Compensation of amplitude imbalance of resolver signal for PMSM drives

This paper proposes a new compensation algorithm for position error due to an amplitude imbalance between resolver output signals. Resolvers are commonly used to obtain absolute rotor position information for motor drive systems in severe environments. However, in actual position sensing systems, rotor position error is caused by amplitude imbalance of the resolver output signals. As a result, the d- and q-axis currents of the synchronous reference frame have periodic ripples of the stator fundamental frequency in permanent magnet synchronous motor (PMSM) drives. In this paper, a new compensation algorithm to reduce the position error generated by amplitude imbalance is proposed. The proposed method does not require any additional hardware, and reduces computational time by simple integral operation according to rotor position. The effectiveness of the proposed compensation algorithm is verified through several simulations and experiments.