Transmission Grid Secondary Voltage Control Method Using PMU Data

Transmission grid voltage collapse can be initiated by unexpected load disturbances. Secondary voltage control, which is to improve overall load bus voltage profiles by appropriate management of reactive power sources, is regarded as one of the effective countermeasures against voltage collapse. A new adaptive method based on synchronized phasor measurement unit data for secondary voltage control is developed. By formulating the voltage control problem as a nonlinear constrained optimization problem, the proposed method determines an optimal control action using a successive approximate vector infinity-norm minimization algorithm to improve voltage profiles. The proposed method is adaptive in the sense that load disturbances are estimated on-line for computing the feasible control action for the minimization of the worst case load voltage deviation. Extensive simulation studies on various IEEE benchmark systems are carried out to demonstrate the feasibility and effectiveness of the proposed method.