Z源光伏并网直接电流单周控制系统

为构建高效且结构简单的光伏并网系统，将单周控制这一非线性控制方法用于电流内环，快速跟踪电流的同时，开关频率得以保持不变，改善了传统并网逆变系统三环控制性能。阻抗源（Z源）变换器将光伏电池板电压提升以满足并网电压条件，并实现最大功率跟踪。给出了综合以上两者的系统结构和单周控制模型，通过对电流跟踪过程的理论分析，结合MATLAB/Simulink仿真结果表明并网电流能很好地跟踪指令电流与电网电压同步。该方案通过了小功率实验验证。

A Direct Current One-cycle Control Method for Z-source Grid-connected Photovoltaic System

To build an efficient grid-connected photovoltaic system with simple structure, one-cycle control, a non-linear control method, is applied to the inner loop current control. The conventional three-loop control performance is improved by keeping the switching frequency constant while maintaining an optimal current-tracking effect. Z-source converter boosts the photovoltaic panel voltage to meet the grid-connecting requirement, also achieve the maximum power point tracking. A system topology and one-cycle control model is proposed. Theoretical analysis and simulation results using Matlab/Simulink reveal that the output current of the inverter synchronizes with the grid voltage effectively. Small power experiments verify the proposed method.