjust tap positions accordingly. When distributed generation (DG) is interconnected to the distribution system, it can impact the system voltage profiles and interact with SVR control operations.