Research on Large-Signal Stability of DC Microgrid Based on Droop Control
Abstract
:1. Introduction
2. DC Microgrid Structure and Large Signal Model
3. Application of Mixed Potential Function Method in the DC Microgrid
3.1. Mixed Potential Function Theory
- Calculate the potential function of all non-energy storage components in the circuit;
- Calculate the energy contained in the capacitive component of the circuit, that is, the product of the capacitor voltage and the capacitor current;
- Add the above two to obtain the mixed potential function of the circuit.
3.2. Large Signal Stability Criterion of the System
4. Nonlinear Droop Control Strategy
4.1. Design of Nonlinear Droop Curve
- The starting point of the droop curve should be set at the initial voltage point of the unloaded state.
- The abscissa of the end point of the droop curve is the maximum current value allowed to flow through the inverter, and the ordinate is the lowest allowable voltage value of the bus.
4.2. Large Signal Stability Analysis with Nonlinear Droop Control
5. Simulation
5.1. Verification of Large Signal Stability Criteria with Conventional Droop Control
5.2. Validity Verification of Nonlinear Droop Control Strategy
6. Conclusions
Author Contributions
Conflicts of Interest
Appendix A
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Parameters | Value |
---|---|
Inductance of converter1 (Lt1) | 0.1 mH |
Inductance of converter2 (Lt2) | 0.15 mH |
Capacitance of converter1 (C1) | 1000 μF |
Capacitance of converter2 (C2) | 2000 μF |
Line inductance of micro-source1 (Ll1) | 70 μH |
Line inductance of micro-source1 (Ll2) | 40 μH |
Droop coefficient of micro-source1 (Rd1) | 0.8 |
Droop coefficient of micro-source1 (Rd2) | 0.6 |
Proportional coefficient of voltage loop (Kvp) | 0.1 |
Integral coefficient of voltage loop (Kvi) | 80 |
Proportional coefficient of current loop (Kip) | 20 |
Integral coefficient of current loop (Kii) | 100 |
Switching frequency | 20 kHz |
Output voltage of load | 200 V |
Sequence Number | Kvp | Rd1 | Rd2 | Calculation Result |
---|---|---|---|---|
1 | 0.05 | 0.8 | 0.6 | Unstable |
2 | 0.15 | 0.8 | 0.6 | Stable |
3 | 0.15 | 2.8 | 2.1 | Unstable |
4 | 0.15 | 0.4 | 0.3 | Stable |
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Liang, H.; Huang, Y.; Sun, H.; Liu, Z. Research on Large-Signal Stability of DC Microgrid Based on Droop Control. Energies 2019, 12, 3186. https://doi.org/10.3390/en12163186
Liang H, Huang Y, Sun H, Liu Z. Research on Large-Signal Stability of DC Microgrid Based on Droop Control. Energies. 2019; 12(16):3186. https://doi.org/10.3390/en12163186
Chicago/Turabian StyleLiang, Haifeng, Yuxi Huang, Hao Sun, and Zhiqian Liu. 2019. "Research on Large-Signal Stability of DC Microgrid Based on Droop Control" Energies 12, no. 16: 3186. https://doi.org/10.3390/en12163186
APA StyleLiang, H., Huang, Y., Sun, H., & Liu, Z. (2019). Research on Large-Signal Stability of DC Microgrid Based on Droop Control. Energies, 12(16), 3186. https://doi.org/10.3390/en12163186