Abstract
Parallel operation of distributed generation is an important topic for microgrids, which can provide a highly reliable
electric supply service and good power quality to end customers when the utility is unavailable. However, there is a well-known
limitation: the power sharing accuracy between distributed generators in a parallel operation. Frequency and voltage droop is a
well-established control method for improving power sharing performance. In this method, the active and reactive power calculations
are used to adjust the frequency and amplitude of the output voltage. This paper describes the digital implementation of a
droop method, and analyzes the influence of power calculation on droop method performance. According to the analysis, the
performance of droop control in a digital control system is limited by the accuracy and speed of the power calculation method. We
propose an improved power calculation method based on p-q theory to improve the performance of the droop control method, and
we compare our new method with two traditional power calculation methods. Finally, simulation results and experimental results
from a three single-phase 1-kW-inverter system are presented, which validate the performance of our proposed method.
electric supply service and good power quality to end customers when the utility is unavailable. However, there is a well-known
limitation: the power sharing accuracy between distributed generators in a parallel operation. Frequency and voltage droop is a
well-established control method for improving power sharing performance. In this method, the active and reactive power calculations
are used to adjust the frequency and amplitude of the output voltage. This paper describes the digital implementation of a
droop method, and analyzes the influence of power calculation on droop method performance. According to the analysis, the
performance of droop control in a digital control system is limited by the accuracy and speed of the power calculation method. We
propose an improved power calculation method based on p-q theory to improve the performance of the droop control method, and
we compare our new method with two traditional power calculation methods. Finally, simulation results and experimental results
from a three single-phase 1-kW-inverter system are presented, which validate the performance of our proposed method.
| Original language | English |
|---|---|
| Journal | Zhejiang University. Journal. Science C: Computers & Electronics |
| Volume | 14 |
| Issue number | 1 |
| Pages (from-to) | 50-64 |
| Number of pages | 15 |
| ISSN | 1869-1951 |
| DOIs | |
| Publication status | Published - 2013 |
Keywords
- Distributed generators
- Distributed energy storages
- Microgrid
- Wireless parallel
- Droop control
- Digital control system
- p-q theory