| 摘要 |
PURPOSE:To make it possible to control the reactive power at a high speed, by multiplying the voltage of 90 deg. lag and the load current, producing the reactive power component containing the second high harmonic little, and compensating this reactive power by means of electrification control of the reactor. CONSTITUTION:The secondary side of the voltage transformer PT connected to the electric power source is connected to the multiplier X1 through the 90 deg. phase shifter PS, its output is connected to the adder A1 through the delay circuit TC which gives delay of a time equivalent to 1/4 cycle, and therefore an output equivalent to two times of the reactive power DELTAq appears in the output terminal of the adder A1 by putting the system voltage V of the 90 deg. lag waveform, and the load current I into the multiplier X1, and taking the product of both of them. The reactive current related to the reactive power is smoothed by the low pass filter LPF2. When the reactive and active current components Iqav, Ipav are subtracted from in the load current I, the reactive power value DELTAq to be generated can be produced in accordance with a sudden variation. The reactive power is controlled by inputting this reactive power value DELTAq to the control pulse generator PG and controlling the thyristor Th. |
