The SVC dynamic reactive power compensation system is refers to the 6~35KV voltage rank the crystal thyratron to throw cuts the capacitor the idle work compensation system, based on does not have the electronic contact switch to throw cuts the capacitor the electrical power distribution system canceller, its main characteristic is compensates the change load the idle work demand, moreover does not have the mechanical movement to be partial, may frequently throw according to the need cuts, cannot pour into the overtone to the system. Each by certain parallel condenser banks constitution, but each condenser bank throws by two groups of polar opposite parallel crystals thyratron cuts. According to all asks the reactive power decision condenser bank rated capacity which compensates. Also is the crystal thyratron which uses may fast pass breaks replaces in the former reactive power self-compensating system the mechanical contact device, slowly overcame threw cuts when the electric capacity the speed of response, has been easy to damage, the reliable low status shortcomingThe condenser bank designs according to the filter time, Is suitable in having the harmony wave source the place to make the overtone absorption installment, Also has absorbed the higher harmonic, Also carried on dynamically to the reactive power has compensated.