| 摘要 |
PURPOSE:To eliminate reverse phase current in a generator by calculating in-phase component and quadrature component of the reverse phase current with respect to a reference voltage and individually controlling two sets of phase lead or phase lag load currents of a parallel phase lead and phase lag circuit based on thus calculated in-phase and quadrature components. CONSTITUTION:A reverse phase current compensator 5 determines a reverse phase current I2 = 1/3(Ia+a<2>Ib+aIc) with phase (a) voltage Va as a reference. Here, a = -1/2+jsq. rt. 2/3, Ia is phase (a) current, Ib is phase (b) current and Ic is phase (c) current. In-phase component I2d and 90 deg. phase lead component I2q of the reverse current with respect to the phase (a) voltage Va are then determined according to following formulas. I2d = I2costheta = P/V, I2q=I2sintheta = -Q/V. IQab = sq. rt. 3I2q-I2d and IQac = sq. rt. 3I2q+I2d are then determined based thereon and a control signal IQab is fed to a reverse phase current compensator for phase a-b whereas a control signal IQac is fed to a compensator for phase a-c. |
