Maxwell Technologies, Inc.

Other

Powerware Corporation

I-Bus Corporation

I-Bus / Phoenix, Incorporated

Valhalla Scientific Incorporated

Guy C Thrap

James Borkenhagen

Adrian Schneuwly

Philippe Lauper

Mark Wardas

Johni Chan

Dinesh Shah

Electronic circuits couple energy storage devices, such as double layer capacitors or rechargeable battery cells, to a power supply output, thereby improving noise suppression and extending ride-through capability of the power supply. In a typical circuit, an energy storage device is coupled in series with a switch that controls the charging current into the energy storage device. The switch is controlled by a comparator that receives a signal related to the voltage level of the power supply. In some embodiments, the comparator also receives a feedback signal related to a charging current flowing into the energy storage device. The circuit is configured so that the switch limits the charging current to a predetermined current level, or does not allow the charging current to flow until the output voltage of the power supply reaches a predetermined voltage level.

Capacitor start-up apparatus and method with fail-safe short circuit protection

A thermally fitted interconnect couples energy storage cells without the use of additional materials of fasteners. Variations of the interconnect can be used to facilitate fitting of multiple energy storage cell with multiple cell to cell spacings in a rapid and inexpensive manner.

Thermal interconnects for coupling energy storage devices

A power module includes double layer capacitors, a voltage booster, a charging circuit, and a switching assembly. In discharging mode, the switching assembly connects the voltage booster to the output of the power module. The voltage booster enhances the voltage of the cells as needed for operation of a load at the output of the module. In charging mode, the switching assembly connects the charging circuit to the output of the module to receive electric energy from an external charger connected to the output of the module. The charging circuit converts the received energy into energy suitable for recharging the cells. In end-of-cycle discharging mode, the switching assembly connects the voltage booster to the charging circuit, causing these devices to loop into each other. Inefficiencies in the voltage booster and the charging circuit dissipate the energy in the cells, rendering the battery fail-safe.

Apparatus and method for discharging electrical energy storage cells

Thermal protection is provided in systems utilizing high-current double-layer capacitors.

Thermal interconnection for capacitor systems

An energy storage system is described for use in, for example, electronics systems such as a bank of computers. The disclosed energy storage systems allows the use of an efficient energy source, such as ultracapacitors, while providing a desired voltage level for an extended period of time. One embodiment of the energy storage system provides power to a load. The system includes a power module including at least one ultracapacitor adapted to store and discharge energy. The power module provides an output voltage as the ultracapacitor discharges energy. The system also includes a voltage regulator for boosting the output voltage of the power module. The voltage regulator may include a voltage converter. The voltage converter may be adapted to boost the output voltage when the output voltage falls below a predetermined threshold. The voltage converter may include a plurality of interleaving inductor circuits, each of the circuits including a switch and an inductor. The switches are adapted to be sequentially closed and opened, thereby in sequence storing energy in the inductors and discharging energy to the load.

Energy storage system

Thermal protection is provided in systems utilizing high-current double-layer capacitors. For example, in one implementation, an interconnection coupled to at least one double-layer capacitor that carries capacitor current to or from the at least one double-layer capacitor is functionally coupled to the at least one double-layer capacitor to reduce a temperature of the capacitor is provided.

Capacitor start-up apparatus and method with fail safe short circuit protection

A plurality of high capacitance capacitors are coupled to supply or accept large currents. Bus bars are welded to the capacitors to provide improved thermal performance as well as self-supporting rigidity to the geometrical structure formed by the capacitors and the bus bars.

Self-supporting capacitor structure

A rapid charging circuit for charging a power module is disclosed. The power module includes one or more ultracapacitors. The power module is charged using an energy source connected to the power module. The charging circuit includes a control circuit adapted to maintain a constant power level at the power module during charging as the voltage level across the power module increases. The control circuit includes a pulse-width modulator and an inductor connected in series with the power module. The pulse-width modulator can control a charge level of the inductor. The charge level may correspond to a current level which is in accordance with a desired power level at the power module and an instantaneous voltage level across the power module. The inductor may be adapted to limit a current level through the power module to a predetermined peak level. The control circuit may be adapted to provide a current level through the power module greater than a current level from said energy source during at least a portion of a charging period.

Rapid charger for ultracapacitors

High capacitance capacitors are provided to supply or accept large currents. As current flow through a capacitor increases, heat may be generated. Above a certain threshold temperature or current, a capacitor may fail. The present invention addresses capacitor's tendency to fail at higher currents and/or higher temperatures.

Capacitor heat reduction apparatus and method

Capacitor heat protection

Self-oscillating, current controlled switching power supplies, used for example, as energy storage device charging circuits, and related methods are provided herein. In one implementation, a switching power supply comprises a power transformer having a primary and a secondary, a switching element that switches a voltage source to the primary, and a control circuit that controls the operation of the switching element in response to the measured primary current and secondary current. The switching element disconnects the voltage source from the primary when the primary current reaches a first threshold, causing the secondary current to conduct. The switching element switches back to the primary when the secondary current drops to second threshold. The switching power supply oscillates between charging and discharging the power transformer. In one embodiment, a high value energy storage capacitor is coupled to the secondary and is charged with the secondary current.

Switching power supply

A charge balancing circuit is disclosed that is configured to provide charge balancing for a bank of series connected charge storage devices such as capacitors. One embodiment of the charge balancing circuit comprises a voltage divider, an operational amplifier, and a negative feedback resistor connected between every two capacitors. The circuit is configured to monitor the voltage in each of the capacitors and, if the voltage in one of the capacitors is higher than the other, the circuit transfers energy from the higher charged capacitor to the lower charged capacitor until the capacitors are balanced. A current limiting resistor can be included for limiting the output current of the operational amplifier to a safe value and for providing feedback information regarding the health of the capacitor. An additional gain stage can also be included for increasing the output current of the operational amplifier for banks of large charge storage devices such as capacitors.

Charge balancing circuit

An isolated power input architecture that includes hot swappable input modules that are electrically isolated from each other so that each may provide input power to power supplies for an electronic device without adverse interactions between the voltages provided by each input module. The isolated input modules are each configured to lock the other out so that only one input module is providing power to the power supplies for the electronic device. The power supply for the electronic device preferably includes N&plus;1 power supplies where N power supplies are required by the electronic device. Either of the isolated input modules provides enough power to supply power to all the N&plus;1 power supplies.

Growing community of inventors

Del Mar, CA, United States of America

Guy C Thrap