Dynamics Analysis of Parallel Three-Phase Converters

In a distributed power system based on power electronics building blocks (PEBBs), it is desirable to use a parallel structure with standardized PEBB modules in order to increase power level, provide redundancy and improve system performance. Nonlinear couplings and interactions, however, may occur among the parallel modules. Compared with their counterpart DC/DC converters, three-phase AC/DC or DC/AC converters exhibit stronger dynamics when they operate in parallel. The objective of this paper is to comprehensively analyze the nonlinear dynamics among two parallel three-phase converters. The paper firstly develops a nonlinear average model in rotating coordinates. Based on the model, the nonlinear dynamics, such as small-signal interaction, zero-sequence circulating current and high frequency noise, are analyzed. To improve the system performance and minimize the interactions, some feedback control strategies are proposed. To deal with high-frequency noise, a feedforward control scheme is proposed. The scheme can significantly reduce both common-mode and differential-mode noise. Simulations and preliminary experimental results are presented.

[1]  L. Matakas,et al.  Multi converter implementation by parallel association of K voltage source converters-control method , 2002 .

[2]  T. Kawabata,et al.  Parallel Operation of Voltage Source Inverters , 1986, 1986 Annual Meeting Industry Applications Society.

[3]  Hirofumi Akagi,et al.  A novel control scheme of a parallel current-controlled PWM inverter , 1992 .

[4]  Yifan Zhao,et al.  Space vector PWM control of dual three phase induction machine using vector space decomposition , 1994 .

[5]  Joachim Holtz,et al.  A high-power multitransistor-inverter uninterruptable power supply system , 1988 .

[6]  S. Halasz,et al.  Sinusoidal PWM techniques with additional zero-sequence harmonics , 1994, Proceedings of IECON'94 - 20th Annual Conference of IEEE Industrial Electronics.

[7]  Y. Zhao,et al.  Space vector PWM control of dual three phase induction machine using vector space decomposition , 1994, Proceedings of 1994 IEEE Industry Applications Society Annual Meeting.

[8]  V. Blasko,et al.  Analysis of a hybrid PWM based on modified space vector and triangle comparison methods , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[9]  Dushan Boroyevich,et al.  Modeling and control of zero-sequence current in parallel multi-phase converters , 2000, 2000 IEEE 31st Annual Power Electronics Specialists Conference. Conference Proceedings (Cat. No.00CH37018).

[10]  T. Lipo,et al.  Elimination of common mode voltage in three phase sinusoidal power converters , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[11]  Dushan Boroyevich,et al.  Control of circulating current in parallel three-phase boost rectifiers , 2000, APEC 2000. Fifteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.00CH37058).

[12]  A. Kamel,et al.  Harmonic reduction in single-phase inverter using a parallel operation technique , 1989, Proceedings, Fourth Annual IEEE Applied Power Electronics Conference and Exposition.