Step wave power converter

• US 6,608,404 B2
• Filed: 12/19/2000
• Issued: 08/19/2003
• Est. Priority Date: 12/22/1998
• Status: Expired due to Term

• Current Assignee: International Power Systems, Inc
• Original Assignee: International Power Systems, Inc
• Inventors: Donnelly, Matthew K., Harris, Brent Earle, Droppo, Gerald W., Schienbein, Lawrence A.
• Primary Examiner(s): Riley, Shawn
• Application Number:
  US09/740,783
• Publication Number:
  US 20010004170A1
• Time in Patent Office: 973 Days
• Field of Search: 307/82, 307/83, 307/17, 363/71, 363/43
• US Class Current: 307/82
• CPC Class Codes: H02M 7/49 Combination of the output voltage waveforms of a plurality of converters

Abstract

A single- or multi-phase step wave power converter includes multiple transformers configured to receive DC voltage from one or more power sources. Each of the transformers includes a primary winding and a secondary winding. The transformers are each configured to supply a step for a step wave AC output. Bridge circuits are supplied for controlling input of DC voltage into the primary windings of the transformers. Steps for the step wave AC output are output from the secondary windings based upon the input provided to the primary windings. DC source management circuitry manages which DC power source(s) supplies DC voltage input to each of the bridge circuits. The management circuitry provides seamless power switching between the plurality of DC power sources based on each power source'"'"'s performance characteristics. A pulse-width modulator can also be provided to the step wave power converter to modulate the input into a selected primary winding. In this way, the step wave AC output can be fine-tuned in substantial conformance with an ideal AC waveform.

Claims

1. A step wave power converter comprising:

a plurality of transformers, each configured to selectively receive a DC voltage from one or more of a plurality of independently-generated power sources, including at least one variable power source, each transformer being configured to selectively supply one or more steps for a step wave AC output;

a plurality of bridge circuits, each adapted to selectively supply DC voltage input from one or more of the multiple independently generated power sources, including the variable power source, into one or more of the transformers to generate steps for the step wave AC output from the transformers; and

source management circuitry capable of evaluating performance characteristics of each power source, including the variable power source, and managing how and when each of the individual DC voltage inputs is supplied by the bridge circuits to the transformers based on those performance characteristics.

2. The step wave power converter according to claim 1, wherein the source management circuitry determines an amount of power available from each of the power sources at a particular time and allocates power from the power sources to the step wave AC output based on the amount of power available from each of the power sources at the particular time.

3. The step wave power converter according to claim 1, wherein the source management circuitry comprises a plurality of high frequency converters tied to each power source.

4. The step wave power converter according to claim 3, wherein the source management circuitry determines an amount of power that can be contributed by each power source at a particular time and permits each source to contribute up to a total amount of power required depending on a type of the power source and on the amount of power that can be contributed at that particular time by each power source.

5. A step way power converter comprising:

a plurality of transformers, each configured to receive DC voltage from one or more power sources and being further configured to supply a step for a step wave AC output;

a plurality of bridge circuits for controlling DC voltage inputs from a plurality of DC sources into windings of the transformers to generate the steps of the step wave AC output from the transformers; and

wherein the plurality of transformers comprise a plurality of three-phase transformers, each three-phase transformer being configured to receive DC voltage from one or more power sources and to supply a step for each phase of a three-phase step wave AC output.

6. The step wave power converter according to claim 5, further comprising:

a pulse width modulator for controlling an input into a selected one of the transformers to fine tune the step wave AC output in substantial conformance with an ideal AC waveform by ramping up or down the input into the selected one of the transformers to cause the output to more closely approximate an ideal AC waveform.

7. The step wave power converter according to claim 5, wherein:

each of the plurality of bridge circuits comprising multiple gate pairs arranged in parallel, wherein each gate pair comprises two or more gates arranged in series; and

each bridge circuit being connected to one of the transformers, wherein opposite ends of a transformer winding are connected between gates in separate gate pairs.

8. The power converter of claim 7, wherein a first set of transformer windings are arranged in a delta configuration.

9. The power converter of claim 8, wherein a first end of a first winding is connected between gates in a first one of the gate pairs and a second end of the first winding is connected between gates of a third one of the gate pairs;

wherein a first end of a second winding is electrically couple to the second end of the first winding and a second end of the second winding is connected between gates in a second one of the gate pairs; and

wherein a first end of a third winding is electrically coupled to the second end of the second winding and a second end of the third winding is electrically coupled to the first end of the first winding.

10. The power converter of claim 8, wherein a second set of windings are arranged in a wye configuration.

11. The power converter of claim 10, further comprising a phase management controller for enhancing a resolution of the three-phase step wave AC output by managing characteristics of the voltage transformation between the delta configuration of the first set of windings and the wye configuration of the second set of windings.