To improve the performances of grid-connected inverter under the non-ideal microgrid conditions requires a higher detection method of the positive-negative sequences and harmonic components. We proposed a novel detection method of positive-negative sequence and harmonic components based on the one-order vector proportional-integral resonant controller（OVPR）. The detection structure with multiple subsystem are proposed based on the different frequency OVPR. The mathematical model is set up to reveal the mechanism of the presented detection method and determine the feedback parameter. The presented method can eliminate the effects of harmonics and imbalance and extract the positive-negative sequences and harmonic components from the polluted grid voltage directly

without symmetrical components decomposition. The theoretical and simulation results have verified the validity of the presented detection method.