Voltage regulation based on hierarchical and district-dividing control for active distribution network

For conventional radial distribution network, the voltage profile of each feeder can be controlled within the reasonable level by adjusting the OLTC transformer terminal voltage and local shunt capacitors. But for active distribution grid, this traditional voltage regulation scheme may fail. Therefore, a novel coordinated voltage control strategy is proposed to regulate voltage of distribution network with the integration of DGs. Both OLTC and DGs are considered as voltage regulators. The voltage control zones (VCZs) of OLTC and DGs are determined initially and the hierarchical voltage regulation method is adopted in each VCZ to eliminate the overlimit voltage. Simulations carried out on the IEEE 33-bus radial distribution network demonstrate that the proposed strategy can regulate voltage more efficiently, increasing energy efficiency and reducing the number of multiple regulating devices action.