考虑到内置式永磁同步电机( IPMSM) 滑模观测器易受 d、q 轴电感差异的影响，提出了一种 IPMSM 的 L q 模型，并构造了 IPMSM 在 L q 模型下的合成反电动势，设计了基于合成反电动势的滑模状态观测器，同时采用两级滤波器串联的方式来提取反电动势信息，并采用变截止频率调节的方法实现恒相位补偿，采用锁相环技术实现系统的高速运行． 然后在电机起动时采用相应的控制方法以满足不同的应用要求，并在低、中速切换时采用了一种新的切换策略以实现系统的平稳切换． 在一台 IPMSM 上的实验结果表明，文中提出的滑模无位置传感器控制算法、起动控制选择及主动切换策略能实现 IPMSM 在宽速阈范围内的无位置传感器高性能控制，从而验证文中所提控制算法的有效性．

As the sliding mode observer of the interior permanent magnet synchronous motor (IPMSM) is easily affected by the d/q-axis inductance difference，this paper proposes an L q model of IPMSM，constructs a synthetic back EMF of IPMSM under the L q model，and designs a sliding mode state observer based on the synthetic back EMF． Meanwhile，the back EMF information is extracted through the two-stage filter method，the constant phase compensation is realized by means of the variable cutoff frequency method，and the high-speed running of system is achieved by using a phase locked loop technique． Then，corresponding control strategies are adopted to meet various requirements for actual applications when the motor starts． Moreover，a new switching strategy is presented for realizing smoothly and steady switching of system at low-to-medium speed switching． Experimental results on an IPMSM indicate that the proposed sliding-mode sensorless control algorithm，the starting control selection and the initiative switching strategy can realize the sensorless high-performance control of IPMSM within a wide speed range． Thus，the effectiveness of the proposed control algorithm is verified．