基于改进型锁相环的单相并网逆变器

单相并网逆变器广泛地应用在新能源发电领域,它的一个关键技术就是对电网电压的锁相。分析了基于Park变换的锁相环原理,并进行了改进。针对并网逆变器采用的LCL滤波器,采用了基于电容电流前馈的有源阻尼控制方案,推导了LCL滤波器的模型,在此基础上加入电容电流前馈,推导出加入前馈后的数学模型,给出了不同前馈系数的bode图,分析出不同前馈系数的变化趋势。通过单相并网逆变器的仿真实验,验证了改进型锁相环和有源阻尼控制的正确性。搭建了硬件平台,进行了并网硬件实验,验证了以上理论的正确性和可行性。

Single-phase grid-connected inverter based on improved phase-locked-loop

Single-phase grid-connected inverter is widely used in the field of new energy power generation , one of its key technologies is phase locked loop of the power grid voltage .The principle of the phase-locked loop based on Park transform was analyzed , and some improvements were made on the basis of this method .For the LCL filter used in the grid-connected inverter , the active damping control scheme based on capacitive current feed-forward was adopted .First the LCL filter model was deduced , on the base of this model the capacitor current feed-forward was added .On the basis of this model the bode diagram was built at different feed-forward coefficient and the change trend at different feed-forward coefficient was analyzed .Then the simulation experiment of single phase grid-connected inverter was made and the hardware platform of it was set up , which verified the correctness of the im-proved phase-locked loop and the active damping control .