Patents by Inventor Scott D. Downer

Scott D. Downer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7061134
    Abstract: The present invention includes a method for thermal management in a voltage source inverter. The method includes sensing a low output frequency condition, determining a zero vector modulation responsive to the sensed low output frequency condition, and applying the determined zero vector modulation to reduce thermal stress in the voltage source inverter. The step of determining the zero vector modulation responsive to the sensed low output frequency condition includes mapping an output voltage requirement to a space vector structure and determining state switching space vectors based on the mapped output voltage requirement.
    Type: Grant
    Filed: August 1, 2003
    Date of Patent: June 13, 2006
    Assignee: General Motors Corporation
    Inventors: Silva Hiti, Constantin C. Stancu, Khwaja Rahman, Scott D. Downer, James M. Nagashima, Eric R. Ostrom
  • Patent number: 6864646
    Abstract: A multiple inverter system is powered from a common energy source such as a battery. First and second inverters are coupled to the common energy source and drive corresponding motors. First and second controllers provide pulse width modulated signals, modulated with respect to first and second clock signals, respectively, to the respective first and second inverters. A capacitor coupled between a power bus and a ground bus smoothes power bus ripples caused by simultaneous switching. To reduce the size needed for the capacitor, different modulation schemes, such as center based interleaved, and leading and lagging edge coincident, are used when both motors are in the motoring mode or both motors are in the regeneration mode. However, the same modulation scheme is used when one motor is in the motoring mode and the other motor is in the regeneration mode.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: March 8, 2005
    Assignee: General Motors Corporation
    Inventors: Khwaja M. Rahman, Silva Hiti, Scott D. Downer, Brian Welchko
  • Publication number: 20040160201
    Abstract: A multiple inverter system is powered from a common energy source such as a battery. First and second inverters are coupled to the common energy source and drive corresponding motors. First and second controllers provide pulse width modulated signals, modulated with respect to first and second clock signals, respectively, to the respective first and second inverters. A capacitor coupled between a power bus and a ground bus smoothes power bus ripples caused by simultaneous switching. To reduce the size needed for the capacitor, different modulation schemes, such as center based interleaved, and leading and lagging edge coincident, are used when both motors are in the motoring mode or both motors are in the regeneration mode. However, the same modulation scheme is used when one motor is in the motoring mode and the other motor is in the regeneration mode.
    Type: Application
    Filed: February 14, 2003
    Publication date: August 19, 2004
    Inventors: Khwaja M. Rahman, Silva Hiti, Scott D. Downer, Brian Welchko
  • Patent number: 6608396
    Abstract: A power control system for an electric traction motor in a vehicle comprising at least one inverter for providing conditioned electrical power to the electric traction motor, a plurality of power stages for providing DC power to the at least one inverter, each stage including a battery and boost/buck DC—DC converter, the power stages wired in parallel, and where the power stages are controlled to maintain an output voltage to the at least one inverter.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: August 19, 2003
    Assignee: General Motors Corporation
    Inventors: Scott D. Downer, James F. Lazar, James M. Nagashima
  • Publication number: 20030107352
    Abstract: A power control system for an electric traction motor in a vehicle comprising at least one inverter for providing conditioned electrical power to the electric traction motor, a plurality of power stages for providing DC power to the at least one inverter, each stage including a battery and boost/buck DC-DC converter, the power stages wired in parallel, and where the power stages are controlled to maintain an output voltage to the at least one inverter.
    Type: Application
    Filed: December 6, 2001
    Publication date: June 12, 2003
    Inventors: Scott D. Downer, James F. Lazar, James M. Nagashima
  • Patent number: 6404628
    Abstract: A power electronics cooling housing for use in a power electronics system. The power electronics cooling housing has a body with a coolant cavity formed in one surface and a capacitor bus assembly potting cavity formed in an opposite surface. A bus bar passthrough opening is formed through the body. The bus bar passthrough opening provides an opening from the coolant cavity and the capacitor bus assembly potting cavity. A coolant inlet manifold having a coolant cavity inlet and a coolant outlet manifold having a coolant cavity outlet are formed in the body that are coupled to respective ends of the coolant cavity. An environmental sealing gasket surrounds the coolant cavity.
    Type: Grant
    Filed: July 21, 2000
    Date of Patent: June 11, 2002
    Assignee: General Motors Corporation
    Inventors: James M. Nagashima, Terence G. Ward, Scott D. Downer
  • Patent number: 6381110
    Abstract: A method for detecting an isolation fault in a system comprising a source connected an inverter through a circuit interrupter, the inverter connected to windings of an electric motor for driving the electric motor, is presented. The method comprising operating the inverter (1) to yield a zero net current in the windings of the electric motor other than leakage current resulting from an isolation fault or (2) to apply a voltage to at least one of the windings of the electric motor for a period of time given an ohmic level of an isolation fault to be detected; and measuring a voltage in the system, wherein a voltage level measured during this operation of the inverter is indicative of the existence of an isolation fault. Thereafter, the circuit interrupter is actuated in response to the voltage level indicative of the existence of the isolation fault.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: April 30, 2002
    Assignee: General Motors Corporation
    Inventors: James Nagashima, James Souther, Scott D. Downer
  • Patent number: 6369319
    Abstract: A power electronics chassis (10) for electric vehicles and other applications that use liquid coolant to cool power electronic devices (20) contained within the chassis. The chassis (10) includes an electrically conductive housing (12) and an electrically non-conductive manifold (16) that permits coolant flow into and out of the housing. The housing (12) has at least one wall (34) that includes an outer surface (42) and a pair of recessed apertures (36,72), each of which provide access to an interior region (38) of the housing (12) via a passageway (40,74). The manifold (16) has an inlet (26) and an outlet (28), each of which has a connecting tube (54,80) that extends through one of the passageways (40,74). Each passageway (40,74) is defined by an axial wall (44,78) of the housing (12) that extends towards the interior region (38) from the outer surface (42) to its respective aperture.
    Type: Grant
    Filed: April 19, 2000
    Date of Patent: April 9, 2002
    Assignee: General Motors Corporation
    Inventors: James Nagashima, Terence G. Ward, Scott D. Downer
  • Patent number: 6313991
    Abstract: A thermally cooled power electronics system. A cooling housing has a body with a coolant cavity formed in one surface and a capacitor bus assembly potting cavity formed in an opposite surface. A bus bar passthrough opening is formed through the body, along with a coolant inlet and outlet manifolds having a coolant cavity inlet outlet that are coupled to respective ends of the coolant cavity. An environmental sealing gasket surrounds the coolant cavity. A plurality of laminated copper bus bars are disposed through the bus bar passthrough opening. A laminated horizontal bus bar assembly extends along the length of the housing above the coolant cavity and has horizontal bus bars that are coupled to the laminated copper bus bars. A battery input connector is coupled by way of a vertical bus bar assembly to the horizontal bus bar assembly. A plurality of power switching devices are coupled to the laminated horizontal bus bar assembly.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: November 6, 2001
    Assignee: General Motors Corporation
    Inventors: James M. Nagashima, Terence G. Ward, Scott D. Downer
  • Patent number: 6307346
    Abstract: A power steering system and induction motor load compensation algorithm or processing method for use in a vehicle. The power steering system comprises a power supply, a power steering motor, a steering subsystem, and a power steering controller coupled to the power supply. The controller processes a frequency command input corresponding to the power steering frequency requested by the steering subsystem and data contained in one or more software lookup tables to adjust the output frequency produced by the power supply to control the speed of the power steering, motor. The lookup tables are generated empirically and characterize the output power of the power supply at different system pressures over a range of motor speeds. The software lookup tables provide a power band that implements a power limiting state machine.
    Type: Grant
    Filed: April 20, 2000
    Date of Patent: October 23, 2001
    Assignee: General Motors Corporation
    Inventors: Scott D. Downer, Stanley K. Fujii, Wade E. Char
  • Patent number: 6273756
    Abstract: A chassis cast power connector with coaxial shielding is presented according to the present invention. In an exemplary embodiment, the chassis cast power connector comprises a connector receptacle which is integrally cast with a chassis and extends away from one surface of the chassis. The connector receptacle includes an opening which receives male and female connector members, wherein the male connector member is capable of being slidably received in the female connector receptacle to form an electrical connection therebetween. The integral connector receptacle provides coaxial shielding of the electrical connection.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: August 14, 2001
    Assignee: General Motors Corporation
    Inventors: Terence G. Ward, Scott D. Downer
  • Patent number: 6274999
    Abstract: An induction motor control system for use in a power steering system, comprising: a power steering induction motor coupled to a power supply and providing motive input to pressurize a hydraulic steering subsystem; a phase current sensor for sensing the phase current output by the power supply; and a power steering controller coupled to the power supply for processing a commanded frequency input, the sensed phase current, and data contained in a plurality of software lookup tables using a transfer function to adjust the motor voltage produced by the power supply to control the speed of the power steering motor.
    Type: Grant
    Filed: December 16, 1999
    Date of Patent: August 14, 2001
    Assignee: General Motors Corporation
    Inventors: Stanley K. Fujii, Scott D. Downer, Wade E. Char
  • Patent number: 6219245
    Abstract: A power electronics chassis (10) and liquid-cooled heat sink mounting assembly for electric vehicles and other applications that use liquid coolant to cool power electronic devices (20) contained within an electrically conductive housing (12). The power electronics chassis (10) includes an inverter (18) containing power switching devices (20) that are heat sunk using the liquid-cooled mounting assembly. The mounting assembly includes a heat exchanger (22) and a plastic, electrically non-conductive coolant manifold (16) that has an inlet (26) and outlet (28) for passage of liquid coolant into and out of the electronics housing (12). The power switching devices (20) are attached to a mounting surface (40) of the heat exchanger (22) and are thermally coupled to the coolant within the heat exchanger (22) via the mounting surface (40).
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: April 17, 2001
    Assignee: General Motors Corporation
    Inventors: James Nagashima, Terence G. Ward, Scott D. Downer
  • Patent number: 6173758
    Abstract: A pin fin heat sink having mixed geometry pin fin configurations is presented. The mixed geometry pin fin configuration are designed to optimize the positive attributes of each individual pin fin geometry to provide a low cost overall system and provide better system performance in high flow rate systems. In an exemplary embodiment, the pin fin heat sink comprises a base surface having a plurality of pin fins perpendicular to and protruding therefrom. The plurality of pin fins actually comprises a plurality of pin fins having a first configuration and a plurality of pin fins having a second configuration. The second configuration pin fins are intended to streamline any turbulence created by the first configuration pin fins which are located upstream of the second configuration pin fins. Preferably, the first configuration comprises substantially circular shaped pin fins and the second configuration comprises substantially elliptical shaped pin fins.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: January 16, 2001
    Assignee: General Motors Corporation
    Inventors: Terence G. Ward, Scott D. Downer
  • Patent number: 5777273
    Abstract: An electrical cable for use in high-frequency, high power applications, such as with an inductive charging system used to charge batteries of an electric vehicle. The cable has multiple twisted-pairs of separately insulated stranded wire arranged in a pseudo-Litz wire architecture that surround a coaxial cable. The coaxial cable carries bidirectional RF communication signals between a power source of the charging system and the vehicle. The cable has an outer EMI shield that includes a metalized mylar layer surrounded by a high coverage tinned-copper braid layer. The multiple twisted-pairs of wires and coaxial cable are embedded in a polytetrafluoroethylene filler material that surrounds them inside the outer EMI shield. An outer silicone cover is disposed around the outside of the cable. The cable efficiently transfers power at high-frequency AC power, between 100 KHz to 400 KHz at high-voltage levels, on the order of from 230 V to 430 V. The cable carries bidirectional RF communication signals using a 91.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: July 7, 1998
    Assignee: Delco Electronics Corp.
    Inventors: George R. Woody, Scott D. Downer
  • Patent number: 5703462
    Abstract: An inductive coupler having an antenna and primary winding formed as part of a single structure that can be readily and consistently produced using printed wiring board manufacturing techniques. The coupler has the primary winding and antenna are formed as part of a printed wiring board. A coupler housing having two mating coupler halves secures a center magnetic core and the printed wiring board therebetween. The coupler housing also secures a cable that is coupled between selected printed circuit layers of the primary winding and a power source for coupling energy to the charging coupler.
    Type: Grant
    Filed: July 15, 1996
    Date of Patent: December 30, 1997
    Assignee: Delco Electronics Corp.
    Inventors: George R. Woody, Scott D. Downer