Method and apparatus for charging batteries with energy storage

• US 20060033476A1
• Filed: 08/10/2004
• Published: 02/16/2006
• Est. Priority Date: 08/10/2004
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Stanzel, David A., Reynolds, Jon O.
• Granted Patent: US 7,202,636 B2
• Time in Patent Office: Days
• US Class Current: 320/141
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• 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 1/0096 Means for increasing hold-up time, i.e. the duration of time that a converter's output will remain within regulated limits following a loss of input power
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• 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

Abstract

According to a first aspect of the invention a battery charger and method of charging a battery includes an input circuit that receive an ac input having a period of T seconds and provides a dc signal. A converter receives the first dc signal and provides a converter output across a dc bus having a peak voltage of V volts. An output circuit receives the dc signal and provides a battery charging signal having a power of P watts. A controller, controls the converter to provide power factor correction. A bus capacitor is connected across the dc bus and has a capacitance of at least (3PT)/(V²) farads, or a capacitance to store sufficient energy to maintain the available output power signal through the duration of mechanical transient. The capacitance may be at least (4PT)/(V²), (5PT)/(V²), or (5.5PT)/(V²). Multiple output circuits may be provided, connected either one at a time, or a number at a time.

Claims

1. A battery charger, comprising:

an input circuit configured to receive an ac input having a period of T seconds and to provide a first dc signal;

a converter configured to receive the first dc signal and to provide a converter output across a dc bus having a peak voltage of V volts, and configured to receive at least one control input;

an output circuit configured to receive the dc signal and to provide a battery charging signal having a power of P watts;

a controller, including a power factor correction circuit, configured to provide at least one control signal to the converter; and

a bus capacitor connected across the dc bus wherein the bus capacitor has a capacitance of at least (3PT)/(V²) farads.

2. The battery charger of claim 1 wherein the capacitance is at least (4PT)/(V²).

3. The battery charger of claim 1 wherein the capacitance is at least (5PT)/(V²).

4. The battery charger of claim 1 wherein the input stage includes an input rectifier configured to receive the ac input signal.

5. The battery charger of claim 1, further comprising a second output circuit designed for a second battery voltage, wherein both of the output circuit and second output circuit are connected at any given time.

6. The battery charger of claim 1, further comprising a second output circuit designed for a second battery voltage, wherein one of the output circuit and second output circuit are connected at any given time.

7. The battery charger of claim 5 wherein the converter is one of a buck converter, boost converter, buck-boost convert and a combined rectifier-boost converter

8. The battery charger of claim 1 wherein the output circuit includes a switched transformer.

13. The battery charger of claim 1 wherein the input stage includes an input rectifier configured to receive the ac input signal.

14. The battery charger of claim 13, further comprising a second output circuit designed for a second battery voltage, wherein one of the output circuit and second output circuit are connected at any given time.

15. The battery charger of claim 14 wherein the converter is one of a buck converter, boost converter, buck-boost convert and a combined rectifier-boost converter.

25. The method of claim 1 wherein the capacitance is at least (4PT)/(V²).

26. The method charger of claim 1 wherein the capacitance is at least (5PT)/(V²).

9. A battery charger, comprising:

an input circuit configured to receive an ac input having a period of T seconds and to provide a first dc signal;

a converter configured to receive the first dc signal and to provide a converter output across a dc bus having a peak voltage of V volts, and configured to receive at least one control input;

an output circuit configured to receive the dc signal and to provide a battery charging signal having a power of P watts;

a controller, including a power factor correction circuit, configured to provide at least one control signal to the converter; and

a bus capacitor connected across the dc bus wherein the bus capacitor has a capacitance to store sufficient energy to maintain the available output power signal through the duration of mechanical transients.

10. A battery charger, comprising:

an input circuit configured to receive an ac input having a period of T seconds and to provide a first dc signal;

a converter configured to receive the first dc signal and to provide a converter output across a dc bus, and having a peak voltage of V volts, configured to receive at least one control input;

a plurality of user-removable output circuits, each configured to receive the first dc signal and each designed to provide a battery charging signal at a desired voltage and a desired current, wherein a chosen one of the plurality is connected at a time and the maximum power of the battery charging signal for any of the plurality of output circuits is P watts;

a controller, including a power factor correction circuit, configured to provide at least one control signal to the converter; and

a bus capacitor connected across the dc bus wherein the bus capacitor has a capacitance of at least (3PT)/(V²) farads.

11. The battery charger of claim 10 wherein the capacitance is at least (4PT)/(V²).

12. The battery charger of claim 10 wherein the capacitance is at least (5PT)/(V²).

16. The battery charger of claim 10 wherein the output circuit includes a switched transformer.

17. A battery charger, comprising:

an input circuit configured to receive an ac input having a period of T seconds and to provide a first dc signal;

a converter configured to receive the first dc signal and to provide a converter output across a dc bus having a peak voltage of V volts, configured to receive at least one control input;

a plurality of output circuits, each configured to receive the first dc signal and each designed to provide a battery charging signal at a desired voltage and a desired current, wherein each the total power provided by the plurality is of output circuits is P watts;

a controller, including a power factor correction circuit, configured to provide at least one control signal to the converter; and

a bus capacitor connected across the dc bus wherein the bus capacitor has a capacitance of at least (3PT)/(V²) farads.

18. The battery charger of claim 17 wherein the capacitance is at least (4PT)/(V²).

19. The battery charger of claim 17 wherein the capacitance is at least (5PT)/(V²).

20. The battery charger of claim 17 wherein the input stage includes an input rectifier configured to receive the ac input signal.

21. The battery charger of claim 17 wherein the input stage includes a combined rectifier-boost configured to receive the ac input signal.

22. The battery charger of claim 20 wherein the converter is one of a buck converter, boost converter, buck-boost convert and a combined rectifier-boost converter.

23. The battery charger of claim 20 wherein the output circuit includes a switched transformer.

24. A method of battery charging, comprising:

rectifying an ac input having a period of T seconds to provide a first dc signal;

converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;

switching the dc bus to provide a battery charging signal having a power of P watts;

controlling, including power factor correcting, the converting, and

storing energy across the bus on a bus having a capacitance of at least (3PT)/(V²) farads.

27. The method of claim 24, further comprising a second switching of the dc bus to provide a second battery charging signal.

28. A method of charging a battery, comprising:

rectifying an ac input having a period of T seconds to provide a first dc signal;

converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;

switching the dc bus to provide a battery charging signal having a power of P watts;

controlling, including a power factor correcting, the converting, and

storing energy across the bus on a bus having a capacitance to store sufficient energy to maintain the available output power signal through the duration of mechanical transients.

29. A method of charging a battery, comprising:

rectifying an ac input having a period of T seconds to provide a first dc signal;

converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;

switching the dc bus with a plurality of output circuits to provide a plurality of battery charging signals having a combined power of P watts;

controlling, including a power factor correcting, the converting, and

storing energy across the bus on a bus having a capacitance of at least (3PT)/(V²) farads.

30. The method of claim 29 wherein the capacitance is at least (4PT)/(V²).

31. The method of claim 29 wherein the capacitance is at least (5PT)/(V²).

32. A battery charger, comprising:

means for rectifying an ac input having a period of T seconds to provide a first dc signal;

means for receiving the first dc signal and for converting it and providing a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;

means for switching the dc bus to provide a battery charging signal having a power of P watts;

means for controlling, including power factor correcting, the converting, and

means for storing energy across the bus on a bus having a capacitance of at least (3PT)/(V²) farads.

33. The battery charger of claim 32 wherein the capacitance is at least (4PT)/(V²).

34. The battery charger of claim 33 wherein the capacitance is at least (5PT)/(V²).

35. The battery charger of claim 32, further comprising a second means for switching of the dc bus to provide a second battery charging signal.

36. A battery charger, comprising:

means for rectifying an ac input having a period of T seconds to provide a first dc signal;

means for converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;

means for switching the dc bus to provide a battery charging signal having a power of P watts;

means for controlling, including a power factor correcting, the converting, and

means for storing energy across the bus on a bus having a capacitance to store sufficient energy to maintain the available output power signal through the duration of mechanical transients.

37. A battery charger, comprising:

means for rectifying an ac input having a period of T seconds to provide a first dc signal;

means for converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;

means for switching the dc bus with a plurality of output circuits to provide a plurality of battery charging signals having a combined power of P watts;

means for controlling, including power factor correcting, the converting, and

means for storing energy across the bus on a bus having a capacitance of at least (3PT)/(V²) farads.

38. The battery charger of claim 37 wherein the capacitance is at least (4PT)/(V²).

39. The battery charger of claim 37 wherein the capacitance is at least (5PT)/(V²).