Control Techniques to Directly Parallel Line-Side Converters for Wind Energy System

Abstract:

The direct paralleled converters can increase the power rating, reliability, efficiency, as well as decrease the cost and current/voltage ripples which are suitable for high power converters. However, when converters are in direct parallel, the circulating currents will be generated automatically. This will result in high current distortion which causes the line inductors saturation and damage the power switches; and therefore overall performance of the system will be degraded. This paper purposes a zero sequence current control technique to reduce the circulating current in directly parallel line-side converter of the wind energy conversion system. The case studies are carried out on a 2 MW wind turbine to investigate the effects of non-identical line inductors and PWM carrier phase shift of each converter to the circulating current. The simulation results confirm that zero sequence current controllers that can reduce the zero sequence current in any conditions. The dynamic responses of the direct parallel converters and a single converter are nearly the same but the direct parallel converters have better current ripple and THDi.

• Periodical: Applied Mechanics and Materials (Volume 704)
• Pages: 161-169
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.704.161
• Online since: December 2014
• Authors: Jirawut Benjanarasut, Bunlung Neammanee
• Keywords: Direct Parallel Technique, Line-Side Converter, Wind Energy, Wind Turbine

References

[1] F. Hinrichsen and L. Feddersen : A Modular Converter Concept for Multi-Megawatt Wind Turbines, FeCon GmbH, Flensburg, Germany.

[2] Ching-Tsai Pan and Yi-Hung Liao: Modeling and Coordinate Control of Circulating Currents in Parallel Three-Phase Boost Rectifiers, IEEE Transaction On Industrial Electronics, Vol. 54, No. 2, April 2007, p.825–838.

DOI: 10.1109/tie.2007.891776

[3] Weihao Hu, Yue Wang, Weizheng Yao, Hailong Zhang, Jinlong Wu and Zhaoan Wang: Modeling and Control of Zero-Sequence Currentin Multiple Grid Connected Converter, Power Electronics Specialists Conference, 2008 (PESC 2008), p.2064-(2069).

DOI: 10.1109/pesc.2008.4592247

[4] Zhihong Ye, Dushan Boroyevich, Jae-Young Choi, and Fred C. Lee: Control of Circulating Current in Parallel Three-phase Boost Rectifiers, Applied Power Electronics Conference and Exposition, 2000 (APEC 2000), vol. 1, pp.506-512.

DOI: 10.1109/apec.2000.826151

[5] S. A. Soliman, R. A. Alammari, M. E. EL-Hawary, and A. H. MANTAWAY in: Park's Transformation Application for Power System Harmonics Identification and Measurements, Electric Power Components and Systems, Taylor & Francis Inc. online (2003).

DOI: 10.1080/15325000390219767

[6] Silva Hiti and Dushan Boroyevich: Control of Front-End Three-phase Boost Rectifier, Applied Power Electronics Conference and Exposition (APEC '94. ), Ninth Annual (1994), pp.927-933.

DOI: 10.1109/apec.1994.316307

[7] Remus Teodorescu, Marco Liserre and Pedro Rodr´ıguez: Grid Converter for Photovoltaic and Wind Power System, A John Wiley and Sons, Ltd., Publication, (2011).

[8] IEEE Std 519-1992, IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems, New York, NY: IEEE.