| 摘要 |
PURPOSE:To reduce the estimation error of the load reactive power caused by the waveform distortions and to obtain a controller having high accuracy of estimation, by comparing the function related to the continuous integration value of the load current with the function related to the control phase angle of a thyristor and producing the ignition signal for ignition of the thyristor. CONSTITUTION:A sample and hold circuit 11 samples the value of Esinpsi at a time point iL=0 and this sampled value is multiplied by the continuous integration value 2<-1/2>integral iLdtheta of iL delivered from an integrator 12 through a multiplier 13a. Thus EsinpsiX2<-1/2>integral iLdtheta (signal c) is obtained. While a voltage setter 16 which sets the non- variation component QLO of QL multiplies the value of the signal (c) by the output of a function generator 17 which produces the function of (1-costheta) from iL=0 through a multiplier 13b. Thus QLOX(1-costheta), i.e., a signal (i) is obtained. Then the signal (i) is subtracted from the signal (c) by a subtractor 19 and the sensitivity of compensation is amplifier by KF times by a compensation sensitivity controller 20. Thus a signal (j) is obtained. While the output of a function generator 18 which produces the function of f(B) at a time point min is multiplied by the output of the generator 17 which produces (1-costheta) through a multiplier 13c. Thus a signal (l) is obtained. Then the signal (j) is compared with the signal (l) by a comparator 21. |
