In this paper

the issue of resonance and suppression method possibly caused by reactive power compensation capacitor in dynamic voltage restorer（DVR）system is studied. It is shown by the result that when compensation capacitor is at the grid side

grid voltage distortion is caused by the resonance between capacitor and equivalent inductance of grid and

at this time

DVR can operate stably but the harmonic compensation result is decreased. While compensation capacitor is at the load side

the resonance between capacitor and the DVR filtering inductance will likely lead to the system unstable due to insufficient damp. By introducing compensation capacitors into the control loop

the system damp is increased by way of reducing the feed forward coefficient of load current to assure system stability. The correctness of above analysis is verified by the simulation result.