Research on Harmonic Suppression Strategy of Photovoltaic Grid-connected Inverter Based on Grid Voltage Control
Yingchun Bu, Guangping Lu, Lanhong Zhang and Yunlong Zhou
The solar energy, a green, ecofriendly one, occupies an important position in the current energy structure. The application of photovoltaic power generation systems in today’s society becomes to be wider and wider. Therefore, it is of great significance for us to study the photovoltaic power generation systems, because they vital for the development of social economy. On the basis of the space vector pulse width modulation (SVPWM) technology, the fundamental and the harmonic wave in the inverter are represented in the αβ coordinate system, and the lower control limit (LCL) type three-phase grid-connected inverter is modeled. By comparing the ideal proportional resonant (PR) controller and quasi-PR controller, a finally used controller is determined. The stability of the system is improved by using the power supply feed-forward compensation strategy. Finally, an experiment is carried out to verify the whole strategy. The results show that the proposed strategy can help to avoid the influence of grid voltage harmonics on the grid power quality and omit the three capacitor current detection, saving in this way the manpower and the material resources. Therefore, the harmonic suppression strategy of grid voltage feed-forward and PR regulator has a good prospect in the solar energy harvesting.
Keywords: photovoltaic grid-connected inverter; harmonic suppression; PR controller; grid voltage feed-forward strategy