內藏式永磁同步電機之寬廣速度範圍無差拍直接轉矩控制研究

Abstract

本研究採用直接轉矩控制作為主要架構，結合無差拍控制理論以及空間向量調變技術並應用於內藏式永磁同步電機，來達到快速的動態響應與較低的響應漣波。其中，採用定子電流與定子磁通鏈觀測器加強了此策略應用於數位訊號處理器的性能，並透過觀測器所觀測到的回授訊號，給予無差拍直接轉矩控制正確時脈的訊號輸入。為了達到拓展電機的運轉範圍，提升電機於高轉速時的電磁轉矩響應，採用了寬廣速度範圍控制演算法，其中包含每安培最大轉矩控制、弱磁控制以及每伏特最大轉矩控制，分別應用於定轉矩區以及定功率區。為了進一步增加電機於高轉速時的性能，改良了寬廣速度範圍控制的控制訊號切換規則，提升電機於低轉矩命令時的定轉矩操作範圍，同時改良了弱磁控制與每伏特最大轉矩控制的電壓限制式，其優化了電機運轉於高速時的轉矩響應並避免其振盪的情況發生。為了驗證控制策略之可行性與性能，透過Matlab/Simulink模擬軟體進行電機模型以及演算法的建模，並與採用比例積分控制器的直接轉矩控制進行對比，確認了無差拍直接轉矩控制的優勢。

This study employs direct torque control (DTC) as the principal framework, combined with deadbeat control theory and space vector modulation (SVM) techniques, and applied to interior permanent magnet synchronous machines (IPMSM) to achieve rapid dynamic response and reduced response ripple. It utilizes a stator current and stator flux observer to enhance the strategy's performance on digital signal processors (DSP), providing the deadbeat direct torque control with the correct timing of signal inputs through the feedback signals observed. To expand the operating range of the machines and improve the electromagnetic torque response at high speeds, a wide speed range control algorithm is adopted, including maximum torque per ampere (MTPA) control, flux-weakening (FW) control, and maximum torque per voltage (MTPV) control, each applied in the constant torque and constant power regions respectively. To further enhance machines performance at high speeds, the control signal switching rules of the wide speed range control are refined, extending the constant torque operation range during low torque commands, while the voltage limitation strategies for flux-weakening and maximum torque per voltage control are improved, optimizing the torque response of the motor at high speeds and preventing oscillations. To validate the feasibility and performance of the control strategy, the motor model and algorithms are simulated using Matlab/Simulink software, and compared with a proportional-integral (PI) controller-based direct torque control, confirming the advantages of the deadbeat-direct torque control.