Stray load losses calculation routine based on the eh-star method

Abstract

The eh-star method is a procedure proposed in the IEC 60034-2-1 standard to determine the stray load losses in three-phase induction motors. In this test, the motor is fed by an unbalanced supply, which is obtained using an electrical resistance (Reh) in parallel with two phases of the star-connected motor and a single-phase source. The purpose of this paper is to present a new calculation routine that determines the stray load losses from eh-star test data. This routine is obtained from an electrical circuit, in which the unbalanced supply results from two phases and the neutral of the generator, eliminating Reh. The results show that the proposed method presents good agreement with the conventional eh-star method.