TRANSFORMER REDUCING ERROR OF IN-SERVICE POTENTIAL TRANSFORMERS Russian patent published in 2005 - IPC

FIELD: electrical engineering.

SUBSTANCE: primary winding of additional potential transformer having transformation ratio of unity is connected to low-voltage measuring winding of in-service potential transformer so that potential transformer cascade is formed and its measurement error equals sum of errors of in-service transformer and additional transformer whose error throughout entire range of loads connected to its secondary winding is equal in absolute value to that of in-service transformer and its error polarity is reverse to that of in-service transformer. Additional potential transformer has magnetic circuit, primary and secondary windings; magnetic circuit has a number of cores wound with ferromagnetic material ribbon and inserted one into other or placed one onto other and separated by nonmagnetic spacers. Secondary winding is wound on magnetic circuit assembled of separate cores so that part of its turns passed via through holes in nonmagnetic spacers covers at least one core.

EFFECT: enhanced measurement accuracy.

1 cl, 1 dwg