The Z-source inverter employs a unique impedance network to couple the converter main circuit to the power source, it can provide a shoot-through state of inverter bridges to boost voltage, and make it suitable for a wind PMSG grid-connected system. The operation principle of Z-source converter is analyzed. An Active & Reactive power decoupling method is proposed for a double closed-loop control system, which ensures the stability of voltage of the Z-source network capacitor. In order to enhance the low voltage ride-through(LVRT) capability, a combined protection and control strategy including Pulse Block, Battery Energy Storage System, Reverse Power Tracking are proposed. Simulation results demonstrate rapid response of the double closed-loop decoupling method, the effectiveness of the combined protection and control strategy.
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