減小變頻空調壓縮機低速范圍內轉速脈動的方法

張猛 李永東 趙鐵夫 黃立培

清華大學電力系統國家重點實驗室 北京 100084

摘要 近年來永磁同步電機因其固有優點在空調壓縮機中得到了廣泛的應用，但常用的永磁同步電機−單轉子式壓縮機系統由于工作條件的限制無法安裝位置編碼器，受位置估算精度的制約一般采用方波驅動，必然導致電機本身輸出轉矩脈動偏大。同時在每個機械周期內壓縮機負載脈動非常劇烈，也造成整個系統低速運行時轉速脈動大噪聲高效率降低。本文將模型參考自適應方法推廣到凸極永磁同步電機中對電機轉速和轉子位置進行準確估算，實現了正弦波矢量控制針對空調壓縮機脈動負載。定義了機械周期內電磁轉矩對位置積分的能量，函數有效地估算出當前負載狀況通過查表法獲得估算的負載轉矩，然后根據估算的轉子位置對負載脈動轉矩進行轉矩電流前饋補償，顯著降低了壓縮機低頻噪聲和振動仿真和實驗結果驗證了本文所提方法的有效性和實用性。關鍵詞 永磁同步電機空調壓縮機 無速度傳感器控制 模型參考自適應

中圖分類號 TM341

A New Method to Reduce the Periodic Speed Ripples of Air-Conditioners in Low Speed Range

Zhang Meng Li Yongdong Zhao Tiefu Huang Lipei

Tsinghua University Beijing 100084 China

Abstract Recently, permanent magnetic synchronous motors(PMSM) are widely used inhousehold appliance. For a common PMSM-Single Rotator Compressor system, encoder is not usedbecause of the limitation of the working environment. The vibration of the compressor during eachmechanical period is serious due to the pulsating load torque in low speed range and the ripple of themotor output torque caused by square wave driving method. In this paper, a speed estimation methodbased on model reference adaptive system(MRAS) is extended to a interior PMSM. With the speed andposition obtained, vector control of the interior PMSM is realized. A new energy function is defined toestimate the load condition. According to the energy function, the load torque can be estimated by alook-up table. Then a feedforward compensation of load torque current is utilized to reduce the speedripple caused by the pulsating load torque. Simulation and experiment results prove the effectiveness ofthe proposed method.

Keywords PMSM, compressor, sensor-less control, MRAS

1 引言

采用永磁同步電機驅動的變頻式滾動轉子壓縮機效率高零部件少重量輕體積小起動電流小節能效果明顯在小型家用空調中正日益得到廣泛應用[1] 但目前還存在的一些問題限制了這種變頻壓縮機的推廣應用其中z*嚴重的是低速范圍內的轉速波動及由此帶來的低頻噪聲和震動問題。

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