A new optimized pole placement strategy of grid-connected inverter with LCL-filter based on state variable feedback and state observer

The LCCL control strategy, which was brought forward as a solution for the resonance of LCL-filter, provides good steady-state performance but unsatisfactory dynamic performance. In this paper, based on an improved discrete state space model and state observer of the LCCL control, a new optimized pole placement strategy is proposed to achieve the best damping performance of the whole system with LCL-filter, with which the dynamic performance of the system can be greatly improved without additional sensors. Furthermore, the proposed method has almost the same performance in suppressing power grid disturbances and the non-linearity of an inverter, resulting in the same steady-state performance compared with LCCL control strategy. A 10 kW grid-connected inverter with LCL-filter prototype is set up to verify the effectiveness of the proposed control strategy and observer configuration, as well as the overall improvement of system performance.

[1]  Dehong Xu,et al.  An Improved Control Strategy for Grid-Connected Voltage Source Inverters With an LCL Filter , 2006, IEEE Transactions on Power Electronics.

[2]  H. Kubota,et al.  DSP-based speed adaptive flux observer of induction motor , 1991, Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting.

[3]  M. Liserre,et al.  Stability improvements of an LCL-filter based three-phase active rectifier , 2002, 2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289).

[4]  M. Liserre,et al.  Design and control of an LCL-filter based three-phase active rectifier , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[5]  Dehong Xu,et al.  An improved control strategy for grid-connected voltage source inverters with a LCL filter , 2006, Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, 2006. APEC '06..

[6]  Dehong Xu,et al.  A New Feedback Method for PR Current Control of LCL-Filter-Based Grid-Connected Inverter , 2010, IEEE Transactions on Industrial Electronics.

[7]  F.W. Fuchs,et al.  Active damping of LCL-filter resonance based on virtual resistor for PWM rectifiers — stability analysis with different filter parameters , 2008, 2008 IEEE Power Electronics Specialists Conference.

[8]  Katsuhiko Ogata,et al.  Discrete-time control systems , 1987 .

[9]  Donald Grahame Holmes,et al.  Grid current regulation of a three-phase voltage source inverter with an LCL input filter , 2002, 2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289).

[10]  P.W. Lehn,et al.  Digital current control of a voltage source converter with active damping of LCL resonance , 2005, Twentieth Annual IEEE Applied Power Electronics Conference and Exposition, 2005. APEC 2005..

[11]  Steffen Bernet,et al.  Design of $LCL$ Filters of Active-Front-End Two-Level Voltage-Source Converters , 2009, IEEE Transactions on Industrial Electronics.

[12]  Zhengyu Lu,et al.  Investigation of fully digital controlled Li-ion battery power recovery system , 2010, 2010 Twenty-Fifth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[13]  Yukihiko Sato,et al.  Damping of transient oscillations on the output LC filter of PWM inverters by using a virtual resistor , 2001, 4th IEEE International Conference on Power Electronics and Drive Systems. IEEE PEDS 2001 - Indonesia. Proceedings (Cat. No.01TH8594).

[14]  Frede Blaabjerg,et al.  Overview of Control and Grid Synchronization for Distributed Power Generation Systems , 2006, IEEE Transactions on Industrial Electronics.

[15]  Friedrich Wilhelm Fuchs,et al.  PI state space current control of grid- connected PWM converters with LCL filters , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[16]  Kaustuva Acharya,et al.  A Universal Grid-Connected Fuel-Cell Inverter for Residential Application , 2010, IEEE Transactions on Industrial Electronics.

[17]  Yu Zhang,et al.  Optimized pole and zero placement with state observer for LCL-type grid-connected inverter , 2011, 2011 IEEE Energy Conversion Congress and Exposition.

[18]  H. Tuusa,et al.  LCL Type Supply Filter for Active Power Filter - Comparison of an Active and a Passive Method for Resonance Damping , 2007, 2007 IEEE Power Electronics Specialists Conference.

[19]  Jeyraj Selvaraj,et al.  Multilevel Inverter For Grid-Connected PV System Employing Digital PI Controller , 2009, IEEE Transactions on Industrial Electronics.