光伏并网发电系统的MPPT-电压控制策略仿真

Simulation of photovoltaic grid-connected generation system with maximum power point tracking and voltage control strategy

在配电网络的末端,负载的无功波动将会对电网供电电压产生较大的影响,对光伏发电系统并网处系统侧的交流电压进行控制,可以提高系统的电压水平。根据光伏并网系统的结构,采用外环为电压环、内环为并网电流环的双环控制。通过abc/dq0变换将并网电流解耦为有功分量和无功分量,引入最大功率点跟踪(maximum power point tracking,MPPT)提供的直流侧电压参考量的闭环控制调节并网电流的有功分量,引入交流侧电压参考量的闭环控制调节并网电流的无功分量,实现了具有MPPT和电压控制能力的三相光伏并网发电技术。仿真结果表明MPPT-电压控制策略既能够实现光伏并网的最大功率点跟踪,也能够控制光伏发电系统接入点的交流电压,进一步提升了光伏并网发电系统的应用前景。

The fluctuating of the reactive load could largely affect the terminal voltage in distribution systems.By controlling the AC voltage of grid-connected bus in photovoltaic generation system,it could improve the voltage level of distribution systems.Based on the structure of the photovoltaic grid-connected system,it established the dual-loop feedback control strategy.The voltage loop was considered as the external loop,and the grid-connected current loop as the internal loop.The grid-connected current was decoupled into active current and reactive current via the abc/dqo coordinates transformation.The DC voltage reference from the maximum power point tracking（MPPT）used to adjust the active current,and the AC voltage reference from the system voltage used to dominate the reactive current.In this way,it achieved the MPPT and voltage control technology of the three phase photovoltaic grid-connected generation.The simulation results show that the MPPT and voltage control strategy can not only implement the maximum power point tracking but also control the AC voltage of grid-connected bus.It can further upgrade the application future of photovoltaic grid-connected generation system.