Abstract:
Methods and apparatus are provided for aligning a control reference axis with a magnetic north of a permanent magnet motor. The method includes the steps of injecting a predetermined stator current on an estimated reference axis of the permanent magnet motor and introducing predetermined error on the estimated reference axis. The method further includes the steps of determining if a speed of the permanent magnet motor is greater than a predetermined threshold speed and setting the control reference axis to 180° added to the estimated reference axis if the speed of the permanent magnet motor is greater than the predetermined threshold speed or setting the control reference axis to the estimated reference axis if the speed of the permanent magnet motor is less than or equal to the predetermined threshold speed.
Abstract:
A method for decoupling a harmonic signal from an input signal wherein the harmonic signal is harmonic relative to a signal other than the input signal. An angular position of the other signal is multiplied by a value representing the harmonic to obtain an angular position multiple. A harmonic decoupling block uses the angular position multiple to obtain correction signals representing the harmonic signal, and subtracts the correction signals from the input current to decouple the harmonic signal from the input signal. This method is useful for decoupling unwanted harmonics from currents into which high-frequency signals have been injected for control of electric motors.
Abstract:
A control system for a vehicle powered by a fuel cell includes a voltage conversion device that communicates with the fuel cell through a voltage bus and a propulsion system that is selectively powered by the fuel cell through the voltage bus and that selectively generates a ripple current in the voltage bus. The voltage conversion device is regulated to selectively generate a counter-ripple current that reduces the ripple current.
Abstract:
An embodiment of a system for multiple source power conversion is implemented in a vehicle that includes an alternating current (AC) power source and first and second direct current (DC) power sources. The system includes an inverter, a DC-to-DC converter, and a controller. The controller receives external commands, inverter feedback signals, and DC-to-DC converter feedback signals, and executes and inverter control algorithm and DC-to-DC converter control algorithm. An embodiment of a method for multiple source power conversion between an AC power source, and first and second DC power sources includes receiving external commands from a remote source, inverter feedback signals from an inverter, and DC-to-DC converter feedback signals from a DC-to-DC converter. The method also includes executing an inverter control algorithm and a DC-to-DC converter control algorithm to generate drive signals for the inverter and DC-to-DC converter, respectively, based on the received commands and feedback signals.
Abstract:
A method and system for operating a power converter having an electrical component and a switch coupled to a voltage source are provided. A signal is received that is representative of a desired current flow through the electrical component. A signal is generated that is representative of a difference between the desired current flow and an actual current flow through the electrical component. A duty cycle for the switch is calculated based on the signal representative of the difference and a voltage generated by the voltage source.
Abstract:
A method and system for determining a current flowing through an electrical component are provided. A switch electrically coupled to the electrical component and two voltage sources is activated. The activation of the switch causes current to flow through the electrical component after an amount of time. The amount of time between said activating the switch and the flow of current through the electrical component is determined. The current flowing through the electrical component is measured to determine a measured current value. The measured current value is modified based at least in part on the amount of time between said activating the switch and the flow of current through the electrical component.
Abstract:
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.
Abstract:
A drive system that is suitable for high bandwidth current control of a three-phase voltage source inverter in the overmodulation region includes a feedback path that has a harmonic decoupling block that subtracts selected harmonic components from signals representative of a corresponding motor phase current signal. The harmonic decoupling block thereby generates corrected feedback signals. The drive system also includes subtractor blocks that subtract the corrected feedback signals from signals representative of open-loop magnetizing reference currents to generate difference signals. Also included is a modulation block that utilizes the difference signals to produce signals to drive a three-phase voltage source inverter in an overmodulated six-step mode.
Abstract:
A control algorithm or method for use in controlling a voltage-fed induction machine. The control algorithm includes the following steps. The DC link voltage supplied to an inverter driving the induction machine is monitored. When the DC link voltage is high enough, the algorithm controls the amount of current supplied to the induction machine to provide current controlled operation of the induction machine. When the DC link voltage is not high enough to control the current under transient conditions, the induction machine is controlled by imposing the maximum possible phase voltage and optimal slip angle on the machine to provide maximal torque per ampere operation of the induction machine. The maximal torque per ampere operation is performed when either of the following conditions is met: a) the torque level required by the induction machine is such that efficiency optimization cannot be performed, or b) current regulators approach saturation. The current controlled operation is performed when a) the torque level required by the induction machine is at a level that allows efficiency optimization, and b) the current regulators are not near saturation. The efficiency optimization in the current controlled mode is performed by using a single constant over the whole operating range.
Abstract:
An integrated rotary transformer and resolver and a motor including an integrated rotary transformer and resolver is provided. The integrated rotary transformer and resolver may include, but is not limited to, a stator having an outer surface and a plurality of slots disposed along the outer surface, a plurality of sensing coils, the plurality of sensing coils disposed in at least some of the plurality of slots, a rotor having a surface varying from a first predetermined thickness to a second predetermined thickness, and a controller electrically coupled to the plurality of sensing coils and configured to determine a position of the rotor based upon a voltage induced in each of the coils due to a relative thickness of the rotor opposed to the respective sensing coil.