Enhancing the Frequency Adaptability of Periodic Current Controllers for Grid-Connected Power Converters

Yang, Y., Zhou, K. and Blaabjerg, F. (2015) Enhancing the Frequency Adaptability of Periodic Current Controllers for Grid-Connected Power Converters. In: 2015 IEEE Energy Conversion Congress and Exposition (ECCE), Montreal, QC, Canada, 22-24 Sept 2015, pp. 5998-6005. (doi:10.1109/ECCE.2015.7310501)

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Abstract

It is mandatory for grid-connected power converters to synchronize the feed-in currents with the grid. Moreover, the power converters should produce feed-in currents with low total harmonic distortions according to the demands, by employing advanced current controllers, e.g., Proportional Resonant (PR) and Repetitive Controllers (RC). The synchronization is actually to detect the instantaneous grid information (e.g., frequency and phase of the grid voltage) for the current control, which is commonly performed by a Phase-Locked-Loop (PLL) system. As a consequence, harmonics and deviations in the estimated frequency by the PLL could lead to current tracking performance degradation, especially for the periodic signal controllers (e.g., PR and RC) of high frequency-dependency. In this paper, the impacts of frequency deviations induced by the PLL and/or the grid disturbances on the selected current controllers are investigated by analyzing the frequency adaptability of these current controllers. Subsequently, strategies to enhance the frequency-variation-immunity for the current controllers are proposed for the power converters to produce high quality feed-in currents even in the presence of frequency deviations. Experiments on a single-phase grid-connected inverter system are presented, which have verified the proposals and also the effectiveness of the frequency adaptive current controllers.

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Zhou, Dr Keliang
Authors: Yang, Y., Zhou, K., and Blaabjerg, F.
Subjects:T Technology > TK Electrical engineering. Electronics Nuclear engineering
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
ISSN:2329-3721

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