Nissan Motor Company Limited

Shinsuke Yoshida

Tsuyoshi Morita

Hayato Nagakura

Hiroshi Kaneko

Yukio Uesugi

A voltage detection device that is connected to a DC circuit to which a DC voltage is applied and that detects the DC voltage applied to the DC circuit includes a voltage conversion unit for outputting a first voltage that increases as the DC voltage increases and a second voltage that decreases as the DC voltage increases, an error detection unit for detecting an error for the first voltage and the second voltage based upon the first voltage and the second voltage when the DC voltage is, and a voltage calculation unit for correcting a difference between the first voltage and the second voltage based upon the error detected by the error detection unit and calculating the DC voltage based upon the corrected difference between the first voltage and the second voltage.

Voltage detection device and voltage detection method

A battery pack capacity adjusting device for adjusting a capacity of a battery pack having a plurality of secondary cells includes a control circuit board and a control section. The control circuit board is installable in the battery pack, and includes a capacity adjusting section to be electrically connected to the secondary cells to adjust a capacity of each of the secondary cells. The control section is configured to determine a number of the secondary cells whose capacities are adjustable together based on a relationship between a heat radiation amount of the control circuit board and a heat emission amount of the capacity adjusting section, and to control the capacity adjusting section to adjust the capacities of the number of the secondary cells that were determined to be adjustable together.

Battery pack capacity adjusting device and method

A voltage detection device that is connected to a DC circuit to which a DC voltage is applied and that detects the DC voltage applied to the DC circuit comprises a voltage conversion means for outputting a first voltage that increases as the DC voltage increases and a second voltage that decreases as the DC voltage increases, a voltage calculation means for inputting the first voltage and the second voltage outputted from the voltage conversion means and calculating the DC voltage based upon a difference between the inputted first voltage and the inputted second voltage, and a first failure judgment means for judging that failure has occurred if at least one of the first voltage and the second voltage is not inputted to the voltage calculation means.

An abnormality diagnostic device is configured to diagnose an abnormality in a battery pack having a plurality of cells connected in series. Each of a plurality of diagnostic voltage detecting circuits is configured to detect one of a voltage across a corresponding one of discharging circuits. An abnormality diagnostic control section is configured to perform a first diagnostic operation in which the switches corresponding to alternate ones of the cells are turned on and a second diagnostic operation in which all of the switches are turned on, and to determine whether a break exists in an electrical connection or an abnormality exists in one of the switches based on the voltages detected by the diagnostic voltage detecting circuits during the first diagnostic operation and the voltages detected by the diagnostic voltage detecting circuits during the second diagnostic operation.

Abnormality diagnostic device

In input/output power control apparatus and method for a secondary battery, in a case where neither a current sensor nor a voltage sensor fails, allowable input/output powers which are an allowable input power by which the secondary battery allowably inputs and an allowable output power by which the secondary battery allowably outputs are calculated on the basis of an input and/or output current and a terminal voltage of the secondary battery and, in a case where the failure in either one of the current sensor and the voltage sensor is detected, the allowable input/output powers are calculated on the basis of a detected value of one of the current and voltage sensors in which no failure is detected, and each of input and output powers of the secondary battery is limited to be equal to or smaller than the corresponding one of the allowable input/output powers.

Input/output power control apparatus and method for secondary battery

A remaining-capacity dispersion detecting apparatus for a battery pack having a plurality of cells includes a total voltage sensing section adapted to sense a total voltage which is a terminal voltage of the whole of battery pack; a storing section adapted to store a value of the total voltage when the battery pack becomes under unloaded condition from loaded condition; and a dispersion detecting section. The dispersion detecting section is adapted to detect a value of the total voltage at a time of activation before the battery pack becomes under the loaded condition from the unloaded condition, to compare the currently-detected total voltage value with the total voltage value previously stored by the storing section, and to detect a dispersion in respective remaining capacities of the plurality of cells in the case where a difference between the currently-detected total voltage value and the previously-stored total voltage value is greater than or equal to a predetermined value.

Remaining-capacity dispersion detecting apparatus and remaining-capacity control apparatus for battery pack

A capacity adjustment circuit provided in conjunction with each cell discharges the corresponding cell if the cell voltage is higher than a bypass operating voltage and, as a result, the extent of inconsistency among the voltages at the individual cells is minimized. A cell switching circuit switches the connections between the individual cells and the capacity adjustment circuits over predetermined time intervals.

Capacity adjustment apparatus and capacity adjustment method for battery pack

In a chargeable-and-dischargeable power supply system, a plurality of battery cell sections are connected in series with one another, a plurality of cell state detecting sections are installed for the respective battery cell sections and configured to detect a charge state in the respectively corresponding battery cell sections, a power control section is configured to carry out a power supply control for the battery cell sections, a first electrical isolation section is installed in a first signal route from the power control section to one of the cell state detecting sections which is for a highest potential positioned battery cell section, and a second electrical isolation section is installed in a second signal route from one of the cell state detecting sections which is for a lowest potential positioned battery cell section to the power control section.

Growing community of inventors

Hadano, Japan

Shinsuke Yoshida