Direct Current Tracking Using Boundary Control With Second-Order Switching Surface for Three-Phase Three-Wire Grid-Connected Inverter

Cascaded boundary-deadbeat controller can ensure system stability of single-phase grid-connected inverter operated under different grid conditions. However, it will require using numerous sensors and may experience performance degradation caused by unbalanced filter parameters in controlling a three-phase three-wire inverter. Furthermore, the system is in variable frequency operation. A boundary controller using second-order switching surface with direct current tracking capability, reduced number of current sensors, and fixed frequency operation of three-phase three-wire grid-connected inverter with inductive-capacitive-inductive (LCL) filter is presented. By applying the 60° discontinuous pulsewidth modulation scheme for a fictitious decoupled dual-buck structure in each operation sector, two separate sets of switching criteria for dictating the states of the switches of two half-bridge legs are formulated. Such technique can avoid dealing with the challenges caused by the interactions among three independent current regulators. A switching table with null voltage vectors excluded is designed to dictate the switching actions. Sensitivities of the system transfer characteristics to the parametric variations are investigated. A 3 kW prototype has been built and evaluated under stiff- and weak-grid conditions. The experimental results are favorably compared with theoretical predictions.

[1]  Frede Blaabjerg,et al.  A New Design Method for the Passive Damped LCL and LLCL Filter-Based Single-Phase Grid-Tied Inverter , 2013, IEEE Transactions on Industrial Electronics.

[2]  J.W. Kolar,et al.  A Modified Direct Power Control Strategy Allowing the Connection of Three-Phase Inverters to the Grid Through $LCL$ Filters , 2005, IEEE Transactions on Industry Applications.

[3]  H.A. Ashour,et al.  Digital hysteresis current control for grid-connected converters with LCL filter , 2011, IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society.

[4]  V. Blasko,et al.  A novel control to actively damp resonance in input LC filter of a three-phase voltage source converter , 1997 .

[5]  Tao Liu,et al.  A Sliding-Mode Controller With Multiresonant Sliding Surface for Single-Phase Grid-Connected VSI With an LCL Filter , 2013, IEEE Transactions on Power Electronics.

[6]  Henry Shu-Hung Chung,et al.  Use of Boundary Control With Second-Order Switching Surface to Reduce the System Order for Deadbeat Controller in Grid-Connected Inverter , 2016, IEEE Transactions on Power Electronics.

[7]  Donald Grahame Holmes,et al.  Regions of active damping control for LCL filters , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[8]  J. M. Galvez,et al.  Introducing the Natural Switching Surface for reference frame systems: Three-phase boost PFCs , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[9]  Mariusz Malinowski,et al.  A Simple Voltage Sensorless Active Damping Scheme for Three-Phase PWM Converters With an $LCL$ Filter , 2008, IEEE Transactions on Industrial Electronics.

[10]  Yun Wei Li,et al.  A Flexible Harmonic Control Approach Through Voltage-Controlled DG–Grid Interfacing Converters , 2012, IEEE Transactions on Industrial Electronics.

[11]  Toshihiko Noguchi,et al.  Direct power control of PWM converter without power source voltage sensors , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[12]  Holmes,et al.  Pulse width modulation for power converters , 2003 .

[13]  Frede Blaabjerg,et al.  Optimal Design of High-Order Passive-Damped Filters for Grid-Connected Applications , 2016, IEEE Transactions on Power Electronics.

[14]  John E. Quaicoe,et al.  Selection of a curved switching surface for buck converters , 2006, IEEE Transactions on Power Electronics.

[15]  T. Geyer,et al.  Model Predictive Direct Power Control for a grid-connected converter with an LCL-filter , 2013, 2013 IEEE International Conference on Industrial Technology (ICIT).

[16]  Frede Blaabjerg,et al.  An Efficient and Robust Hybrid Damper for $LCL$- or $LLCL$-Based Grid-Tied Inverter With Strong Grid-Side Harmonic Voltage Effect Rejection , 2016, IEEE Transactions on Industrial Electronics.

[17]  Nils Hoffmann,et al.  Minimal Invasive Equivalent Grid Impedance Estimation in Inductive–Resistive Power Networks Using Extended Kalman Filter , 2014, IEEE Transactions on Power Electronics.

[18]  Friedrich W. Fuchs,et al.  FRT capability of direct power controlled converters connected by an actively damped LCL-filter for wind power applications , 2011, Proceedings of the 2011 14th European Conference on Power Electronics and Applications.

[19]  Frede Blaabjerg,et al.  Proportionalresonant controllers and filters for gridconnected voltagesource converters , 2006 .

[20]  F.W. Fuchs,et al.  Discrete sliding mode current control of grid-connected three-phase PWM converters with LCL filter , 2010, 2010 IEEE International Symposium on Industrial Electronics.

[21]  Xinbo Ruan,et al.  Capacitor-Current-Feedback Active Damping With Reduced Computation Delay for Improving Robustness of LCL-Type Grid-Connected Inverter , 2014, IEEE Transactions on Power Electronics.

[22]  K.K.S. Leung,et al.  Derivation of a second-order switching surface in the boundary control of buck converters , 2004, IEEE Power Electronics Letters.

[23]  Hasan Komurcugil,et al.  A Three-Level Hysteresis Function Approach to the Sliding-Mode Control of Single-Phase UPS Inverters , 2009, IEEE Transactions on Industrial Electronics.

[24]  Jian Sun,et al.  Impedance-Based Stability Criterion for Grid-Connected Inverters , 2011, IEEE Transactions on Power Electronics.

[25]  Necmi Altin,et al.  Sliding-Mode Control for Single-Phase Grid-Connected $\mbox{LCL}$-Filtered VSI With Double-Band Hysteresis Scheme , 2016, IEEE Transactions on Industrial Electronics.

[26]  Zhengming Zhao,et al.  Direct Power Control Based on Natural Switching Surface for Three-Phase PWM Rectifiers , 2015, IEEE Transactions on Power Electronics.

[27]  Ahmet M. Hava,et al.  Common-Mode Voltage Reduction Pulsewidth Modulation Techniques for Three-Phase Grid-Connected Converters , 2013, IEEE Transactions on Power Electronics.

[28]  Xiaowei Fu,et al.  Direct Grid Current Control of LCL-Filtered Grid-Connected Inverter Mitigating Grid Voltage Disturbance , 2014, IEEE Transactions on Power Electronics.

[29]  Frede Blaabjerg,et al.  A Series-LC-Filtered Active Damper With Grid Disturbance Rejection for AC Power-Electronics-Based Power Systems , 2015, IEEE Transactions on Power Electronics.

[30]  M. Liserre,et al.  Grid Impedance Estimation via Excitation of $LCL$ -Filter Resonance , 2007, IEEE Transactions on Industry Applications.

[31]  M. Liserre,et al.  Analysis of the Passive Damping Losses in LCL-Filter-Based Grid Converters , 2013, IEEE Transactions on Power Electronics.

[32]  Jon Are Suul,et al.  Synchronous Reference Frame Hysteresis Current Control for Grid Converter Applications , 2010, IEEE Transactions on Industry Applications.

[33]  H. Chung,et al.  A Comparative Study of the Boundary Control of Buck Converters Using First- and Second-Order Switching Surfaces -Part I: Continuous Conduction Mode , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[34]  L.A. Serpa,et al.  A Virtual-Flux Decoupling Hysteresis Current Controller for Mains Connected Inverter Systems , 2007, IEEE Transactions on Power Electronics.

[35]  Henry Shu-hung Chung,et al.  A Comparative Study of Boundary Control With First- and Second-Order Switching Surfaces for Buck Converters Operating in DCM , 2007, IEEE Transactions on Power Electronics.

[36]  M.T. Iqbal,et al.  Advanced boundary control of inverters using the natural switching surface: Normalized geometrical derivation , 2008, 2008 IEEE Power Electronics Specialists Conference.

[37]  Frede Blaabjerg,et al.  Proportional-resonant controllers and filters for grid-connected voltage-source converters , 2006 .

[38]  Frede Blaabjerg,et al.  Active Damping of LLCL-Filter Resonance Based on LC-Trap Voltage or Current Feedback , 2016, IEEE Transactions on Power Electronics.

[39]  P.K.W. Chan,et al.  A Generalized Theory of Boundary Control for a Single-Phase Multilevel Inverter Using Second-Order Switching Surface , 2009, IEEE Transactions on Power Electronics.

[40]  Weidong Xiao,et al.  Two Degrees of Freedom Active Damping Technique for $LCL$ Filter-Based Grid Connected PV Systems , 2014, IEEE Transactions on Industrial Electronics.

[41]  H. Shu-hung Chung,et al.  High-Order Switching Surface in Boundary Control of Inverters , 2007, IEEE Transactions on Power Electronics.

[42]  J.W. Kolar,et al.  A modified direct power control strategy allowing the connection of three-phase inverter to the grid through LCL filters , 2005, Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005..

[43]  S. Cobreces,et al.  Influence analysis of the effects of an inductive-resistive weak grid over L and LCL filter current hysteresis controllers , 2007, 2007 European Conference on Power Electronics and Applications.

[44]  Christian Wessels,et al.  Limitations of Voltage-Oriented PI Current Control of Grid-Connected PWM Rectifiers With $LCL$ Filters , 2009, IEEE Transactions on Industrial Electronics.

[45]  M. Liserre,et al.  Stability of photovoltaic and wind turbine grid-connected inverters for a large set of grid impedance values , 2006, IEEE Transactions on Power Electronics.