单相光伏并网控制的研究

Research on a Single-phase Photovoltaic Grid-connected Control

以DSP为控制平台设计单相光伏并网系统,在改进型单纯型加速法的基础上设计新型光伏阵列最大跟踪控制优化算法,跟踪光伏阵列最大输出功率点,使负载获得最大功率。在线调节步长改变电压收敛速度,设计锁相控制电路,自动同步跟踪电网频率和相位。测试数据表明,结合优化技术的变步长MPPT(Maximum Power Point Tracking)算法能快速准确跟踪最大功率点,系统波动小稳定性高,逆变器电流和电网电压同频同相,有效提高系统逆变效率及可靠性。

A single-phase photovohaic system in the platform of DSP is introduced in this paper. A new way is applied to trace the maximum power point based on the improved accelerating simplex method. The online variable step can also regulate the voltage convergence rate, and the phase-locked control circuit is designed to synchronously trace frequency and phase of power grid automatically. Test data show that the variable step MPPT （ Maximum Power Point Tracking） algorithms combined with the optimization technology can quickly and accurately track the maximum power point. So the smaller fluctuations and the higher stability can be achieved. Furthermore, the inverter current and the power voltage feed back to the power grid with the same frequency and the same phase can effectively improve the efficiency and reliability of inverter system.