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Single-Cycle-Lag Compensator-Based Active Damping for Digitally Controlled LCL/LLCL-Type Grid-Connected Inverters
- Source :
- IEEE Transactions on Industrial Electronics. 67:1980-1990
- Publication Year :
- 2020
- Publisher :
- Institute of Electrical and Electronics Engineers (IEEE), 2020.
-
Abstract
- The control delay weakens the active damping (AD) performance of digitally controlled LCL/LLCL -type grid-connected inverters (GCIs). The equivalent virtual impedance paralleled with the filter branch explains the effect of the capacitor-current-feedback AD. However, the virtual impedance appears capacitive or even negative due to the delay, which significantly weakens the effectiveness of AD. This paper proposes a single-cycle-lag compensator (SCLC) to eliminate the adverse effects caused by the control delay. The method retains effectiveness in applications with high resonant frequency or large control delay. It keeps system a positive equivalent resistance with a high equivalent inductance. The positive equivalent resistance leads to positive damping effect, while the high equivalent inductance causing little resonant frequency deviation can be neglected. Moreover, the effect of the impedance variation that causes the resonant frequency deviation is analyzed and the restrictions of the proposed method are discussed. By optimizing the LCL/LLCL filter parameters, the adaptability of the SCLC to the grid impedance variation can be further improved. With the SCLC, the LCL/LLCL -type GCIs achieve better steady-state and dynamic performances. Finally, experimental results are presented to verify the proposed method.
- Subjects :
- Physics
Equivalent series resistance
020208 electrical & electronic engineering
Equivalent series inductance
02 engineering and technology
Filter (signal processing)
Frequency deviation
Inductance
Control and Systems Engineering
Control theory
0202 electrical engineering, electronic engineering, information engineering
Electrical and Electronic Engineering
Lead–lag compensator
Electrical impedance
Pulse-width modulation
Subjects
Details
- ISSN :
- 15579948 and 02780046
- Volume :
- 67
- Database :
- OpenAIRE
- Journal :
- IEEE Transactions on Industrial Electronics
- Accession number :
- edsair.doi...........db45cdeb8bffc78881ea4fc6dfe23763
- Full Text :
- https://doi.org/10.1109/tie.2019.2903759