A novel power weighted synchronous control method for parallel inverters

For parallel inverters, the sinusoidal output ac voltages in the same-phase should be ensured. This paper presents a power weighted synchronous control method, which is suitable for parallel inverters of different power capabilities. The key concept of the proposed strategy is that the sinusoidal reference signal is decided by the common synchronous pulse signal, which is determined by the majority of the inverters, and the power weighting factor is taken into account. By doing so, the sinusoidal reference signal cannot be interrupted even though one of the modules is fault or dropout. Firstly, the operation principle is described by comparing the conventional method and the proposed method in this paper. Secondly, the hardware implementation is given. Then a detailed reliability failure analysis of synchronous regulation is presented, which shows that higher precision of the control system is obtained compared with the existing methods. At last, the experimental results prove that the control strategy can be well achieved by the designed circuit, and the synchronization of each module is realized.

[1]  J. Miret,et al.  A wireless controller to enhance dynamic performance of parallel inverters in distributed generation systems , 2004, IEEE Transactions on Power Electronics.

[2]  P.D. Ziogas,et al.  A phase-locked-loop synchronization scheme for parallel operation of modular power supplies , 1989, 20th Annual IEEE Power Electronics Specialists Conference.

[3]  Wu Weiyang,et al.  An Alternating-master-salve Parallel Control Research for Single Phase Paralleled Inverters Based on CAN Bus , 2006, 2006 CES/IEEE 5th International Power Electronics and Motion Control Conference.

[4]  Zhang Chun-jiang,et al.  Analysis of the conflict between close-loop control and the current-sharing of ac parallel inverters and parallel control strategy , 2009, 2009 IEEE 6th International Power Electronics and Motion Control Conference.

[5]  Chih-Hong Lin,et al.  Current limitation control for multi-module parallel operation of UPS inverters , 2004 .

[6]  Namho Hur,et al.  A robust load-sharing control scheme for parallel-connected multisystems , 2000, IEEE Trans. Ind. Electron..

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

[8]  K.. De Brabandere,et al.  A Voltage and Frequency Droop Control Method for Parallel Inverters , 2007, IEEE Transactions on Power Electronics.