Abstract: Methods and apparatus are provided for discharging a direct current (DC) bus providing power to a motor control circuit in an electric motor system. The method includes the steps of detecting a predetermined discharge signal and generating operational control signals comprising phase currents for dissipating energy from the DC bus through a passive load in response to detecting the predetermined discharge signal, wherein the passive load includes motor windings of an electric motor of the electric motor system. The method also includes the step of providing the operational control signals to the motor control circuit for discharging the DC bus through the motor control circuit and the motor windings of the electric motor.

Abstract: Methods and apparatus are provided for improved discharge of a DC bus which provides power to an inverter. An electric motor system provided with the improved discharge method for discharge of the DC bus includes an electric motor, the inverter which provides electric control for the permanent magnet electric motor, the direct current (DC) bus which provides power to the inverter, and a processor. The processor generates operational control signals and provides such operational control signals to the inverter. In response to detecting a predetermined discharge signal, the processor generates operational control signals for generating a ripple current in motor windings of the electric motor to dissipate energy from the DC bus through a passive load, the passive load including the motor windings of the electric motor.

Abstract: Methods and systems for operating a motor coupled to an electrical bus in a vehicle are provided. Selected resonant frequencies of the electrical bus are determined. The selected resonant frequencies include a low resonant frequency and a high resonant frequency. Power is provided to the motor through at least one switch operating at a switching frequency. The switching frequency is controlled as a function of a rate of operation of the motor. The function is characterized by one of a first substantially linear portion having a first slope when the switching frequency is less than or equal to a selected switching frequency and a second substantially linear portion having a second slope if the switching frequency is greater than the selected frequency, the selected switching frequency being greater than the low resonant frequency and a substantially linear portion having a y-intercept being greater than the low resonant frequency.

Abstract: A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed.

Abstract: Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. A signal controlling the power inverter is modified utilizing a first voltage distortion compensation method if a modulation index of the signal is less than a first modulation index value. The signal is modified utilizing a second voltage distortion compensation method if the modulation index is at least equal to the first modulation index value.

Abstract: In various embodiments, a phase current sampling apparatus (300, 600, FIGS. 3, 6), an electric motor drive system (100, FIG. 1), and a motor vehicle (1200, FIG. 12) include switching circuitry adapted to receive first and second phase current waveforms. The switching circuitry provides the first phase current waveform during at least two offset sampling instants, and provides the second phase current waveform during a reference sampling instant. An analog-to-digital converter is adapted to sample the first phase current waveform at the offset sampling instants, and to sample the second phase current waveform at the reference sampling instant. An embodiment of a method for regulating phase current waveforms includes an analog-to-digital converter generating samples of a first phase current waveform at sampling instants that occur before and after a reference sampling instant, and generating a sample of a second phase current waveform at the reference sampling instant.

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: In various embodiments, an electric motor drive system (400, FIG. 4) and a motor vehicle (1000, FIG. 10) include an inverter (404, FIG. 4) adapted to generate (604, FIG. 6), based on inverter control inputs, a number, N, of phase current waveforms (118, FIG. 1), and a phase current sampling apparatus (408, FIG. 4) having a same number, N, of current sensors (502, 503, 504, FIG. 5). Each of the current sensors is adapted to receive one of the phase current waveforms, and the current sensors are adapted simultaneously to sample the phase current waveforms and to generate digital values representing amplitudes of the phase current waveforms. The system and motor vehicle also include a controller (410, FIG. 4) adapted to receive the digital values, to perform an evaluation of the digital values, and to generate the inverter control inputs (462, FIG. 4) based on the evaluation.

Abstract: Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. The various embodiments control the power inverter by, responsive to a commanded torque of the electric motor being below a first torque level, controlling the power inverter to set a switching frequency of the power inverter at a first set frequency; and, responsive to the commanded torque of the electric motor being between the first torque level and a second torque level, controlling the power inverter to determine the switching frequency of the power inverter as a function of the commanded torque of the electric motor while maintaining the switching frequency above a dynamic frequency limit. The method reduces switching frequencies in the inverter at high commanded torques, while maintaining the switching frequencies above dynamic frequency limit that provides effective control over the motor.

Abstract: Methods and systems for controlling a power inverter in automobiles utilizing two-mode transmissions are provided. The various embodiments control the power inverter by, responsive to a commanded torque of the electric motor being below a first torque level, controlling the power inverter to set a switching frequency of the power inverter at a first set frequency; and, responsive to the commanded torque of the electric motor being between the first torque level and a second torque level, controlling the power inverter to determine the switching frequency of the power inverter as a function of the commanded torque of the electric motor while maintaining the switching frequency above a dynamic frequency limit. The method reduces switching frequencies in the inverter at high commanded torques, while maintaining the switching frequencies above dynamic frequency limit that provides effective control over the motor.

Abstract: Methods and systems for controlling a power inverter in an electric drive system of an automobile are provided. The various embodiments control the power inverter by, responsive to either a commanded torque of the electric motor being above a first torque level, or a commanded speed of the electric motor being above a first speed level, controlling the power inverter with a discontinuous pulse width modulated (DPWM) signal to generate a modulated voltage waveform for driving the electric motor. Additionally, the embodiments control the power inverter by, responsive to both a commanded torque of the electric motor being below the first torque level, and a commanded speed of the electric motor being below the first speed level, controlling the power inverter with a continuous pulse width modulated (CPWM) signal to generate the modulated voltage waveform for driving the electric motor.

Abstract: A method for controlling an alternating current (AC) motor includes choosing a pulse sequence based on a ripple current in the AC motor at a sampling instant; and providing a voltage to the AC motor based on the pulse sequence.

Abstract: Electric motor systems are provided for use in vehicles. In an embodiment, by way of example only, the system includes a first inverter, a second inverter, and a motor electrically coupled to the first and the second inverters. The motor includes a stator including a plurality of slots formed therein and a plurality of windings. The plurality of windings is disposed at least partially in the slots, and each winding includes a first coil and a second coil. The first coil has a first number of turns, and the second coil has a second number of turns that is unequal to the first number of turns. The first coil of each winding is electrically coupled to the first inverter, and the second coil of each winding is electrically coupled to the second inverter.

Abstract: According to an example embodiment, a method is provided for limiting an operational temperature of a motor. The method includes generating a maximum allowable current I*S(max) for a motor based on a temperature difference between a temperature reference T* of a power inverter module and a semiconductor device temperature T of the power inverter module. The method further includes generating a maximum allowable torque T*e(max) based on the maximum allowable current I*S(max) and a maximum allowable flux ?*S(max), and using the maximum allowable torque T*e(max) to limit the torque command T*e in order to suppress the semiconductor device temperature T to below the temperature reference T*.

Abstract: Methods and systems for driving an automobile are provided. The system includes a prime mover power source and a two-mode, compound-split, electromechanical transmission, including first and second motors, coupled to the prime mover power source, a power inverter coupled to the first and second motors, and a processor coupled to the first and second motors and the power inverter. The processor is configured to modify a signal controlling the power inverter utilizing a first voltage distortion compensation method if a modulation index of the signal is less than a first modulation index value and modify the signal utilizing a second voltage distortion compensation method if the modulation index is at least equal to the first modulation index value.

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.

Abstract: Systems and methods are disclosed for a two-source series inverter. The systems and methods combine operation of a first voltage source and a second voltage source in series powering a novel voltage combining arrangement and a conventional inverter via a switch configuration to power a load. The switch configuration is controlled by a plurality of control signals generated by a controller based on a variety of control modes, and feedback signals.

Abstract: A method and system for limiting the operating temperature of an electric motor is provided. A maximum operational temperature of the motor is determined. A current operational temperature within the motor is sensed. A maximum allowable power dissipation of the motor is calculated based at least in part on the maximum operational temperature and the current operational temperature of the motor. A torque command for the motor is generated based on the maximum allowable power dissipation.

Abstract: Systems and methods are provided for an automotive drive system using an absolute position sensor for field-oriented control of an induction motor. An automotive drive system comprises an induction motor having a rotor, and a position sensor coupled to the induction motor. The position sensor is configured to sense an absolute angular position of the rotor. A processor may be coupled to the position sensor and configured to determine a relative angular position of the rotor based on a difference between the absolute angular position and an initial angular position obtained when the induction motor is started. A controller may be coupled to the induction motor and the processor and configured to provide field-oriented control of the induction motor based on the relative angular position of the rotor.

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.