各種脈寬調變技術應用於內藏式永磁同步馬達磁場導向控制比較

Abstract

本論文旨在研究比較使用各種脈寬調變技術(Pulse Width Modulation, PWM)之磁場導向控制(Field Oriented Control, FOC)控制策略應用於內藏式永磁同步電動機(Interior Permanent Magnet Synchronous Motor, IPMSM)的控制效果，並在FOC控制中搭配每安培最大轉矩控制算法(Maximum Torque Per Ampere, MTPA)。 PWM中載波訊號的選擇上，高頻對稱三角波因為波形的對稱性所以會使定子電流總諧波失真(Total Harmonic Distortion, THD)較小，因此是比高頻鋸齒波更好的選擇；另外PWM的種類有很多種，空間向量脈寬調變(Space Vector Pulse Width Modulation, SVPWM)相較於弦波脈寬調變(Sinusoidal Pulse Width Modulation, SPWM)會因為電壓利用率較佳而有較好的控制效果，接著簡化空間向量脈寬調變(Simplified Space Vector Pulse Width Modulation, SSVPWM)提供一個和SVPWM控制效果相同，但運算更簡單的方法；最後優化空間向量脈寬調變(Optimum Space Vector Pulse Width Modulation, OSVPWM)的目的為降低逆變器輸入電流的諧波成分，進而讓前級使用轉換器電路之應用的並聯電容壽命更長，但缺點為定子電流總諧波失真(THD)較差，因此需根據需求斟酌使用。 本論文透過Matlab/Simulink進行模擬，比較各方法的轉速、轉矩響應等指標，最後比較出優劣勢與適用場合。

This thesis aims to investigate and compare the performance of various Pulse Width Modulation (PWM) techniques applied to Field Oriented Control (FOC) strategies for Interior Permanent Magnet Synchronous Motors (IPMSMs). Also the Maximum Torque Per Ampere (MTPA) algorithm is used in the FOC strategy to improve torque efficiency. In terms of carrier waveform selection, high-frequency symmetrical triangular waveforms are preferred over sawtooth waveforms due to symmetry of waveform, which helps reduce Total Harmonic Distortion (THD) in stator current. Among the PWM techniques, Space Vector Pulse Width Modulation (SVPWM) offers better voltage utilization and possesses better performance compared to Sinusoidal Pulse Width Modulation (SPWM). Simplified Space Vector Pulse Width Modulation (SSVPWM) provides a computationally efficient method that achieves same performance to SVPWM. Optimum Space Vector Pulse Width Modulation (OSVPWM) is designed to minimize harmonic components in the inverter input current, thereby extending the lifespan of the front-end parallel capacitors in the power converter. However, OSVPWM typically results in higher stator current Total Harmonic Distortion (THD), which requires thorough trade-off considerations depending on system requirements. All methods are simulated and analyzed using Matlab/Simulink to evaluate performance indicators such as speed and torque response. The comparative results are used to assess the advantages and limitations of each PWM strategy.