Control circuit of reactive power compensating capacitors for pumping unit

The invention relates to a control circuit of reactive power compensating capacitors for a pumping unit, which comprises a vacuum circuit breaker, an AC contactor, a PLC (Programmable Logic Controller) control module, a transformer and three reactors, wherein a three-phase AC enters an input end of a three-phase motor for the pumping unit after passing through the vacuum circuit breaker, three reactive power compensating capacitors are connected with a three-phase AC line through three main normally open contacts of the AC contactor, and any two phases in the three-phase AC line are connected with both ends of a primary coil of the transformer respectively; a normally open output contact of the PLC control module and a coil of the AC contactor are serially connected and then connected to both ends a first secondary coil of the transformer in parallel; an auxiliary contact of the vacuum circuit breaker and an input coil of the PLC control module are serially connected and then connected to both ends of a secon