BATTERY PEAKING UNIT FOR FUEL CELL POWER PLANTS

• US 3,823,358 A
• Filed: 06/18/1973
• Issued: 07/09/1974
• Est. Priority Date: 06/18/1973
• Status: Expired due to Term

• Current Assignee: Paul R. Rey
• Original Assignee: Paul R. Rey
• Inventors: Rey, Paul R.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/371,196
• Time in Patent Office: 386 Days
• Field of Search: 320/2-6,39,40,15,21,16-18,61 307/66
• US Class Current: 320/101
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04567 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04955 Shut-off or shut-down of fuel cells
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 320/14 Battery acts as buffer

Abstract

An auxiliary storage battery or other DC rechargeable power source is connected in parallel with a fuel cell to supply additional current to a load when an overload such as the starting of a motor causes the fuel cell voltage to drop. The fuel cell voltage is sensed and when it reduces below a preselected value the auxiliary battery supplies current to the load for a preselected time interval. The storage battery is recharged by power supplied by the fuel cell only during periods when the battery is not supplying current to the load. Excessive battery drain is prevented by shutting down the peaking unit whenever fluctuations in the fuel cell voltage cause multiple peaking cycles.

Claims

1. A battery peaking unit for a fuel cell comprising:

a fuel cell having a pair of output terminals through which current is supplied to a load, a battery adapted to supply additional current to said load and connected across said fuel cell output terminals, normally high impedance switch means connected in series with said battery, means connected across said fuel cell output terminals for generating an output pulse of fixed time duration when the output voltage from said fuel cell drops below a predetermined value, and means connecting said output pulse to said switch means to cause activation of said switch means and to permit current to flow from said battery to said load only for the duration of said output pulse.

2. A battery peaking unit as in claim 1 in which said switch means is a transistor which is normally nonconducting and which is rendered conducting by said output pulse.

3. A battery peaking unit as in claim 1 in which an inverter is connected to receive the current supplied by said fuel cell, the output current from said inverter being supplied to said load, and battery charging means for supplying a portion of said inverter output current to charge said battery when the voltage of said battery drops below a preselected value.

4. A battery peaking unit as in claim 1 and including a diode connected in series with said battery for preventing current flow from said fuel cell to said battery.

5. A battery peaking unit as in claim 1 and including means for disabling said battery peaking unit upon the occurrence of an oscillating condition thereof.