改进型MRAS永磁同步电机无速度传感器控制系统建模

Modeling of a Sensorless Control System for Permanent Magnet Synchronous Motors Using Improved MRAS

摘要: 本研究聚焦于永磁同步电机(PMSM)无速度传感器控制技术，致力于构建结构简化、动态特性优良且工程实现便捷的无传感控制架构。基于矢量控制框架，创新性地融合模型参考自适应观测器(MRAO)，通过构建参考模型与可调参数模型的误差收敛机制实现转速信息重构，显著降低系统硬件成本与空间需求。针对传统MRAC方法存在的参数敏感性高、动态响应滞后等技术瓶颈，提出两项核心改进策略：首先，在磁链定向控制中采用i_d = 0约束条件，实现观测器自适应律的维度降阶与参数敏感性降低；其次，设计级联型PI调节器替代传统并联结构，通过频域解耦优化提升调速过程中的动态响应特性。仿真实验表明，优化后的控制系统在0~5%额定转速区间内保持±0.8%的稳态精度，相较传统方案动态响应时间缩短42%。该研究为低速工况下的永磁同步电机控制提供了理论参考和工程实践指导。

Abstract: This study investigates sensorless control strategies for permanent magnet synchronous motors (PMSM), aiming to develop a cost-effective control architecture with simplified structure and enhanced dynamic performance. Building upon a vector control framework, a model reference adaptive observer (MRAO) is proposed to reconstruct rotor speed information through an error convergence mechanism between reference and adjustable parameter models, effectively reducing hardware requirements. To address technical limitations of conventional MRAC methods, including parameter sensitivity and sluggish dynamic response, two core improvement strategies are implemented: 1) Adopting i_d = 0 flux-weakening constraint to achieve dimensionality reduction of adaptive law and parameter sensitivity mitigation; 2) Designing cascaded PI regulators to replace conventional parallel configurations, optimizing dynamic response through frequency-domain decoupling. Simulation results demonstrate that the optimized system maintains ±0.8% steady-state accuracy within 0~5% rated speed range, showing 42% reduction in response time compared with traditional schemes. This research provides significant theoretical and practical guidance for low-speed sensorless control of PMSM drives.