Patents by Inventor Venkateshwarlu Yadha
Venkateshwarlu Yadha 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: 9969297Abstract: The performance of a fuel cell power plant that decays, in an electric vehicle which makes frequent starts, is recovered by partially shutting down the power plant. Recovery is enabled by a recovery enable flag upon conditions such as vehicle using low or no power, vehicle speed at or near zero, electric storage SOC above a threshold, and no recovery during the last half-hour (or other duration). The recovery restart resets a timer to ensure that recovery is not attempted too often. The power plant then remains in a recovery stand-by mode until a recovery restart flag is set to 1. The restart causes start-up of the fuel cell power plant, reaching an operational mode.Type: GrantFiled: June 28, 2016Date of Patent: May 15, 2018Assignee: Audi AGInventors: Sitaram Ramaswamy, Venkateshwarlu Yadha, Matthew P. Wilson
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Patent number: 9509002Abstract: A fuel cell power plant keeps track, such as with a fuel-off timer (41), of the extent to which shutdown of the fuel cell power plant has occurred, in case the fuel cell power plant is quickly commanded to resume full operation. In one embodiment, if the fuel-off timer has not timed out at the time that the fuel cell power plant is ordered to resume full operation, a fuel-on timer is set (51) equal to the value of the fuel-off timer when the fuel cell power plant is ordered to resume full operation. Then, the fuel cell power plant is refueled (22), in a duration of time related to the setting of the fuel-off timer, rather than doing a full fuel purge.Type: GrantFiled: May 20, 2010Date of Patent: November 29, 2016Assignee: Audi AGInventors: Venkateshwarlu Yadha, Matthew P. Wilson, Matthew I. Riley, Sitaram Ramaswamy
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Publication number: 20160303994Abstract: The performance of a fuel cell power plant that decays, in an electric vehicle which makes frequent starts, is recovered by partially shutting down the power plant. Recovery is enabled by a recovery enable flag upon conditions such as vehicle using low or no power, vehicle speed at or near zero, electric storage SOC above a threshold, and no recovery during the last half-hour (or other duration). The recovery restart resets a timer to ensure that recovery is not attempted too often. The power plant then remains in a recovery stand-by mode until a recovery restart flag is set to 1. The restart causes start-up of the fuel cell power plant, reaching an operational mode.Type: ApplicationFiled: June 28, 2016Publication date: October 20, 2016Inventors: Sitaram Ramaswamy, Venkateshwarlu Yadha, Matthew P. Wilson
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Patent number: 9403444Abstract: The performance of a fuel cell power plant that decays, in an electric vehicle which makes frequent starts, is recovered by partially shutting down (65-67) the power plant. Recovery is enabled by a recovery enable flag (25) upon conditions such as vehicle using (22) low or no power (16), vehicle speed at or near zero (22), electric storage SOC above a threshold (23), and no recovery (19) during the last half-hour (or other duration). The recovery restart resets a timer (79) to ensure (19) that recovery is not attempted too often. The power plant then remains in a recovery stand-by mode (72) until a recovery restart flag (35) is set to 1 (74). The restart causes start-up of the fuel cell power plant (50, 52, 55), reaching an operational mode (57).Type: GrantFiled: September 15, 2010Date of Patent: August 2, 2016Assignee: Audi AGInventors: Sitaram Ramaswamy, Venkateshwarlu Yadha, Matthew P. Wilson
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Patent number: 8808934Abstract: A fuel cell power plant (5) includes a stack (6) of fuel cells, each of which have an anode (9), a cathode (10), and a PEM (11) disposed between the anode and the cathode. A controller (17) recognizes an indication (67) of no load demand (68) by a load (59), to operate (45) an air recycle loop (44-46) utilizing the process air blower (35) and transfer the power output (57) of the stack from the load (59) to an auxiliary load (60), comprising a resistance which will consume a predetermined small amount of power in response to the current applied thereto, when the stack operates at a critical voltage above which fuel cell corrosion is unacceptable. Fuel and air will also be reduced (16, 40). The controller may cause increased cathode recycle when the critical voltage is reached and increased air when the voltage is a fraction of a volt below the critical voltage.Type: GrantFiled: October 3, 2008Date of Patent: August 19, 2014Assignee: Ballard Power Systems Inc.Inventors: Matthew P. Wilson, Venkateshwarlu Yadha, Carl A. Reiser
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Publication number: 20130197729Abstract: The performance of a fuel cell power plant that decays, in an electric vehicle which makes frequent starts, is recovered by partially shutting down (65-67) the power plant. Recovery is enabled by a recovery enable flag (25) upon conditions such as vehicle using (22) low or no power (16), vehicle speed at or near zero (22), electric storage SOC above a threshold (23), and no recovery (19) during the last half-hour (or other duration). The recovery restart resets a timer (79) to ensure (19) that recovery is not attempted too often. The power plant then remains in a recovery stand-by mode (72) until a recovery restart flag (35) is set to 1 (74). The restart causes start-up of the fuel cell power plant (50, 52, 55), reaching an operational mode (57).Type: ApplicationFiled: September 15, 2010Publication date: August 1, 2013Applicant: UTC Power CorporationInventors: Sitaram Ramaswamy, Venkateshwarlu Yadha, Matthew P. Wilson
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Publication number: 20130108941Abstract: A fuel cell power plant keeps track, such as with a fuel-off timer (41), of the extent to which shutdown of the fuel cell power plant has occurred, in case the fuel cell power plant is quickly commanded to resume full operation. In one embodiment, if the fuel-off timer has not timed out at the time that the fuel cell power plant is ordered to resume full operation, a fuel-on timer is set (51) equal to the value of the fuel-off timer when the fuel cell power plant is ordered to resume full operation. Then, the fuel cell power plant is refueled (22), in a duration of time related to the setting of the fuel-off timer, rather than doing a full fuel purge.Type: ApplicationFiled: May 20, 2010Publication date: May 2, 2013Inventors: Venkateshwarlu Yadha, Matthew P. Wilson, Matthew I. Riley, Sitaram Ramaswamy
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Patent number: 8142950Abstract: The invention is a hydrogen passivation shut down system for a fuel cell power plant (10, 200). During shut down of the plant (10, 200), hydrogen fuel is permitted to transfer between an anode flow path (24, 24?) and a cathode flow path (38, 38?). A controlled-oxidant flow device (209) near an oxygen source (58?) permits a minimal amount of atmospheric oxygen to enter the power plant (200) during shut down to equalize pressure between ambient atmosphere and the flow paths (24?, 28?) and to keep limited atmospheric oxygen entering the power plant (200) through the device (209) as far as possible from fuel cell flow fields (28?, 42?). A non-leaking hydrogen inlet valve (202), a non-leaking cathode exhaust valve (208), and a combined oxidant and fuel exhaust line (206) also minimize penetration of oxygen into the shut down power plant (200).Type: GrantFiled: May 4, 2009Date of Patent: March 27, 2012Assignee: UTC Power CorporationInventors: Carl A. Reiser, Venkateshwarlu Yadha, Matthew P. Wilson
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Patent number: 8062801Abstract: A fuel cell power plant (100) having a stack of fuel cells (102), each having an anode (104), a fuel reactant gas flow field plate (118), a cathode (106), an oxidant reactant gas flow field plate (120), and an electrolyte (101) between the anode and cathode. The stack has coolant channels (131), an air blower (144), air inlet (139a) and outlet (141a) valves, and a cathode recycle loop using either the primary air blower or a cathode recycle blower (135). A shutdown process includes recycling air through the cathodes with only one of an air inlet valve or air exit valve closed, while applying fresh fuel and recycling fuel through the anodes until oxygen is about 4% or less, or average cell voltage is about 0.2 or less, or for predetermined period of time.Type: GrantFiled: August 31, 2006Date of Patent: November 22, 2011Assignee: UTC Power CorporationInventors: Mark J. Moran, Venkateshwarlu Yadha, Matthew P. Wilson
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Publication number: 20110171547Abstract: A fuel cell power plant (5) includes a stack (6) of fuel cells, each of which have an anode (9), a cathode (10), and a PEM (11) disposed between the anode and the cathode. A controller (17) recognizes an indication (67) of no load demand (68) by a load (59), to operate (45) an air recycle loop (44-46) utilizing the process air blower (35) and transfer the power output (57) of the stack from the load (59) to an auxiliary load (60), comprising a resistance which will consume a predetermined small amount of power in response to the current applied thereto, when the stack operates at a critical voltage above which fuel cell corrosion is unacceptable. Fuel and air will also be reduced (16, 40). The controller may cause increased cathode recycle when the critical voltage is reached and increased air when the voltage is a fraction of a volt below the critical voltage.Type: ApplicationFiled: October 3, 2008Publication date: July 14, 2011Inventors: Matthew P. Wilson, Venkateshwarlu Yadha, Carl A. Reiser
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Publication number: 20100310955Abstract: A fuel cell power plant (100) includes a stack of fuel cells (102), each having an electrolyte (101) between an anode (104), and a cathode (106), coolant channels (103), an air blower (144), air inlet and outlet valves (139a, 141a), a cathode recycle loop an (135) using the air blower, and a cathode exhaust mix box (173). Shutdown includes recycling cathode air while applying fresh fuel and recycled fuel through the anodes until oxygen is about is about 0.2 or less, or expiration of time. On startup, the air blower is started with the cathode recycle valve (135) open, and the air inlet valve is opened to allow about one-half of the flow of air used during normal operation, to cause hydrogen in the cathode to be gradually consumed, thereby avoiding H2 levels above lower flammability levels in the air outlet manifold. H2 is monitored at exhaust; full air flow is provided after H2 peaks.Type: ApplicationFiled: December 28, 2007Publication date: December 9, 2010Inventors: Venkateshwarlu Yadha, Marc Moran, Matthew Wilson
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Publication number: 20100239927Abstract: A fuel cell power plant (100) having a stack of fuel cells (102), each having an anode (104), a fuel reactant gas flow field plate (118), a cathode (106), an oxidant reactant gas flow field plate (120), and an electrolyte (101) between the anode and cathode. The stack has coolant channels (131), an air blower (144), air inlet (139a) and outlet (141a) valves, and a cathode recycle loop using either the primary air blower or a cathode recycle blower (135). A shutdown process includes recycling air through the cathodes with only one of an air inlet valve or air exit valve closed, while applying fresh fuel and recycling fuel through the anodes until oxygen is about 4% or less, or average cell voltage is about 0.2 or less, or for predetermined period of time.Type: ApplicationFiled: August 31, 2006Publication date: September 23, 2010Inventors: Mark J. Moran, Venkateshwarlu Yadha, Matthew P. Wilson
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Publication number: 20100068565Abstract: A fuel cell includes a cathode having an air flow field. An anode includes an inlet and an outlet for providing unused fuel to a fuel recycling line. A pressure regulator is arranged upstream from an ejector and communicates with the air flow field for adjusting a fuel pressure at the motive inlet in response to an air pressure associated with the air flow field. The cathode and/or anode includes a porous water transport plate adjacent to the air flow field and/or fuel flow field respectively. A back pressure valve is arranged downstream from the air flow field for producing an air back pressure that generates a desired differential pressure across the water transport plate. The back pressure valve is controlled to achieve the desired differential pressure across the water transport plate so that the fuel cell maintains water balance.Type: ApplicationFiled: December 19, 2006Publication date: March 18, 2010Inventors: Venkateshwarlu Yadha, Matthew P. Wilson, Praveen Narasimhamurthy
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Publication number: 20090220832Abstract: The invention is a hydrogen passivation shut down system for a fuel cell power plant (10, 200). During shut down of the plant (10, 200), hydrogen fuel is permitted to transfer between an anode flow path (24, 24?) and a cathode flow path (38, 38?). A controlled-oxidant flow device (209) near an oxygen source (58?) permits a minimal amount of atmospheric oxygen to enter the power plant (200) during shut down to equalize pressure between ambient atmosphere and the flow paths (24?, 28?) and to keep limited atmospheric oxygen entering the power plant (200) through the device (209) as far as possible from fuel cell flow fields (28?, 42?). A non-leaking hydrogen inlet valve (202), a non-leaking cathode exhaust valve (208), and a combined oxidant and fuel exhaust line (206) also minimize penetration of oxygen into the shut down power plant (200).Type: ApplicationFiled: May 4, 2009Publication date: September 3, 2009Inventors: Carl A. Reiser, Venkateshwarlu Yadha, Matthew P. Wilson