Abstract: A speed sensorless control strategy of dual three-phase permanent magnet synchronous motor (DTP-PMSM) is investigated based on an adaptive sliding mode observer (SMO) and multi proportional resonant (PR) control with the consideration of the fundamental component in α-β subspace and harmonic element in x-y subspace. First, a current sliding mode observer is designed in α-β subspace based on vector space decomposition transformation for DTP-PMSM model by replacing signum function with hyperbolic tangent function as switching function to reduce system chattering and obtain the equivalent signal of back electromotive force (EMF). Then, an adaptive observer of back EMF is built to estimate the velocity and rotor position of DTP-PMSM, which eliminates the low-pass filter and phase compensation module in speed sensorless control system and improves the estimation accuracy. And then, PR controllers are employed in α-β subspace, which can track and control the given current without static error; also PR controllers are introduced to x-y subspace to reduce the 6k±1 th, k=1, 3, 5, … harmonics, which results in a decrease of power consumption and inverter capacity and improvement of control performance. Simulation results show the feasibility and effectiveness of the proposed method.

Key words: dual three-phase permanent magnet synchronous motor, speed sensorless control, adaptive sliding mode observer, multi proportional resonant control