为提高基于 Boost 电路的两级式光伏逆变器的低电压穿越( LVＲT) 能力，设计了 以基于 Boost 的直流母线电压控制环为核心的兼顾有功、无功电流协调控制的 LVＲT 策 略． 首先分析了两级式光伏逆变器的常规 Boost 电压控制模式和输出电流控制策略; 在电 网电压跌落时，通过引入基于故障前光伏阵列最大功率点电压前馈的母线电压控制外环 改变 Boost 电压控制模式来快速调节光伏阵列的输出功率，以稳定直流母线电压和防止 逆变器过流;同时，根据电压跌落深度，按比例减小有功电流 id，在保证逆变器不过流的前 提下输出无功电流 iq，为电网提供无功支撑，以帮助电网故障恢复． 最后，利用 PSCAD/ EMTDC 仿真软件搭建 100 kW 两级式光伏逆变器模型进行控制策略验证，结果表明该策 略不仅在电压发生深度跌落时仍能快速、有效地抑制直流母线电压升高，使光伏逆变器安 全地实现低电压穿越，而且提高了其在电网故障期间的无功支撑能力． 

In order to enhance the low-voltage ride capability of the twostage grid-connected system PV inverter based on Boost circuit，a control strategy with the DC bus voltage control loop based on Boost for LVＲT is designed in this paper． Firstly， the conventional Boost voltage control mode and output current control strategy of the twostage PV inverter are analyzed． A DC bus voltage control outer loop based on PV array maximum power point voltage feed forward is introduced to change the Boost voltage control mode． In this way，the purposes of making the DC bus voltage stable and preventing over current of the inverter are to be achieved． At the same time，the reference value of the active current is adjusted according to the voltage drop depth． On the premise that the inverter is not over current， the maximum reactive current is provided to help the power grid recovery． Finally，a 100kW PV inverter PSCAD simulation model is built to verify the proposed control strategy． The result shows that the method not only can suppress the DC bus voltage rise rapidly and effectively，but also can make the inverter provide more dynamic reactive power support for the grid even when the voltage drops．