多并网逆变器系统谐振抑制策略

Research on resonance suppression strategy of system with multiple grid-connected inverters

多并网逆变器之间的交互影响会引发谐振,威胁系统的安全稳定运行。为了解决谐振问题,建立了多并网逆变器阻抗网络,分析了谐振抑制机理,基于导纳重构原理,提出了一种基于虚拟导纳的全局谐振抑制策略。该策略利用公共连接点处谐波电压产生和谐振频率相关的虚拟导纳,动态调整网络阻抗,抑制系统的谐振。以两个并网逆变器系统为例,理论分析了谐振抑制效果,仿真和实验验证了所提全局谐振抑制策略的可行性和有效性。

The interactions between multiple grid-connected inverters can cause resonance and threaten the security and stability of the system.To address the problem of the resonance,the impedance network is built and the resonance suppression mechanism is analyzed,then a global resonance suppression strategy is proposed based on the principle of admittance reconstruction.The strategy is to dynamically reshape the impedance network using the virtual impedance generated by the public connection point harmonic voltage,such that the potential oscillations and resonance propagation in the parallel grid-connected converters can be mitigated.To validate the effectiveness of the active damper,simulations and experimental tests on a two converter-based setup are carried out.Simulation and experimental results are provided to verify the feasibility and validity of the proposed strategy.