Conference paper
Grid-connected Photovoltaic Micro-inverter with New Hybrid Control LLC Resonant Converter
A high-efficiency photovoltaic (PV) micro-inverter consisting of two power stages i.e. a LLC resonant converter with a new hybrid control scheme and a dc-ac inverter is proposed, studied and designed in this paper. In the first power stage, the new hybrid control combining pulse-frequency modulation (PFM) and phase-shift pulse-width modulation (PS-PWM) is employed on a full-bridge LLC dc-dc converter, in order to achieve high efficiency when PV output voltage varies in a wide range.
Moreover, a maximum power point tracking (MPPT) method based on power perturbation is implemented in the dc-ac inverter. Therefore, the complexity of regulating LLC converter can be reduced effectively, and efficiency optimal design can be carried out through the proposed designing procedure for the resonant tank of LLC converter.
Finally, a prototype of the proposed PV micro-inverter (PVMI) is developed with rated power of 250W and output voltage of 220VAC/50Hz. The experiment shows that the peak efficiency of the PVMI is 95.5%, where efficiency of LLC converter is up to 97.7%, and the MPPT accuracy is more than 99%. Thus the validity of the proposed system structure, design and control method is verified.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2016 |
| Pages: | 2319-2324 |
| Proceedings: | 42nd Annual Conference of the IEEE Industrial Electronics Society |
| ISBN: | 1509034749 , 1509034757 , 9781509034741 and 9781509034758 |
| Types: | Conference paper |
| DOI: | 10.1109/IECON.2016.7793632 |
| ORCIDs: | Zhang, Zhe and Andersen, Michael A. E. |
LLC resonant converter MPPT PFM Phase-shift PWM Photovoltaic micro-inverter SDG 7 - Affordable and Clean Energy
Control systems DC-AC inverter Inverters LC circuits MPPT method Magnetic resonance Maximum power point trackers PS-PWM PV output voltage PVMI PWM invertors Switching frequency Voltage control bridge circuits frequency 50 Hz full-bridge LLC DC-DC converter hybrid control LLC resonant converter maximum power point trackers maximum power point tracking perturbation techniques phase shifters phase-shift PWM phase-shift pulse-width modulation photovoltaic microinverter photovoltaic power systems power 250 W power perturbation pulse frequency modulation pulse-frequency modulation resonant tank voltage 220 V voltage control
