Online Optimal Operation of Parallel Voltage-Source Inverters Using Partial Information

In this paper, a novel optimal learning algorithm for partially unknown voltage-source inverters (VSIs) operating in parallel is presented. The algorithm designs game-theory-based distributed controllers to provide the appropriate working voltage magnitude and frequency at the load by converting dc voltage to ac voltage at the parallel VSIs. It takes advantage of information from the neighboring low pass $L\hbox{-}C$ filters to improve harmonic distortion and guarantee equal sharing of the load current across the VSIs while avoiding current circulation during transient and ensuring stability and robustness. It builds upon the ideas of approximate dynamic programming (ADP) and uses only partial information of the system and the exosystem, which is connected only to some of the VSIs. The proposed framework was tested in simulations to show its effectiveness.

[1]  J. Svensson,et al.  Control of a voltage-source converter connected to the grid through an LCL-filter-application to active filtering , 1998, PESC 98 Record. 29th Annual IEEE Power Electronics Specialists Conference (Cat. No.98CH36196).

[2]  Fuzhen Zhang.  The Schur complement and its applications , 2005 .

[3]  Donald C. Wunsch,et al.  Applications of Approximate Dynamic Programming in Power Systems Control , 2004 .

[4]  Ivo Barbi,et al.  A Control Strategy for Parallel Operation of Single-Phase Voltage Source Inverters: Analysis, Design and Experimental Results , 2013, IEEE Transactions on Industrial Electronics.

[5]  D. Ernst,et al.  Power systems stability control: reinforcement learning framework , 2004, IEEE Transactions on Power Systems.

[6]  J. Miret,et al.  Decentralized Control for Parallel Operation of Distributed Generation Inverters Using Resistive Output Impedance , 2005, IEEE Transactions on Industrial Electronics.

[7]  Francesco Bullo,et al.  Synchronization and power sharing for droop-controlled inverters in islanded microgrids , 2012, Autom..

[8]  Rudy R. Negenborn,et al.  Multi-agent model predictive control with applications to power networks , 2007 .

[9]  Zhong-Ping Jiang,et al.  Robust Adaptive Dynamic Programming With an Application to Power Systems , 2013, IEEE Transactions on Neural Networks and Learning Systems.

[10]  Leonardo A. B. Tôrres,et al.  Comparison of Three Single-Phase PLL Algorithms for UPS Applications , 2008, IEEE Transactions on Industrial Electronics.

[11]  E.J. Bueno,et al.  Current control of voltage source converters connected to the grid through an LCL-filter , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[12]  Michael Chertkov,et al.  Sparse and optimal wide-area damping control in power networks , 2013, 2013 American Control Conference.

[13]  Ganesh K. Venayagamoorthy,et al.  Dynamic, Stochastic, Computational, and Scalable Technologies for Smart Grids , 2011, IEEE Computational Intelligence Magazine.

[14]  João Pedro Hespanha,et al.  Synchronization of Identical Oscillators Coupled Through a Symmetric Network With Dynamics: A Constructive Approach With Applications to Parallel Operation of Inverters , 2015, IEEE Transactions on Automatic Control.

[15]  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).

[16]  Timothy C. Green,et al.  Control and filter design of three-phase inverters for high power quality grid connection , 2003 .

[17]  F. Zare,et al.  Hysteresis Band Current Control for a Single Phase Z-source Inverter with Symmetrical and Asymmetrical Z-network , 2007, 2007 Power Conversion Conference - Nagoya.

[18]  R.N. do Prado,et al.  Fluorescent lamp model based on the equivalent resistance variation , 2002, Conference Record of the 2002 IEEE Industry Applications Conference. 37th IAS Annual Meeting (Cat. No.02CH37344).

[19]  Josep M. Guerrero,et al.  Design and Analysis of the Droop Control Method for Parallel Inverters Considering the Impact of the Complex Impedance on the Power Sharing , 2011, IEEE Transactions on Industrial Electronics.

[20]  Donald Grahame Holmes,et al.  Frequency domain analysis of three phase linear current regulators , 1999 .

[21]  Salman Mohagheghi,et al.  Particle Swarm Optimization: Basic Concepts, Variants and Applications in Power Systems , 2008, IEEE Transactions on Evolutionary Computation.

[22]  A.G. Beccuti,et al.  Analysis and optimal current control of a voltage source inverter connected to the grid through an LCL filter , 2008, 2008 IEEE Power Electronics Specialists Conference.

[23]  W. Dixon.  Optimal Adaptive Control and Differential Games by Reinforcement Learning Principles , 2014 .

[24]  B. Anderson,et al.  Linear Optimal Control , 1971 .

[25]  T. Başar,et al.  Dynamic Noncooperative Game Theory, 2nd Edition , 1998 .

[26]  P. Olver.  Nonlinear Systems , 2013 .

[27]  Takao Kawabata,et al.  Dead beat control of three phase PWM inverter , 1987 .

[28]  Marios M. Polycarpou,et al.  On-line approximation control of uncertain nonlinear systems: issues with control input saturation , 2003, Proceedings of the 2003 American Control Conference, 2003..

[29]  Babu Narayanan,et al.  POWER SYSTEM STABILITY AND CONTROL , 2015 .

[30]  Haibing Hu,et al.  Distributed Control for AC Motor Drive Inverters in Parallel Operation , 2011, IEEE Transactions on Industrial Electronics.