Efficient Integration of Three-Phase Step Voltage Regulators in the Z-Bus Power Flow Method

Abstract

This letter presents a comprehensive Step Voltage Regulator (SVR) model suitable for the three-phase Z<sub>BUS</sub> power flow. The model can be applied in all SVR configurations such as open delta, close delta, wye. Its advantage is that the tap variations are simulated outside the Y<sub>BUS</sub> matrix, without compromising the convergence of the power flow. Therefore, a refactorization of the Y<sub>BUS</sub> matrix is not required after every tap change reducing significantly the computation time of the power flow. The proposed SVR model is validated in a 4-Bus network, while its performance is tested in the IEEE 8500-Node test feeder.