Patents by Inventor Balasubramanian Lakshmanan
Balasubramanian Lakshmanan 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: 11872909Abstract: A torque generating system is described, and includes a fuel cell power device, a high-voltage battery, an electric drive unit, and a controller. The fuel cell power device has a non-linear power-temperature relationship that has a local temperature maxima at a first electric power level and a local temperature minima at a second electric power level. A first operating point of the fuel cell power device is less than the first electric power level, and a second operating point of the fuel cell power device is set at a third electric power level that is greater than the first electric power level, wherein the third electric power level generates a fuel cell temperature that is less than the local temperature maxima. The fuel cell power device is controlled to one of the first operating point or the second operating point to transfer electric power to the electric drive unit.Type: GrantFiled: July 29, 2021Date of Patent: January 16, 2024Assignee: GM Global Technology Operations LLCInventors: William H. Pettit, Charles E. Freese, V, Balasubramanian Lakshmanan
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Publication number: 20230138029Abstract: Presented are shock-force mitigation systems for fuel cell stacks, methods for making/using such systems, and electric-drive vehicles equipped with such systems. A fuel cell system includes multiple electrochemical fuel cells that are stacked face-to-face along a stack axis to define a fuel cell stack. A push plate abuts each longitudinal end of the fuel cell stack; these push plates translate rectilinearly along the stack axis inside a fuel cell stack housing. An end plate is located in facing spaced relation to each push plate to define a plate pair at each end of the stack. An active or passive force-modifying device is interposed between the two plates in each plate pair; these devices modify stack forces experienced by the fuel cell stack. For an active shock-force mitigation system, each force-modifying device may include a bladder system, spring, and/or linear actuator; an electronic system controller controls activation of the bladders/actuators.Type: ApplicationFiled: November 1, 2021Publication date: May 4, 2023Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Yeh-Hung Lai, Jeffrey A. Rock, Balasubramanian Lakshmanan
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Publication number: 20230045299Abstract: A torque generating system is described, and includes a fuel cell power device, a high-voltage battery, an electric drive unit, and a controller. The fuel cell power device has a non-linear power-temperature relationship that has a local temperature maxima at a first electric power level and a local temperature minima at a second electric power level. A first operating point of the fuel cell power device is less than the first electric power level, and a second operating point of the fuel cell power device is set at a third electric power level that is greater than the first electric power level, wherein the third electric power level generates a fuel cell temperature that is less than the local temperature maxima. The fuel cell power device is controlled to one of the first operating point or the second operating point to transfer electric power to the electric drive unit.Type: ApplicationFiled: July 29, 2021Publication date: February 9, 2023Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: William H. Pettit, Charles E. Freese, V, Balasubramanian Lakshmanan
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Publication number: 20220049367Abstract: A bipolar plate includes at least one electrically conductive plate having an anode flow field on an anode major side and a cathode flow field on a cathode major side opposite to the anode major side, an electrically insulating first capping plate containing a first plenum area, and located over the anode major side, and an electrically insulating second capping plate containing a second plenum area, and located over the cathode major side. The at least one electrically conductive plate, the first capping plate and the second capping plate are bonded to each other.Type: ApplicationFiled: August 16, 2021Publication date: February 17, 2022Inventors: Arne BALLANTINE, Vikas Devoji CHAWAN, Muralidhar VENKATRAMAN, Balasubramanian LAKSHMANAN, Chockkalingam KARUPPAIAH
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Patent number: 11158871Abstract: A fuel cell assembly includes a fuel cell stack. A vehicle includes a propulsion system and the fuel cell assembly configured to provide power to the propulsion system in at least one mode. The fuel cell assembly also includes an air compressor and an air pump spaced from the air compressor. The air compressor includes an on position in which the air compressor is configured to supply air to the fuel cell stack and an off position in which the air compressor does not supply air to the fuel cell stack. The air compressor also includes a bearing configured to be levitated via air. The air pump is configured to supply air to the fuel cell stack when the air compressor is in the off position and configured to supply air to the bearing when the air compressor is in the on position.Type: GrantFiled: July 18, 2018Date of Patent: October 26, 2021Assignee: GM Global Technology Operations LLCInventors: Kelsey M. Rollag, Balasubramanian Lakshmanan
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Patent number: 10811713Abstract: The present disclosure provides a method for manufacturing an integrated MEA, the method includes the following steps: (1) providing a substrate having an AA region and a WVT region; (2) coating a hydrophobic microporous layer across the substrate; (3) coating a catalyst layer onto the hydrophobic microporous layer in the AA region; (4) coating a first fuel cell membrane ionomer layer onto the catalyst layer in the AA region and onto the hydrophobic microporous layer in the WVT region; (5) optionally applying a membrane support layer to the first fuel cell membrane ionomer layer in the AA region and the WVT region; (6) optionally applying a coating of second fuel cell membrane ionomer layer thereby forming a coated substrate; and (7) assembling the coated substrate to a companion coated substrate.Type: GrantFiled: January 29, 2018Date of Patent: October 20, 2020Assignee: GM Global Technology Operations LLCInventors: Mark F. Mathias, Balasubramanian Lakshmanan, Swaminatha P. Kumaraguru, Scott C. Moose
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Patent number: 10680266Abstract: The present disclosure provides a method for manufacturing an integrated MEA, the method includes the following steps: (1) providing a substrate having an AA region and a WVT region; (2) simultaneously coating a microporous layer, a catalyst layer, and a first membrane ionomer layer onto the substrate; (3) applying an optional membrane support layer to the first membrane ionomer layer in the AA region and the WVT region; (4) applying an optional second membrane ionomer layer; (5) heating treating a coated substrate; and (6) assembling the coated substrate to a companion coated substrate.Type: GrantFiled: February 15, 2018Date of Patent: June 9, 2020Assignee: GM Global Technology Operations LLCInventors: Mark F. Mathias, Balasubramanian Lakshmanan, Swaminatha P. Kumaraguru, Scott C. Moose
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Patent number: 10547074Abstract: A fuel cell system that includes a component for removing anionic contaminants is provided. The fuel system including a fuel cell stack, a fuel gas feed subsystem in communication with fuel cell anodes in the fuel cell stack, an oxygen-containing gas feed subsystem system in communication with fuel cell cathodes in the fuel cell stack, and an anionic scavenging subsystem in communication with the fuel gas feed subsystem and/or the an oxygen-containing gas feed subsystem.Type: GrantFiled: October 5, 2016Date of Patent: January 28, 2020Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Qiang Li, Paul Taichiang Yu, Jingxin Zhang, Balasubramanian Lakshmanan
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Publication number: 20200028189Abstract: A fuel cell assembly includes a fuel cell stack. A vehicle includes a propulsion system and the fuel cell assembly configured to provide power to the propulsion system in at least one mode. The fuel cell assembly also includes an air compressor and an air pump spaced from the air compressor. The air compressor includes an on position in which the air compressor is configured to supply air to the fuel cell stack and an off position in which the air compressor does not supply air to the fuel cell stack. The air compressor also includes a bearing configured to be levitated via air. The air pump is configured to supply air to the fuel cell stack when the air compressor is in the off position and configured to supply air to the bearing when the air compressor is in the on position.Type: ApplicationFiled: July 18, 2018Publication date: January 23, 2020Applicant: GM Global Technology Operations LLCInventors: Kelsey M. Rollag, Balasubramanian Lakshmanan
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Patent number: 10522855Abstract: A method for creating an oxygen depleted gas in a fuel cell system, including operating a fuel cell stack at a desired cathode stoichiometry at fuel cell system shutdown to displace a cathode exhaust gas with an oxygen depleted gas. The method further includes closing a cathode flow valve and turning off a compressor to stop the flow of cathode air.Type: GrantFiled: October 19, 2015Date of Patent: December 31, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Thomas W. Tighe, Steven G. Goebel, Gary M. Robb, Abdullah B. Alp, Balasubramanian Lakshmanan, Joseph N. Lovria
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Patent number: 10522859Abstract: A fuel cell system includes a fuel cell stack and a controller. The fuel cell stack includes a catalyst and a stack voltage. The controller increases efficiency of the fuel cell stack by minimizing or removing an accumulation of oxides on the catalyst during a low-power operating mode of the fuel cell system. The controller executes a method for dynamically controlling the stack voltage during a detected low-power operating mode. The method includes commanding low-voltage/high-power pulses to the fuel cell stack via the controller at a magnitude and frequency sufficient for minimizing or removing the oxides. The system may include a direct current-direct current (DC-DC) boost converter, with the controller programmed to command the power pulses from the DC-DC boost converter. Or, the controller may be configured to command the power pulses by controlling a feed rate of the oxygen and/or the hydrogen.Type: GrantFiled: May 1, 2017Date of Patent: December 31, 2019Assignee: GM Global Technology Operations LLCInventors: Srikanth Arisetty, Andrew J. Maslyn, Balasubramanian Lakshmanan, Robert J. Moses
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Patent number: 10446862Abstract: Disclosed are fuel cell architectures, thermal sub-systems, and control logic for regulating fuel cell stack temperature. A method is disclosed for regulating the temperature of a fuel cell stack. The method includes determining a pre-start temperature of the fuel cell stack, and determining, for this pre-start temperature, a target heating rate to heat the stack to a calibrated minimum operating temperature. The method then determines a hydrogen bleed percentage for the target heating rate, and executes a stack heating operation including activating the fuel cell stack and commanding a fluid control device to direct hydrogen to the cathode side at the hydrogen bleed percentage to generate waste heat. After a calibrated period of time, the method determines if an operating temperature of the stack exceeds the calibrated minimum stack operating temperature. Responsive to the operating temperature being at or above the minimum operating temperature, the stack heating operation is terminated.Type: GrantFiled: May 8, 2017Date of Patent: October 15, 2019Assignee: GM Global Technology Operations LLCInventors: Srikanth Arisetty, Aaron R. Rogahn, Balasubramanian Lakshmanan
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Patent number: 10439241Abstract: A method for reducing fuel cell voltage loss in a fuel cell that includes an anode catalyst layer including an anode catalyst and a cathode catalyst layer including a cathode catalyst with a proton exchange layer interposed between the anode catalyst layer and the cathode catalyst layer. The method includes a step of initiating shutdown of the fuel cell. Carbon monoxide or carbon monoxide-like species contaminating the anode catalyst is oxidized during shutdown such that carbon monoxide or carbon monoxide-like species is removed from the anode catalyst.Type: GrantFiled: October 28, 2015Date of Patent: October 8, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Jingxin Zhang, Paul Taichiang Yu, Balasubramanian Lakshmanan
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Publication number: 20190252705Abstract: The present disclosure provides a method for manufacturing an integrated MEA, the method includes the following steps: (1) providing a substrate having an AA region and a WVT region; (2) simultaneously coating a microporous layer, a catalyst layer, and a first membrane ionomer layer onto the substrate; (3) applying an optional membrane support layer to the first membrane ionomer layer in the AA region and the WVT region; (4) applying an optional second membrane ionomer layer; (5) heating treating a coated substrate; and (6) assembling the coated substrate to a companion coated substrate.Type: ApplicationFiled: February 15, 2018Publication date: August 15, 2019Inventors: Mark F. Mathias, Balasubramanian Lakshmanan, Swaminatha P. Kumaraguru, Scott C. Moose
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Publication number: 20190237787Abstract: The present disclosure provides a method for manufacturing an integrated MEA, the method includes the following steps: (1) providing a substrate having an AA region and a WVT region; (2) coating a hydrophobic microporous layer across the substrate; (3) coating a catalyst layer onto the hydrophobic microporous layer in the AA region; (4) coating a first fuel cell membrane ionomer layer onto the catalyst layer in the AA region and onto the hydrophobic microporous layer in the WVT region; (5) optionally applying a membrane support layer to the first fuel cell membrane ionomer layer in the AA region and the WVT region; (6) optionally applying a coating of second fuel cell membrane ionomer layer thereby forming a coated substrate; and (7) assembling the coated substrate to a companion coated substrate.Type: ApplicationFiled: January 29, 2018Publication date: August 1, 2019Inventors: Mark F. Mathias, Balasubramanian Lakshmanan, Swaminatha P. Kumaraguru, Scott C. Moose
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Patent number: 10329150Abstract: A system and method for determining the purity level of hydrogen gas fuel provided to an anode side of a fuel cell stack, and then modifying models and algorithms used by the system based on the purity level. The method includes determining whether predetermined criteria have been met that are necessary to obtain an accurate hydrogen gas fuel purity level, and if so, comparing a measured voltage or current of the fuel cell stack to a modeled voltage or current of the fuel cell stack. If the comparison between the measured voltage or current and the modeled voltage or current is greater than a predetermined threshold, then the method adapts a hydrogen gas concentration value to a lower purity level to be used by downstream models.Type: GrantFiled: June 29, 2017Date of Patent: June 25, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: William J. Dwyer, Jeffrey J. Gagliardo, Pamela M. Vecasey, Balasubramanian Lakshmanan
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Patent number: 10276878Abstract: A fuel cell flow field plate includes an aluminum substrate plate having a first side and a second side wherein the first side of the aluminum substrate plate defines a plurality of channels for transporting a first fuel cell reactant gas. The flow field plate also includes a first metal interlayer deposited on the first side of the aluminum substrate plate, a second metal interlayer deposited on the second side of the aluminum substrate plate, a first amorphous carbon layer deposited on the first metal interlayer, and a second amorphous carbon layer deposited on the second metal interlayer. The first amorphous carbon layer and second amorphous carbon layer each independently have a density greater than or equal to 1.2 g/cc.Type: GrantFiled: July 8, 2016Date of Patent: April 30, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Smuruthi Kamepalli, Balasubramanian Lakshmanan, Elizabeth Dicocco
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Publication number: 20190123364Abstract: The present disclosure provides an integrated fuel cell having a water vapor transfer region wherein the integrated fuel cell includes a first bipolar plate, a second bipolar plate, and a membrane electrode assembly (MEA) disposed between the first and second bipolar plates. The membrane electrode assembly further includes a water vapor transfer portion and at least one active area portion configured to generate electricity and provide a water byproduct upon facilitating a reaction involving an input stream containing hydrogen and an input stream containing oxygen.Type: ApplicationFiled: October 24, 2017Publication date: April 25, 2019Inventors: Mark F Mathias, Balasubramanian Lakshmanan, Wenbin Gu
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Patent number: 10236517Abstract: A method for manufacturing a coated metal substrate includes the steps of: (1) inserting a substrate with a chromium(III) oxide layer inside a CVD chamber; (2) heating the substrate to a temperature which falls in the range of 400 to 500 degrees Celsius; (3) transporting gaseous nitrogen (N2) and tantalum chloride (TaCl5) into the CVD chamber for at least two cycles; (4) ceasing the transportation of tantalum chloride (TaCl5) while nitrogen continues to flow from the inlet to the outlet; (5) reacting the tantalum chloride and the chromium(III) oxide and creating by-products; and (6) vacuuming the by-product matter from the CVD chamber via the flowing nitrogen gas.Type: GrantFiled: August 16, 2017Date of Patent: March 19, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Smuruthi Kamepalli, Balasubramanian Lakshmanan
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Publication number: 20190058200Abstract: A method for manufacturing a coated metal substrate includes the steps of: (1) inserting a substrate with a chromium(III) oxide layer inside a CVD chamber; (2) heating the substrate to a temperature which falls in the range of 400 to 500 degrees Celsius; (3) transporting gaseous nitrogen (N2) and tantalum chloride (TaCl5) into the CVD chamber for at least two cycles; (4) ceasing the transportation of tantalum chloride (TaCl5) while nitrogen continues to flow from the inlet to the outlet; (5) reacting the tantalum chloride and the chromium(III) oxide and creating by-products; and (6) vacuuming the by-product matter from the CVD chamber via the flowing nitrogen gas.Type: ApplicationFiled: August 16, 2017Publication date: February 21, 2019Inventors: Smuruthi Kamepalli, Balasubramanian Lakshmanan