虚拟磁链定向直接功率控制多并联逆变器控制策略研究

Research on control strategy of multi parallel inverter based on virtual flux-linkage oriented direct power control

针对传统的下垂控制策略瞬时功率估算鲁棒性能较差、抑制逆变电流总谐波效果不理想的缺点,提出一种基于虚拟磁链的定向直接控制策略,建立逆变器并联运行等效电路模型,搭建定频的虚拟磁链直接功率控制拓扑结构电路。最终利用仿真实验平台对并网逆变器的输出电流在两种控制策略下的波形鲁棒性和稳态时的频谱进行对比分析,仿真验证虚拟磁链的定向直接控制策略相对于下垂控制策略系统在调节逆变电流、稳定输出幅值且抑制逆变电流总谐波方面更具有优势。

Considering the traditional droop control strategy of active power and reactive power detection calculation of complex,dynamic response,poor stability and inhibition of the disadvantage of the inverter current total harmonic effect is not ideal,the virtual flux linkage direct power control is proposed in the control strategy of parallel inverters,equivalent circuit model for parallel operation of inverters is established,topological structure of the direct power control of constant frequency virtual flux linkage is built.The waveform robustness and the steady-state spectrum of the output current of the grid connected inverter are analyzed under the two control strategies by simulation experiment platform.The simulation results show that the direct control strategy of virtual flux linkage has more advantage than the droop control strategy system in regulating the inverter current,the stable output amplitude and the suppression of the total harmonics of the inverter current.