Denso Corporation

Other

Nippon Soken, Inc.

Tetsuya Kobayashi

Takashi Yamashita

Keisuke Tanigawa

Toshiyuki Kawai

Hidetoshi Kato

Masaya Itou

Osamu Ishikawa

Takumi Shimizu

Shinya Goto

Hiroaki Nishikawa

Shoji Sakai

Hiroshi Fujita

Kouji Shibata

Isamu Ogawa

Junichi Iino

Kenji Hamazaki

Kazuhiko Tsugita

Yasunori Ieki

Moriaki Okuda

Naoki Wada

An apparatus is provided, which monitors an operation state of a battery composed of a plurality of cells mutually connected in series. In this apparatus, a cell voltage of each of the plurality of cells is detected as information indicating an operation state of the battery. Based on the detected cell voltages, an operation state is monitored for a cell having a highest cell voltage and a cell having a lowest cell voltage among the plurality of cells.

Apparatus for monitoring operation state of battery pack composed of plurality of cells mutually connected in series

A voltage balancer device has a plurality of discharge paths. Each pair of the discharge paths correspond to each secondary battery unit. Each of a pair of the discharge paths has a resistance of a different value. Discharging the voltage of each secondary battery unit is at first performed through the discharge path of a smaller resistance value. The voltage balancer device switches the currently used discharge path to another discharge path having a large resistance value at the time the voltage of the secondary battery unit nearly equal a desired voltage.

Voltage balancer device for battery pack

The dual type vehicle power-supply apparatus includes a bidirectional power transmission unit capable of performing bidirectional electric power transmission between a high voltage source of a high power-supply voltage supply system and a low voltage source of a low power-supply voltage supply system, and a power transmission controller controlling the bidirectional power transmission unit to perform the bidirectional electric power transmission. The power transmission controller has a function of detecting a surplus amount of electric power in the low power-supply voltage supply system, a function of detecting a shortage amount of electric power in the high power-supply voltage supply system, and a function of commanding the bidirectional power transmission unit to transmit electric power from the low voltage source to the high voltage source by an mount equal to the detected shortage amount when the detected surplus amount is larger than the detected shortage amount.

Dual type vehicle power-supply apparatus

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.

Flying capacitor type battery voltage detector

A discharging circuit, connected to both terminals of a lithium battery, includes a first discharge resistor, a second discharge resistor, and a transistor for occasionally discharging the lithium battery to reduce the SOC difference among respective lithium batteries constituting a combination battery. A voltage detecting circuit detects a terminal voltage of the lithium battery via the first discharge resistor. A discharge controller judges a failure occurring in the discharging circuit based on a comparison between a terminal voltage value detected when the transistor is turned on and a terminal voltage value detected when the transistor is turned off.

Apparatus for discharging a combination battery consisting of a plurality of secondary batteries

A battery cell voltages are read in parallel to a capacitor for each battery block of a battery pack by the use of analog switches. The stored voltages of the capacitors are A/D-converted sequentially through the analog switches. Thereby, each cell voltage is measured with suppression of measurement error by the use of the simple flying capacitor type circuit structure, while the circuit safety is secured by providing the current limitation resistor having a large resistance value between each cell and the analog switch. A noise reduction circuit having a pair of capacitors is provided.

Battery pack voltage detection apparatus

A battery control system is provided which charges or discharges a storage battery installed in a hybrid vehicle to bring a state-of-charge of the storage battery into agreement with a target one. The system determines whether the state-of-charge lies within a given narrower range defined around the target state-of-charge and corrects the state-of-charge based on an open-circuit voltage of the battery when the state-of-charge lies within the given narrower range, thereby eliminating a cumulative error in calculating the state-of-charge of the battery caused by a variation in charge/discharge efficiency of the battery.

Battery control method for hybrid vehicle

The discharge lamp lighting apparatus includes: a direct current power supply E; switching elements Q and Q for switching a direct current supplied from the direct current power supply E so as to generate a high frequency current; a discharge lamp load circuit LAC which is constructed in a manner that a discharge lamp LA and a coupling capacitor C are connected in series, and the discharge lamp LA is lit by a high frequency current generated by the switching elements Q and Q ; a switching element control circuit IC for controlling the switching elements Q and Q . The discharge lamp lighting apparatus is further provided with a protective circuit NP which distinguishes a fault of the discharge lamp LA by detecting a voltage generated in the coupling capacitor C , and outputs a control signal to the switching element control circuit IC

Discharge lamp lighting apparatus

A set battery which generates a high voltage comprises a number of battery modules connected to each other in series. A module voltage of each of the battery modules is detected by a corresponding differential voltage detecting circuit and is transmitted to an A/D convertor. Each of Several voltage detecting blocks is constituted by a plurality of the differential voltage detecting circuits for detecting module voltages of a plurality of the battery modules contiguous to each other. Each of the differential voltage detecting circuits belonging to the same voltage detecting block is applied with a common reference potential which is used to detect the module voltage. The reference potential is set to values which differ from each other for the respective voltage detecting blocks.

Voltage detecting device for set battery

This invention provides a method of controlling condition of an assembled battery mounted in a self-generation electric vehicle. The method is comprised of the following steps: detecting battery voltage and battery current repeatedly; estimating a constant-power voltage on the basis of the battery voltage and the battery current; setting a target voltage; comparing the constant-power-discharge voltage with the target voltage to provide a difference therebetween; and charging or discharging the battery to reduce the difference when the battery is not operated. The constant-power voltage is set as a function of a remaining capacity of the battery when a preset constant power is charged to or discharged from the battery.

Method of controlling battery condition of self-generation electric vehicle

A method and device for determining whether a battery for a hybrid vehicle is fully charged includes: detecting the battery current, providing a unit of stored battery energy, detecting Joule heat loss and battery temperature, calculating changes in the battery Joule heat loss and battery temperature while the battery is charged by the unit of stored energy and a ratio between the Joule heat loss and temperature changes, and comparing the ratio of the Joule heat loss and temperature changes with a predetermined level.

Growing community of inventors

Anjo, Japan

Tetsuya Kobayashi