Performance Improvement of Parallel Active Power Filters Using Droop Control Method

In this paper, a new method based on droop control scheme is proposed for controlling parallel operation of active filters. The harmonic components of the load current are extracted by an enhanced phase-locked loop (EPLL). In the parallel group, each filter operates as a conductance and the harmonic workload is shared among them. A droop relationship between the conductance and non-fundamental apparent power controls the operation of each unit. The non-fundamental apparent power has been calculated based on IEEE Std 1459. Principles of operation are explained in this paper and simulation results which are presented approve the effectiveness of this method. The results indicate a significant reduction in Total Harmonic Distortion (THD) in a rectifier application. Keywords-Power quality; Parallel active filters; Power system harmonics; Droop

[1]  M. Castilla,et al.  A wireless load sharing controller to improve dynamic performance of parallel-connected UPS inverters , 2003, IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03..

[2]  S. J. Chiang,et al.  Parallel operation of three-phase four-wire active power filters without control interconnection , 2002, 2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289).

[3]  M. Castilla,et al.  Droop control method for the parallel operation of online uninterruptible power systems using resistive output impedance , 2006, Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, 2006. APEC '06..

[4]  Frede Blaabjerg,et al.  Harmonic Mitigation Improvement with a New Parallel Topology for Shunt Active Power Filters , 2006 .

[5]  Yuan Chang,et al.  On the control of active power filters , 2007, 2007 7th Internatonal Conference on Power Electronics.

[6]  M.R. Iravani,et al.  A method for synchronization of power electronic converters in polluted and variable-frequency environments , 2004, IEEE Transactions on Power Systems.

[7]  Po-Tai Cheng,et al.  Distributed active filter systems (DAFS): a new approach to power system harmonics , 2004, Conference Record of the 2004 IEEE Industry Applications Conference, 2004. 39th IAS Annual Meeting..

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

[9]  Wanneng Yu,et al.  The Study of Fault-Tolerant Control for Shunt Active Power Filter , 2007, 2007 IEEE International Conference on Control and Automation.