US 7,595,613 B2 · Method and apparatus for electronic power control

Abstract

The method of the invention in one aspect involves electronic power control by varying the amplitude of an electrical power supply voltage, independent of frequency, whereby the output frequency will always be the same as the input frequency. An electrical circuit apparatus for accomplishing this function in a specific embodiment is also disclosed herein. The specific circuitry of this aspect of the invention uses eight solid state switches, such as IGBT's, eight diodes, an inductor, input and output filters and novel controlling circuitry. The controller apparatus and methods of the invention may be used to implement all otherwise conventional converter types, buck, boost, and inverting (and duals of these) versions to obtain different regulating characteristics, including galvanic isolation of the output from the input. Indeed, the eight-switch controller can act to either buck or boost the input voltage, and can switch between bucking and boosting during a cycle, thus providing more control of the regulated output voltage. The inventive methods and devices may be used in power factor correction, voltage and/or current harmonic filtering and neutralization, line and load conditioning, control of power transfer between two power grids, and programmable control of surges, sags, dropouts and most other voltage regulation problems.

Claims23

Dependent claims

An AC to AC power controller having an output for connection to a load, the controller comprising:

a power regulator circuit comprising:
first, second, third and fourth independently controllable switches, wherein the first switch is connected to the second switch, the second switch is connected to the third switch, and the third switch is connected to the fourth switch;
and
an inductor connected to at least one of the switches;
a polarity detector in parallel with an input voltage to the power regulator;
a duty cycle modulator;
and
a logic control circuit comprising a first output connected to the first switch, a second output connected to the second switch, a third output connected to the third switch and a fourth output connected to the fourth switch, wherein the logic control circuit is connected to receive as input at least one output of the polarity detector and at least one output of the duty cycle modulator, and wherein the logic control circuit is configured to control the first, second, third and fourth switches such that there is always an electrically conducting path through the switches and such that at least one switch is conducting.

5 more elements

A variable power factor corrector comprising:

a power factor capacitor connected in parallel with a load on an AC line;
a power controller for regulating an AC to AC input voltage conversion, the power controller connected in series with the power factor capacitor, wherein the power controller comprises:
a power regulator circuit comprising a pair of switches and an inductor, wherein each of the pair of switches is bi-directional and implemented as a pair of unidirectional switches;
a polarity detector in parallel with an input voltage to the power regulator;
a duty cycle modulator;
and
a logic control circuit comprising a first output connected to a first unidirectional switch, a second output connected to a second unidirectional switch, a third output connected to a third unidirectional switch and a fourth output connected to a fourth unidirectional switch, wherein the logic control circuit is connected to receive as input at least one output of the polarity detector and at least one output of the duty cycle modulator, and wherein the logic control circuit is configured to control the unidirectional switches such that there is always an electrically conducting path through the switches and such that at least one switch is conducting;
and
wherein the power controller generates a line-driven variable voltage output that varies an amount of capacitance reflected back onto the AC line.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for electronic power control

Life of this patent

Method and apparatus for electronic power control

Life of this patent

Abstract

Claims23