Impedance-based stability analysis of single-phase inverter connected to weak grid with voltage feed-forward control

Voltage feed-forward control (VFFC) is widely used due to its good low-frequency-harmonics suppression and easy implementation, however, it will worsen system stability under the weak grid condition. In this paper, the stability of single-phase grid-connected inverter with VFFC is studied based on impedance analysis method. With this method, the instability mechanism and the unstable area caused by VFFC are easily obtained. Based on this, system can be stabilized simply by adding phase-lead compensation, avoiding the real-time detection of grid impedance. Simulation and experimental results verify the analysis and the proposed control method.

[1]  Dongsheng Yang,et al.  Impedance Shaping of the Grid-Connected Inverter with LCL Filter to Improve Its Adaptability to the Weak Grid Condition , 2014, IEEE Transactions on Power Electronics.

[2]  J L Agorreta,et al.  Modeling and Control of $N$ -Paralleled Grid-Connected Inverters With LCL Filter Coupled Due to Grid Impedance in PV Plants , 2011, IEEE Transactions on Power Electronics.

[3]  Shaojun Xie,et al.  Evaluations of current control in weak grid case for grid-connected LCL-filtered inverter , 2013 .

[4]  Shaojun Xie,et al.  Improved control strategy with grid-voltage feedforward for LCL-filter-based inverter connected to weak grid , 2014 .

[5]  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.

[6]  Modeling the output impedance negative incremental resistance behavior of grid-tied inverters , 2014, 2014 IEEE Applied Power Electronics Conference and Exposition - APEC 2014.

[7]  Jih-Sheng Lai,et al.  Admittance Compensation in Current Loop Control for a Grid-Tie LCL Fuel Cell Inverter , 2008 .

[8]  Fred Wang,et al.  Influence of voltage feed-forward control on small-signal stability of grid-tied inverters , 2015, 2015 IEEE Applied Power Electronics Conference and Exposition (APEC).

[9]  Jian Sun,et al.  Impedance shaping of three-phase grid-parallel voltage-source converters , 2012, 2012 Twenty-Seventh Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

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

[11]  Bo Wen,et al.  Impedance-Based Analysis of Grid-Synchronization Stability for Three-Phase Paralleled Converters , 2014, IEEE Transactions on Power Electronics.

[12]  Xinbo Ruan,et al.  Full Feedforward of Grid Voltage for Grid-Connected Inverter With LCL Filter to Suppress Current Distortion Due to Grid Voltage Harmonics , 2010, IEEE Transactions on Power Electronics.

[13]  Jian Sun,et al.  Renewable Energy Systems Instability Involving Grid-Parallel Inverters , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.