Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Keisuke Tanigawa

Takumi Shimizu

Tetsuya Kobayashi

Yoshiaki Kikuchi

Teruo Ishishita

Tomomichi Mizoguchi

Ryo Mano

Manabu Sasaki

Jyunta Izumi

Katsutoyo Misawa

Tatsuya Machi

Hiroki Komura

A power supply system includes a plurality of DC-DC converters and at least one operating unit. The DC-DC converters are connected in parallel to one another. The at least one operating unit operates the DC-DC converters such that power is supplied through the DC-DC converters to a predetermined power-supplied object. The at least one operating unit includes a voltage controller, a current limiter, and an increasing unit. The voltage controller operates the DC-DC converters such that output voltages thereof are controlled to be respective target voltage. The current limiter limits output currents of the DC-DC converters so that they are limited with respect to a respective specified value. The increasing unit increases a specified value for at least one DC-DC converter of the DC-DC converters, when all of the plurality of DC-DC converters are activated and output current of at least one other DC-DC converter of the DC-DC converters reaches a specified value for the at least one other DC-DC converter.

Power supply system

A plurality of voltage switching circuitsare provided in a switching unitto relatively change a reference voltage to plural levels, thus detecting a spontaneous change of the reference voltage. A range of relative change in the reference voltage by the plurality of voltage switching circuitsis set to a usage voltage rangeoras a part of a total voltage rangeof each of cellsto. This eliminates the need to provide voltage switching circuitsrequired to relatively change the reference voltage over the total voltage range of each of the cellsto, making it possible to minimize the number of the voltage switching circuitsfor each of the cellsto. Thus, it is possible to prevent the size of a battery pack control apparatusfrom increasing.

Battery pack control apparatus

A first monitor circuitand a second monitor circuiteach having an identical configuration are provided in a voltage monitor. A threshold switching sectionswitches a threshold of each of switching unitsandprovided in the respective monitor circuitsandto a same value. Each of comparatorsandcompares the threshold with a reference voltage to output a result of the comparison. A fault detecting sectioncompares the respective outputs from the comparatorsandwith each other to detect a characteristic shift of the threshold of each of the monitor circuitsand

Voltage monitor for monitoring voltage of a battery

The battery pack management apparatus for managing a battery pack having a series connection of battery cells is provided with a management unit for each of unit batteries each of which includes a single battery cell or a plurality of adjacent battery cells included in said battery pack. The battery pack management apparatus includes a selection circuit selecting one of the unit batteries, and a voltage detection circuit detecting a voltage across the selected unit battery. The management unit provided for the selected unit battery is configured to perform a management process (discharge process, for example) other than detection of the voltage across the selected unit battery on the selected unit battery.

Battery pack management apparatus

In a battery pack manager that manages series-connected rechargeable unit cells, a cell equalizer equalizes the cell voltages by individually discharging the unit cells according to deviations from reference voltages. An overcharge/overdischarge detector detects an overcharge and an overdischarge state of each unit cell. An inhibit circuit prevents the cell equalizer from discharging the unit cells when the overcharge/overdischarge detector is activated to reduce the cell voltage variability, which would otherwise occur as a result of interference from the overcharge/overdischarge detector, so that the overcharge/overdischarge states of all unit cells can be determined with precision. Connecting lines of the unit cells are monitored to detect a line-cut. The inhibit circuit further inhibits the cell equalizer when the connecting lines are being monitored to reduce the cell voltage variability, which would otherwise occur as a result of interference from the line-cut detection, so that false line-cut detection is avoided.

Battery pack manager and method of detecting a line cut

In a flying capacitor type battery voltage detector on a circuit substrate, a large number of photo MOS switches having performance highly depending from temperature are dividedly disposed on front and back surfaces of the circuit substrate such that the photo MOS switches of the back surface are lying over the photo MOS switches of the front surface. Each of pairs of photo MOS switches connects a pair of surface lines with first and second floating lines to transmit an output voltage of each cell of a battery pack connected with the surface lines to a differential amplifier through a flying capacitor connected with the floating lines. Because of the division of the photo MOS switches on the surfaces of the circuit substrate, temperatures of the photo MOS switches have less dispersion, and an S/N ratio of each signal indicating the output voltage can be improved.

Growing community of inventors

Nishio, Japan

Keisuke Tanigawa