A New Overvoltage Protection for Powerformer Based on the Variety of Reactive Power

Based on the analysis of the relationship between the terminal voltages and the reactive power of a generator, the shortcomings of the available scheme to protect generators in parallel from overvoltage have been pointed out, and a novel overvoltage protection scheme is put forward. For machines connected directly to busbars, especially for powerformers, a novel type of high voltage generators, this protection makes it possible to identify which machine that is the source of the overvoltage by virtue of the variety of reactive power. Use a compensated voltage factor to modify the operating time of the protection and trip the generator which has the most vital impact on the overvoltage of the busbar first. The effectiveness of this scheme is validated with the EMTDC simulation results.