The DWK is a new type of pole-mounting high-voltage var (reactive power) compensators. It consists of current transformers, potential transformers, controller, vacuum contactor and shunt capacitors. The DWK features high level automation, small size, light weight, and easy installation. It is mostly applied to 6kV and 10kV distribution lines, switching capacitors automatically on multiple modes such as voltage, time, voltage/time, voltage/var, and power factor. Integrating static and dynamic compensation and multi-step switching has realized more precise reactive power compensation on HV distribution lines, thus greatly raising the power factors in the system and reducing power loss on distribution transformers and lines. The DWK is a powerful instrument for enhancing power delivery efficiency and improving user power quality. The DWK has been patented for originality, Patent Number: ZL02 2 92526.0. 1ú«Parameters of compensator 1)Compensation capacityú¦50kvar~1000kvar 2)Primary circuit power frequency withstand voltageú¦42kV/min 3)Break power frequency withstand voltageú¦ 42kV/1min 4)Secondary circuit withstand voltageú¦ 2.5kV/min 5)Lightning impulse withstand voltage (peak)ú¦75kV.