Due to the insufficient current withstanding capacity, the grid-connection converter of the new energy unit is easy to cause large-scale off grid in case of grid failure, which will lower the low voltage ride-through (LVRT) capability of the new energy system and endanger the stable operation of the power system. A motor-generator pair (MGP) system is proposed to improve the LVRT capability of the new energy generation system. Firstly, the mathematical model and control method of the MGP system are given. Then the fault isolation mechanism is analyzed from the mechanical motion equation, and the regulation mechanism of the DC voltage feedback control in the process of voltage drop is illustrated in detail. Taking the photovoltaic (PV) generation system as an example, the simulation model is built to verify the LVRT capability and reactive power support by adopting the MGP system. Finally, experimental validation on the LVRT effect is performed, and the results show that the MGP system can effectively improve the LVRT capability of PV inverter with DC voltage feedback control.