By means of the change of control strategy, successfully achieve the low voltage ride through of PV inverter under the grid fault. The direct power control strategy and double closed-loop vector control based on positive sequence, negative sequence current are respectively proposed under the balance fault and unbalance fault. When the voltage of grid is balanced, adopt the method of limiting active power to change the input power order,
thus reduces the output active power of PV and realize LVRT successfully. When the unbalanced fault happens, carry out positive and negative sequence separation, positive and negative sequence current double-loop vector control are controlled. The simulation results show that the reasonable and effectiveness of the control strategy.