| 摘要: | 轉子位置估測的準確性對於高性能馬達的閉迴路控制至關重要。傳統上，轉子位置訊號通常透過機械式編碼器或霍爾感測器獲取，但此類感測器的應用不僅會增加系統的生產成本、體積及佈線複雜度，亦可能在惡劣的工作環境下發生故障，影響系統的可靠性。因此，本論文旨在開發無感測器估測方法，以降低系統對硬體的依賴性並提升控制性能。
本研究採用基於自適應滑模觀測器 (Adaptive Sliding Mode Observer, ASMO) 的反電動勢估測技術，並結合鎖相迴路 (Phase-Locked Loop, PLL)以提高轉子位置與速度估測的準確性。然而，在馬達低速運行或靜止狀態時，雜訊的影響會導致可用訊號難以提取，進而降低估測精度。因此，本研究使用了一種基於電流振幅閉迴路電流頻率比 (I-F) 控制的啟動策略，透過該方法先將馬達轉速提升至穩定後，再切換至基於ASMO的磁場導向控制 (Field-Oriented Control, FOC)。
在I-F啟動階段，由於頻率與電流幅值同步增加，電流向量會產生一定的偏移，無法直接對齊 ?? 軸，導致切換FOC控制時可能產生瞬間不匹配的問題。因此，本研究透過馬達的等效數學模型控制內部反應虛功率，使I-F座標系逐步旋轉並對齊 ???? 座標系，以滿足FOC控制下 ?? 軸電流為零的特性，實現兩個方法間的無縫切換。
本論文研究成果可有效提升無感測器永磁同步馬達 (Permanent Magnet Synchronous Motor, PMSM) 控制系統在低速啟動階段的穩定性與可靠性，並減少對額外硬體感測器的依賴，有助於提升系統整體效能及應用範圍。;The accuracy of rotor position estimation is crucial for high-performance motor closed-loop control. Traditionally, rotor position signals are obtained using encoders or Hall sensors, which increase system costs, size, and wiring complexity while posing reliability risks in harsh environments. Therefore, this thesis develops a sensorless estimation method to reduce hardware dependence and enhance control performance.
This study employs an adaptive sliding mode observer (ASMO)-based back electromotive force (back-EMF) estimation technique, combined with a phase-locked loop (PLL) to improve rotor position and speed estimation accuracy. However, at low speeds or standstill, noise interference makes it difficult to extract useful signals, reducing estimation accuracy. To address this, a current amplitude closed-loop I-F control strategy is used for startup, raising the motor speed to a stable level before transitioning to ASMO-based field-oriented control (FOC).
During I-F startup, simultaneous increases in frequency and current amplitude cause current vector misalignment with the q-axis, leading to potential mismatches during the transition to FOC control. To ensure a seamless transition, this study utilizes an equivalent motor mathematical model to regulate internal reactive power, gradually aligning the I-F coordinate system with the dq frame while maintaining zero d-axis current in FOC control.
The proposed method improves the stability and reliability of sensorless permanent magnet synchronous motor (PMSM) control during low-speed startup while reducing dependence on additional hardware. This enhances overall system performance and expands its applicability. |
