Parallel voltage sag compensation device

A parallel voltage sag compensation device is disclosed. The device comprises: a three-phase reactor, a three-phase back-to-back converter, a filter and the filter. One end of the three-phase reactor is connected into a three-phase network and the other end is connected to a three-phase load. D terminals of three inductors in the filter are connected to the three-phase load. Upper ends of three capacitors are connected to the D terminals of the three inductors respectively, lower ends are connected with each other and then are grounded. A terminals of the three inductors in the filter are connected to the three-phase network. The upper ends of the three capacitors are connected to the A terminals of the three inductors respectively, the lower ends are connected with each other and then are grounded. The three-phase back-to-back converter is formed by a rectifier, a voltage stabilization capacitor and an inverter. The device has the following advantages that: a dynamic voltage recovery and reactive compensation function and a harmonic wave treatment function are organically combined; dynamic voltage recovery can be rapidly realized when the system generates voltage sag; the reactive compensation and harmonic wave inhibition can be performed to the load when the system operates normally; reliability is good, efficiency is high and various functions are possessed. In the parallel voltage sag compensation device, the three-phase reactor can increase line impedance but can not cause obvious reduction of the voltage of a load side.