In this paper

the causes of reactive power and its reduction method are firstly introduced.Then the low voltage intelligent reactive power compensation controller with ATmega64 single chip microcomputer（SCM） as core is achieved.Since the circuit used in the design is simple and reliable

and hardware zero trigger circuit is creatively used to trig synchronous sampling of voltage and current

so as to overcome such shortcomings of previous reactive power compensation controller as complicated detection calculation algorithm and weak anti-interference ability etc.Finally

the result of the controller is verified through experiment.The controller

at less variation of power grid frequency

can accurately control the switching of capacitor bank and reach preset power factor.