并聯(lián)逆變器功率均分控制研究
兩臺(tái)逆變器并聯(lián)模型如圖3所示,R1、R2為逆變器等效輸出電阻,X1,、X2為等效輸出電抗,UO1∠φ1,、 UO2∠φ2分別為兩臺(tái)逆變器輸出電壓,UO∠0O為并聯(lián)母線上的電壓,RL為負(fù)載[2]。

逆變器1輸出復(fù)功率為:

可推導(dǎo)出逆變器1輸出有功功率PO1和無(wú)功功率QO1表達(dá)式:


相位差







當(dāng)


當(dāng)


由式(12)和式(13)可得當(dāng)并聯(lián)逆變器的輸出電壓幅值有差時(shí),有功功率差和無(wú)功功率差的比值等于等效輸出阻抗的電阻和電感的比值,當(dāng)并聯(lián)逆變器的輸出電壓相位有差時(shí),有功功率差和無(wú)功功率差的比值等于等效輸出阻抗的電阻和電感比值倒數(shù)的負(fù)數(shù)。因而在實(shí)際電路中可以通過(guò)改變并聯(lián)逆變器的幅值差或相位差檢測(cè)出其有功功率差和無(wú)功功率差,再根據(jù)式(12)或式(13)得出逆變器等效輸出阻抗的電阻和電感比值。
當(dāng)



可以通過(guò)調(diào)節(jié)C、KP、K、Kvf和KI使R=X,由式(14)和式(15)可以根據(jù)并聯(lián)逆變器輸出的有功功率差和無(wú)功功率差來(lái)對(duì)輸出電壓的相位和幅值進(jìn)行調(diào)節(jié)。
評(píng)論