Studies On The New Complex Switch And Dynamic Reactive Power Compensation System

Due to increasing loads of electric power system, demand on reactive power was also increasing. Because transmission of reactive power in electric network can lead to network loss and step-down voltage, transmission of a great deal of reactive power necessarily resulted in reduction of using efficiency of power energy and severely effected voltage quality. It became necessary means that reactive power compensation devices were installed in proper position of electric network.Aiming at the disadvantages in the application of reactive power compensation device with electromagnetic or power electronic switches for pulling in or out the capacitor, a reactive power compensation device based on the complex switch, which can realize grading and fast compensation for each phase using both collective compensation and separate compensation, is developed to switch capacitor. Interior single-chip and zero-cross detection & triggering circuit of it insure that thyristor is triggered in the zero-voltage condition, then relay is shorted, relay is switched off when outer control signal is disappeared, and after a while so does thyristor in the zero-current, thus greatly reduced surge current. This sort of switch circuit achieved switching of capacitors without transition course and was simple and reliable.The thesis also analyzed the hardware and software of controller about complex switch and compensation device in detail. ATmega8 was a sort of cheap Single Chip computer and was applied to control system. The test shows that this device can fleetly and truly compensate reactive power and be used in low network.