CO2冷媒壓縮機之弦波電流變頻控制技術開發

Abstract

為協助提高CO2冷媒循環系統效率，擬針對高效率CO2直流變頻壓縮機，開發無感測弦波電流變頻控制技術。其中高效率馬達設計，考慮減少轉子部分損失，一般會採用永磁式同步馬達或直流無刷馬達設計；然而此類馬達，在一般狀況下，必須輔助以馬達轉子位置感測器，方能依據轉子位置，完成正確電流換相操作。但在冷媒循環之高溫環境下，壓縮機內部高溫之工作溫度，往往會使霍爾位置感測器失去正常功能。因此，為順利應用此類高效率直流變頻技術於商用大型冷凍系統，必須發展無位置感測器之弦波電流變頻控制(簡稱無位置感測控制)，並包含啟動策略，與無位置感測電路設計應用。 因此，本計劃主要目的在於發展CO2冷媒壓縮機專用永磁同步馬達之無位置感測弦波電流變頻控制策略，預期完成之工作項目如下： (1) CO2壓縮機PMSM馬達之磁場導向模型建立。 (2) PSIM磁場導向弦波電流控制模擬程式建立 (3) TMS320F2812磁場導向驅動軟體建立 (4) 無位置感測弦波電流變頻控制實作 (5) 完成報告

DC inverter-fed technologies including motor design, mechanical design and variable-speed motor control, have been proved to be a good solution to upgrade the system efficiency of commercial refrigerators. In the high-efficiency motor design, the permanent-magnet synchronous motor (or so-called brushless DC motor, BDCMs) have usually been utilized in the refrigeration compressor after considering the rotor loss. In general, the rotor position sensors are required for BDCMs to obtain helpful position signals and, hence, to force current commutation adequately. However, the Hall-effect position sensors will not work well at high-temperature environment, especially inside the compressor of the refrigeration cycle. Therefore, developing the control strategy for BDCMs without any position sensors (or called sensorless control) is very important in successfully applying high-efficiency inverter-fed technology in commercial refrigeration systems. The above sensorless control also includes the starting strategy and the design of sensorless circuits. Based on the above descriptions, the main purpose of this project is to develop the sinusoidal-current inverter-fed control for CO2 refrigerant compressors. All the sensorless control will be implemented in DSP and demonstrated in the experiment. The followings are the items expected to be finished: (1) Study of the field-oriented PMSM model (2) Simulation of field-oriented PMSM control in PSIM (3) Hardware implementation of field-oriented PMSM control (4) TMS320F2812-Based software of field-oriented PMSM control (5) Implementation of Sensorless field-oriented PMSM control