Power distribution system and method

• US 6,355,990 B1
• Filed: 03/24/1999
• Issued: 03/12/2002
• Est. Priority Date: 03/24/1999
• Status: Expired due to Term

• Current Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: Mitchell, Daniel M.
• Primary Examiner(s): Fleming, Fritz
• Assistant Examiner(s): Deberadinis, Robert L.
• Application Number:
  US09/275,297
• Time in Patent Office: 1,084 Days
• Field of Search: 307/18, 307/19, 307/20, 307/31, 307/33, 307/43, 307/145, 307/139, 307/131, 307/126, 307/69, 307/64, 307/109, 307/66, 307/41, 307/125, 323/313, 320/124, 320/15, 363/21, 324/416
• US Class Current: 307/64
• CPC Class Codes: H02J 1/06 Two-wire systems
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 3/155 using semiconductor devices only

Abstract

A power distribution system and method, including a direct-current current source which is commutated among a number of distribution circuits which function as independent and modular power sources. Each distribution circuit includes a capacitor which is connected to the direct-current current source through a switch. The load is connected in parallel with the capacitor. The capacitor is charged to a predetermined level, generally matching the required load voltage, and periodically checked and recharged as necessary. There may be a plurality of distribution circuits to provide power to separate circuits or specific portions of a larger circuit. By varying the switch timing and logic, the output voltage of each distribution circuit may be varied, allowing a centralized power supply to provide power to a variety of electrical components with varying voltage requirements.

Claims

1. A power distribution system for delivering power to a plurality of loads comprising, in combination:

a current source for supplying a charging current;

a plurality of distribution circuits connected to the current source for distributing the charging current, the plurality of distribution circuits including energy storage devices for delivering power to the plurality of loads said energy storage devices connected in a parallel circuit arrangement with the current source, and switches connected between the energy storage devices and an output terminal of the current source; and

a switch control for activation of the switches in the plurality of distribution circuits wherein said switch control further comprises a clock for providing sequential clock cycles for operation of the switches at a selected clock cycle frequency.

2. A power distribution system as described in claim 1 wherein the current source is a modified single-ended primary inductor converter.

3. The power distribution system of claim 2 wherein the modified single-ended primary inductor converter comprises:

a voltage supply having an output terminal and a return terminal for supplying the charging current;

a first inductor connected to the output terminal of the voltage supply;

a switch connected to the first inductor and to the return terminal of the voltage supply;

a first capacitor connected the switch and the first inductor;

a second inductor connected to the capacitor and to the return terminal of the voltage supply;

a current transformer connected to the first capacitor and the second inductor and to the switches in the plurality of distribution circuits for sensing the charging current; and

a pulse width modulator connected to the switch and the current transformer for comparing the sensed charging current to a reference current and for driving the switch with a duty factor in accordance with the sensed charging current.

4. A power distribution system as described in claim 1 further comprising a plurality of diodes connected between the current source and the energy storage devices to prevent discharge in a reverse direction of the energy storage devices.

5. A power distribution system as described in claim 1 wherein the switch control includes:

a plurality of comparators for comparing the predetermined voltages on the energy storage devices to reference voltages and for producing comparator output signals indicative of the predetermined voltage levels; and

a plurality of control logic circuits connected to the clock and the plurality of comparators to produce switch activation signals when enabled by the sequential clock cycles and the comparator output signals.

6. A power distribution system for supplying predetermined voltages to a plurality of loads comprising, in combination:

a modified single ended primary inductor converter for supplying a charging current;

a plurality of switches connected to the modified single ended primary inductor converter for switching the charging current;

a plurality of diodes connected to the plurality of switches for providing isolation;

a plurality of energy storage devices connected to the plurality of diodes said energy storage devices being charged by the charging current; and

a switch control for controlling the plurality of switches to charge the plurality of energy storage devices to the predetermined voltages.

7. A power distribution system as described in claim 6 wherein the energy storage device is a capacitor.

8. A power distribution system as described in claim 6 wherein the modified single-ended primary inductor converter comprises:

a voltage supply having an output terminal and a return terminal for supplying the charging current;

a first inductor connected to the output terminal of the voltage supply;

a switch connected to the first inductor and to the return terminal of the voltage supply;

a first capacitor connected the switch and the first inductor;

a second inductor connected to the capacitor and to the return terminal of the voltage supply;

a current transformer connected to the first capacitor and the second inductor and to the plurality of switches in the plurality of distribution circuits for sensing the charging current; and

a pulse width modulator connected to the switch and the current transformer for comparing the sensed charging current to a reference current and for driving the switch with a duty factor in accordance with the sensed charging current.

9. A power distribution system as described in claim 6 wherein the switch control includes

a clock for generating sequential clock cycles;

a plurality of comparators for comparing the predetermined voltages on the plurality of energy storage devices to reference voltages and for producing a comparator output signal indicative of the predetermined voltage level; and

a plurality of control logic circuits connected to the clock and the plurality of comparators to produce switch activation signals when enabled by the sequential clock cycles and the comparator output signals.

10. A method of distributing power to multiple loads, the method comprising, in combination:

supplying a charging current from a current source;

distributing the charging current to energy storage devices connected to the current source through switches connected between the energy storage devices and the current source;

activating the switches sequentially in accordance with sequential clock cycles from a switch control; and

charging the energy storage devices to predetermined voltages with the charging current.

11. The method of claim 10 wherein the step of activating the switches further comprises the steps of:

comparing the predetermined voltages to predetermined reference voltages in comparator circuits;

generating the sequential clock cycles at a selected clock frequency with a clock in the switch control; and

activating the switches sequentially when the predetermined voltages are less the predetermined reference voltages in accordance with the sequential clock cycles.

12. The method of claim 11 further comprising the step of asynchronously overriding the sequential order of charging when one of the energy storage devices is in need of charging and all other energy storage devices are not in need of charging.

13. The method of claim 12 further comprising allowing energy to return to the source when no energy storage devices are in need of charging through a return path switch.

14. The method of claim 13 where the return path switch is a diode.