Stability Improvement of Distributed Power Generation Systems with an LCL-Filter Using Gain Scheduling Based on Grid Impedance Estimations

Dae-Keun Choi; Kyo-Beum Lee

Stability Improvement of Distributed Power Generation Systems with an LCL-Filter Using Gain Scheduling Based on Grid Impedance Estimations

Dae-Keun Choi

Kyo-Beum Lee

Vol. 11, No. 4, pp. 599-605, Jul. 2011

10.6113/JPE.2011.11.4.599

Active damping

Distributed power generation

Grid-connected system

Grid impedance estimation

LCL-filter

PDF

Abstract

This paper proposes a gain scheduling method that improves the stability of grid-connected systems employing an LCL-filter. The method adjusts the current controller gain through an estimation of the grid impedance in order to reduce the resonance that occurs when using an LCL-filter to reduce switching harmonics. An LCL-filter typically has a frequency spectrum with a resonance peak. A change of the grid-impedance results in a change to the resonant frequency. Therefore an LCL-filter needs a damping method that is applicable when changing the grid impedance for stable system control. The proposed method instantaneously estimates the grid impedance and observes the resonant frequency at the same time. Consequently, the proposed method adjusts the current controller gain using a gain scheduling method in order to guarantee current controller stability when a change in the resonant frequency occurs. The effectiveness of the proposed method has been verified by simulations and experimental results.

Statistics

Show / Hide Statistics

Cumulative Counts from September 30th, 2019
Multiple requests among the same browser session are counted as one view. If you mouse over a chart, the values of data points will be shown.

Cite this article

[IEEE Style]

D. Choi and K. Lee, "Stability Improvement of Distributed Power Generation Systems with an LCL-Filter Using Gain Scheduling Based on Grid Impedance Estimations," Journal of Power Electronics, vol. 11, no. 4, pp. 599-605, 2011. DOI: 10.6113/JPE.2011.11.4.599.

[ACM Style]

Dae-Keun Choi and Kyo-Beum Lee. 2011. Stability Improvement of Distributed Power Generation Systems with an LCL-Filter Using Gain Scheduling Based on Grid Impedance Estimations. Journal of Power Electronics, 11, 4, (2011), 599-605. DOI: 10.6113/JPE.2011.11.4.599.