This article establishes an enhanced sliding-mode observer (SMO) with current measurement error compensators for the speed and position estimation in the permanent-magnet synchronous machine (PMSM) sensorless drive scheme. First, hyperbolic tangent switching function-based SMO with a self-adjusted shape coefficient is realized using a fuzzy logic controller (FLC) to not only eliminate the low-pass filter (LPF) and angular compensator in the conventional SMO, but also to reduce chatter caused by the constant boundary layer thickness. On the basis of Lyapunov's second theory, reachable and stable conditions of the enhanced SMO are founded. Then, as the current controller in the PMSM sensorless drive system needs to detect phase currents using current sensors, inevitable measurement errors exist. Two major kinds of current measurement errors, namely, the offset error and the scaling error, are analyzed. Their influences on the current fluctuations and corresponding compensation strategies are given in detail. By integrating current compensators into the enhanced SMO, a practical PMSM sensorless field-oriented control (FOC) scheme is constructed. The effectiveness of the enhanced SMO and current compensators is validated separately by comparative experiments. Final results indicate satisfactory chatter reduction and current ripple suppression performance of the proposed method.

中文翻译：

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具有电流测量误差补偿的增强型基于 SMO 的永磁同步电机无传感器驱动方案


本文建立了一种带有电流测量误差补偿器的增强型滑模观测器（SMO），用于永磁同步电机（PMSM）无传感器驱动方案中的速度和位置估计。首先，使用模糊逻辑控制器（FLC）实现基于双曲正切切换函数的具有自调整形状系数的SMO，不仅消除了传统SMO中的低通滤波器（LPF）和角度补偿器，而且还减少了由恒定边界层厚度引起的颤振。在Lyapunov第二理论的基础上，建立了增强型SMO的可达且稳定的条件。那么，由于PMSM无传感器驱动系统中的电流控制器需要使用电流传感器来检测相电流，因此不可避免地存在测量误差。分析了两种主要的电流测量误差，即偏移误差和比例误差。详细给出了它们对当前波动的影响以及相应的补偿策略。通过将电流补偿器集成到增强型 SMO 中，构建了实用的 PMSM 无传感器磁场定向控制 (FOC) 方案。通过对比实验分别验证了增强型 SMO 和电流补偿器的有效性。最终结果表明所提出方法的颤振减少和电流纹波抑制性能令人满意。