Method of detecting and resolving memory effect
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
G01N-027/416
H02J-007/00
출원번호
US-0174204
(2002-06-17)
우선권정보
JP-0186187 (2001-06-20)
발명자
/ 주소
Kimura, Tadao
Toyota, Masayoshi
Yamabe, Norito
Murakami, Yusai
출원인 / 주소
Matsushita Electric Industrial Co., Ltd.
대리인 / 주소
Merchant & Gould P.C.
인용정보
피인용 횟수 :
8인용 특허 :
2
초록▼
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 ΔSOC in a residual battery capacity for a predetermined
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 ΔSOC 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 ΔV 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). If the ratio exceeds a predetermined threshold value kst, then the battery is judged to have a memory effect (S307), and the usage range of the SOC is extended for a predetermined time period (S308) or the correction of the SOC using voltages is prohibited for a predetermined time period(S309).
대표청구항▼
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 ΔSOC in a residual battery capacity for a predetermined
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 ΔSOC 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 ΔV 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). If the ratio exceeds a predetermined threshold value kst, then the battery is judged to have a memory effect (S307), and the usage range of the SOC is extended for a predetermined time period (S308) or the correction of the SOC using voltages is prohibited for a predetermined time period(S309). sient calculation comprises determining a magnetic flux density of each of said plurality of polyhedral elements from the calculated transient magnetic field, and updating said magnetic permeability to a magnetic permeability obtained from a magnetic flux density using a predetermined magnetic permeability-magnetic flux density characteristic. 3. The method as claimed in claim 1, wherein said step of performing transient calculation comprises providing secondary absorption boundary conditions to the calculated transient electric field at a boundary of said region to be analyzed, by using the transient electric field calculated at two preceding time steps (2Δt) and the transient electric field calculated at one preceding time step (Δt). 4. The method as claimed in claim 1, wherein the transient electric field Enis calculated by where σ is the conductivity, ε is eth dielectric constant, Δt is a time step, Hn-1/2is a magnetic field at 1/2 preceding time step and Jn-1/2is a current density at 1/2 preceding time step. 5. The method as claimed in claim 1, wherein the transient magnetic field Hn+1/2is calculated by where μ is the magnetic permeability and Jmnis a magnetizing current at 1/2 preceding time step. 6. A method for analyzing characteristics of a magnetic transducer, comprising the steps of: sub-dividing a region to be analyzed, in a magnetic transducer into a plurality of polyhedral elements, based on at least data representing a shape of said region in said magnetic transducer; and performing a transient calculation, said transient calculation including: calculating a transient electric field of each of said plurality of polyhedral elements by using a conductivity and a dielectric constant of each of said plurality of polyhedral elements, a transient electric field of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt), a transient magnetic field of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2), and a current density of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2); calculating a transient magnetic field of each of said plurality of polyhedral elements by using a transient magnetic field of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt), a transient electric field of each of said plurality of polyhedral elements, at 1/2 preceding time step (Δt/2), and a magnetizing current corresponding to a magnetization of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt); calculating an effective magnetic field of each of said plurality of polyhedral elements, from the calculated transient magnetic field; and determining a derivative of magnetization of each of said plurality of polyhedral elements, by using the calculated effective magnetic field to calculate a magnetization at that time, said step of performing transient calculation being repeated until a predetermined number of time steps have been completed, to determine electric fields, magnetic fields and magnetizations of all of said plurality of polyhedral elements in said region to be analyzed. 7. The method as claimed in claim 6, wherein said step of performing transient calculation comprises providing secondary absorption boundary conditions to the calculated transient electric field at a boundary of said region to be analyzed, by using the transient electric field calculated at two preceding time steps (2Δt) and the transient electric field calculated at one preceding time step (Δt). 8. The method as claimed in claim 6, wherein the transient electric field Enis calculated by where σ is the conductivity, ε is eth dielectric constant, Δt is a time step, Hn-1/2is a magnetic field at 1/2 preceding time step and Jn-1/2is a current densit y at 1/2 preceding time step. 9. The method as claimed in claim 6, wherein the transient magnetic field Hn+1/2is calculated by where μ is the magnetic permeability and Jmnis a magnetizing current at 1/2 preceding time step. 10. The method as claimed in claim 6, wherein a derivative ΔM of said magnetization is calculated by where α is a damping constant, γ is a gyro constant, Heffis the effective magnetic field and M is the magnetization. 11. The method as claimed in claim 6, wherein the effective magnetic field Heffis calculated by Heff=H+Hk+Hex,where H is the calculated transient magnetic field, Hkis an anisotropy magnetic field and Hexis an exchange magnetic field. 12. A program for analyzing characteristics of a magnetic transducer, said program containing computer instructions which when executed perform the following steps: sub-dividing a region to be analyzed, in a magnetic transducer into a plurality of polyhedral elements, based on at least data representing a shape of said region in said magnetic transducer; and performing a transient calculation, said transient calculation including: calculating a transient electric field of each of said plurality of polyhedral elements by using a conductivity and a dielectric constant of each of said plurality of polyhedral elements, a transient electric field of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt), a transient magnetic field of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2), and a current density of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2); calculating a transient magnetic field of each of said plurality of polyhedral elements by using a transient magnetic field of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt), a transient electric field of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2), and a magnetic permeability of each of said plurality of polyhedral elements; and updating said magnetic permeability in accordance with a magnetic flux density determined from said calculated transient magnetic field, said function of performing transient calculation being repeated until a predetermined number of time steps have been completed, to determine electric fields and magnetic fields of all of said plurality of polyhedral elements in said region to be analyzed. 13. A program for analyzing characteristics of a magnetic transducer, said program containing computer instructions which when executed perform the following steps: sub-dividing a region to be analyzed, in a magnetic transducer into a plurality of polyhedral elements, based on at least data representing a shape of said region in said magnetic transducer; and performing a transient calculation, said transient calculation including: calculating a transient electric field of each of said plurality of polyhedral elements by using a conductivity and a dielectric constant of each of said plurality of polyhedral elements, a transient electric field of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt), a transient magnetic field of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2), and a current density of each of said plurality of polyhedral elements, calculated at 1/2 preceding time step (Δt/2); calculating a transient magnetic field of each of said plurality of polyhedral elements by using a transient magnetic field of each of said plurality of polyhedral elements, calculated at one preceding time step (Δt), a transient electric field of each of said plurality of polyhedral elements, at 1/2 preceding time step (Δt/2), and a magnetizing current corresponding to a magnetization o f each of said plurality of polyhedral elements, calculated at one preceding time step (Δt); calculating an effective magnetic field of each of said plurality of polyhedral elements, from the calculated transient magnetic field; and determining a derivative of magnetization of each of said plurality of polyhedral elements, by using the calculated effective magnetic field to calculate a magnetization at that time, said function of performing transient calculation being repeated until a predetermined number of time steps have been completed, to determine electric fields, magnetic fields and magnetizations of all of said plurality of polyhedral elements in said region to be analyzed. ysics] B307, pp. 53-82, Plenum Press (New York 1993).
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이 특허에 인용된 특허 (2)
Champlin Keith S. (5438 Elliot Ave. South Minneapolis MN 55437), Electronic battery tester with automatic compensation for low state-of-charge.
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