Optimal real-time voltage control with an advanced LTC control system

The implementation of an automatic LTC control system that closes the loop between the autotransformer and the system energy control center is presented. The scheme uses the input of an optimal power flow (OPF) calculation on the energy management system computer to bias the centerband setpoint via a supervisory control and data acquisition (SCADA) of the voltage regulating relay installed on the transformers. Data regarding system parameters at the transformer are then sent back through SCADA to the energy management system computer for any further refinements for optimum power flow. The net effect of this control action is to flatten the transmission network voltage levels and rebalance the reactive flows to meet the load conditions and available reactive sources