Lets rethink negative reactance transformer paralleling

摘要

A means for the control of the load tap changer (LTC) of multiple power transformers operating in parallel is based on judiciously employing the line drop compensation (LDC) capability available on the basic control. By using the LDC reactance element in reverse polarity, the tendency is such as to bias the controls on the independent transformers so as to trend the respective tap changers to the same tap position, as is desired for the great preponderance of such applications. The installation requires no correspondence such as a current loop, serial communication or any other interconnection between the controls. The means also circumvents many of the difficulties of implementation encountered with other better known means of paralleling. It may be that distribution system improvements over the years which have resulted in a high and generally steady power factor of the substation load, plus technical advancements now incorporated into commonly used digital controls, revives this long forgotten means of transformer paralleling.