Abstract: A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset.

Abstract: Methods and systems are provided for producing a commanded torque in an electric motor in a vehicle. A method comprises obtaining a torque command, obtaining a speed of the electric motor, and operating the inverter based at least in part on a voltage command that corresponds to minimal current through the electric motor for producing the commanded torque at the instantaneous speed of the electric motor.

Abstract: Methods and systems are provided for controlling an electric motor in a vehicle. A method comprises measuring current associated with a first phase of the electric motor using a first current sensor resulting in a measured first phase current and measuring current associated with a second phase of the electric motor using a second current sensor resulting in a measured second phase current. The method further comprises determining a target value for the measured second phase current based on a value corresponding to a peak current for the first phase and identifying a current sensor error based on a difference between the measured second phase current and the target value.

Abstract: Systems and methods are provided for a double-ended inverter drive system for a fuel cell vehicle. An electric drive system for a vehicle comprises an electric motor configured to provide traction power to the vehicle. A first inverter is coupled to the electric motor, and is configured to provide alternating current to the electric motor. A fuel cell is coupled to the first inverter to provide power flow from the fuel cell to the electric motor. A second inverter is coupled to the electric motor, and is configured to provide alternating current to the electric motor. An energy source is coupled to the second inverter to provide power flow between the energy source and the electric motor. A controller is coupled to the first inverter and the second inverter, and is configured to provide a constant power from the fuel cell during operation of the electric motor.

Abstract: Methods and apparatus are provided for operation of a voltage source inverter. A method of operating a voltage source inverter having an output with multiple voltage phases having a DC voltage level, the method comprising sensing a low output frequency condition; determining a DC voltage offset responsive to the low output frequency condition; and applying the DC voltage offset when operating the voltage source inverter resulting in a change to the DC voltage level of the multiple voltage phases.

Abstract: A double ended inverter system for an AC electric traction motor of a vehicle is disclosed. The inverter system serves as an interface between two different energy sources having different operating characteristics. The inverter system includes a first energy source having first operating characteristics associated therewith, and a first inverter subsystem coupled to the first energy source and configured to drive the AC electric traction motor. The inverter system also includes a second energy source having second operating characteristics associated therewith, wherein the first operating characteristics and the second operating characteristics are different, and a second inverter subsystem coupled to the second energy source and configured to drive the AC electric traction motor. In addition, the inverter system has a controller coupled to the first inverter subsystem and to the second inverter subsystem.

Abstract: Systems and methods are provided for charging energy sources with a rectifier using a double-ended inverter system. An apparatus is provided for an electric drive system for a vehicle. The electric drive system comprises an electric motor configured to provide traction power to the vehicle. A first inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A first energy source is coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor. A second inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A rectifier is coupled to the second inverter and configured to produce a direct current output. The second inverter is configured to provide power from the rectifier to the electric motor.

Abstract: Systems and methods are provided for controlling a double-ended inverter system having a first inverter and a second inverter. The method comprises determining a required output current and determining a desired second inverter current. The method further comprises determining a second inverter switching function, wherein only a selected leg in the second inverter is modulated at a duty cycle, determining a first inverter switching function based on the second inverter switching function, and modulating the first inverter and the second inverter using the first inverter switching function and the second inverter switching function.

Abstract: A double ended inverter system for an AC traction motor of a vehicle includes a fuel cell configured to provide a DC voltage, an impedance source inverter subsystem coupled to the fuel cell, a DC voltage source, and an inverter subsystem coupled to the DC voltage source. The impedance source inverter subsystem, which includes an ultracapacitor, is configured to drive the AC traction motor. The inverter subsystem is configured to drive the AC electric traction motor. The ultracapacitor is implemented in a crossed LC network coupled to the fuel cell.

Abstract: Systems and methods are provided for an inverter system for use in a vehicle having a first energy source and a second energy source. The system comprises a motor having a first set of windings and a second set of windings. The first set of windings is electrically isolated from the second set of windings. The system further comprises a first inverter coupled to the first energy source and adapted to drive the motor, wherein the first set of windings are coupled to the first inverter. The system also comprises a second inverter coupled to the second energy source and adapted to drive the motor, wherein the second set of windings are coupled to the second inverter. A controller is coupled to the first inverter and the second inverter.

Abstract: Systems and apparatus are provided for an inverter system for use in a vehicle. The inverter system comprises a six-phase motor having a first set of three-phase windings and a second set of three-phase windings and a three-phase motor having a third set of three-phase windings, wherein the third set of three-phase windings is coupled to the first set of three-phase windings and the second set of three-phase windings. The system further comprises a first energy source coupled to a first inverter adapted to drive the six-phase motor and the three-phase motor, wherein the first set of three-phase windings is coupled to the first inverter, and a second energy source coupled to a second inverter adapted to drive the six-phase motor and the three-phase motor, wherein the second set of three-phase windings is coupled to the second inverter. A controller is coupled to the first inverter and the second inverter.

Abstract: A method for controlling an induction machine having a rotor includes the steps of obtaining a torque command, calculating an estimated squared value of resistance of the rotor using the torque command, determining an offset for the resistance of the rotor, and generating an updated measure of rotor resistance using the estimated squared value and the offset.

Abstract: Systems and apparatus are provided for an inverter system for use in a vehicle having a first energy source and a second energy source. The inverter system comprises an electric motor having a first set of windings and a second set of windings. The inverter system further comprises a first inverter coupled to the first energy source and adapted to drive the electric motor, wherein the first set of windings are coupled to the first inverter. The inverter system also comprises a second inverter coupled to the second energy source and adapted to drive the electric motor, wherein the second set of windings are coupled to the second inverter. A controller is coupled to the first inverter and the second inverter to achieve desired power flow between the first energy source, the second energy source, and the electric motor.

Abstract: A double ended inverter system suitable for use with an AC electric traction motor of a vehicle is provided. The double ended inverter system cooperates with a first DC energy source and a second DC energy source, which may have different nominal voltages. The double ended inverter system includes an impedance source inverter subsystem configured to drive the AC electric traction motor using the first energy source, and an inverter subsystem configured to drive the AC electric traction motor using the second energy source. The double ended inverter system also utilizes a controller coupled to the impedance source inverter subsystem and to the inverter subsystem. The controller is configured to control the impedance source inverter subsystem and the inverter subsystem in accordance with a boost operating mode, a traditional inverter operating mode, and a recharge operating mode of the double ended inverter system.

Abstract: Systems and methods are provided for controlling a double-ended inverter system coupled to a first energy source and a second energy source. The method comprises determining a constant power line associated with operation of the double-ended inverter system, the constant power line representing a desired power flow to the second energy source. The method further comprises determining an operating point on the constant power line, the operating point producing a minimum power loss in the double-ended inverter system for a required output current, and modulating the double-ended inverter system using a first voltage command and a second voltage command corresponding to the operating point.

Abstract: Methods and systems are provided for producing a commanded torque in an electric motor in a vehicle. A method comprises obtaining a torque command, obtaining a speed of the electric motor, and operating the inverter based at least in part on a voltage command that corresponds to minimal current through the electric motor for producing the commanded torque at the instantaneous speed of the electric motor.

Abstract: Methods and systems are provided for controlling an electric motor in a vehicle. A method comprises measuring current associated with a first phase of the electric motor using a first current sensor resulting in a measured first phase current and measuring current associated with a second phase of the electric motor using a second current sensor resulting in a measured second phase current. The method further comprises determining a target value for the measured second phase current based on a value corresponding to a peak current for the first phase and identifying a current sensor error based on a difference between the measured second phase current and the target value.

Abstract: Methods and systems are provided for operating an electric motor having at least one winding coupled to first and second power supplies. A torque command for the electric motor is received. A present power reserve for the first and second power supplies is determined based at least in part on the torque command. An operating voltage for the second power supply is determined based on the present power reserve. The operating voltage for the second power supply is applied to the at least one winding. The application of the operating voltage allowing the present power reserve to flow between the first and second power supplies and the motor.

Abstract: Methods and apparatus are provided for operation of a voltage source inverter. A method of operating a voltage source inverter having an output with multiple voltage phases having a DC voltage level, the method comprising sensing a low output frequency condition; determining a DC voltage offset responsive to the low output frequency condition; and applying the DC voltage offset when operating the voltage source inverter resulting in a change to the DC voltage level of the multiple voltage phases.

Abstract: An inverter circuit couples a DC voltage source having a primary side and a reference side to an electric motor or other AC machine having multiple electrical phases. An inverter circuit includes switches, diodes and a controller. For each of the electrical phases, a first switch couples the electrical phase to the primary side of the DC voltage source and a second switch couples the electrical phase with the reference side of the DC voltage source. For each of the first and second switches, an associated anti-parallel diode is configured to provide an electrical path when the switch associated with the diode is inactive.