The Intelligent Reactive Power Compensation Based On MCS-51

The reactive power compensation is an important project in the power system. This project designs reactive power automatic controller which casts or cuts off parallel capacitors in order to achieve reactive power compensation, ensuring qualified power factor.The principle of the design is that we judge by both power factor and voltage to cast or cut capacitors. When voltage is in the quality limit, we raise power factor and degrade electric power loss. When voltage is beyond assigned voltage, we cut of capacitors that are working.In hard ware design, AT89S52 is used in the controller, which carries out the function such as sampling and calculating, regulating the reactive power automatically, giving an alarm and protection in case of faults, data saving etc. The cast-cut equipment uses compound switch which composed of contactor and thyristor. A zero triggered circuit is used to restrict the inrush current.The control apparatus can display the condition of voltage, current, power factor and capacitors operation, and have the function of warning and bottoming. Moreover users can set some parameters such as power factor upper limit, lower limit and so on. In this system, we use RS-485 bus standard realizing serial data communications of PC and single-chip computer. The PC can monitor the condition of power factor, voltage and so on.