When generators are directly connected to the same busbar, their AVRs should operate at a 5% voltage droop. When generators are connected to busbars via step-up transformers, the transformer impedance ensures the voltage droop characteristic, and it is recommended to set the generator AVRs to fixed voltage. In some cases, busbars will also be supplied by transformers which import power from other sources in the system. When these transformers are equipped with on-load tap changers (OLTC) care must be taken that there is no conflict with the generator AVRs. [1]. Conflicts can occur when different devices with different operating modes and characteristics try to control the voltage on the same busbar. It is not recommended to operate the generators at fixed power factor and allow the transformer to supply the reactive power necessary to maintain the busbar voltage. Generators operating at fixed power factor cannot contribute to maintaining system voltages after a disturbance and this is detrimental to the robustness that is required.