單相及三相變頻器廣泛地應用於多種電力電子設備以增進其操控性能。然而，欲得到高輸出性能之變頻器，除其組件需妥適搭配設計外，得宜之控制亦不可或缺。因此，本論文旨在從事以數位信號處理器為主模組化變頻器系統之建構及其強健波形控制。

本文首先從事高性能單相變頻器模組之研製，在設計製作其電力電路後，即從事其數位信號處理器為主數位控制機構之建構。所提變頻器之切換控制信號由內建於數位信號處理器之數位脈寬調制機構產生，而其電流及電壓控制器均各含一迴授控制器、一命令前向控制器及一簡易強健估測擾動消去控制器，以使其具有良好及強健之波形追控特性。

接著，本文研製由二個及三個單相模組組接形成之三相變頻器，含Delta-接、Y-接、V-接、Scott-T接等。其特色為以一共用之數位信號處理器從事所有組成變頻器模組之數位控制，文中詳細介紹其數位控制實務及操控性能評估。最後，在具良好波形追控之變頻器下，本文亦從事其任意波形規劃控制研究。組成電路及控制機構之設計及實作於本論文中將仔細介紹，實測結果顯示所研製之單相及三相變頻器具有良好之輸出性能，含線性負載調控特性、波形之強健追控特性、非線性負載波形追控特性、三相輸出之不平衡特性等。

Single-phase and three-phase inverters are widely applied to many kinds of power electronic equipments to promote their control performance. However, to obtain high inverter output performance, in addition to the proper match and design for its constituted circuit components, appropriate control is also indispensable. Hence the major purposes of this thesis lie in the establishment of digital signal processor (DSP) based modular inverter and performing their robust waveform control.

For facilitating the research concerning inverter modular connection and operation control, the design and implementation of high-performance single-phase inverter module are first made. After designing and realizing the power circuit, its DSP-based control scheme is established. The switching control signals of the inverters are generated from the digital pulse width modulators embedded in the DSP. Both the current and voltage controllers consist of a feedback controller, a command feedforward controller and a simple observer based robust disturbance cancellation controller. Through proper controller design, the established inverter possesses good and robust waveform tracking performance.

Secondly, the establishment of three-phase inverters connected by two and three single-phase modules is studied. These include -connected, Y-connected, V-connected and Scott-T connected inverters. The prominent feature of these systems is that all digital controls of the constituted inverter modules are realized using a common DSP. The practical issues and control performance evaluation of the digital controlled inverters are made. Finally, after establishing the inverters having good waveform tracking characteristics, the arbitrary waveform generation and control are performed. The design and implementation for all circuits and control schemes are described in detail. The experimental results show that the developed single-phase and three-phase inverters possess good output performance, including line and load regulations, robust waveform tracking performance under non-linear load and good three-phase output characteristics under unbalanced loads.

A. Single phase inverters

[1]N. Mohan, T. M. Undeland and W. P. Robbins, Power Electronics: Converters, Applications and Design, New York: John Wiley & Sons, 2003.
[2]B. K. Bose, Modern Power Electronics and AC Drive, New Jersey: Prentice-Hall, 2002.
[3]T. L. Skvarenina and W. E. DeWitt, Electrical Power and Controls, New Jersey: Prentice Hall, 2001.
[4]D. W. Hart, Introduction to Power Electronics, New Jersey: Prentice-Hall, 1997.
[5]J. M. D. Murphy and F. G. Turnbull, Power Electronic Control of AC Motors, New York: Pergamon Press, 1988.
[6]P. J. M. Heskes and J. H. R. Enslin, “Power quality behavior of different photovoltaic inverter topologies,” Power Conversion Intelligent Motion (PCIM) International conference, 2003.
[7]J. Sakly, P. Delarue and R. Bausiere, “Rejection of undesirable effects of input DC-voltage ripple in single-phase PWM inverters,” IEE Conference on Power Electronics and Applications, vol. 4, pp. 65-70, 1993.
[8]P. N. Enjeti and W. Shireen, “A new technique to reject DC-link voltage ripple for inverters operating on programmed PWM waveforms,” IEEE Trans. Power Electron., vol. 7, no. 1, pp. 65-70, 1993.
[9]P. A. Dahono, A. Purwadi and Qamaruzzaman, “An LC filter design method for single-phase PWM inverters,” IEEE International Conference on Power Electronics and Drive Systems, vol. 2, pp. 571-576, 1995.
[10]J. Kim, J. Choi and H. Hong, “Output LC filter design of voltage source inverter considering the performance of controller,” International Conference on Power System Technology, vol. 3, pp. 1659-1664, 2000.
[11]S. Vukosavic, L. Peric, E. Levi and V. Vuckovic, “Reduction of the output impedance of PWM inverters for uninterruptible power supply,” IEEE Conference on Power Electronics Specialists, pp. 757-762, 1990.
[12]E. A. Coelho, P. C. Cortizo and P. F. D. Garcia, “Small signal stability for single phase inverter connected to stiff AC system,” IEEE Conference on Industry Applications, vol. 4, pp. 2180-2187, 1999.
[13]R. O. C´aceres and I. Barbi, “A boost DC-AC converter: analysis, design, and experimentation,” IEEE Trans. Power Electron., vol. 14, no. 1, pp. 134-131, 1999.
[14]E. Koutroulis, J. Chatzakis, K. Kalaitzakis and N.C. Voulgaris, “A bidirectional, sinusoidal, high-frequency inverter design,” IEE Proceedings Electric Power Applications, vol. 148, No. 4, pp. 315-321, 2001.
[15]K. Meghriche, O. Mansouri and A. Cherifi, “On the use of pre-calculated switching angles to design a new single-phase static PFC Inverter,” IEEE Conference on Industry Applications, pp. 906-911, 2005.
[16]J. G..Garcia, J. Cardesin, J. Ribas, A. J. Calleja, M R. Secades; J. M. Alonso and E. L. Corominas, “Minimization of acoustic resonances in HID lamps: analysis and comparison of power harmonics content in high frequency non-resonant inverters,” IEEE Trans. Power Electron., vol. 20, no. 6, pp. 1467-1479, 2005.

B. PWM and current controls

[17]J. Holtz, “Pulsewidth modulation: a survey,” IEEE Trans. Ind. Electron., vol. 39, pp. 410-420, 1992.
[18]G. Venkataramanan, D. M. Divan and T. M. Jahns, “Discrete pulse modulation strategies for high-frequency inverter systems,” IEEE Trans. Power Electron., vol. 8, no. 3, pp. 279-287, 1993.
[19]H. Dehbonei, L. Borle and C. V. Nayar, “A review and a proposal for optimal harmonic mitigation in single-phase pulse width modulation,” IEEE International Conference on Power Electronics and Drive Systems, vol. 1, pp. 408-414, 2001.
[20]D. Czarkowski, D. V. Chudnovsky and I. W. Selesnick, “Solving the optimal PWM problem for single-phase inverters,” IEEE Trans. Circuits Syst. I, vol. 49, no. 4, pp. 465-475, 2002.
[21]P. A. Dahono and I. Krisbiantoro, “A hysteresis current controller for single-phase full-bridge inverters,” IEEE International Conference on Power Electronics and Drive Systems, vol. 1, pp. 415-419, 2001.
[22]N. Abdel-Rahim and J. E. Quaicoe, “Three-phase voltage-source UPS inverter with voltage-controlled current-regulated feedback control scheme,” IEEE International Conference on Industrial Electronics, Control and Instrumentation, vol.1, pp.479-502, 1994.
[23]S. K. Chung, “Steady-state error minimisation technique for single-phase PWM inverters,” IEE Electronics Letters, vol. 38, no. 22, pp. 1043-1048, 2002.
[24]M. P. Kazmierkowskzi and L. Malesani, “Current control techniques for three-phase voltage-source PWM converters: A survey,” IEEE Trans. Ind. Electron., vol. 45, no. 5, pp. 691-703, 1998.
[25]M. Prodanovic, T. C. Green and H. Mansir, “A survey of control methods for three-phase inverters in parallel connection,” IEE International Conference on Power Electronics and Variable Speed Drives, no. 475, pp. 472-477, 2000.
[26]Y. Xing, L. P. Huang and Y. G. Yan, “A decoupling control method for inverters in parallel operation,” IEEE International Conference on Power System Technology, vol. 2, pp. 1025-1028, 2002.
[27]G. Alarcon, V. Cardenas, S. Ramirez, N. Visairo, C. Nunez, M. Oliver and H. Sira-Ramirez, “Nonlinear passive control with inductor current feedback for an UPS inverter,” IEEE Conference on Power Electronics Specialists, vol. 3, pp. 1414-1418, 2000.
[28]J. Gao, X. Zhao, X. Yang and Z. Wang, “The research on avoiding flux imbalance in sinusoidal wave inverter,” IEEE International Conference on Power Electronics and Motion Control, vol. 3, pp. 1122-1126, 2000.
[29]T. Senjyu, H. Kamifurutono and K. Uezato, “Robust current control method with disturbance voltage observer for voltage source PWM inverter,” IEEE International Conference on Power Electronics and Drive Systems, vol. 1, pp. 379-384, 1995.
[30]T. H. Chen and C. M. Liaw, “Vibration acceleration control of an inverter-fed electrodynamic shaker,” IEEE/ASME Trans. Mechatron., vol. 4, no. 1, pp. 60–70, 1999.
[31]B. J. Kang and C. M. Liaw, “Robust hysteresis current-controlled PWM scheme with fixed switching frequency,” IEE Proceedings on Electric Power Applications, vol. 148, no. 6, pp. 503-512, 2001.

C. Dead time compensation

[32]D. Leggate and R. J. Kerkman, “Pulse-based dead-time compensator for PWM voltage inverters,” IEEE Trans. Ind. Electron., vol. 44, pp. 191-197, 1997.
[33]S. G. Jeong and M. H. Park, “The analysis and compensation of dead-time effects in PWM inverters” IEEE Trans. Ind. Electron., vol. 38, no. 2, pp. 108-114, 1991.
[34]T. Sukegawa, K. Kamiyama, K. Mizuno, T. Matsui and T. Okuyama, “Fully digital, vector-controlled PWM VSI-fed AC drives with an inverter dead-time compensation strategy,” IEEE Trans. Ind. Applicat., vol. 27, no. 3, pp. 552-559, 1991.
[35]J. W. Choi and S. K. Sul, “New dead time compensation eliminating zero current clamping in voltage-fed PWM inverter,” IEEE Conference on Industry Applications, vol. 1, no. 3, pp. 977-984, 1994.
[36]W. C. Jong, S. I. Yong and K. S. Seung, “Inverter output voltage synthesis using novel dead time compensation,” IEEE Conference on Industry Applied Power Electronics, vol. 1, no. 3, pp. 100-106, 1994.
[37]S. O. Won, T. K. Yong and J. K. Hee, “Dead time compensation of current controlled inverter using space vector modulation method,” IEEE International Conference on Power Electronics and Drive Systems, vol. 1, no. 3, pp. 374-378, 1995.
[38]C. B. Jacobina, A. M. N. Limal and A. C. Oliveira, “Enhanced PWM voltage waveform and dead time compensation for AC drive systems,” IEEE Conference on Industrial Electronics, vol. 2, no. 3, pp. 694-697, 1997.
[39]J. Llaquet, D. Gonzalez, A. Arias, J. L.Romeral and D. Bedford, “EMI effects of hard-less dead time compensated PWM voltage inverter,” IEEE Conference on Harmonics and Quality of Power, vol. 1, no. 3, pp. 516-520, 1998.
[40]A. R. Munoz and T. A. Lipo, “On-line dead-time compensation technique for open-loop PWM-VSI drives,” IEEE Trans. Power Electron., vol. 14, no. 4, pp. 683-689, 1999.
[41]X. Yu, M. W. Dunnigan and B. W. Williams, “Phase voltage estimation of a PWM VSI and its application to vector-controlled induction machine parameter estimation,” IEEE Trans. Ind. Electron., vol. 47, no. 5, pp. 1181-1184, 2000.
[42]A. C. Oliveira, A. M. N. Lima and C. B. Jacobina, “Varying the switching frequency to compensate the dead-time in pulse width modulated voltage source inverters,” IEEE Conference on Power Electronics, vol. 1, no. 2, pp. 244-249, 2001.
[43]C. Attaianese, D. Capraro and G. Tomasso, “A low cost digital SVM modulator with dead time compensation,” IEEE Conference on Power Electronics, vol. 1, no. 4, pp. 158-163, 2001.
[44]A. Cichowski and J. Nieznanski, “Self-tuning dead-time compensation method for voltage-source inverters,” IEEE Power Electronics Letters, vol. 3, no. 2, pp.72- 75, 2005.
[45]H. S. Kim, H. W. Kim and M. J. Youn, “A new on-line dead-time compensation method based on time delay control,” IEEE Conference on Industrial Electronics, vol. 2, no. 2, pp. 1184-1189, 2001.
[46]J. L. Lin, “A new approach of dead-time compensation for PWM voltage inverters,” IEEE Trans. Circuits Syst., vol. 49, no. 4, pp. 476-483, 2002.
[47]A. C. Oliveira, C. B. Jacobina, A. M. N. Lima and E. R. C. da Silva, “Dead-time compensation in the zero-crossing current region,” IEEE Conference on Power Electronics Specialist, vol. 4, no. 3, pp. 1937-1942, 2003.
[48]H. S. Kim, H. T. Moon and M. J. Youn, “On-line dead-time compensation method using disturbance observer,” IEEE Trans. Power Electron., vol. 18, no. 6, pp. 1336-1345, 2003.

D. Voltage and waveform control

[49]H. van der Broeck and P. Lurkens, “Programmable AC power source,” IEE European Conference on Power Electronics and Applications, vol. 3, pp. 255-260, 1993.
[50]A. Okwi, S. Kaga and H. lkeda, “Control method of PWM inverter for driving LSM to reduce the burden of output transformer,” IEEE Conference on Power Electronics Specialists, vol. 1, pp. 571-577, 1998.
[51]M. Li and Y. Xing, “Digital voltage regulation with flux balance control for sine wave inverters,” IEEE Conference and Exposition on Applied Power Electronics, vol. 3, pp. 1709-1713, 2004.
[52]C. Rech, H. Pinheiro, H. A. Grundling, H. L. Hey and J. R. Pinheiro, “Analysis and design of a repetitive predictive-PID controller for PWM inverters,” IEEE Conference on Power Electronics Specialists, vol. 2, pp. 986-991, 2001.
[53]J. M. Guerrero, L. G. de Vicuna, J. Miret, J. Matas, and M. Castilla, “Integral control technique for single-phase UPS inverter,” IEEE International Symposium on Industrial Electronics, vol. 4, pp. 257-261, 2002.
[54]K. Guo, W. Xuejuan and J. Chen, “PWM VSI waveform control based on feedback and feedforward technology,” IEEE International Conference on Power Electronics and Drive Systems, vol. 2, pp. 638-642, 2001.
[55]O. Kukrer, H. Komurcugil and N. S. Bayindir, “Control strategy for single-phase UPS inverters,” IEE Proceedings Electric Power Applications, vol. 150, no. 6, pp. 743-746, 2003.
[56]J. M. Guerrero, L. Garcia de Vicuna, J. Miret, J. Matas and M. Castilla, “A nonlinear feed-forward control technique for single-phase UPS inverters,” IEEE Conference on Industrial Electronics, vol. 1, pp. 257-261, 2002.
[57]M. J. Ryan, W. E. Brumsickle and R. D. Lorenz, “Control topology options for single-phase UPS inverters,” IEEE Trans. Ind. Applicat., vol. 33, no. 2, pp. 493-501, 1997.
[58]M. Lopez, J. L. Garcia de Vicuna, M. Castilla, J. Matas and O. Lopez, “Control design for parallel-connected DC-AC inverters using sliding mode control,” IEEE International Conference on Power Electronics and Variable Speed Drives, vol. 475, pp. 457-460, 2000.
[59]S. J. Chiang, T. L. Tai and T. S. Lee, “Variable structure control of UPS inverters,” IEE Proceedings Electric Power Applications, vol. 145, no. 6, pp. 559-567, 1998.
[60]M. J. Ryan and R. D. Lorenz, “A synchronous-frame controller for a single-phase sine wave inverter,” IEEE Conference and Exposition on Applied Power Electronics, vol. 2, pp. 813-819, 1997.
[61]O. Kukrer and H. Komurcugil, “Deadbeat control method for single-phase UPS inverters with compensation of computation delay,” IEE Proceedings on Electric Power Applications, vol. 146, no. 1, pp. 123-128, 1999.
[62]K. S. Low, “A DSP-based single-phase AC power source,” IEEE Trans. Ind. Electron., vol. 46, no. 5, pp. 936-941, 1999.
[63]T. Senjyu and K. Uezato, “Sinusoidal voltage controller for uninterruptible power supply by robust control,” IEEE Conference on Power Conversion, pp. 200-205, 1993.
[64]Z. Yang and P. C. Sen, “A novel switch-mode DC-to-AC inverter with nonlinear robust control,” IEEE Trans. Ind. Electron., vol. 45, no. 4, pp.602-608, 1998.
[65]E. G. Carati, V. F. Montagner and H. A. Grundling, “A single-phase AC power source using robust model reference adaptive control,” IEEE Conference on Industrial Electronics, vol. 2, pp. 1428-1432, 2000.
[66]C. M. Richter, E. G.. Carati, H. Pinheiro, H. L. Hey, J. R. Pinheiro and H. A. Grundling, “A three-phase AC power source using multivariable repetitive robust model reference adaptive control,” IEEE Conference on American Control, vol. 3, pp.2300-2305, 2003.
[67]P. Sanchis, A. Ursæa, E. Gubía and L. Marroyo, “Boost DC-AC inverter: a new control strategy,” IEEE Trans. Power Electron., vol. 20, no. 2, pp.343-353, 2005.
[68]X. Sun, M. H. L. Chow, F. H. F. Leung, D. Xu, Y. Wang and Y. S. Lee, “Analogue implementation of a neural network controller for UPS inverter applications,” IEEE Trans. Power Electron., vol. 17, no. 3, pp. 305-313, 2002.

E . Distributed power systems and modular connection of inverters

[69]Y. Xue, L. Chang, S. B. Kjaer, J. Bordonau and T. Shimizu, “Topologies of single-phase inverters for small distributed power generators: an overview,” IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1305-1314, 2004
[70]P. Karlesson and J. Svensson, “DC bus voltage control for a distributed power system,” IEEE Trans. Power Electron., vol. 18, no.6, pp. 1405-1412, 2003.
[71]G. S. Thandi, R. Zhang, K. Xing, F. C. Lee and D. Boroyevich, “Modeling control and stability analysis of a PEBB based DC DPS,” IEEE Trans. Power Delivery, vol. 14, no.2, pp. 497-505, 1999.
[72]J. S. Manguelle and A. Rufer, “Multilevel inverter for power system applications highlighting asymmetric design effects from a supply network point of view,” IEEE Canadian Conference on Electrical and Computer Engineering, vol. 1, pp. 435-440, 2003.
[73]S. Mariethoz and A. Rufer, “New configurations for the three-phase asymmetrical multilevel inverter,” IEEE Conference on Industry Applications, vol. 2, pp. 828-835, 2004.
[74]R. Teodorescu, F. Blaabjerg, J. K. Pedersen, E. Cengelci and P. N. Enjeti, “Multilevel inverter by cascading industrial VSI,” IEEE Trans. Ind. Electron., vol. 49, no. 4, pp. 832-838, 2002.
[75]M. Hashad and J. Iwaszkiewicz, “A novel orthogonal-vectors-based topology of multilevel inverter by cascading industrial VSI,” IEEE Trans. Ind. Electron., vol. 49, no. 4, pp. 832-838, 2002.
[76]E. Cengelci, P. N. Enjeti and J. W. Gray, “A new modular motor-modular inverter concept for medium-voltage adjustable-speed-drive systems,” IEEE Trans. Ind. Applicat., vol. 36, no. 3, pp. 786-796, 2000.
[77]E. Cengelci, P. Enjeti, C. Singh, F. Blaabjerg and J. K. Pederson, “New medium voltage PWM inverter topologies for adjustable speed AC motor drive systems,” IEEE Conference and Exposition on Applied Power Electronics, vol. 2, pp. 565-571, 1998.
[78]C. Rech, H. A. Grundling, H. L. Hey, H. Pinheiro and J. R. Pinheiro, “A generalized design methodology for hybrid multilevel inverters,” IEEE Conference on Industrial Electronics, vol. 1, pp. 834-839, 2002.
[79]Z. Qianzhi, Z. Kai and W. Jugui, “A novel single-three phase inverter adopting CTA scheme,” IEEE Conference on Power Electronics and Motion Control, vol. 2, pp. 980-984, 2000.
[80]K. Sheldon, “Connecting multiple Sunny Boy Inverters to a three phase utility,” Technical Note, SMA American, Incorporated Copyright, rev. 1.6, 2002.
[81]S B. Kjær. “DC-AC inverter concepts for photovoltaic (PV) applications,” Aalborg, 2004.
[82]J. Rodríguez, J. S. Lai and F Z Peng, “Multilevel Inverters: A survey of topologies, controls, and applications,” IEEE Trans. Ind. Electron., vol. 49, no. 4, pp. 724-738, 2002.

F. Multi-modular connection and three phase inverter

[83]M. Milanovic, D. Dolinar, and A. Ravnjak, “DC to Three-phase inverter based on two-phase to three-phase transformation,” IEEE Trans. Ind. Electron.,vol. 3, pp.
784-788, 2002.
[84]P. N. Enjeti, P. D. Ziogas and J. F. Lindsay, “Programmed PWM techniques to eliminate harmonics: a critical evaluation,” IEEE Trans. Ind. Applicat., vol. 26, no. 2, pp. 302-316, 1990.
[85]F. Barzegar and S. Cuk, “A new switched-mode amplifier produces clean three-phase power,” TESLAco, Pasadena, Advances in Switched-Mode Power Conversion, vol. 3, pp. 179-193, 1983.
[86]K. Matsui, Y. Murai, M. Watanabe, M. Kaneko and F. Ueda, “A pulsewidth-modulated inverter with parallel connected transistors using current-sharing reactors,” IEEE Trans. Power Electron., vol. 8, no. 2, pp. 186-191, 1993.
[87]F. Ueda, K. Matsui, M. Asao and K. Tsuboi, “Parallel-connections of pulsewidth modulated inverters using current sharing reactors,” IEEE Trans. Power Electron., vol. 10, no. 6, pp. 673-679, 1995.
[88]F. V. P. Robinson, “The interleaved operation of power amplifiers,” IEE International Conference on Power Electronics and Variable Speed Drives, vol. 456, pp. 606-611, 1998.
[89]B. H. Li, S. S. Choi and D. M. Vilathgamuwa, “Transformerless dynamic voltage restorer,” IEE Proceedings-Generation on Transmission and Distribution, vol. 149, no. 3, pp. 263-273, 2002.
[90]A. Chibani and M. Nakaoka, “A new state-feedback control based 3 phase PWM inverter with improved parallel resonant DC link,” IEEE Conference on Industry Applications, vol. 1, pp. 801-808, 1992.
[91]G. Yao, S. Phillips and L. Norum, “Three-phase inverters-analysis of ability to maintain symmetrical output voltages,” IEEE International Conference on Industrial Electronics, Control, and Instrumentation, vol. 2, pp. 1033-1039, 1993.
[92]V. M. Cardenas, S. Horta and R. Echavarria, “Elimination of dead time effects in three phase inverters,” IEEE International Conference on Power Electronics Congress, pp. 258-262, 1996.
[93]R. Stoicescu, K. Miu, C. O. Nwankpa, D. Niebur and Xiaoguang Yang, “Three-phase converter models for unbalanced radial power-flow studies,” IEEE Trans. Power Syst., vol. 17, no. 4, pp. 1016-1021, 2002.
[94]K. Matsui, Y. Murai, M. Watanabe, M. Kaneko and F. Ueda, “A pulsewidth-modulated inverter with parallel connected transistors using current-sharing reactors,” IEEE Trans. Power Electron., vol. 8, no. 2, pp. 186-191, 1993.
[95]F. Ueda, K. Matsui, M. Asa and K. Tsuboi, “Parallel-connections of pulsewidth modulated inverters using,” IEEE Trans. Power Electron., vol. 10, no.6, pp. 673-679, 1995.
[96]R. J. Kakalec, “A comparison of three phase Scott-T and ferroresonant transformers,” IEEE Conference on Electrical Electronics Insulation, pp. 619-623, 1995.
[97]P. Li, B. Dan, K. Yong, and C. Jian, “Research on three-phase inverter with unbalanced load,” IEEE Conference and Exposition on Applied Power Electronics, vol. 1, pp. 128-133, 2004.
[98]A. M. Cross, P. D. Evans and A. J. Forsyth, ”DC link current in PWM inverters with unbalanced and nonlinear loads,” IEE Proceedings on Electric Power Applications, vol. 146, pp. 620-626, 1999.
[99]M. Marchesoni and M. Mazzucchelli, “Multilevel Converters for High Power AC Drives: a Review,” IEEE Conference on Industrial Electronics, pp. 38-43, 1993.
[100]N. P. Schibli, T. Nguyen and A. C. Rufer, “A three-phase multilevel converter for high-power induction motors,” IEEE Trans. Power Electron., vol. 13, no.5, pp. 978-986, 1998.

G . Digital Signal Processor and Digital Control

[101]G. F. Franklin, J. D. Powell and A. Emami-Naeini, Feedback Control of Dynamic System, 4th ed. Prentice Hall Inc., 2002.
[102]G. F. Franklin, J. D. Powell and M. Workman, Digital Control of Dynamic Systems, 3rd ed. Addison Wesley Inc., 1998.
[103]F. Nekoogar and G. Moriarty, Digital Control Using Digital Signal Processing, Prentice Hall PTR, New Jersey, 1999.
[104]F. L. Luo, H. Ye and M. H. Rashid, Digital Power Electronics and Applications, Academic Press Inc, London Ltd, 2005.
[105]K. Ogata, “Discrete-Time Control Systems,” Prentice-Hall, New Jersey, 1995.
[106]“Single-Chip DSP-Based High Performance Motor Controller ADMC 401,” Analog Devices Inc., 2000.
[107]“Implementing PI controllers with the ADMC401,”Application Note AN401-13, Analog Devices Inc., 2000.
[108]D. Lloyd, ‘‘Control Loop Design,’’ Texas Instruments Inc., 2001.
[109]Á. Tihamér, D. Samad and F József, “Influence of discretization method on the digital control system performance,” Acta Montanistica Slovaca, pp. 197-200, 2003.
[110]L. Mihalache, “DSP control method of single-phase inverters for UPS applications,” IEEE Conference and Exposition on Applied Power Electronics, vol. 1, pp. 590-596, 2002.
[111]P. Xuejun, L. Xinchun, D. Shanxu, K. Yong and C. Jian, “Analysis and design of the DSP-based fully digital-controlled UPS,” IEEE International Conference on Power Electronics and Drive Systems, vol. 1, pp. 296-300, 2001.
[112]L. B. Brahim, T. Yokoyama and A. Kawamura, “Digital control for UPS inverters,” IEEE International Conference on Power Electronics and Drive Systems, vol. 2, pp. 1252-1257, 2003.
[113]H. Pinheiro, F. Botteron, J. R. Pinheiro, H. L. Hey and H. A. Grundling, “A digital controller for single-phase UPS inverters to reduce the output DC component,” IEEE Conference on Power Electronics Specialists, vol. 2, pp. 1311-1314, 2004.
[114]L. Asiminoaei, R. Teodorescu, F. Blaabjerg and U.Borup, “A digital controlled PV-inverter with grid impedance estimation for ENS detection,” IEEE Trans. Power Electron., vol. 20, no. 6, pp. 1480-14900, 2005.
[115]T. Yokoyama and A. Kawamura, “Disturbance observer based fully digital controlled PWM inverter for CVCF operation,” IEEE Trans. Power Electron., vol. 9, no. 5, pp. 473-480, 1994.
[116]K. S. Low, “A digital control technique for a single-phase PWM inverter,” IEEE Trans. Ind. Electron., vol. 45, no. 4, pp. 672-674, 1998.
[117]P. A. Dahono, P. Ismutadi, Y. Sato and T. Kataoka, “A control method for single-phase PWM inverters,” IEEE International Conference on Power Electronics and Drive Systems, vol. 1, pp. 282-285, 2001.
[118]C. Rech, H. Pinheiro, H. A. Grundling, H. L. Hey and J. R. Pinheiro, “A modified discrete control law for UPS applications,” IEEE Trans. Power Electron., vol. 18, no. 5, pp. 1138-1145, 2003.
[119]H. Deng, R. Oruganti and D. Srinivasan, “PWM methods to handle time delay in digital control of a UPS inverter,” IEEE Power Electronics Letters, vol. 3, no. 1, pp. 1-6, 2005.
[120]G. Willmann, D. F. Coutinho and L. F. A. Pereira, “A robust discrete-time controller for DC-AC inverters,” IEEE Conference on Industrial Electronicv, pp. 213-218, 2005.
[121]F. Botteron and H. Pinheiro, “Discrete-time internal model controller for three-phase PWM inverters with insulator transformer,” IEE Proceedings Electric Power Applications, vol. 153, no. 1, pp. 57-67, 2006.
[122]Y. Ito and S. Kawauchi, “Microprocessor based robust digital control for UPS with three-phase PWM inverter,” IEEE Trans. Power Electron., vol. 10, no. 2, pp. 196 - 204, 1995.
[123]T. Kato, K. Inoue, T. Kita and S. Kuroda, “Sinusoidal waveform following method for optimum digital control of PWM inverter,” IEEE Conference on Power Electronics and Motion Control, vol. 3, pp. 1597 - 1602, 2004.
[124]C. Rech and J. R. Pinheiro, “New repetitive control system of PWM inverters with improved dynamic performance under nonperiodic disturbances,” IEEE Conference on Power Electronics Specialists, vol. 1, pp. 54 - 60, 2004.
[125]L. Michels, H. Pinheiro and H. A. Grundling, “Design of plug-in repetitive controllers for single-phase PWM inverters,” IEEE Conference on Industry Applications, vol. 1, pp. 163-170, 2004.
[126]J. W. Jung, M. Dai and A. Keyhani, “Optimal control of three-phase PWM inverter for UPS systems,” IEEE Conference on Power Electronics Specialists, vol. 3, pp. 2054 – 2059, 2004.

H. Commercialized AC power source

[127]“Programmable AC source specification 6400,” Chroma Ate Inc.
[128]“Single and three phase AC power sources models from 500 VA to 12kVA,” Pacific Inc.
[129]“Single and three phase AC power sources models from 1 kVA to 12 kVA manual or programmable control,” Pacific Inc.
[130]“BL1350 series AC power source,” Behlman Electronics Inc.
[131]“Elgar 1203SL 3 phase 1200VA AC Power Source,” Test Equipment Corporation.
[132]“LX series AC power source,” California Instruments Inc.

[133]“How to specify AC Power Sources,” Transisitor Devices Inc., 2000.
[134]“Power Conversion & Line Filter Applications,” Micrometals INC., pp. 12, 2003.