Improvement of step-voltage regulating transformer efficiency through tap changer control modification

A discussion of factors impacting the efficiency of step-voltage regulators along with the motivations to improve efficiency from the viewpoint of the owner — operator. Methods for evaluating efficiency via economic impact of operation are explored. Results of loss testing on step-voltage regulators are presented along with industry-accepted calculations of the associated operating costs. Potential modifications to the method of tap position control are presented along with the impact on efficiency improvement resulting from an alternate tap changer control scheme. An updated loss evaluation process for stepvoltage regulators is presented for apparatus utilizing a non-bridging tap stepping scheme. The feasibility of using a modified stepping scheme with step-voltage regulators and similar apparatus such as on-load tap changing transformers is examined.