An Online Compensation Method of VSI Nonlinearity for Dual Three-Phase PMSM Drives Using Current Injection
Kailiang Yu, Zheng Wang
Abstract
Compensation of voltage-source-inverter (VSI) nonlinearity is of great importance in parameter identification and position sensorless control method for motor drives. In this letter, a simple online compensation method has been proposed for the dual three-phase permanent-magnet synchronous motor (PMSM) drives. The key is to observe the change of voltage references contained VSI nonlinearity after injecting currents in z1z2-axis purposely. Compared with the existing estimation methods for VSI nonlinearity, the proposed method not only can avoid the tedious and time-consuming offline test for modeling inverter but also can achieve real-time estimation without machine parameters. Moreover, the current injection on z1z2 subspace has a slight influence on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> subspace (the torque subspace) thanks to the multiple decoupling subspaces of dual three-phase PMSM. The experiments have been given to verify the validity of the proposed method.