Method and apparatus for measuring residual capacity of an electric-vehicle battery
First Claim
1. A method of measuring a battery residual capacity of an electric vehicle battery during a charging process comprising the repeated steps of:
- measuring a charge current of the battery;
estimating a discharge voltage corresponding to a current battery residual capacity;
computing a power of the battery as a product of the measured charge current of the battery and the estimated discharge voltage; and
accumulatively adding the computed power to the current battery residual capacity to provide a new current battery residual capacity for display,the method of measuring a battery residual capacity during a discharging process comprising the repeated steps ofmeasuring a discharge voltage and a discharge current of the battery;
computing a consumed power as a product of the measured discharge voltage and the measured discharge current; and
subtracting the consumed power from a most recent battery residual capacity to produce a new most recent battery residual capacity for display.
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Accused Products
Abstract
A method and an apparatus are provided for detecting a current residual capacity of a battery employed in an electric vehicle, such as an electric car. During a charging process, a value of the charge current of the battery is measured and an estimated discharge voltage corresponding to a current battery accumulated power is determined. A power of the battery as a product of the value of the charge current of the battery and the estimated discharge voltage is thereafter computed and the computed power is added to the current battery accumulated power to provide a new current battery accumulated power for display. During a discharging process, values of the discharge voltage and the discharge current are measured. The amount of consumed power is thereafter computed as a product of the values of the discharge voltage and the discharge current. The computed amount of consumed power is subtracted from a current battery residual capacity to produce a new current battery residual capacity for display. The above estimated discharge voltage is found from data obtained from test-working experiments or a process of learning the running states of an actual electric vehicle.
74 Citations
6 Claims
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1. A method of measuring a battery residual capacity of an electric vehicle battery during a charging process comprising the repeated steps of:
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measuring a charge current of the battery; estimating a discharge voltage corresponding to a current battery residual capacity; computing a power of the battery as a product of the measured charge current of the battery and the estimated discharge voltage; and accumulatively adding the computed power to the current battery residual capacity to provide a new current battery residual capacity for display, the method of measuring a battery residual capacity during a discharging process comprising the repeated steps of measuring a discharge voltage and a discharge current of the battery; computing a consumed power as a product of the measured discharge voltage and the measured discharge current; and subtracting the consumed power from a most recent battery residual capacity to produce a new most recent battery residual capacity for display. - View Dependent Claims (2, 3, 4)
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5. A battery residual capacity measuring apparatus for measuring a residual capacity of an electric vehicle battery comprising:
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voltage measurement means for measuring a terminal voltage of the battery; current measuring means for measuring a charge current and a discharge current of the battery; and control means, coupled to said voltage measurement means and said current measurement means, for repeatedly computing a consumed power as a product of the measured discharged current and the measured discharged voltage and subtracting the computed consumed power from a most recent battery residual capacity to produce a new most recent battery residual capacity during a discharging process, and repeatedly estimating a discharge voltage corresponding to a current battery residual capacity, computing a power as a product of the measured charge current of the battery and the estimated discharge voltage, and accumulating the computed power of the current battery residual capacity to produce a new current battery residual capacity during a charging process. - View Dependent Claims (6)
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Specification