单级式光伏逆变研究与MPPT方法

Research on Single-stage Photovoltaic Inverters and MPPT Method

提出和研究正弦波周期稳幅条件下基于电荷流积均衡(ICF)的零DC-DC变换的并网型逆变机制和方法,旨在减少电能交换环节和次数,以提高电路逆变效率。还提出流积平衡下基于MPP偏置电压Vm的交换比,分析了这种方法的逆变工作过程,得出约束交换比的计算方法。阐述了正弦单周期逆变调制的光伏环境条件,研究由启动和调节环节构成的无DC-DC变换的MPPT逆变方法,分析建立了功率电压法(DPDVM)的MPPT逆变控制策略及MPP转移调节算法流程。电路实验表明,这些方法和算法下逆变电路可取得很高的效率。

A novel mechanism and method for grid-connected inversion, in the stable photovohaic environment of individual sinusoidalperiods, basedonbalanceofICF （Integral Charge Flows） between the solar cell source and inversion load with no DC-DC conversion, is proposed and conducted in this paper for the purpose to raise inversion efficiency and reduce intermediate exchange of power energy and the exchange rate. The concept ofthe exchange ratio over MPP voltage level Vm is introduced, the inversion process of this method is analyzed, and a calculation formula for the constrained exchange ratio is given. The existence of the periodic stable photovohaic condition is demonstrated by the experimental figure. In thispaper, the inverter method with the functional start and regulator of MPPT is studied and the strategy of the MPP-following inverse control and the adjusting algorithm of MPP-to-MPP transfer are set up usingDPDVM （Differential Power plus Differential Voltage Method）. The experimental inverter shows high inversion efficiency can be achieved by applying the se methods and algorithms.