Patents by Inventor Chandra S. Namuduri
Chandra S. Namuduri 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).
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Patent number: 10436167Abstract: A starter system for a powertrain comprises a brushless electric starter motor operatively connectable to an internal combustion engine. The starter system includes both an ultracapacitor power pack and a battery power pack. A nominal voltage of the ultracapacitor power pack is greater than that of the battery power pack. A DC-DC converter operatively connects the battery power pack and the ultracapacitor power pack and converts direct current at a first voltage level of the battery power pack to direct current at a greater second voltage level of the ultracapacitor power pack. An electronic control system is operable to control the brushless electric starter motor to start the engine using power provided from the ultracapacitor power pack, and to control the DC-DC converter to recharge the ultracapacitor power pack using power provided from the battery power pack through the DC-DC converter. A method of controlling the starter system is included.Type: GrantFiled: April 24, 2018Date of Patent: October 8, 2019Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Venkata Prasad Atluri, Lei Hao
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Patent number: 10432130Abstract: An electric powertrain includes an electric machine, an inverter connected to the electric machine, and an energy storage system for providing an electric current. The energy storage system includes a first energy storage device operable at a first device voltage, and a second energy storage device operable at a second device voltage. A plurality of low-loss switching devices interconnect the first energy storage device and the second energy storage device. The switching devices are selectively controllable between a first operating mode for providing the electric current at a first system voltage, and a second operating mode for providing the electric current at a second system voltage. The first system voltage is different from the second system voltage.Type: GrantFiled: February 13, 2018Date of Patent: October 1, 2019Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Thomas W. Nehl, Lei Hao
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Patent number: 10424429Abstract: A solenoid assembly is provided that includes male and female plungers and an electromagnetic coil configured to be energized to create a magnetic flux. Each plunger has a plunger face, where the female plunger face is configured to correspond with the male plunger face. The male plunger has a plurality of angled plunger steps that define the male plunger face, each angled plunger step including a corner having an angle in the range of 95 degrees to 115 degrees. The female plunger face has a similar, corresponding angled face. The solenoid assembly is suitable for use as a long stroke linear solenoid.Type: GrantFiled: December 18, 2017Date of Patent: September 24, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Alireza Fatemi, Thomas W Nehl, Chandra S Namuduri
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Patent number: 10408184Abstract: An electric starter system for a powertrain or other system having an engine includes a solenoid device coupled to a pinion gear, a brushless starter motor, and a controller. The starter motor has actual machine speed, and is connectable to the flywheel via the pinion gear during a change-of-mind event when a commanded engine auto-stop sequence is interrupted before completion. When engine speed exceeds a threshold speed and is less than a calibrated starting speed, the controller executes a method in which closed-loop speed control of the starter motor is enabled using the engine speed as a reference value until an effective machine speed is within a permissible speed delta of engine speed. The controller causes the solenoid device to translate the pinion gear into engagement with the flywheel and starter motor, disables closed-loop speed control, and commands the starter motor to start the engine.Type: GrantFiled: May 1, 2018Date of Patent: September 10, 2019Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Lei Hao, Suresh Gopalakrishnan
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Patent number: 10369896Abstract: An apparatus for flexible DC fast charging of an electrified vehicle includes a charge receptacle and a vehicle charging controller programmed to establish a wireless communication with a charging station. The apparatus further includes a reconfigurable energy storage system selectively and electrically connected to the charge receptacle. The reconfigurable energy storage system includes a first rechargeable energy storage device selectively and electrically connected to the charge receptacle, a second rechargeable energy storage device selectively connected to the charge receptacle, and a plurality of low-loss switching devices selectively connected to the first rechargeable energy storage device and the second rechargeable energy storage device.Type: GrantFiled: November 28, 2017Date of Patent: August 6, 2019Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Thomas W. Nehl, Lei Hao, Michael Harpster, Andrew K. Chandler
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Publication number: 20190232793Abstract: An electric power system includes an energy recovery system that is operable to convert kinetic energy into electric energy at a first voltage. A primary energy storage device is electrically connected to the energy recovery system at the first voltage. A first voltage autonomous driving system load is disposed in a parallel circuit with the energy recovery system and the primary energy storage device. A bi-directional DC-DC converter is electrically connected to the energy recovery system and the primary energy storage device for converting the electric energy between the first voltage and a second voltage. A secondary energy storage device is electrically connected to the bi-directional DC-DC converter at the second voltage. A second voltage autonomous driving system load is disposed in a parallel circuit with the secondary energy storage device.Type: ApplicationFiled: January 30, 2018Publication date: August 1, 2019Applicant: GM Global Technology Operations LLCInventors: Venkata Prasad Atluri, Chandra S. Namuduri, Massimo Osella, Upali P. Mudalige, Nikhil L. Hoskeri
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Patent number: 10330070Abstract: A starter for an internal combustion engine includes a multi-phase brushless electric motor, a controller and an inverter. A method for controlling the starter includes determining initial current commands for operating the electric motor in response to an activation command. Electrical current supplied to the electric motor and a rotational position of an output member of the electric motor are monitored. The electrical current is monitored directly without an intervening current prediction step. Interim voltage commands are determined based upon the initial current commands and the monitored currents, and final voltage commands are determined by subjecting the interim voltage commands to voltage limits. A rotational position compensation term is determined based upon the rotational position and rotational speed of the electric motor, and operation of the inverter is controlled to control the electric motor based upon the final voltage commands and the rotational position compensation term.Type: GrantFiled: November 14, 2017Date of Patent: June 25, 2019Assignee: GM Global Technology Operations LLC.Inventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
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Publication number: 20190189323Abstract: A solenoid assembly is provided that includes male and female plungers and an electromagnetic coil configured to be energized to create a magnetic flux. Each plunger has a plunger face, where the female plunger face is configured to correspond with the male plunger face. The male plunger has a plurality of angled plunger steps that define the male plunger face, each angled plunger step including a corner having an angle in the range of 95 degrees to 115 degrees. The female plunger face has a similar, corresponding angled face. The solenoid assembly is suitable for use as a long stroke linear solenoid.Type: ApplicationFiled: December 18, 2017Publication date: June 20, 2019Inventors: Alireza Fatemi, Thomas W Nehl, Chandra S Namuduri
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Publication number: 20190165713Abstract: An electric powertrain includes an electric machine, an inverter connected to the electric machine, and an energy storage system for providing an electric current. The energy storage system includes a first energy storage device operable at a first device voltage, and a second energy storage device operable at a second device voltage. A plurality of low-loss switching devices interconnect the first energy storage device and the second energy storage device. The switching devices are selectively controllable between a first operating mode for providing the electric current at a first system voltage, and a second operating mode for providing the electric current at a second system voltage. The first system voltage is different from the second system voltage.Type: ApplicationFiled: February 13, 2018Publication date: May 30, 2019Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Chandra S. Namuduri, Thomas W. Nehl, Lei Hao
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Publication number: 20190160953Abstract: An apparatus for flexible DC fast charging of an electrified vehicle includes a charge receptacle and a vehicle charging controller programmed to establish a wireless communication with a charging station. The apparatus further includes a reconfigurable energy storage system selectively and electrically connected to the charge receptacle. The reconfigurable energy storage system includes a first rechargeable energy storage device selectively and electrically connected to the charge receptacle, a second rechargeable energy storage device selectively connected to the charge receptacle, and a plurality of low-loss switching devices selectively connected to the first rechargeable energy storage device and the second rechargeable energy storage device.Type: ApplicationFiled: November 28, 2017Publication date: May 30, 2019Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Chandra S. Namuduri, Thomas W. Nehl, Lei Hao, Michael Harpster, Andrew K. Chandler
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Patent number: 10293805Abstract: A system includes an engine, a generator assembly, a direct current voltage bus, and a controller. The assembly is coupled to and driven via the engine, and has an electric generator, field windings, and a voltage rectifier collectively producing a generator output voltage. An inner control loop of the controller provides a field duty cycle signal to the field windings in response to an adjusted voltage control signal. An outer control loop of the controller provides a torque-based voltage control signal as an input to the inner control loop in response to a commanded engine torque and an estimated generator torque. An output torque of the generator is directly controlled via the outer control loop. The inner control loop calculates the adjusted voltage control signal as a difference between the torque-based voltage control signal and the output voltage.Type: GrantFiled: July 18, 2017Date of Patent: May 21, 2019Assignee: GM Global Technology Operations LLC.Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan
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Patent number: 10293804Abstract: A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine and configured to start the engine from an inactive state. A high-voltage battery powers both of the first electric machine and the second electric machine over a high-voltage bus. The vehicle further includes a controller programmed to issue a command to start the engine using the second electric machine in response to a threshold acceleration demand following a period of reduced acceleration demand.Type: GrantFiled: May 19, 2016Date of Patent: May 21, 2019Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Lei Hao, Suresh Gopalakrishnan, Thomas W. Nehl
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Publication number: 20190145370Abstract: A starter for an internal combustion engine includes a multi-phase brushless electric motor, a controller and an inverter. A method for controlling the starter includes determining initial current commands for operating the electric motor in response to an activation command. Electrical current supplied to the electric motor and a rotational position of an output member of the electric motor are monitored. The electrical current is monitored directly without an intervening current prediction step. Interim voltage commands are determined based upon the initial current commands and the monitored currents, and final voltage commands are determined by subjecting the interim voltage commands to voltage limits. A rotational position compensation term is determined based upon the rotational position and rotational speed of the electric motor, and operation of the inverter is controlled to control the electric motor based upon the final voltage commands and the rotational position compensation term.Type: ApplicationFiled: November 14, 2017Publication date: May 16, 2019Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
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Patent number: 10284036Abstract: An electric machine is provided that has a rotor assembly having a rotor core configured to support permanent magnets spaced around the rotor core to define a number of rotor poles. The rotor core has multiple rotor slots arranged as multiple barrier layers at each of the rotor poles. The multiple barrier layers are positioned adjacent one another between an inner periphery of the rotor core and an outer periphery of the rotor core and include a first barrier layer nearest the inner periphery. Permanent magnets are disposed in at least the first barrier layer. A stator assembly surrounds the rotor assembly. The electric machine is configured to function as a motor in a motoring mode and as a generator in a generating mode. The electric machine is configured with predetermined operating parameters selected for optimizing operation in the motoring mode and/or the generating mode.Type: GrantFiled: June 28, 2016Date of Patent: May 7, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Thomas W. Nehl
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Patent number: 10259448Abstract: A hybrid vehicle propulsion includes an engine and a first electric machine, where each is configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine to provide torque to start the engine from an inactive state. A high-voltage power source is configured to power both of the first electric machine and the second electric machine over a high-voltage bus. The propulsion system further includes a controller programmed to deactivate the engine and propel the vehicle using the first electric machine in response to the vehicle being driven at a steady-state speed for a predetermined duration of time. The controller is also programmed to restart the engine using the second electric machine powered by the high-voltage power source.Type: GrantFiled: August 17, 2016Date of Patent: April 16, 2019Assignee: GM Global Technology Operations LLCInventors: Norman K. Bucknor, Suresh Gopalakrishnan, Lei Hao, Derek F. Lahr, Dongxu Li, Shifang Li, Chandra S. Namuduri, Thomas W. Nehl, Avoki M. Omekanda, Rashmi Prasad, Farzad Samie, Aaron M. Sullivan
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Publication number: 20190103797Abstract: A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux (?) is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (?). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i1) and an eddy current (i2). The magnetic flux (?) is obtained based at least partially on a third model matrix (C0), the coil current (i1) and the eddy current (i2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (?). In one example, the solenoid actuator is an injector.Type: ApplicationFiled: October 3, 2017Publication date: April 4, 2019Applicant: GM Global Technology Operations LLCInventors: Shifang Li, Thomas W. Nehl, Suresh Gopalakrishnan, Avoki Omekanda, Rashmi Prasad, Chandra S. Namuduri
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Patent number: 10207699Abstract: A vehicle propulsion system includes a combustion engine configured to output a propulsion torque to satisfy a propulsion demand, and a traction electric machine to generate a supplemental torque to selectively supplement the propulsion torque. The propulsion system also includes a controller programmed to forecast an acceleration demand based on at least one estimation model. The controller is also programmed to issue a command indicative of a required axle torque corresponding to the acceleration demand. The controller is further programmed to engage at least one fuel conservation action in response to the required axle torque being within a first predetermined torque threshold range.Type: GrantFiled: October 2, 2017Date of Patent: February 19, 2019Inventors: Chandra S. Namuduri, Venkata Prasad Atluri, Suresh Gopalakrishnan, Jin-Woo Lee, Kevin J. Robinet, Sai Rajagopalan, Chen-fang Chang, Michael Livshiz, Patrick J. O'leary
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Patent number: 10205358Abstract: An electric machine is provided that includes a rotor assembly having a rotor core configured to support permanent magnets spaced around the rotor core to define a number of rotor poles. The rotor core has multiple rotor slots arranged as multiple barrier layers at each of the rotor poles. The rotor core is configured so that the electric machine satisfies predetermined operating parameters. In one embodiment, the electric machine is coupled with an engine through a belt drive train and provides cranking (engine starting), regeneration and torque assist modes.Type: GrantFiled: August 1, 2014Date of Patent: February 12, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Murali Pandi, Thomas Wolfgang Nehl, Avoki M. Omekanda
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Patent number: 10190559Abstract: A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.Type: GrantFiled: May 22, 2018Date of Patent: January 29, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Thomas W. Nehl
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Patent number: 10189469Abstract: A method of controlling a powertrain of a vehicle includes opening and/or closing one or more of a first switching device, a second switching device, a third switching device, and engaging and/or disengaging at least one of a pair of actuators for a starter mechanism or a motor/generator clutch. Many different control modes are provided for the powertrain by changing the operation of a motor-generator between a motor or a generator, and changing the electrical connections between a first energy storage device, a second energy storage device, an auxiliary electric system, the starter mechanism, and the motor-generator.Type: GrantFiled: March 20, 2015Date of Patent: January 29, 2019Assignee: GM Global Technology Operations LLCInventors: Venkata Prasad Atluri, Suresh Gopalakrishnan, Michael G. Reynolds, Chandra S. Namuduri, Kenneth J. Shoemaker, David W. Walters