Substation Local Voltage Controller Using Synchrophasors

This paper continues development of a Substation Local Voltage Controller (SLVC) using synchrophasors. This SLVC is the substation counterpart of a hierarchical two-level voltage controller being developed at Southern California Edison (SCE) Inc. The controller is based on a linearized local reactive power flow approach for estimating the effects of any switching action within a substation on the corresponding voltage changes at the substation buses. Switching actions include tap changes at different sets of transformer banks, and switching in/out the shunt reactive devices (capacitors and reactors) at the substation. The formulation is tested on a power-flow model of a representative substation in the SCE network through simulations, and the local power-flow results are compared to the large-scale full power flow solutions. Different normal and contingency operation conditions as well as various combinations of switching actions are considered, and it is shown that the proposed formulation can estimate the voltage changes within the local network with acceptably small errors.