Highly Accurate Digital Current Controllers for Single-Phase LCL-Filtered Grid-Connected Inverters
Abstract
:1. Introduction
1.1. Background and Literature Review
1.2. Novelties and Goals
2. Single-Phase LCL-Filtered Grid-Connected Inverter
3. Highly Accurate Digital Current Controllers
3.1. System Modeling in s-Domain
3.2. Tuning the Integral Single-Lead Digital Current Controller
3.3. Tuning the Integral Double-Lead Digital Current Controller
3.4. Tuning the Integral Double-Lead Digital Current Controller Considering the PWM Delay Effect
3.5. Tuning the Digital Proportional-Resonant Controller
- Desired resonant frequency in Hz and rad/s, named and , respectively. This frequency must be the grid frequency because the PR controller acts in the fundamental frequency for proper active power injection of the LCL-filtered grid-connected inverter.
- Damping factor, named . Any value between 0.9 and 1 is a good choice.
- Desired bandwidth of the resonant filter in Hz and rad/s, named And .
- Sampling frequency in Hertz and period in seconds, named and .
4. Case Study
5. Hardware-in-Loop Experimental Verification
6. Discussion
7. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
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Parameter | Value | Unit |
---|---|---|
Grid Voltage | 127 | Vrms |
Grid frequency | 60 | Hz |
Converter-side inductor | 2.28 | mH |
Converter-side resistance | 0.01 | Ω |
Grid-side inductor | 990 | uH |
Grid-side resistance | 0.01 | Ω |
LCL capacitance | 1.64 | uF |
LCL damping resistance | 20.5 | Ω |
DC-link voltage | 220 | V |
Grid resistance | 2 | Ω |
Grid inductance | 3 | mH |
Current sensor gain | 0.1 | V/A |
Switching frequency | 10 | kHz |
Sampling period | 1 × 10−4 | s |
Amplitude of the carrier | 1 | V |
Desired cut-off frequency | 1250 | Hz |
Desired phase margin | 60 |
Coefficient | ||||
---|---|---|---|---|
- | 0 | - | ||
- | - | |||
- | - | - | ||
- | - | - |
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Share and Cite
Curi Busarello, T.D.; Zeb, K.; Simões, M.G. Highly Accurate Digital Current Controllers for Single-Phase LCL-Filtered Grid-Connected Inverters. Electricity 2020, 1, 12-36. https://doi.org/10.3390/electricity1010002
Curi Busarello TD, Zeb K, Simões MG. Highly Accurate Digital Current Controllers for Single-Phase LCL-Filtered Grid-Connected Inverters. Electricity. 2020; 1(1):12-36. https://doi.org/10.3390/electricity1010002
Chicago/Turabian StyleCuri Busarello, Tiago Davi, Kamran Zeb, and Marcelo Godoy Simões. 2020. "Highly Accurate Digital Current Controllers for Single-Phase LCL-Filtered Grid-Connected Inverters" Electricity 1, no. 1: 12-36. https://doi.org/10.3390/electricity1010002