Abstract
In DC microgrids, constant power loads (CPLs) reduce the effective damping of the DC-DC converter and may induce destabilizing effects into the DC-DC converter. To overcome such problems regarding CPL and ensure large-signal stability of DC-DC converters in DC microgrids, some feedforward terms are added to V-I droop-based dual-loop controller for a DC-DC converter based on the large-signal model. It is proven that the feedforward terms can not only improve the transient response but also guarantee the exponential stability of the closed-loop system in the whole operating range in regards to a large-signal manner, which is verified by using a singular perturbation model. Moreover, a disturbance observer is designed to estimate the output current, thereby enabling the removal of the current measurement sensor. The proposed technique can be easily plugged into a pre-defined V-I droop-based dual-loop controller without an additional sensor being required. Ultimately, both simulation and experimental tests verify the effectiveness of the proposed method.
Original language | English |
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Article number | 9347789 |
Journal | I E E E Transactions on Energy Conversion |
Volume | 36 |
Issue number | 3 |
Pages (from-to) | 2534-2544 |
Number of pages | 11 |
ISSN | 0885-8969 |
DOIs | |
Publication status | Published - Feb 2021 |
Keywords
- DC microgrid
- DC-DC converter
- DC-DC power converters
- Damping
- Load modeling
- Microgrids
- PI control
- Stability analysis
- Voltage control
- constant power load
- disturbance observer
- exponentially stable