三相并网逆变器直接功率控制

Direct power control for three-phase grid-connected inverters

根据三相并网逆变器的动态数学模型,详细推导和分析了各电压矢量对有功功率变化和无功功率变化的影响。根据有功功率变化的符号与无功功率变化的符号选择最佳的电压矢量,使三相并网逆变器输出的有功功率和无功功率脉动比较小。在此基础上,提出了一种基于新开关表的直接功率控制。该控制策略可实现有功功率、无功功率的解耦控制以及功率因数任意可调。采用直接功率控制的三相并网逆变器具有较好的静、动态性能。通过仿真和实验验证了该方案的可行性和正确性。

According to the dynamic mathematical model of three-phase grid-connected inverters,the influence of voltage vectors on active power change and reactive power change is analyzed. To reduce the ripples of active power and reactive power ,the best voltage vector is selected according to the signs of active power change and reactive power change,based on which,a direct power control is proposed. It realizes the decoupling control of active power and reactive power,as well as the adjustable power factor. The three-phase grid-connected inverter with direct power control has better static and dynamic performances. Its feasibility and correctness are verified by simulation and experiment.