单相并网逆变器功率控制的实现

针对利用LCL滤波器的并网逆变器,当其采用加权电流控制时,在小电流情况下存在幅值误差和相位误差,并且由于引进了电网电压前馈,其电流控制易受电网电压影响.为此,提出了一种采用有功/无功电流控制的策略,以提高逆变器注入电网的电流幅值精度和功率因数,并免受电网电压等因素的影响.给出了该控制策略的理论依据和实现方法,并通过对5 kVA燃料电池逆变并网发电电源的试验,验证了该控制策略的正确性和可行性.

Power Control of Single Phase Grid-connected Inverter

For the LCL filter adoptrd grid-connected inverter,when using weighted-average-current control method, there are the magnitude error and phase error at light load.And the forward feedback from the grid voltage makes the current under the influence of grid voltage,This paper proposes a new current control strategy using weighted-averagecurrent as inner-loop and active/reactive current as out-loop.This method can control the grid current to have high magnitude and phase precision,also it will not be influenced by grid voltage,This paper presents the theoretical analysis and how to realize it.This control method has been experimentally tested on a 5kW grid-connected fuel cell inverter.