A REAL TIME VOLTAGE CONTROL APPARATUS CAPABLE OF SAG VOLTAGE AND PHASE COMPENSATION AND A REAL TIME VOLTAGE CONTROL METHOD THEREOF

摘要

A real-time voltage control apparatus and a controlling method thereof are provided to offer stable power to a load by simultaneously compensating for voltage and phase delay in a voltage sag of a power system. An input voltage and reference voltage generating unit(1) outputs an input voltage amplitude and phase value(VinSinк) obtained by multiplying an amplitude of input voltage of which a phase is delayed by an arbitrary degree with a sine value of the delayed phase and a reference voltage amplitude and phase value(VrefCosк) obtained by multiplying an amplitude(Vref) of reference voltage with a cosine value of the delayed phase, as a 1 x 1 matrix. A forward transforming unit(2) is connected to an output stage of the input voltage and reference voltage generating unit and outputs two output values(Vp,Vq) by multiplying the 1 x 1 matrix of the input voltage amplitude and phase value and the reference voltage amplitude and phase value with a 2 x 2 forward transformation matrix composed of a sine value and a cosine value of a normal reference phase of commercial AC power. A pair of error operation units(3a,3b) are connected to an output stage of the forward transforming unit to output a difference value between two output values of the forward transforming unit and the reference voltage and a difference value between the two output values and zero. A pair of PI(Proportional-Integral) units(4a,4b) are connected to output stages of the pair of error operation units respectively to perform PI of output values of the pair of error operation units. A backward transforming unit(5) is connected to output stages of the pair of PI units and outputs final output voltage to compensate for both voltage and phase delay by multiplying output values of the pair of PI units with a 2 x 2 backward transformation matrix composed of the sine value and the cosine value of the normal reference phase of the commercial AC power.