Patents by Inventor Prakash Shahi

Prakash Shahi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20070248467
    Abstract: A controller for an electric motor in a blower system includes an input for receiving an air flow demand. The controller is configured for producing drive signals for the electric motor from the air flow demand using an equation having a plurality of terms. At least one of the terms includes a composite function S*CFMn, where S is a speed of the electric motor, CFM is the air flow demand, and n>1. These teachings can also be applied to other types of fluid handling systems including, for example, liquid pumps.
    Type: Application
    Filed: April 21, 2006
    Publication date: October 25, 2007
    Inventors: Prakash Shahi, Arthur Woodward, Christopher Schock
  • Publication number: 20070170880
    Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to inputs of demanded torque, rotor position and/or speed. Control methods include calculating a scaled torque demand from the received torque demand to obtain substantially constant torque over a range of motor speeds, calculating an optimal dr-axis injection current using a cost function and a starting method that switches from speed control mode to torque control mode at a predetermined rotor speed or at predetermined start-up timing intervals.
    Type: Application
    Filed: March 27, 2007
    Publication date: July 26, 2007
    Inventors: Prakash Shahi, Arthur Woodward, Joseph Marcinkiewicz, Michael Henderson
  • Publication number: 20060290304
    Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to inputs of demanded torque, rotor position and/or speed. Control methods include calculating a scaled torque demand from the received torque demand to obtain substantially constant torque over a range of motor speeds, calculating an optimal dr-axis injection current using a cost function and a starting method that switches from speed control mode to torque control mode at a predetermined rotor speed or at predetermined start-up timing intervals.
    Type: Application
    Filed: December 2, 2005
    Publication date: December 28, 2006
    Inventors: Joseph Marcinkiewicz, Prakash Shahi, Michael Henderson
  • Publication number: 20060290302
    Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to an input demand such as a demanded speed or torque. Control methods (which can be implemented separately or in combination) include varying the gain of an estimator as a function of a demanded or estimated speed to position control system poles at desired locations, decoupling control system currents to achieve a constant torque with motor speed, compensating flux estimates of the estimator for saturation operation of the stator, estimating rotor position using averages of sample values of energization feedback, and calculating a trim adjusted speed error from a plurality of speed estimates.
    Type: Application
    Filed: December 2, 2005
    Publication date: December 28, 2006
    Inventors: Joseph Marcinkiewicz, Prakash Shahi, Michael Henderson