Apparatus for controlling the input impedance of a power converter

• US 5,144,222 A
• Filed: 02/05/1991
• Issued: 09/01/1992
• Est. Priority Date: 01/07/1991
• Status: Expired due to Term

• Current Assignee: Edward Herbert
• Original Assignee: Edward Herbert
• Inventors: Herbert, Edward
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): STERRETT, JEFFREY L
• Application Number:
  US07/650,914
• Time in Patent Office: 574 Days
• Field of Search: 307/82, 323/266, 323/267, 323/271, 323/272, 323/282, 323/285, 323/351, 363/34, 363/37, 363/65, 363/71
• US Class Current: 323/271
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A DC-DC power converter, which can be adapted for use with a single- or multiple-phase AC input, uses energy control because it transcends the modulators and is linear. The use of feed back control is minimized by the use of feed forward control, and in particular the feed forward of the output power to control the input power. The dynamic resistance of the input is controlled, ensuring high power factor in the AC input embodiments of the converter. A multiple-input buck derived converter can have parallel or series inputs, and one or more of the inputs can be lower than the output, even zero or negative. A multiple output boost derived converter can have parallel or series outputs, and one or more of the outputs can be lower than the input, even zero.

Claims

1. A power converter of the type generally known as a buck converter, comprising

a plurality of inputs,

each of the plurality of inputs being for one of a plurality of power sources

a plurality of switching means

each of the plurality of switching means being connected in series with one of the plurality of inputs and one of the plurality of power sources so that each of the plurality of switching means can either connect or disconnect each one of the power sources,

a plurality of rectifying means, one for each of the plurality of switches and the plurality of power sources

each of the plurality of rectifying means being connected from the return of on of the plurality of power sources to one of the plurality of switching means so as to comprise a bypass circuit for each of plurality of power sources and the plurality of the switching means when the switching means is open so as to disconnect the power source

the plurality of power sources and the plurality of switches comprising a series circuit having a plurality of rectifying means for bypassing such that when any of the plurality of switching means is closed, at least one of the plurality of inputs is in series as part of the series circuit, and when any of the plurality of switching means is open, at least one of the plurality of power sources is bypassed by at least one of the rectifying means

the series circuit comprising the plurality of power sources, the plurality of switching means and the plurality of rectifying means being connected from a ground return to the input of an inductor,, and

an output capacitor connecting from the output of the inductor to the ground return.

2. The power converter of claim 1 wherein the input voltage of at least one of the plurality of power sources is lower than the voltage of the output capacitor.

3. The power converter of claim 1 having multiple inputs wherein each of the multiple inputs is derived from one phase of a multiple phase AC input voltage source.

4. The power converter of claim 3 having an input modulator control such that power factor correction is provided for the multiple phase AC input voltage source.

5. A power converter of the type generally known as a boost converter comprising

a plurality of outputs

each of the plurality of outputs being for one of a plurality of output loads

a plurality of switching means

each of the plurality of switching means connecting from one of the plurality outputs to the output of an inductor, and

an input voltage source means connected to the input of the inductor.

6. The power converter of claim 5 wherein the output voltage of at least one of the plurality of output loads is lower than the voltage of the input voltage source means.

7. The power converter of claim 5 where the input voltage source means is an input modulator circuit having a storage capacitor means.

8. A power converter of the type generally known as a boost converter comprising

an input inductor having an input current

a plurality of outputs

each of the plurality of outputs being for one of a plurality of output loads

each of the plurality of outputs comprising a series circuit such that all of the plurality of loads are effectively in series and the input current can flow in series through all of the plurality of output loads

a plurality of switching means,

each of the plurality of switching means being across one of the plurality of output loads such that when each of the plurality of switching means is closed, the input current flows through one of the plurality of switching means and by passes one of the plurality of output loads, and such that when each of the plurality of switching means is open, the input current flows through at least one of the plurality of output loads, and

an input voltage source means connected to the input of the input inductor.

9. The power converter of claim 8 having isolation transformer means such that the plurality of output loads can be effectively in series while also being isolated.

10. The power converter of claim 8 wherein at least one of the plurality of output loads has a voltage which is lower than the voltage of the input voltage source means.