Research on a new method to achieve low voltage ride through of PV

Abstract

To solve the conflict between limiting the current of a grid-connected photovoltaic inverter and increasing the output reactive current during voltage drop, a low voltage ride through (LVRT) method based on improved Maximum Power Point Tracking (MPPT) control is proposed. When voltage sag occurs, an improved MPPT control based on perturbation and observation (P&O) method is adopted, adjust the operating point of the photovoltaic array to reduce the generated power, prevent the inverter from overcurrent and increase the reactive power output. Both detailed analysis and simulation results show that the method can effectively limit the output current of the inverter, achieve a reasonable allocation of active and reactive power. Consequently, the power shortage and reactive-power support issues are effectively improved.