The Development Of The Integrated Volt/Var Control Device At The Substations

With the increasing demands for the power supply quality, the voltage becomes an important index that measures the power quality, while in power system, voltage is related with reactive power Therefore, comprehensive control of the voltage and reactive power of the substation has the important meaning for improving power quality.This paper proposes the design of a new type integrated volt/var control device at the substations, which overcomes the flaw of the traditional volt/var control device selecting circuit breaker as switch and adopt switch without contact— thyristor to act. It is greatly significant to expand.This paper expatiated the principle of comprehensive control of voltage and reactive power firstly, presents the testing method based on instantaneous power theory and adopt certain improved measures based on traditional nine-zone and aiming at the flaws in nine-zone .The idea of modularization is applied to the design of thehardware and software in the system, so the system is to be replanted well. The programmer computer controller(PCC) is adopted to the controller, which calculates effective value of voltage and the reactive power by three phase voltage and current collected firstly and act accurately ,combining all kind of constraint conditions, according to the control strategy. In soft design, real-time multitasking dispatch system , using the AB language of PCC to program, improves the real-time propriety and operational efficiency of the instrument effectively. During the course of development, a series of anti-jamming measures are applied to the hardware and software.This device has good performance. It can insure electric voltage qualified and reactive power equilibrium under all kinds of operation methods ,and meet the demand for limiting times regulating taps of the on-load voltage regulation transformer and times of hurl slicing of parallel compensation capacitor bank .