[摘 要] 本文研究了用電壓矢量變頻器和感應電動機構成的變頻電動機系統(tǒng)。通過對該閉環(huán)控制系統(tǒng)數(shù)學模型的建立,推導出了它的傳遞函數(shù)。它有著與可控硅直流調(diào)速系統(tǒng)極其相似的傳遞函數(shù),因而可用直流電動機的閉環(huán)控制對該系統(tǒng)加以控制。通過實際的測試,得到比較滿意的結果。
[關鍵詞] 感應電動機;變頻器;傳遞函數(shù);閉環(huán)控制
Abstract: In this paper, we present a frequency conversion electromotor system organized by voltage vector transducer and induction-motor. We export the transfer-function of the close-loop control system by establishing its mathematic model. Because of the surprising similitude of the transfer-functions of the close-loop control system and the controllable silicon timing system, we can control the system using the close-loop control of DC electromotor. We also obtain satisfied result by actual testing.
Keywords: induction-motor, transducer, transfer-function, close-loop control
1. 引言
感應電動機的數(shù)學模型是一個高階非線性強耦合的多變量系統(tǒng)。為了提高感應電動機的靜、動態(tài)性能,將變頻器和感應電動機構成感應電動機系統(tǒng),采用閉環(huán)控制,以達到此目的[1]。采用的變頻器為電感矢量控制PWM變頻器,它是從電動機轉矩直接控制的角度出發(fā),以三相對稱電壓供電,建立電動機定子理想磁鏈為基準,由三相逆變器不同開關模式供電給感應電動機,產(chǎn)生實際磁鏈跟蹤基準磁鏈來決定變頻器的開關模式,從而形成PWM波[2],這樣可以將感應電動機的強耦合得到近似解耦,在忽略旋轉電壓的影響,并認為非線性關系都可按線性化處理,這樣得到的變頻器感應電動機系統(tǒng)和直流電動機的數(shù)學模型極為相似,故可采用直流調(diào)速系統(tǒng)已經(jīng)比較成熟的工程設計法對該系統(tǒng)加以控制,以提高該系統(tǒng)的靜、動態(tài)性能。
詳情請點擊:
感應電動機的閉環(huán)控制系統(tǒng)設計