A Unified Control Strategy for Three-phase Inverter in Distributed Generation
0 likes32 views
This document discusses a unified control strategy for three-phase inverters used in distributed generation, allowing seamless operation in both islanded and grid-tied modes without switching controllers. The proposed strategy includes an inner current loop and a voltage loop in the synchronous reference frame, enhancing performance under varying conditions. Validation of the strategy is provided through simulation and experimental results, demonstrating improved waveform quality for both grid current and load voltage.
![ELECTRICAL PROJECTS USING MATLAB/SIMULINK
Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
For Simulation Results of the project Contact Us
Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
CONCLUSION:
A unified control strategy is proposed for three-phase inverter in DG to operate in both islanded
and grid-tied mode, with no need for switching between two different control architectures or
critical islanding detection. A novel voltage controller is presented. It is inactivated in grid-tied
mode, and the DG operates as a current source with fast dynamic performance. Upon the utility
outage, the voltage controller can automatically be activated to regulate the load voltage.
Moreover, a novel load current feedforward is proposed, and it can improve the waveform
quality of both the grid current in grid-tied mode and the load voltage in islanded mode. The
proposed unified control strategy is verified by the simulation and experimental results.
REFERENCES:
[1] R. C. Dugan and T. E. McDermott, "Distributed generation," IEEE Ind. Appl. Mag., vol. 8,
no. 2, pp. 19-25, Mar./Apr. 2002.
[2] R. H. Lasseter, "Microgrids and distributed generation," J. Energy Eng., vol. 133, no. 3, pp.
144-149, Sep. 2007.
[3] C. Mozina, "Impact of Green Power Distributed Generation," IEEE Ind. Appl. Mag., vol. 16,
no. 4, pp. 55-62, Jul./Aug. 2010.
[4] IEEE Recommended Practice for Utility Interface of Photovoltaic(PV) Systems, IEEE
Standard 929-2000, 2000.
[5] IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems, IEEE
Standard 1547-2003, 2003.](https://image.slidesharecdn.com/aunifiedcontrolstrategyforthree-phase-190614093204/85/A-Unified-Control-Strategy-for-Three-phase-Inverter-in-Distributed-Generation-6-320.jpg)
A Unified Control Strategy for Three-phase Inverter in Distributed Generation
- 1. ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 For Simulation Results of the project Contact Us Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 A Unified Control Strategy for Three-phase Inverter in Distributed Generation ABSTRACT: This paper presents a unified control strategy that enables both islanded and grid-tied operation of three-phase inverter in distributed generation (DG), with no need for switching between two corresponding controllers or critical islanding detection. The proposed control strategy composes of an inner inductor current loop, and a novel voltage loop in the synchronous reference frame (SRF). The inverter is regulated as a current source just by the inner inductor current loop in grid-tied operation, and the voltage controller is automatically activated to regulate the load voltage upon the occurrence of islanding. Furthermore, the waveforms of the grid current in grid- tied mode and the load voltage in islanding mode are distorted under nonlinear local load with the conventional strategy. And this issue is addressed by proposing a unified load current feed forward in the paper. Additionally, the paper presents the detailed analysis and the parameter design of the control strategy. Finally, the effectiveness of the proposed control strategy is validated by the simulation and experimental results. KEYWORDS: 1. Distributed generation 2. Three-phase inverter 3. Islanding 4. Unified control 5. Seamless transfer 6. Load current SOFTWARE: MATLAB/SIMULINK
- 2. ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 For Simulation Results of the project Contact Us Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 CIRCUIT DIAGRAM: Fig. 1 Schematic diagram of the distributed generzation based on the proposed control strategy.
- 3. ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 For Simulation Results of the project Contact Us Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 EXPECTED SIMULATION RESULTS: Fig. 2 Bode plot of the transfer function from load current to grid current with and without the load current feedforward, when DG operates in grid-tied mode.
- 4. ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 For Simulation Results of the project Contact Us Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 Fig. 3 Simulation waveforms of load voltage vCa, grid current iga and inductor current iLa when DG is in grid-tied mode under condition of the step down of the grid current reference from 9A to 5A with: (a) conventional voltage mode control, and (b) proposed unified control strategy.
- 5. ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 For Simulation Results of the project Contact Us Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 Fig. 4 Simulation waveforms of load voltage vCa, grid current iga and inductor current iLa when DG is transferred from grid-tied mode to islanded mode with: (a) conventional hybrid voltage and current mode control, and (b) proposed unified control strategy.
- 6. ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 For Simulation Results of the project Contact Us Gmail: asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in 0-9347143789/9949240245 CONCLUSION: A unified control strategy is proposed for three-phase inverter in DG to operate in both islanded and grid-tied mode, with no need for switching between two different control architectures or critical islanding detection. A novel voltage controller is presented. It is inactivated in grid-tied mode, and the DG operates as a current source with fast dynamic performance. Upon the utility outage, the voltage controller can automatically be activated to regulate the load voltage. Moreover, a novel load current feedforward is proposed, and it can improve the waveform quality of both the grid current in grid-tied mode and the load voltage in islanded mode. The proposed unified control strategy is verified by the simulation and experimental results. REFERENCES: [1] R. C. Dugan and T. E. McDermott, "Distributed generation," IEEE Ind. Appl. Mag., vol. 8, no. 2, pp. 19-25, Mar./Apr. 2002. [2] R. H. Lasseter, "Microgrids and distributed generation," J. Energy Eng., vol. 133, no. 3, pp. 144-149, Sep. 2007. [3] C. Mozina, "Impact of Green Power Distributed Generation," IEEE Ind. Appl. Mag., vol. 16, no. 4, pp. 55-62, Jul./Aug. 2010. [4] IEEE Recommended Practice for Utility Interface of Photovoltaic(PV) Systems, IEEE Standard 929-2000, 2000. [5] IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems, IEEE Standard 1547-2003, 2003.