High-Power Ultracapacitor Energy Storage Pack and Method of Use

Abstract

An ultracapacitor energy storage cell pack includes an ultracapacitor assembly including a plurality of parallel ultracapacitors and balancing resistors in series; an enclosure for the ultracapacitor assembly; a controller; one or more temperature sensors; a pack voltage sensor; a GFI sensor; one or more cooling fans carried by the enclosure; an on/off relay coupled to the ultracapacitor assembly and the controller, the on/off relay activated by the controller during normal operation of the ultracapacitor assembly and deactivated by the controller when the GFI sensor detects a ground fault interrupt condition, the one or more temperature sensors detect an over-temperature condition, or the pack voltage sensor detects an over-voltage condition; and a pre-charge resistor and a pre-charge relay coupled to the ultracapacitor assembly and the controller, and activated by the controller to cause the pre-charge resistor to limit pack charge current until the ultracapacitor assembly reaches a minimum voltage.

1 . An ultracapacitor energy storage pack specially adapted for a hybrid electric vehicle, the ultracapacitor energy storage pack comprising:
 an ultracapacitor assembly including a plurality of parallel ultracapacitors and balancing resistors in series, each balancing resistor in parallel with each ultracapacitor and configured to automatically discharge each ultracapacitor over time, thereby balancing the ultracapacitors of the ultracapacitor assembly;   an enclosure configured to enclose and protect the ultracapacitor assembly;   a pack voltage sensor configured to monitor voltage of the ultracapacitor assembly;   one or more temperature sensors configured to monitor temperature of the ultracapacitor assembly;   a ground fault sensor configured to monitor for a ground fault condition between the ultracapacitor assembly and the hybrid electric vehicle;   an on/off relay coupled to the ultracapacitor assembly and an on/off relay control input, the on/off relay activated during normal operation of the ultracapacitor assembly and deactivated by the on/off relay control input to terminate normal operation of the ultracapacitor assembly; and,   a cooling system configured to cool the ultracapacitor assembly.   
   
   
       2 . The ultracapacitor energy storage cell pack of  claim 1 , wherein the ultracapacitor energy storage cell pack is configured to capture braking regeneration energy of the hybrid electric vehicle. 
   
   
       3 . The ultracapacitor energy storage cell pack of  claim 2 , wherein the ultracapacitor energy storage cell pack is further configured to supply vehicle acceleration power to the hybrid electric vehicle. 
   
   
       4 . The ultracapacitor energy storage cell pack of  claim 1 , wherein the cooling system comprises one or more cooling fans carried by the enclosure. 
   
   
       5 . The ultracapacitor energy storage cell pack of  claim 4 , further comprising an air filter carried by the enclosure, the air filter configured to filter cooling air entering the enclosure. 
   
   
       6 . The ultracapacitor energy storage cell pack of  claim 5 , wherein the air filter and the one or more cooling fans are positioned on opposite sides of the enclosure; and,
 wherein the air filter interfaces with one or more cutouts in the enclosure; and,   wherein the one or more cooling fans are configured to force air from the enclosure that is drawn in through the air filter.   
   
   
       7 . The ultracapacitor energy storage cell pack of  claim 1 , further comprising a controller. 
   
   
       8 . The ultracapacitor energy storage cell pack of  claim 7 , wherein the controller is coupled to cooling system and is configured to provide automatic cooling of the ultracapacitor assembly in response to the one or more temperature sensors. 
   
   
       9 . The ultracapacitor energy storage cell pack of  claim 8 , wherein the cooling system comprises one or more cooling fans coupled to the enclosure; and,
 wherein the controller is further configured to turn the one or more cooling fans on and off in response to the one or more temperature sensors.   
   
   
       10 . The ultracapacitor energy storage cell pack of  claim 7 , further comprising a pre-charge resistor and a pre-charge relay coupled to the on/off relay, to the ultracapacitor assembly, and to the controller, the pre-charge relay activated by the controller to cause the pre-charge resistor to limit electrical current entering the ultracapacitor energy storage cell pack until the ultracapacitor assembly reaches a minimum voltage, or to limit electrical current leaving the ultracapacitor energy storage cell pack until an external load circuit reaches a minimum voltage. 
   
   
       11 . The ultracapacitor energy storage cell pack of  claim 7 , wherein the controller is coupled to at least one of the voltage sensor, the one or more temperature sensors, the ground fault sensor, the on/off relay, a fire sensor, and a fire suppression subassembly. 
   
   
       12 . The ultracapacitor energy storage cell pack of  claim 11 , wherein the controller is configured to control one or more of the on/off relay and the fire suppression subassembly in response to at least one of the voltage sensor, the one or more temperature sensors, the ground fault sensor, the on/off relay, and the fire sensor. 
   
   
       13 . The ultracapacitor energy storage cell pack of  claim 7 , wherein the controller comprises a programmable logic controller module. 
   
   
       14 . The ultracapacitor energy storage cell pack of  claim 13 , wherein the hybrid electric vehicle includes a vehicle communications bus, the ultracapacitor energy storage cell pack further comprising a digital data interface to the vehicle communications bus; and,
 wherein the programmable logic controller module is coupled to the digital data interface and is configured to be programmed across the vehicle communications bus via the digital data interface.   
   
   
       15 . The ultracapacitor energy storage cell pack of  claim 14 , wherein the controller monitors and reports sensor inputs across the vehicle communications bus via the digital data interface, and controls the cooling system and on/off relay in response to commands from the vehicle communications bus received via the digital data interface. 
   
   
       16 . The ultracapacitor energy storage cell pack of  claim 15 , wherein the digital data interface and the vehicle communications bus are compliant with an SAE standard J1939 Control Area Network (CAN). 
   
   
       17 . The ultracapacitor energy storage cell pack of  claim 1 , wherein the ultracapacitor energy storage cell pack stores at least a nominal 325 watt-hours of electrical energy at a nominal 360 volts DC. 
   
   
       18 . The ultracapacitor energy storage cell pack of  claim 1 , wherein the enclosure includes an inside surface with an anti-corrosion and electrical insulation coating thereon. 
   
   
       19 . The ultracapacitor energy storage cell pack of  claim 1 , wherein the ultracapacitor assembly includes two polycarbonate middle plate supports with cutouts that receive the plurality of parallel ultracapacitors and balancing resistors. 
   
   
       20 . The ultracapacitor energy storage cell pack of  claim 1 , wherein the ultracapacitor assembly includes an end support plate made of a glass fabric laminate with an epoxy resin, and has a pattern of holes for mounting the ultracapacitors.