Method and device for supplying electrical energy, and apparatus provided with such a device

• US 6,034,443 A
• Filed: 01/30/1998
• Issued: 03/07/2000
• Est. Priority Date: 08/01/1995
• Status: Expired due to Fees

• Current Assignee: Bartoli N.V.
• Original Assignee: Bartoli N.V.
• Inventors: Bartels, Michael J.G., Oliemuller, Robbert J., Butter, Albertus
• Primary Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US09/015,951
• Time in Patent Office: 767 Days
• Field of Search: 307/43, 307/70, 307/64, 307/66, 307/87, 320/135, 320/127, 320/137
• US Class Current: 307/70
• CPC Class Codes: H02J 9/061 for DC powered loads

Abstract

A method and device for supplying electrical energy to an electrical load using a set of chargeable and dischargeable direct current sources is provided. In a first step, all the direct current sources of the set are charged. In a second step, the first of the set of direct current sources is connected to the load in order to supply electrical energy to the latter. After a predetermined time, the connection between the first direct current source and the load is broken. The two preceding steps are repeated for each following direct current source. The three preceding steps are repeated, during which the direct current source connected to the load charges, via a charging device, at least one of the other direct current sources such that each direct current source of the set of direct current sources passes through a discharge-charge cycle.

Claims

1. A method for supplying electrical energy to an electrical load using a set of chargeable and dischargeable direct current sources, the method comprising the following steps:

(a) charging all the direct current sources of the set;

(b) connecting a first of the set of direct current sources to the load, in order to supply electrical energy to the load, during which time the first of the set of direct current sources is partly discharged;

(c) after a predetermined time, breaking the connection between the first of the set of direct current sources and the load;

(d) repeating steps (b) and (c) for each following direct current source of the set of direct current sources;

(e) repeating steps (b), (c) and (d), the direct current source connected to the load charging, via a charging device, at least one of the other direct current sources, this being done such that each direct current source of the set of direct current sources passes through a discharge-charge cycle.

2. The method of claim 1, wherein the connection between a direct current source and the load is broken only after a connection has been made between a following direct current source and the load.

3. The method of claim 1, wherein for each direct current source the sum of the discharging time and the charging time per discharge-charge cycle is smaller than the duration of the discharge-charge cycle.

4. The method of claim 1, wherein for each direct current source the charging time is longer than the discharging time.

5. The method of claim 1, wherein for a set of m direct current sources and a discharge-charge cycle duration of n seconds, each direct current source is connected to the load for a time of at least n/m seconds.

6. A device for supplying electrical energy to an electrical load, the device comprising:

a set of m chargeable and dischargeable direct current sources;

discharging switch means for making and breaking a connection between the first up to and including the m-th direct current sources and the load;

charging switch means for making and breaking a connection of at least one of the m direct current sources to at least one other one of the m direct current sources with the interposition of a charging device; and

control means for controlling the discharging switch means and the charging switch means such that in succession;

(a) the first of the set of direct current sources is connected to the load, in order to supply electrical energy to the latter, during which time the first direct current source is partly discharged;

(b) after a predetermined time the connection between the first direct current source and the load is broken;

(c) steps (a) and (b) are repeated for each following direct current source of the set of direct current sources; and

(d) steps (a), (b) and (c) are repeated, the direct current source connected to the load charging, via the charging device, at least one of the other direct current sources, this being done such that each direct current source of the set of direct current sources passes through a discharge-charge cycle.

7. The device of claim 6, wherein the direct current source is an accumulator.

8. The device of claim 7, wherein the accumulator is an NiCd accumulator.

9. The device of claim 7, wherein the control means are arranged for discharging and charging the accumulator in the capacity range above 100%.

10. The device of claim 6, wherein the direct current source is a capacitor, at most m-1 capacitors being used.

11. The device of claim 6, wherein the charging device comprises a combination of a motor and a generator driven by the motor.

12. The device of claim 6, wherein the charging device comprises a direct current/direct current converter.

13. The device of claim 12, wherein the direct current/direct current converter has an alternating voltage intermediate stage.