Gm Global Technolgoy Operations, Inc.

Eric R Ostrom

James Michio Nagashima

Constantin C Stancu

Gregory S Smith

Karl David Conroy

George John

Young Mok Doo

Robert T Dawsey

Silva Hiti

Khwaja M Rahman

George R Woody

Terence G Ward

David Yuang Tang

Scott D Downer

David F Nelson

Cooling systems and methods are provided for an integrated electric motor-inverter, where the integrated electric motor-inverter includes a housing, a motor, and an inverter, the motor and the inverter are disposed within the housing, and the motor includes a stator. The system includes a cooling jacket, a first coolant, a condenser, a spray head, and a second coolant. The cooling jacket is disposed concentric to the stator and includes an inner wall and an outer wall. The inner wall is in direct contact with the stator. The first coolant is disposed between the cooling jacket inner and outer walls. The condenser is disposed concentric to the cooling jacket. The spray head is disposed adjacent the inverter. The second coolant is in flow communication with the spray head.

Cooling systems and methods for integration electric motor-inverters

A coaxial stack of laminations for a stator of an electrical machine uses laminations that are substantially identical and in direct abutment with one another. Each of the laminations has an outer periphery and an inner periphery with the outer periphery being defined by an array of outwardly projecting pins and the inner periphery being defined by an array of inwardly projecting teeth. The outwardly projecting pins cooperate with a jacket surrounding the stack to provide a cooling space through which cooling liquid flows while the teeth provide spaces therebetween for receiving for receiving stator windings. The number of pins (n) is proportional to the number of teeth (n) according to the relationship (2K+1)/(2K) times the number of teeth (n), where K is a selected integer number and Kis the number of teeth past which each lamination is rotated with respect to adjacent laminations so that spaces between the teeth of adjacent laminations are aligned.

Apparatus for cooling stator lamination stacks of electrical machines

Power electronics for electric traction motors used to drive automotive vehicles are cooled in a closed system by spraying a dielectric liquid coolant directly onto inverter circuitry. The liquid coolant changes phase and vaporizes as it absorbs heat from power transistors in inverter circuitry comprising the power electronics. The resultant vapor is condensed back to a liquid in a heat exchange arrangement having pipes carrying a second coolant from a radiator used to cool an engine or fuel cell stack in the automotive vehicle. Overspray coolant, which remains liquid, can also be cooled by the heat exchange arrangement. By utilizing the latent heat of evaporation of the dielectric coolant and increasing the rate recycling of the coolant as power output increases, temperature increases in the power electronics are controlled.

Arrangements for and methods of phase change cooling of power electronics

A rotor for an interior permanent magnet machine has a rotor body having an output shaft and a first cavity filled with magnetic material. Second cavities are disposed inboard of the first cavities and are not filled with magnetic material. Non-magnetic rods extend through the second cavities and protrude beyond end faces of the rotor body. The rods are press-fit in blind bores formed in non-magnetic end plates disposed adjacent the end faces of the rotor body. Shrink disks are shrunk around projecting ends of the output shaft in abutting relation with the end plates. In order to prevent induced voltage from generating current in the cage formed by the rods and end plates, an oxide layer is disposed between the rods and blind bores in the end plates.

Permanent magnet machine rotor

In order to provide a modular arrangement, an inverter for an electric traction motor used to drive an automotive vehicle is positioned in proximity with the traction motor. The inverter is located within a compartment adjacent to one end of the electric traction motor and is cooled in a closed system by spraying a liquid coolant directly onto the inverter. The liquid coolant absorbs heat from the inverter and is cooled by a heat exchange arrangement comprising a reservoir with pipes carrying a second coolant from the radiator of the automotive vehicle. In a preferred embodiment, the coolant is collected from the inverter in an annular reservoir that is integral with the compartment containing the inverter. In accordance with one embodiment of the cooling arrangement, heat from the inverter vaporizes the liquid coolant by absorbing heat from the inverter during a phase change from a liquid to a vapor. The vaporized coolant is condensed by a circulating second coolant in pipes connected to the vehicle's radiator through a condenser that is preferably coaxial with the motor and the annular reservoir, which annular reservoir in the second embodiment collects overspray liquid coolant. In order to avoid degrading the inverter, the coolant is a dielectric fluid.

Cooling arrangements for integrated electric motor-inverters

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. The step of determining the state switching space vector includes determining active state switching space vectors associated with the state switching space vectors, determining duty cycles for the active state switching space vectors based on the active state switching space vectors, and determining a duty cycle for at least one zero state switching space vector based on the determined duty cycles of the active state switching space vectors and a switching period.

Method and system for improved thermal management of a voltage source inverter operating at low output frequency utilizing a zero vector modulation technique

Growing community of inventors

Bellflower, CA, United States of America

Eric R Ostrom