Series SEW and DEW single-phase and three-phase high-power full-automatic compensating power voltage stabilizers (Hereinafter called as the voltage stabilizers.)are designed for stabilizing AC current by importing and absorbing the advanced technology from Western Europe，and conforming to the situation in our country simultaneously．When the voltage fluctuation of outside power-supply network or the load charge causes the voltage to be flucuated，it can automatically keep the output voltage stable．Compared with the otherstabilizers．the serial products have the advantages of large capacity，hiah efficiency，no waveform distortion，stable voltage control and so on．Furthermore，the serial stabilizers own the wide service load，the capacity for bearing the momentary overload，long-term continuous operation．the switching for manual and automatic operation，the protection against the overvoltage，overcurrent，phase shortage，phase-sequence and the automatic protection against mechanical failure，small size，light weight，easy installation and operation，reliable operation，etc．So，they are widely used in the equipment of the large electromchanical，the metal proceeing，constructional engineering，embroidery textiles，and production flow-line，electrical lift，medical apparatus and instruments，air-conditioner，broadcast television，household appliances，lighting etc．in the line of industry，agriculture，transportation，post and telecommunications，military affairs，railway，scientific research culture and so on．