Path test for a DC battery back-up system

• US 6,278,279 B1
• Filed: 08/28/1998
• Issued: 08/21/2001
• Est. Priority Date: 08/28/1998
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Daun-Lindberg, Timothy C., Steele, Steven W.
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): KERVEROS, DEMETRIOS C
• Application Number:
  US09/143,539
• Time in Patent Office: 1,089 Days
• Field of Search: 324/427, 324/434, 324/426, 324/432, 324/433, 324/771, 320/121, 320/124
• US Class Current: 324/427
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A power supply includes a rectifier which receives alternating current as an input, and which provides an output of direct current pulses at a positive polarity output line thereof with respect to a negative polarity output line thereof. A back-up circuit is coupled between the positive and negative polarity output lines of the rectifier. The back-up circuit includes the series connection of a switching device, a current blocking device, at least one electrical energy source device, and a current measuring device. A circuit protection device may also be provided in the series connection. The back-up circuit can be tested while the rectifier is providing the direct current output pulses by closing the switching device and detecting at least one pulse of a test current flowing through the back-up circuit and/or a terminal voltage of the at least one electrical energy source device during the testing.

Claims

1. A power supply comprising:

a rectifier which receives alternating current as an input, and which provides a train of output pulses at an output terminal; and

a battery back-up circuit coupled to the rectifier output terminal, for providing back-up power to the load;

wherein the battery back-up circuit includes a series connection of a switching device, a current blocking device, at least one electrical energy storage battery, and a current measuring device;

wherein the battery back-up circuit is tested while the rectifier is providing the output pulses by closing the switching device between the output pulses, and detecting at least one of;

a test current flowing through the battery back-up circuit to the load; and

a terminal voltage of the at least one electrical energy storage battery across the load.

2. The power supply according to claim 1, wherein the switching device comprises at least one of:

a mechanical switch;

a relay switch;

a reed switch; and

a solid state switching device.

3. The power supply according to claim 2, wherein the solid state switching device comprises at least one of:

a bipolar transistor;

a field effect transistor; and

a silicon controlled rectifier.

4. The power supply according to claim 1, wherein the rectifier comprises a half-wave rectifier.

5. The power supply according to claim 1, wherein the rectifier comprises a full-wave rectifier.

6. The power supply according to claim 5, wherein the rectifier comprises a full-wave bridge rectifier.

7. The power supply according to claim 1, wherein the current blocking device comprises a diode.

8. The power supply according to claim 7, wherein the diode comprises a solid state diode.

9. The power supply according to claim 1, wherein the series connection further includes a circuit protection device;

wherein the switching device comprises a transistor;

wherein the current blocking device comprises a solid state diode;

wherein the rectifier comprises a full-wave bridge rectifier; and

wherein the current measuring device comprises a resistance.

10. The power supply according to claim 9, wherein the transistor comprises a field effect transistor.

11. The power supply according to claim 9, wherein the transistor comprises a bipolar transistor.

12. A method of testing a power supply used as a back-up power system without adversely affecting an electrical device load being backed-up, the method comprising utilizing the power supply according to claim 9.

13. The power supply according to claim 1, wherein the current measuring device comprises a resistance.

14. The power supply according to claim 1, wherein the current measuring device comprises a Hall effect device.

15. The power supply according to claim 1, wherein the current measuring device comprises an inductance.

16. The power supply according to claim 15, wherein the inductance comprises a pulse current transformer.

17. The power supply according to claim 1, wherein the current measuring device includes a capacitive coupling.

18. The power supply according to claim 1, wherein the current measuring device comprises a capacitance and an inductance.

19. The power supply according to claim 1, wherein the at least one electrical energy storage battery comprises a plurality of battery packs.

20. The power supply according to claim 19, wherein the plurality of battery packs comprises a plurality of 12 volt battery packs.

21. The power supply according to claim 19, wherein the plurality of battery packs comprises a plurality of 48 volt battery packs.

22. The power supply according to claim 1, wherein the output pulses provided by the rectifier have a peak voltage greater than a terminal voltage of the battery back-up circuit, whereby when the switching device is closed, and the instantaneous voltage of the output of the rectifier drops below the terminal voltage of the battery back-up circuit, the test current flows through the battery back-up circuit.

23. The power supply according to claim 22, wherein the alternating current input is from a nominal 220 volts root-mean-square source, wherein the peak voltage of the direct current output pulses provided by the rectifier is approximately 311 volts, and wherein the terminal voltage of the battery back-up circuit comprises approximately 192 volts minus any voltage drops and/or threshold voltages of the series connection components;

whereby, when the switching device is closed and the instantaneous voltage of the output of the rectifier drops below approximately 192 volts, the test current flows through the battery back-up circuit.

24. A method of testing a power supply used as a back-up power system without adversely affecting an electrical device load being backed-up, the method comprising utilizing the power supply according to claim 1.

25. A power supply comprising:

a rectifier which receives alternating current as an input, and which provides a train of output pulses at an output terminal; and

a back-up circuit coupled to the rectifier output terminal, for providing back-up power to the load;

wherein the back-up circuit includes a series connection of a switching device, a current blocking device, at least one electrical energy source device, a circuit protection device, and a current measuring device;

wherein the back-up circuit can be tested while the rectifier is providing the output pulses by closing the switching device between the output pulses, and detecting at least one of;

a test current flowing through the back-up circuit to the load; and

a terminal voltage of the at least one electrical energy source device during the testing across the load.

26. The power supply according to claim 25, wherein the at least one electrical energy source device comprises at least one of:

a dry cell electrical storage battery;

a wet cell electrical storage battery;

a fossil fuel powered electrical generator;

a hydroelectric powered electrical generator;

a wind powered electrical generator;

a tide powered electrical generator;

a solar powered steam turbine electrical generator;

a nuclear powered steam turbine electrical generator;

a fuel cell; and

a photo-voltaic cell.

27. A method of testing a back-up power system having a series connection of a switching device, a current blocking device, at least one electrical energy source device, a circuit protection device, and a current measuring device, in a power supply without adversely affecting an electrical device load being backed-up, the method comprising:

supplying a train of rectified current pulses to the load at output terminals of the power supply;

while the train of rectified current pulses is being supplied to the load at the output terminals of the power supply, connecting the back-up power system to the output terminals of the power supply by closing the switching device between the current pulses; and

detecting at least one electrical parameter of the back-up power system.

28. The method according to claim 27, wherein the at least one electrical parameter of the back-up power system comprises a current magnitude flowing through the back-up power system to the load.

29. The method according to claim 27, wherein the at least one electrical parameter of the back-up power system comprises a terminal voltage magnitude of the back-up power system across the load.

30. The method according to claim 27, further comprising:

prior to the connecting the back-up power system to the output terminals of the power supply, measuring a terminal voltage of the back-up power system; and

if the measured terminal voltage of back-up power system is below a threshold, signaling a back-up power system problem and aborting further testing.