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: An electric traction system for a vehicle having a high voltage battery and a low voltage battery is provided. The system includes an AC electric motor and a double ended inverter system coupled to the AC electric motor. The AC electric motor has a first set of windings and a second set of windings that occupy common stator slots, where the first set of windings and the second set of windings are electrically isolated from each other. The double ended inverter system drives the AC electric motor using energy obtained from the high voltage battery and energy obtained from the low voltage battery. The double ended inverter system utilizes a first inverter subsystem coupled between the first set of windings and the high voltage battery, and a second inverter subsystem coupled between the second set of windings and the low voltage battery.

Abstract: Systems and methods are disclosed for a DC boost converter. The systems and methods combine operation of an inductor with the input capacitor of a DC/AC inverter via a switch configuration to power the DC/AC inverter. 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: Methods and apparatus are provided for dynamic voltage control of electric motors. An inverter provides an output voltage to an electric motor based on a gate voltage. The method includes determining a speed of the electric motor and modifying the gate voltage based on the speed of the electric motor. The apparatus includes a gate drive circuit and a controller coupled to the gate drive circuit. The gate drive circuit provides a gate voltage to a switch network, and the switch network produces the output voltage in response to the gate voltage. The controller modifies the gate voltage based on a speed of the electric motor.

Abstract: Methods and apparatus are provided for reducing voltage distortion effects at low speed operation in electric drives. The method comprises receiving a first signal having a duty cycle with a range between minimum and maximum achievable duty cycles, producing a second duty cycle based on the minimum achievable duty cycle if the duty cycle is within a distortion range and less than a first clipping value, producing a second duty cycle based on the closer of minimum and maximum pulse widths if the duty cycle is within the distortion range and between the first and a second clipping value, producing a second duty cycle based on the maximum achievable duty cycle if the duty cycle is within the distortion range and greater than the second clipping value, and transmitting a second signal to the voltage source inverter having the second duty cycle.

Abstract: Methods and systems are provided for controlling permanent magnet machines. The method includes determining a maximum torque of the PM machine based on an error between a commanded d-axis flux and an estimated d-axis flux of the PM machine, and adjusting a torque command based on the maximum torque. The error associated with a variation between a current temperature and a nominal temperature of the PM machine.

Abstract: Methods and apparatus are provided for protecting a motor control circuit in a permanent magnet electric motor system. The permanent magnet electric motor system includes a permanent magnet electric motor having a predetermined number of windings corresponding to the phases of the permanent magnet electric motor and a direct current (DC) bus coupled to a power source for providing operational power for the electric motor system. A motor control circuit is connected to the DC bus for receiving the operational power therefrom and is connected to the windings of the permanent magnet electric motor for controlling the permanent magnet electric motor. A protection circuit is connected to the DC bus for receiving the voltage therefrom for operation of the protection circuit and for detecting predetermined motor control circuit fault conditions from voltage sensed on the DC bus and in response thereto providing protection for the motor control circuit.

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: Apparatus, systems, and methods are provided for reducing voltage source inverter losses. One apparatus includes a sensor couplable to the motor and configured to sense an operating frequency of the motor and an amount of torque produced by the motor. The apparatus also includes a controller coupled to the sensor, the controller configured to determine a zero vector modulation (ZVM) based on the sensed frequency and torque. A system includes means for sensing a threshold output frequency of the motor and means for sensing a threshold torque of the motor. The system also includes means for determining a ZVM for the inverter based on the sensed threshold frequency and threshold torque. One method includes sensing that a motor is operating below a threshold frequency and is producing torque above a threshold torque amount. The method also includes determining a ZVM for the inverter based on the sensed frequency and torque.

Abstract: Methods and systems are provided for aligning a resolver in an electric motor system. The method includes commanding a d-axis current command and a speed command, operating an electric motor without a load in response to the d-axis current command and the speed command, determining a rotor speed in response to the speed command, and determining an offset of the resolver based on the speed command and the rotor speed when the rotor speed has substantially stabilized.

Abstract: Method and system are provided for controlling an alternating current (AC) motor via an inverter. The method includes selecting a pulse sequencing method based on a modulation index of the inverter, and providing a voltage to the AC motor based on the pulse sequencing method. The system includes an inverter having a modulation index (Mi) and a controller coupled to the inverter. The controller selects a pulse sequencing method based on Mi and produces a signal based on the pulse sequencing method. The inverter includes a switch network producing a voltage in response to the signal, and the voltage drives the AC motor.

Abstract: An inverter is provided for controlling application of voltage from a power source to a motor having a plurality of windings. The inverter includes a first set of one or more switching elements and a second set of one or more switching elements. The first and second sets of one or more switching elements are connected between a high voltage side and a low voltage side of the power source. Each of the first set of one or more switching elements is connected to one of a first set of nodes, where each of the first set of nodes is connected to a first winding end of one of the plurality of windings of the motor. Each of the second set of one or more switching elements is connected to one of a second set of nodes and each of the second set of nodes is connected to a second winding end of one of the plurality of windings.

Abstract: An electrical system for a vehicle includes a power source providing electrical power to a first and a second electrical motor. Each motor has two or more windings, and each winding has a first end and a second end. A boost link such as a battery or capacitor is configured to store electrical energy for subsequent retrieval and use by either electrical motor. A first inverter circuit includes a first grouping of switches, wherein each of the first group of switches couples one of the first ends of the windings to the power source. A second inverter circuit includes a second group of switches, each coupling one of the second ends of the windings to the boost link. A controller is coupled to activate each of the first and second groups of switches to thereby allow the electrical energy to be placed on and retrieved from the boost link.

Abstract: A method for controlling an inverter uses sequences of predetermined states where each state uniquely corresponding to a set of control signals provided to the inverter that is coupled to a motor. The method includes repeatedly applying a first center null timing sequence of the states while monitoring a zero crossing condition and then changing the repeated application of the first center null timing sequence of the states into a repeated application of a second center null timing sequence of states when the monitoring detects a zero crossing condition. The repeated application of the first center null timing sequence sequentially provides the inverter with a first predetermined sequence of sets of control signals. The monitoring of a zero crossing condition monitors for a zero crossing condition in an electrical current flowing between the inverter and a terminal of the motor. The second center null timing sequence defines a second predetermined sequence of sets of control signals.

Abstract: Methods and apparatus are provided for reducing voltage distortion effects at low speed operation in electric drives. The method comprises receiving a first signal having a duty cycle with a range between minimum and maximum achievable duty cycles, producing a second duty cycle based on the minimum achievable duty cycle if the duty cycle is within a distortion range and less than a first clipping value, producing a second duty cycle based on the closer of minimum and maximum pulse widths if the duty cycle is within the distortion range and between the first and a second clipping value, producing a second duty cycle based on the maximum achievable duty cycle if the duty cycle is within the distortion range and greater than the second clipping value, and transmitting a second signal to the voltage source inverter having the second duty cycle.

Abstract: Methods and apparatus are provided for modifying a pulse width modulation signal controlling a voltage source inverter. The method comprises the steps of determining a duty cycle of the signal, clipping the duty cycle when a modulation index is greater than a minimum modulation index and less than a maximum modulation index, clipping the duty cycle when the modulation index is greater than or equal to the maximum modulation index, and transmitting the duty cycle to the voltage source inverter. The minimum modulation index indicates a distortion range.

Abstract: Power capacitors for AC motors are mounted diametrically on associated transmissions. The power capacitors are in one embodiment annular and in another embodiment, arcuate. By having power capacitors mounted on transmission housings diametrically, cooling of the power capacitors is facilitated for both air and liquid cooling.

Abstract: In an embodiment of a method, the method includes measuring currents and voltages that are coupled to a motor that includes an internal permanent magnet and determining a reactive power in response to the measured currents and voltages. The method further includes estimating a first flux orthogonal to an axis of the internal permanent motor and estimating a second flux aligned with the axis of the internal permanent motor. Additionally, the method includes estimating a torque in response to the measured currents and the first and second fluxes.

Abstract: Power capacitors for AC motors are mounted diametrically on associated transmissions. The power capacitors are in one embodiment annular and in another embodiment, arcuate. By having power capacitors mounted on transmission housings diametrically, cooling of the power capacitors is facilitated for both air and liquid cooling.

Abstract: A dynamic pulse width modulation (PWM) selection device automatically switches between discontinuous PWM (DPWM) control methods. The PWM selection device comprises a PWM control module. The PWM control module determines a desired pulse width of a switching control signal according to a desired output signal. The PWM control module controls an actual pulse width of the switching control signal according to the desired pulse width and a first PWM control method. A selection module determines whether the desired pulse width exceeds a pulse width threshold. The selection module selects a second PWM control method when the desired pulse width exceeds the pulse width threshold.