US 5,349,283 A · Automatic voltage control circuit by using reactive power

Abstract

An automatic voltage control circuit by using reactive power is disclosed. The circuit comprises a proportional integrator, a triangular wave generator, a comparing circuit having first and second comparators, an inventer, and a reactive power control circuit, wherein the proportional integrator proportionally integrates the differences between output voltages and a reference voltage, the triangular wave generator outputs first and second triangular waves with a difference of phase angle 90.degree., the comparing circuit compares the output from the proportional integrator with the first and second triangular waves, the inverter controls the effective power by the output from the first comparator, and the reactive power control circuit controls the reactive power due to the variations of the load in response to the output from the second comparator, so that the output voltage can be maintained stably regardless of the variations of the load.

Claims10

Dependent claims

An automatic voltage control circuit by using reactive power including inverter output adjusting means having a low-pass filter for filtering output voltage of said inverter to supply to a load, said automatic voltage control circuit comprising:

proportional integrator means for proportionally integrating difference between an output voltage and a reference voltage;
triangular wave generator means for generating a first triangular wave and a second triangular wave with a difference of a phase angle 90.degree. ;
comparing means having a first comparator and a second comparator for comparing an output from said proportional integrator means with said first and second triangular waves;
inverter means for controlling effective power according to an output from said second first comparator;
and
reactive power control means connected to said comparing means for controlling reactive power due to variations of said load according to an output from said comparator.

3 more elements

The automatic AC output voltage control circuit comprising:

an impulse commutating-type thyristor inverter for converting a supplied DC voltage into an AC output voltage;
a reactive power control means comprising polarity detector means for providing first and second logic signals in respective response to polarities of the AC output voltage, a monostable pulse generator responsive to the second output voltage for providing a third logic signal, AND gates respectively responsive to the first and third and second and third logic signals and switching means respectively responsive to the AND gates for oppositely shunting the AC output voltage;
and
a feedback means comprising, proportional integrator means responsive to the AC output voltage and a reference voltage for providing the second output voltage, triangular wave generator means for producing a first triangular wave and a second triangular wave that lags 90.degree. in phase from the first triangular wave and comparing circuit means responsive to the second output voltage and the first and second triangular waves for controlling the inverter and reactive power control means.

1 more element

Dependencies are inferred from the claim text.

Automatic voltage control circuit by using reactive power

Life of this patent

Automatic voltage control circuit by using reactive power

Life of this patent

Abstract

Claims10