Patents by Inventor Yusai Murakami
Yusai Murakami 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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Publication number: 20060273802Abstract: The present invention provides an apparatus for correcting a voltage of a secondary battery, wherein accuracy in measurement of battery voltages between battery blocks in different voltage measurement systems.Type: ApplicationFiled: April 19, 2004Publication date: December 7, 2006Applicant: PANASONIC EV ENERGY CO., LTD.Inventors: Yusai Murakami, Norito Yamabe
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Publication number: 20060232277Abstract: The present invention provides an apparatus that can estimate the charge/discharge electricity amount without being affected by current measurement error. If specific selection conditions are met, a no-load voltage calculation part (105) takes a plurality of pairs of data consisting of current data I(n) and voltage data V(n) corresponding to the current data and calculates a no-load voltage Vsep as the voltage intercept at a current of zero in a straight-line approximation obtained by statistical processing such as regression analysis using a least squares method with respect to the plurality of pairs of data. In addition, if specific current conditions continue to be met for a certain amount of time, an open circuit voltage calculation part (106) calculates the terminal voltage of the secondary battery as the open circuit voltage Voc.Type: ApplicationFiled: July 26, 2004Publication date: October 19, 2006Applicant: PANASONIC EV ENERGY CO., LTD.Inventors: Yusai Murakami, Norito Yamabe
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Publication number: 20060196954Abstract: A temperature management apparatus for managing the temperature of cells 11, which includes an air intake duct 1, a fan unit 3, a first temperature detector (temperature sensors 25, a temperature detecting part 23) for detecting temperature Tb of the cells 11, a second temperature detector (a temperature sensor 26, a temperature detecting part 23) for detecting ambient temperature Ta, and a control device 20. The fan unit 3 has a fan 4 and a motor 5. The control device 20 has a storage part 22 and a deciding part 21. The storage part 22 stores a cooling-necessitating temperature Tc and a heating-necessitating temperature Th. The deciding part 21 directs the fan unit 3 to drive the fan 4 in a case where the temperature Tb of the cells becomes equal to or higher than both the temperature Ta of the air and the cooling-necessitating temperature Tc, or in a case where the temperature Tb of the cells becomes equal to or lower than both the temperature Ta of the air and the heating-necessitating temperature Th.Type: ApplicationFiled: March 2, 2006Publication date: September 7, 2006Applicant: PANASONIC EV ENERGY CO., LTD.Inventors: Jun Okuda, Akihiro Aoyama, Yusai Murakami
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Patent number: 7026792Abstract: There is provided a battery pack system that allows an output limit during short-time discharging and long-time discharging of a secondary battery, and limits the output appropriately upon request of a vehicle. An output limiting section 104 is provided for changing a limit value of output electric power from the secondary battery when voltage data V (n) from a voltage measuring section 102 reaches a predetermined discharging termination voltage. The output limiting section 104 has short-time output information (Pp) for allowing short-time discharging of the secondary battery and normal output information (Pn) for allowing long-time discharging of the secondary battery, and sets a first discharging termination voltage (V1) during short-time discharging to be lower than a second discharging termination voltage (V2) during long-time discharging.Type: GrantFiled: December 2, 2002Date of Patent: April 11, 2006Assignee: Panasonic Ev Energy Co., Ltd.Inventors: Yusai Murakami, Teruyoshi Egoshi, Norito Yamabe
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Publication number: 20050104558Abstract: There is provided a battery pack system that allows an output limit during short-time discharging and long-time discharging of a secondary battery, and limits the output appropriately upon request of a vehicle. An output limiting section 104 is provided for changing a limit value of output electric power from the secondary battery when voltage data V (n) from a voltage measuring section 102 reaches a predetermined discharging termination voltage. The output limiting section 104 has short-time output information (Pp) for allowing short-time discharging of the secondary battery and normal output information (Pn) for allowing long-time discharging of the secondary battery, and sets a first discharging termination voltage (V1) during short-time discharging to be lower than a second discharging termination voltage (V2) during long-time discharging.Type: ApplicationFiled: December 2, 2002Publication date: May 19, 2005Inventors: Yusai Murakami, Teruyoshi Egoshi, Norito Yamabe
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Publication number: 20050073315Abstract: When a power switch portion 10 is in an open state and a charge/discharge path of the secondary battery 100 is in a disconnected state, an electromotive force calculation portion 109 calculates a battery electromotive force Veq by subtracting a polarized voltage Vpol stored in a polarized voltage storage portion 113 from an open-circuit voltage OCV measured by a voltage measurement portion 102. Based on the electromotive force, a state-of-charge estimation portion 110 estimates a state of charge SOC. Thus, a polarized voltage to be considered for the estimation of SOC can be limited. The state of charge (SOC) of a secondary battery can be estimated with high accuracy and quickly.Type: ApplicationFiled: September 29, 2004Publication date: April 7, 2005Applicant: PANASONIC EV ENERGY CO., LTD.Inventors: Yusai Murakami, Norito Yamabe, Keiichi Minamiura, Tadao Kimura
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Publication number: 20050017725Abstract: There is provided a battery pack system with estimation accuracy of a remaining capacity of a secondary batter enhanced. A current accumulation coefficient correction section 109 calculates a correction amount ? with respect to a current accumulation coefficient k in accordance with a battery electromotive force Veq from an electromotive force calculation section 105. A remaining capacity calculation section 112 estimates a remaining capacity SOC by current accumulation, based on the current accumulation coefficient k calculated from a correction amount ?, and a charging efficiency ? based on a currently estimated remaining capacity calculated by a charging efficiency calculation section 110.Type: ApplicationFiled: December 2, 2002Publication date: January 27, 2005Inventors: Yusai Murakami, Masahiro Takada, Teruyoshi Egoshi, Norito Yamabe
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Publication number: 20040257087Abstract: There is provided a battery pack system with enhanced estimation accuracies of a polarization voltage and a remaining capacity of a secondary battery. A polarization voltage calculation section 108 calculates a polarization voltage Vpol from a filtered variation LPF (&Dgr;Q) of an accumulated capacity with reference to a look-up table (LUT) 1081. An electromotive force calculation section 113 subtracts the polarization voltage Vpol from an effective no-load voltage V0OK to determine a battery electromotive force Veq. A remaining capacity estimation section 114 estimates a remaining capacity SOC from the battery electromotive force Veq with reference to a look-up table (LUT) 1141.Type: ApplicationFiled: February 17, 2004Publication date: December 23, 2004Inventor: Yusai Murakami
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Patent number: 6791299Abstract: A method for activating a secondary battery is provided that enables sufficient activation of a secondary battery in a short time. A secondary battery is activated with a varying current, e.g., pulse current, in which current values in a charge direction and a discharge direction are repeated alternately in a cycle ranging from 1 to 30 seconds.Type: GrantFiled: March 29, 2002Date of Patent: September 14, 2004Assignees: Matsushita Electric Industrial Co., Ltd., Toyota Jidosha Kabushiki KaishaInventors: Yusai Murakami, Tadao Kimura, Seiji Bito
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Patent number: 6700383Abstract: A method of detecting and resolving a memory effect capable of detecting the memory effect with ease and with high precision and resolving even when the vehicle is in motion is provided. A current in a secondary battery is detected, a variation &Dgr;SOC in a residual battery capacity for a predetermined time period is calculated according to at least current integration by multiplying the detected current by a predetermined charge efficiency (S302), a temperature of the secondary battery is detected and a variation &Dgr;V in a no-load voltage for the predetermined time period is calculated based on the detected current, and an internal resistance corresponding to the detected temperature and the SOC is calculated (S303). A ratio k of the variation in the no-load voltage to the variation in the residual battery capacity is calculated (S304).Type: GrantFiled: June 17, 2002Date of Patent: March 2, 2004Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Tadao Kimura, Masayoshi Toyota, Norito Yamabe, Yusai Murakami
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Patent number: 6573687Abstract: A battery pack is formed by serially connecting a plurality of cells, that are individually constructed as rechargeable batteries. Charging and discharging of this battery pack are controlled such that, the proportion of discharge current with respect to the charge current equals to a value obtained by multiplying the charge current by a charging efficiency corresponding to a target SOC value.Type: GrantFiled: May 15, 2001Date of Patent: June 3, 2003Assignees: Matsushita Electric Industrial Co., Ltd., Toyota Jidosha Kabushiki KaishaInventors: Tadao Kimura, Yusai Murakami
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Patent number: 6501250Abstract: A device and method of input/output control capable of exhibiting the battery performance by nature by rapidly raising the temperature of the secondary battery by the regeneration at a low temperature. A temperature rise controller controls the temperature rise of the battery pack based on the battery temperature, thereby determining a central value of the state-of-charge control in the range of the state of charge. A battery input/output controller voluntarily controls the state of charge based on the central value of the state-of-charge control from the temperature rise controller and the state of charge at the point of time from the state-of-charge operator, and controls charge and discharge based on the charge and discharge request from the outside to the battery pack.Type: GrantFiled: April 5, 2001Date of Patent: December 31, 2002Assignees: Matsushita Electric Industrial Co., Ltd., Toyota Jidosha Kabushiki KaishaInventors: Seiji Bito, Yusai Murakami, Toshiaki Nakanishi, Kiwamu Inui, Kunio Kanamaru, Tadao Kimura, Masayoshi Iwase, Katsuhiko Yamaguchi
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Publication number: 20020195999Abstract: A method of detecting and resolving a memory effect capable of detecting the memory effect with ease and with high precision and resolving even when the vehicle is in motion is provided. A current in a secondary battery is detected, a variation &Dgr;SOC in a residual battery capacity for a predetermined time period is calculated according to at least current integration by multiplying the detected current by a predetermined charge efficiency (S302), a temperature of the secondary battery is detected and a variation &Dgr;V in a no-load voltage for the predetermined time period is calculated based on the detected current, and an internal resistance corresponding to the detected temperature and the SOC is calculated (S303). A ratio k of the variation in the no-load voltage to the variation in the residual battery capacity is calculated (S304).Type: ApplicationFiled: June 17, 2002Publication date: December 26, 2002Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Tadao Kimura, Masayoshi Toyota, Norito Yamabe, Yusai Murakami
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Patent number: 6465988Abstract: A device and a method are provided in which memory effects can be cancelled by controlling charging and discharging of a secondary battery during driving of a vehicle. When a memory effect determinator determines that the discharging memory effect has occurred, based on at least one of the following determinations: whether a time of charging/discharging of a secondary battery has reached a predetermined time; whether a charging/discharging amount in the secondary battery has reached a predetermined amount; and whether a voltage per cell has reached a voltage V1 at a lower-limit state of charge in a range of capacity actually used, a discharging controller discharges the secondary battery until the voltage per cell reaches a voltage V3 that is higher than 1.0 V and is lower than the voltage V1 at the lower-limit state of charge.Type: GrantFiled: April 20, 2001Date of Patent: October 15, 2002Assignees: Matsushita Electric Industrial Co., Ltd., Toyota Jidosha Kabushiki KaishaInventors: Shinichiro Ito, Yusai Murakami, Seiji Bito, Tadao Kimura
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Publication number: 20020145405Abstract: A method for activating a secondary battery is provided that enables sufficient activation of a secondary battery in a short time. A secondary battery is activated with a varying current, e.g., pulse current, in which current values in a charge direction and a discharge direction are repeated alternately in a cycle ranging from 1 to 30 seconds.Type: ApplicationFiled: March 29, 2002Publication date: October 10, 2002Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Yusai Murakami, Tadao Kimura, Seiji Bito
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Patent number: 6380717Abstract: A device and method is provided that can detect overcharge reliably by separating heat generated by internal resistance and heat chemically generated upon overcharging in a secondary battery. Based on the temperature of the secondary battery detected every first predetermined time by a battery temperature detection section, a temperature gradient operation section calculates a temperature gradient indicating a temperature increase per unit time for every second predetermined time that is longer than the first predetermined time. When a temperature gradient determination section determines that the temperature gradient is larger than a predetermined temperature gradient threshold, which is preset according to the charged state of the secondary battery, N times in a row (where N is a natural number), a fully charged state of the secondary battery is detected.Type: GrantFiled: March 8, 2001Date of Patent: April 30, 2002Assignees: Matsushita Electric Industrial Co., Ltd., Toyota Jidosha Kabushiki KaishaInventors: Yusai Murakami, Tadao Kimura, Toshiaki Nakanishi, Toshihiro Katsuda, Yoshiaki Kikuchi
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Publication number: 20020003417Abstract: A device and method of input/output control capable of exhibiting the battery performance by nature by rapidly raising the temperature of the secondary battery by the regeneration at a low temperature. A temperature rise controller controls the temperature rise of the battery pack based on the battery temperature, thereby determining a central value of the state-of-charge control in the range of the state of charge. A battery input/output controller voluntarily controls the state of charge based on the central value of the state-of-charge control from the temperature rise controller and the state of charge at the point of time from the state-of-charge operator, and controls charge and discharge based on the charge and discharge request from the outside to the battery pack.Type: ApplicationFiled: April 5, 2001Publication date: January 10, 2002Inventors: Seiji Bito, Yusai Murakami, Toshiaki Nakanishi, Kiwamu Inui, Kunio Kanamaru, Tadao Kimura, Masayoshi Iwase, Katsuhiko Yamaguchi
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Publication number: 20010035741Abstract: A device and method is provided that can detect overcharge reliably by separating heat generated by internal resistance and heat chemically generated upon overcharging in a secondary battery. Based on the temperature of the secondary battery detected every first predetermined time by a battery temperature detection section, a temperature gradient operation section calculates a temperature gradient indicating a temperature increase per unit time for every second predetermined time that is longer than the first predetermined time. When a temperature gradient determination section determines that the temperature gradient is larger than a predetermined temperature gradient threshold, which is preset according to the charged state of the secondary battery, N times in a row (where N is a natural number), a fully charged state of the secondary battery is detected.Type: ApplicationFiled: March 8, 2001Publication date: November 1, 2001Inventors: Yusai Murakami, Tadao Kimura, Toshiaki Nakanishi, Toshihiro Katsuda, Yoshiaki Kikuchi
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Publication number: 20010035742Abstract: A device and a method are provided in which memory effects can be cancelled by controlling charging and discharging of a secondary battery during driving of a vehicle. When a memory effect determinator determines that the discharging memory effect has occurred, based on at least one of the following determinations: whether a time of charging/discharging of a secondary battery has reached a predetermined time; whether a charging/discharging amount in the secondary battery has reached a predetermined amount; and whether a voltage per cell has reached a voltage V1 at a lower-limit state of charge in a range of capacity actually used, a discharging controller discharges the secondary battery until the voltage per cell reaches a voltage V3 that is higher than 1.0 V and is lower than the voltage V1 at the lower-limit state of charge.Type: ApplicationFiled: April 20, 2001Publication date: November 1, 2001Applicant: Matsushita Electric Industrial Co., Ltd.Inventors: Shinichiro Ito, Yusai Murakami, Seiji Bito, Tadao Kimura
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Publication number: 20010033150Abstract: A battery pack is formed by serially connecting a plurality of cells, that are individually constructed as rechargeable batteries. Charging and discharging of this battery pack are controlled such that, the proportion of discharge current with respect to the charge current equals to a value obtained by multiplying the charge current by a charging efficiency corresponding to a target SOC value.Type: ApplicationFiled: May 15, 2001Publication date: October 25, 2001Applicant: Matsushita Electric Industrial Co., LtdInventors: Tadao Kimura, Yusai Murakami