光伏并网电流与电网电压同频同相的技术实现

摘要

通过性能稳定的DSP控制器程序设计及外围硬件检测电路、采样电路的配合来实现在光伏并网发电中对并网电流与电网电压的频率和相位控制,达到两者同频同相.阐述了锁相环技术原理及软件实现锁相的基本模型;分别介绍了软件实现锁相所需的三部分硬件电路即电网电压采样电路、电网电压过零检测电路、DSP内部功能单元;采用DSP作为控制芯片,进行内部功能设置;完成锁相环的软件设计,通过连续调整可实现并网电流与电网电压周期趋近相同来实现输出电流与电网电压同频同相控制,从而实现了逆变器输出电流是单位功率因数.%Through programming of the stable DS P controller and combination of the peripheral devices such as hardware detection circuit and sampling circuit, the frequency and phase control of the photovoltaic (pv) grid current and grid voltage are implemented to make the same frequency and phase. This paper introduces the principle of PLL and the basic model of software phase lock;It respectively introduces the software implementation phase locking the three parts of hardware circuit, i.e. power grid voltage sampling circuit, grid voltage zero crossing detection circuit and DSP internal functional units;It uses DSP as control chip to set the internal function, and uses the software of SPLL design, through the continuous adjustment of grid current for approaching the grid voltage cycle to the same output current frequency, to control the current and the voltage in the same frequency and phase and make the inverter output current with the unit power factor.