基于虚拟磁链的APF准谐振控制研究

摘要

The detection method based on traditional instantaneous reactive power theory need rely on the grid voltage phase-locked loop( PLL),but that the network side voltage waveform distortion,frequency fluctuations and other ad-verse conditions will have great impacts on the detection accuracy. An improved control solution is proposed in this paper ,which is based on a virtual flux orientation method to get the phase angle signal as same as the grid voltage fre-quency and phase. A low-pass filter is adopted at the input of cross-compensation link so as to avoid the integrator sat-uration phenomena and to improve the flux observer accuracy. In the rotating coordinate system,there are the cou-pling phenomena between d-axis and q-axis in the three-phase shunt active filter mathematical model. The state feed-back decoupling control and grid voltage feed forward decoupling control method are taken to avoid the grid voltage disturbance effects. Moreover,the use of quasi-resonant controller will compensate the characteristic frequency har-monics. Simulation results verify the effectiveness of the control solution.%传统基于瞬时无功功率理论检测方法需用到锁相环对电网电压进行锁相，在网侧电压波形畸变、频率波动等恶劣电网环境下会影响检测的准确性，提出了一种改进的控制方案。采用基于虚拟磁链的定向方法来得到与电网电压同频同相的相角信号，通过在低通滤波器的输入端设置交叉补偿环节，避免积分器饱和现象出现，提高磁链观测的准确性。在旋转坐标系下，三相并联有源滤波器数学模型的d轴和q轴之间存在耦合，这里采用状态反馈解耦控制和电网电压前馈的方法实现解耦控制，避免了电网电压扰动影响，采用准谐振控制器有针对地对特征次数谐波进行补偿。仿真结果验证了该控制方案的有效性。