| 摘要 |
PURPOSE:To compensate the strain of output voltage by a simple constitution by generating a PWM signal in response to the quantity of a deviation between output voltage and reference voltage and a higher harmonic component in output voltage. CONSTITUTION:An output from a DC voltage source 1 is fed to a load 4 through a semiconductor switching device 2 and an AC filter 3. Output voltage is detected through a transformer 5, rectified by a rectifying circuit 6, applied to a comparator 8 and compared with output voltage from a reference DC voltage source 7. An output from the comparator 8 is transmitted over a multiplier 10 through an amplifier 9 for controlling voltage, multiplied by a reference sine wave signal from a sine wave generating circuit 11, added to a phase- inverted signal in a higher harmonic component in output voltage by an adder 22, and given to a PWM signal generating circuit 13. Switching elements S1-S4 for the semiconductor switching device 2 are ON-OFF controlled by an output from the PWM generating circuit 13. |
