【正文】 03.[11] 宋 強,劉文華, 電壓源逆變器的LC 濾波器設計. 清華大學學報（自然科學版）, 2003，43（3）.[12] 田松亞,孫 燁,. 電焊機 , 2007，37(40) .[13] . 電子開發(fā)網(wǎng).[14] （SPWM）信號發(fā)生器SM2001. 沈陽單片機開發(fā)網(wǎng).[15] 陳鹮,李梓星,. 電工技術雜志,2004，1 .[16] 孔雪娟. 全數(shù)字三相大功率逆變器及并聯(lián)運行：[碩士學位論文]. 武漢：華中科技大學圖書館，2000.[17] 石磊 ,. 電氣開關, 2007，6 .[18] 曲血基,曲敬鎧,于明揚. 逆變技術基礎與應用[M]. 北京： 電子工業(yè)出版社, 2007.[19] 王久海,. 機械工程與自動化, 200763. [20] 黃先進, 鄭瓊林. IGBT驅動電路模塊化設計. 自動化技術與應用, 2007,26(12 ) .[21] , , et al. Multilevel converter – a ’99,1999,CDROM.[22] Du Toit Mouton,H. Natural balancing of threelevel neutralpointclamped Ind. Electron, 2002,49(5) ：1017 ~1025.[23] Keith Corzine, Yakov New Cascaded Multilevel HBridge on Power , 17(1) ：125~131.[24] Xiao min Kou, Keith L. Familiant. Full Binary Combination Schema for Floating Voltage Source Multilevel Inverters. IEEE Trans. on PowerElectron,2002,17(6) ：891~897.致謝本次設計是在張育軍老師的悉心關懷和精心指導下完成的。張老師淵博的理論知識、豐富的實踐經(jīng)驗、敏銳的洞察力、嚴謹?shù)闹螌W態(tài)度、忘我的工作精神、謙虛和藹的為人、坦蕩的胸襟給我留下了深刻的印象。他對工作兢兢業(yè)業(yè)的精神、對待科學研究的嚴謹細致態(tài)度是我學習的榜樣。師恩難忘，謹向張老師致以衷心的感謝，祝愿張老師身體健康、工作順利、萬事如意。同時也感謝我的所有在這次畢業(yè)設計中真誠無私地幫助我的同學們，他們熱情智慧、真誠友好，對于我所不知道的知識給予盡可能詳細的講解，對于我不熟悉的軟件盡最大的努力來幫助我學習，可以說我能順利完成這次畢業(yè)設計，他們的貢獻也是不可以忽略的，在此，我忠心地謝謝他們的支持和幫助，愿他們能夠在學業(yè)上更上一層樓，在生活上一切順利。也感謝我的親人和幫助了我的所有的朋友們。謝謝大家！附錄英文文獻 AN Active Circuit for Cancellation ofCommonMode Voltage Generated by a PWM InverterSatoshi Qgasawara, Hideki Ayano and Hirofumi AkagiDepartment of Electrical EngineeringOkayama University311 TsushimaNaka, Okayama, 700 .JAPANAbstractThis paper proposes an “Active Commonnoise Canceller (ACC)” that is capable of eliminating the monmode voltage produced by a PWM inverter. An emitter follower using plementary transistors and a monmode transformer are incorporated into the ACC, the design method of which is also presented in detail. A prototype ACC designed and constructed in this paper verifies the viability and effectiveness in a induction motor drive using an IGBT inverter. Some experimental results show that the ACC makes significant contributions to reducing a ground current and a conducted EMI. In addition, the ACC can prevent an electric shock on a nongrounded motor frame and can suppress a motor shaft voltage.I. INTRODUCTIONAn emergence of highspeed switching devices such as IGBT’s has enabled to increase, a carrier frequency of voltage source PWM inverters, thus leading to much better operating characteristics. Highspeed switching, however, can acpany the following serious problems originating from a steep change in voltage and/or current:o. ground current escaping to earth through stray capacitors inside motors[1][2]o .conducted and radiated EMI[3][6]o. bearing current and shaft voltage [7][9] o. shortening of insulation life of motors and transformers[10][13]The voltage and/or current change caused by highspeed switching produces highfrequency oscillatory monmode and normalmode currents at the instant of every switching, because parasitic stray capacitors inevitably exist inside an ac motor. The oscillatory currents with a frequency range of 100 kHz to several MHz can create a magnetic field, and radiate ElectroMagnetic Interference (EMI) noises throughout, thus producing a bad effect on electronic devices such as AM radio receivers and medical equipment.Generally, monmode chokes and EMI filters, based on passive elements, could not solve the problems perfectly. The authors have proposed a monmode transformer with an additional winding shorted by a resistor [2]. It can damp the oscillatory ground current, but a small amount of a periodic ground current still remains. Some attempts introducing active circuits have been made to eliminate the ground current or monmode voltage [14][15].This paper proposes an “Active Commonnoise Canceller (ACC)” that is able to eliminate the monmode voltage produced by a PWM inverter. The ACC superimposes a pensating voltage on the inverter output. The pensating voltage applied by the ACC has the same amplitude as, but the opposite polarity to, the monmode voltage produced by the PWM inverter. As a result, the monmode voltage applied to a load is canceled pletely.A prototype ACC, constructed in this paper, verifies the viability and effectiveness in a kW induction motor drive using an IGBT inverter. Some experimental results show that the proposed ACC makes significant contributions to reducing the monmode current, ., the ground current, and the conducted EMI. The ACC can also prevent an electric shock from being received when someone touches a nongrounded motor frame. Furthermore, the ACC can suppress a motor shaft voltage stemming from the monmode voltage caused by the PWM inverter.II. PRINCIPLE OF ACTIVE COMMONNOISE CANCELLER shows the configuration of an experimental system including an active monnoise canceller proposed in this paper. A voltagesource PWM inverter using IGBTs drives an induction motor of through three feeder wires, and the motor frame is connected to an earth terminal on a switch board. A shaft voltage is measured between the frame and a carbon brush touching to the motor shaft. Measurement of conducted EMI is performed by using a LISN and a spectrum analyzer. The ACC is connected between the inverter output terminals and the three feeder wires. It consists of the following elements。 a pushpull emitter follower using transistors having plementary symmetry, a monmode transformer [2], three capacitors to detect the monmode voltage appearing at the inverter output terminals, and two dcside capacitors to prevent a dc current from flowing in the additional winding of the monmode transformer.A monmode current ic , flows to the earth terminal through stray capacitors between the windings and the frame of the motor, because a zerosequence output voltage of the inverter, ., a monmode voltage, varies every switching of the inverter. The ACC aims to cancel this monmode voltage perfectly, so that no monmode current flows, ., ic= 0. shows a monmode circuit equi