Patents Assigned to Active Power, Inc.
  • Patent number: 7127895
    Abstract: Backup energy systems utilizing compressed air storage (CAS) systems and bridging energy systems to supply backup power to a load are provided. During a power failure, the bridging energy system provides backup power to the load at least until the CAS system begins supplying adequate power. In various embodiments, backup power capability is enhanced through the use of one or more exhaustless heaters, which are used to heat compressed air. The compressed air, in turn, drives a turbine which is used to power an electrical generator. In various embodiments, ambient air heat exchangers or other types of heat exchangers are used to heat compressed air prior to the compressed air being routed to the turbine, thereby increasing system efficiency. Backup power and backup HVAC are also provided by utilizing turbine exhaust, heat exchangers and various resistive heating elements.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: October 31, 2006
    Assignee: Active Power, Inc.
    Inventors: Joseph F Pinkerton, David Beatty, David E Perkins
  • Patent number: 7086231
    Abstract: Combined thermal and compressed air storage systems are provided that utilize an exhaustless heater, such as a thermal storage unit, to provide power with enhanced efficiency. Compressed air is heated by the thermal storage unit prior to entering a turbine, which powers an electrical generator. In various embodiments, ambient air temperature, turbine exhaust or other types of waste heat are used to preheat the compressed air prior to the compressed air entering the thermal storage unit, thereby further increasing system efficiency.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: August 8, 2006
    Assignee: Active Power, Inc.
    Inventor: Joseph F. Pinkerton
  • Patent number: 7030593
    Abstract: The present invention relates to variable speed constant frequency (VSCF) devices and methods for maximizing engine generator efficiency. In one embodiment, a VSCF device may include at least two paths for conducting power to the load. One path, a line inductor path, may advantageously incur minimal power loss when the engine generator is supplying rated power to a load. A second path, a VSCF path, may be used to ensure that the frequency of the power is maintained at a substantially constant frequency under various load conditions. Another embodiment of the invention describes a process for determining optimal engine generator speed for a particular load. Because engine speed can be varied using any VSCF device, this process determines a speed that minimizes fuel consumption, emissions, and noise pollution for a given load.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: April 18, 2006
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, III, David A. Badger
  • Patent number: 6955050
    Abstract: A thermal storage unit having at least one annular flow channel formed between an inner and outer member is provided. The thermal storage unit uses conventional mill products to create annular flow channels that economically maximize the surface area of flow in contact with the thermal mass included in the inner and outer members. This enables the thermal storage unit to economically provide heat storage as well as effective heat delivery and pressure containment for a fluid flowing through the annular channel.
    Type: Grant
    Filed: December 16, 2003
    Date of Patent: October 18, 2005
    Assignee: Active Power, Inc.
    Inventors: David E. Perkins, Robert S. Hudson
  • Patent number: 6914349
    Abstract: Systems and methods of universal uninterruptible power supply (UPS) input circuitry are provided. The input circuitry of the present invention enables a UPS system to simply connect and operate in conjunction with any suitable backup power system. In particular, once a user indicates what backup system is attached to the input circuitry, a software unit automatically configures the input circuitry to operate with the coupled backup system. Once configured, the software unit may control portions of the input circuitry such that power is continuously provided to a load. For example, once a user indicates that a flywheel based backup system is attached, the software unit may instruct the input circuitry to maintain a predetermined flywheel speed (e.g., RPM) to ensure that the system is in constant ready state to deliver backup power.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: July 5, 2005
    Assignee: Active Power, Inc.
    Inventor: Ramamoorthy Rajagopalan
  • Patent number: 6844706
    Abstract: The present invention relates to variable speed constant frequency (VSCF) devices and methods for maximizing engine generator efficiency. In one embodiment, a VSCF device may include at least two paths for conducting power to the load. One path, a line inductor path, may advantageously incur minimal power loss when the engine generator is supplying rated power to a load. A second path, a VSCF path, may be used to ensure that the frequency of the power is maintained at a substantially constant frequency under various load conditions. Another embodiment of the invention describes a process for determining optimal engine generator speed for a particular load. Because engine speed can be varied using any VSCF device, this process determines a speed that minimizes fuel consumption, emissions, and noise pollution for a given load.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: January 18, 2005
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, III, David A. Badger
  • Patent number: 6777823
    Abstract: A continuous power system assembly is provided that includes an integrated shaft-driven unit. The unit contains a turbine, an alternator, a flywheel and a feed pump, all of which are coupled to the shaft. During various modes of operation, any of the turbine, alternator or flywheel may provide the torque used to drive the shaft. When the alternator is not providing the necessary torque to drive the shaft, it is operated as a generator that provides back-up power to a load. The present invention also includes a unique nozzle design that improves the ease with the nozzles may be manufactured in comparison to known designs. The nozzle is manufactured as two halves which are mated as part of the manufacturing process. The individual nozzles may, because only half of the nozzle segments exist on either half of the nozzle block, be easily manufactured using conventional machining.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: August 17, 2004
    Assignee: Active Power, Inc.
    Inventors: Gail Roberts, Philip Keene, David Lowe, James Hunt, Joseph F. Pinkerton, David B. Clifton
  • Publication number: 20040124813
    Abstract: The present invention relates to variable speed constant frequency (VSCF) devices and methods for maximizing engine generator efficiency. In one embodiment, a VSCF device may include at least two paths for conducting power to the load. One path, a line inductor path, may advantageously incur minimal power loss when the engine generator is supplying rated power to a load. A second path, a VSCF path, may be used to ensure that the frequency of the power is maintained at a substantially constant frequency under various load conditions. Another embodiment of the invention describes a process for determining optimal engine generator speed for a particular load. Because engine speed can be varied using any VSCF device, this process determines a speed that minimizes fuel consumption, emissions, and noise pollution for a given load.
    Type: Application
    Filed: August 30, 2002
    Publication date: July 1, 2004
    Applicant: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David A. Badger
  • Patent number: 6657320
    Abstract: Integrated flywheel uninteruptible power supply (UPS) systems provide reliable back-up power protection in a single integrated housing unit. The integration of the two normally independent systems results in a synergism such that various components may be shared between the systems. For example, the flywheel unit and the UPS electronics unit may utilize a single cooling system that is less complex and requires less energy to operate than two independent cooling systems. Other shared components may include at least control circuitry, user and display interface circuitry, fusing, DC bus capacitors, and emergency shut-off circuitry.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: December 2, 2003
    Assignee: Active Power, Inc.
    Inventors: James A. Andrews, David A. Badger, Robert L. Fuller, Randal A. Lee, David E. Perkins, James R. Pitt, Dave J. Wehrlen
  • Patent number: 6642682
    Abstract: The motor-generator circuitry of a flywheel energy conversion device can be utilized to preheat the rotor of the flywheel device. It may be desirable to preheat the rotor prior to normal operation because a rotor operating in cold temperature may be more susceptible to brittle fracture or other damage than a rotor operating at a specified operating temperature. The present invention may utilize the principle of induction heating to preheat the rotor. In preferred embodiments, high frequency current may be passed through armature windings of the motor-generating circuitry to induce surface currents into the periphery of the rotor. Heat may then be generated in portions of the rotor receiving the induced currents and then radiate from those portions to raise the rotor temperature to a desired level.
    Type: Grant
    Filed: February 21, 2002
    Date of Patent: November 4, 2003
    Assignee: Active Power Inc.
    Inventors: David E. Perkins, Charles S. Richey
  • Patent number: 6512305
    Abstract: An uninterruptible power supply (UPS) system supplies power to computers, medical apparatus or other critical loads when primary power supply falters. The UPS system includes an electrical machine connected to a turbine that can be rotated by a motive fluid from a fluid supply. The electrical machine can be a dual purpose electrical machine (a motor/generator) or a two unit machine (one motor and one generator in a single housing or in separate housings) connected to the turbine. When power is supplied from the primary power supply to the critical load, the electrical machine acts as a motor to rotate the turbine and energy is stored by the turbine rotor in the form of rotational momentum. When power from the primary power supply falters, the rotational momentum of the turbine rotor initially rotates the electrical machine which acts as a generator to provide power to the critical load.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: January 28, 2003
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6463738
    Abstract: A continuous power system provides a continuous supply of power to a load in the event that primary power fails or is degraded. The continuous power system includes an electrical machine, a turbine and a flywheel coupled to a shaft. When utility power is present, the machine operates as a motor to drive the shaft. During outages, the electrical machine operates as a generator to provide power to the load. Kinetic energy stored in the flywheel drives the shaft during initial power interruptions. During further short-term interruptions, a thermal energy supply (or thermal storage device) is used to provide vaporized liquid to the turbine so that the turbine drives the shaft. If the power loss or failure is extended, the turbine is driven by vapor produced by an evaporator heated from an external fuel supply. Numerous methods and apparatus are also described for reducing system losses and improving overall performance.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: October 15, 2002
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton, Kenneth E. Nichols, Michael D. Forsha, James E. Dillard, William D. Batton
  • Patent number: 6408627
    Abstract: A continuous power system accumulator assembly is provided that stores thermal energy as sensible heat and minimizes the amount of thermal energy wasted by the system. The assembly includes an accumulator at its core. A preheater assembly is wrapped around the accumulator such that it may absorb heat radiated and conducted from the accumulator. An evaporator is wrapped around the preheater so that most of the heat that is radiated and conducted from the preheater is utilized to heat the vaporizer. The outer housing of the assembly may be a double-walled housing having a layer of insulation located between the two walls. This configuration minimizes heat losses by the assembly.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: June 25, 2002
    Assignee: Active Power, Inc.
    Inventors: William D. Batton, Kevin Hotton, Gary Frey, Gail Roberts
  • Patent number: 6323573
    Abstract: An inductor-alternator provides highly efficient conversion between mechanical and electrical energy. The inductor-alternator produces increased output by providing armature coils in a single air gap formed between two halves of a toothed rotor. In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within the rotating rotor. Airgap armature coils are mounted with the field coils to form a stationary assembly that is placed within the single air gap in the rotor so that the changing flux density (due to the rotating teeth) induces an output voltage in the armature coils. The rotor and stationary assembly are mounted in a housing by bolts that may also be used as terminals for the armature coils to reduce assembly complexity and production cost. The combined assembly provides high energy and power density because tip speed of the rotor is maximized and the use of air gaps is minimized.
    Type: Grant
    Filed: March 23, 2000
    Date of Patent: November 27, 2001
    Assignee: Active Power, Inc.
    Inventor: Joseph F. Pinkerton
  • Patent number: 6255743
    Abstract: An uninterruptible power supply (UPS) system supplies electric power to computers, medical apparatus or other critical loads when a primary power supply fails. The UPS system includes an electrical machine drivingly connected to a turbine which can be rotated by a motive fluid from a fluid supply. The electrical machine can be a dual purpose electrical machine (a motor/generator) or a two unit machine (one motor and one generator in a single housing or in separate housings) drivingly connected to a turbine which can be rotated by a motive fluid supply. When power is supplied from the primary power supply to the critical load, the electrical machine acts as a motor to rotate the turbine, and energy is stored by the turbine rotor in the form of rotational momentum. When power from the primary power supply fails, the rotational momentum of the turbine rotor initially rotates the electrical machine which acts as a generator to provide power to the critical load.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: July 3, 2001
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6236123
    Abstract: An electrical generator has at least one rotating ring of field magnets which produce a circular array of magnetic fields, and a ring of generator output coils which are in the magnetic fields. The field magnets are permanent magnets or electromagnets. The generator output coils are movable in a displacement path toward and away from a null position at which they are exposed to zero net flux from the magnetic fields. Movement of the coils by an actuator varies the amplitude of the voltage induced in these coils by the rotating field magnets. The actuator is energized by an alternating current to create a mechanical oscillation of the generator output coils in their displacement path. The coils provide a raw amplitude-modulated signal that has a carrier frequency which is a function of the rotational velocity of the field magnets and a modulation frequency that is proportional to the mechanical oscillation of the generator output coils.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: May 22, 2001
    Assignee: Active Power, Inc.
    Inventor: Joseph F. Pinkerton
  • Patent number: 6208056
    Abstract: A field replaceable air-gap cartridge armature device for use in rotating electric machines is presented. The cartridge armature includes a plurality of bent-shaped air-gap windings rigidly arranged in a circular fashion to form an inner rim, an outer rim and an active section. The inner and outer rims are formed by end turn sections that are bent toward and away, respectively, from the center of the cartridge device. The windings may be generally arranged into a Z-shaped cross-section that is embedded in a fiber reinforced epoxy resin matrix to provide a rigid structure for transferring torque from the air-gap windings to a stator. Countersunk fasteners are used to easily attach and remove the cartridge armature from a rotating electric machine. The cartridge armature can be configured as a three phase, Y-connected armature circuit, and provides electrically insulated, substantially vacuum tight terminal penetration of a rotating electric machine for electrical feed-throughs.
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: March 27, 2001
    Assignee: Active Power, Inc.
    Inventor: David E. Perkins
  • Patent number: 6192687
    Abstract: Uninterruptible power supplies are provided that utilize a material to provide a source of thermal energy that may be converted to electrical energy to produce backup electrical power for a load. In some embodiments, a hot tank assembly is utilized to hold a liquid heated to a predetermined temperature. A closed-loop pipe containing, water for example, is immersed in the heated liquid. Upon the loss of primary power, the water flows into the heat exchanger where it is raised above its boiling temperature. The steam is then passed to a heat engine (e.g., a turbine-based system) that converts the heated steam to mechanical energy by causing the heat engine rotor to rotate. A generator is physically coupled to the heat engine so that the rotation of the heat engine rotor drives the generator. The generator produces AC power which is converted to DC and again back to AC before being provided to the load. In other embodiments, a solid mass, such as a block of iron, is heated to a predetermined temperature.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: February 27, 2001
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton
  • Patent number: 6166472
    Abstract: A flywheel energy conversion device provides highly efficient conversion between kinetic and electrical energy. The flywheel produces increased output by providing armature coils in an air gap formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor having teeth cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth passing across an armature air gap. Airgap armature coils are preferably utilized in which the changing flux density (due to the rotating teeth) induces an output voltage in the coils.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: December 26, 2000
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, Scott R. Little
  • Patent number: 6124702
    Abstract: Electrical machine cycloconverter devices are provided that produce output signals in which the frequency, amplitude and phase are independent of rotor speed. The cycloconverters produce highly efficient increased output by providing multi-tap armatures that include multiple armature coils arranged such that at least two coils may be connected in series to an electrical load. Such configurations produce output signals that include multiple distinct voltage amplitude steps. In preferred embodiments, either rotating permanent magnets or field coils in conjunction with rotating steel teeth induce a voltage in the armature coils. The level of induced voltage is determined by the switching sequence of one or more armature coils that are switched ON and OFF in series, parallel, or series and parallel by semiconductor switches.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: September 26, 2000
    Assignee: Active Power, Inc.
    Inventors: Joseph F. Pinkerton, David B. Clifton