Battery charge equalization is carried out utilizing modules (70) connectable in staggered relation between pairs of batteries (31) in a series connected string of batteries. Each module (70) is standardized and has the same construction as the other modules. The modules (70) may be constructed to provide unidirectional charge distribution down the string from a more highly charged battery to a lower charged battery and from a more highly charged last battery in the string back to a less highly charged first battery in the string, or may be constructed to provide bidirectional charge redistribution up or down the string of batteries (N). The charge equalizer modules (36) are forward-based and reduce the charging current as the voltages on the two batteries to which the module is connected equalize. A controllable switching device (71) is connected in series with the primary winding (79) between a high side terminal and a first intermediate terminal of the module. A diode (72) is connected in series with the secondary winding (80) between a low side terminal and a second intermediate terminal of the module.

Modular battery charge equalizers and method of control

A powertrain system includes an engine coupled to an input member of a transmission device operative to transmit torque between the input member and a torque machine and an output member. The torque machine is connected to an energy storage device. A method for controlling the powertrain system include monitoring a temperature of the torque machine, selecting a candidate powertrain system operating point, determining an electrical power input and a motor power output of the torque machine for the candidate powertrain system operating point, determining a power loss for the torque machine associated with the motor power output of the torque machine and the electrical power input, and determining operating costs for operating the powertrain system at the candidate powertrain system operating point associated with the power loss from the torque machine and based upon the temperature of the torque machine.

Method for controlling a powertrain system based upon torque machine temperature

A shared vehicle system includes a central facility, at least one vehicle distribution port facility and a plurality or fleet of vehicles, each having a vehicle subsystem. In general, the central station and port facility and the vehicle subsystems communicate in a manner to allow a user to enter information at a port facility. That information is then communicated to the central facility, where the information is processed to select a vehicle from the fleet to allocate to the user at the port facility. Selection of a vehicle for allocation to a user may be based on selecting an available or soon to be available vehicle according to various algorithms that take into account the vehicles state of charge. The central station also communicates with the port facility and the vehicle subsystem to notify the user of the selected vehicle, to provide secure user access to the selected vehicle, to monitor the location and operating status of vehicles in the fleet, to monitor the state of charge of electric vehicles and to provide other functions. The vehicles communicate with the central station to notify the central station of the PIN number of the individual attempting to use the vehicle, and of vehicle parameters such as state of charge and location of the vehicle.

Vehicle sharing system and method for allocating vehicles based on state of charge

A two-stage charge equalization apparatus for a series-connected battery string according to the present invention comprises a two-stage DC-DC converter including a first DC-DC converter which is inputted with a total voltage of the battery string and outputs a voltage lower than the voltage inputted; and a second DC-DC converter which is inputted with an output of the first DC-DC converter and outputs a charge current for charging a particular battery cell, wherein the battery string is divided into one or more battery modules having a plurality of battery cells connected in series and the second DC-DC converter is provided for each battery module; a current conversion switch module which forms a path of the charge current between the battery module and the second DC-DC converter to allow the charge current to be applied to the particular battery cell composing the battery module and controls an application direction of the charge current; and a microprocessor which determines a battery cell to be charged of a low-charged battery cell and controls the current conversion switch module to allow the charge current to be applied to the battery cell to be charged.

Two-Stage Charge Equalization Method and Apparatus for Series-Connected Battery String

Methods and systems are provided for controlling a power transfer rate in to and/or out of a vehicle energy storage device to affect a current state of charge of the energy storage device. The vehicle may be on a mission comprising a plurality of future power transfer opportunities. In one example, the method comprises adjusting the power transfer rate based on an estimated duration of a future power transfer opportunity. Further, the method may include, if the estimated duration of the future power transfer opportunity is different from a predetermined threshold, changing the power transfer rate at the future power transfer opportunity. The method allows the operating life of the energy storage device to be extended.

Method and system for extending life of a vehicle energy storage device

A hybrid electric vehicle includes a lead-acid traction battery made up of a plurality of series-connected modules. During operation of the vehicle, the traction battery is discharged for acceleration, and charged by an ancillary power source. To maximize the capacity of the traction battery to accept regeneration charge current from dynamic braking, and to produce useful traction motor current, the modules of the traction battery are equalized during normal operation of the hybrid electric vehicle.

Method for equalizing the voltage of traction battery modules of a hybrid electric vehicle

PROBLEM TO BE SOLVED: To equalize the module voltage of the traction battery of a hybrid electric vehicle by partially discharging higher modules and using energy which is made available by this partial discharge to charge lower modules. SOLUTION: Selected modules are charged maximally and partially discharged. This partial discharge is performed by a first method or a second method, depending on the circumstance. In the first method, the selected modules are partially discharged to a voltage before part of the full charge is started in the maintaining process, using energy from the selected modules fully charged to recharge an auxiliary battery 36 by inverting the direction of the operation of a direct current-direct current converter 16c. In the second method one selected module is partially discharged by a direct current-direct current converter 16c, and energy taken out of the selected modules during this partial discharge is applied to the other modules of the traction battery, which are in turn charged until the voltage of the selected modules is reached.

Hoffman Jr David William

Papers

Method for equalizing the voltage of traction battery modules of a hybrid electric vehicle

Method for equalizing voltage of traction battery module of hybrid electric vehicle