The utility model discloses a photovoltaic grid -connected inverter, by MPPT, a controller, the PV array, the wave filter, the electric wire netting, voltage current detection module and topology circuit structure constitute, the PV array passes through electric capacity and is connected with topology circuit structure, the signal input part that the signal output part of PV array passes through MPPT and controller is connected, the output and the topology circuit structure of controller constitute, topology circuit structure is connected with the wave filter, the wave filter passes through the electric wire netting and is connected with voltage/current detecting circuit's input, voltage current detection's output is connected with the signal input part of controller. Compared with the prior art, the utility model discloses on photovoltaic grid -connected inverter's control strategy's the basis, plan adopting a novel phaselock technique and non -linear control strategy to improve photovoltaic grid -connected inverter's performance under in -depth study photovoltaic grid -connected inverter's mathematic model and asymmetric electric wire netting, on reasonable reactive compensation basis, perfect its low voltage ride through's ability.