Gm Global Technolgoy Operations, Inc.

John T Guerin

Andrew H Leutheuser

Steven J Vance

John C Mentzer

Mark D Nemesh

Wei Liu

Kris Sevel

Sudhakar Inguva

Ramesh Rebba

Rashed S Rabaa

Sanjay K Mahajan

A thermal management system for a battery pack having a conductive cooling plate and battery cells includes a compressor, flow control valves, temperature sensor(s), and a controller. The compressor circulates refrigerant through the plate to cool the cells. The temperature sensor measures a temperature of the battery pack. The controller is programmed to receive the temperature from the temperature sensors and selectively transmit switching control signals to the valves to command a change in direction or flow of the refrigerant through the cooling plate. This limits a temperature variance between the battery cells over time. A vehicle includes a transmission, an electric traction motor, a battery pack, and the thermal management system noted above. A method includes receiving the temperature, transmitting switching control signals to the valves, and controlling a flow of refrigerant through the plate via the valves in response to the switching control signals.

Actively-switched direct refrigerant battery cooling

Disclosed herein are various systems and methods for capturing and utilizing temperature information in a battery pack. An electrical measurement system may be configured to determine a subdivision electrical parameter associated with one or more subdivisions, and a thermal measurement system configured to determine and track a thermal parameter associated with one or more subdivisions. A battery model may utilize the thermal parameter and the electrical parameter to estimate a characteristic of one or more battery subdivisions. In some embodiments, the battery model may further estimate a second thermal parameter of a second subdivision based upon a location of the second subdivision within the battery pack and based on the estimated characteristic of a first subdivision. Some embodiments may further estimate a life assessment of one or more subdivisions based at least in part on the subdivision electrical parameter and the thermal parameter.

Systems and methods to capture and utilize temperature information in a battery system

A battery cell by-pass circuit that has particular application for by-passing cells in a high voltage battery for a vehicle. The battery includes a plurality of battery cells electrically coupled in series. The by-pass circuit includes a first switch electrically coupled in series with one or more of the battery cells, a by-pass line electrically coupled around the one or more battery cells and a second switch electrically coupled in the by-pass line and in parallel with the one or more battery cells. During normal cell operation, the first switch is closed and the second switch is open so that current flows through the one or more battery cells. If the one or more battery cells fail or are failing, the first switch is opened and the second switch is closed so that current by-passes the one or more cells and they are removed from the battery circuit.

Battery fault tolerant architecture for cell failure modes series bypass circuit

A method of providing an electrical charge to a vehicle traction battery using a power inverter module includes sensing a temperature of the power inverter module and sensing a temperature of the traction battery. From the sensed temperatures, an engine control unit may determine an expected voltage oscillation amplitude of the electrical charge. This amplitude may be used to calculate a maximum allowable nominal voltage of the electrical charge by subtracting the expected voltage oscillation amplitude from a maximum allowable voltage of the traction battery. The maximum allowable nominal voltage of the electrical charge may then be used to limit the available power provided to the traction battery by the power inverter module.

Hybrid battery power limit control

A method and system for battery pack cell state of charge balancing using a proportional-integral feedback control combined with a feedforward control. The proportional-integral feedback control acts on the difference between the average discharge for all cells over a previous driving cycle and the discharge of a specific cell over the previous driving cycle. Thus, the feedback term is based on whether an individual cell discharges more quickly or less quickly than the battery pack average during driving. A cell which discharges more quickly will receive decreased resistive discharge balancing. The feedforward control acts on the difference between an individual cell's state of charge and the battery pack average state of charge at the beginning of a current driving cycle. The overall control effort, which determines the resistive discharge balancing on-time duty cycle for each cell, is the sum of the feedback control signal and the feedforward control signal.

Combined PI feedback and feedforward cell balancing method

A by-pass circuit for a battery system that disconnects parallel connected cells or modules from a battery circuit or controls the current through the parallel connected cells or modules. If a cell has failed or is potentially failing in the system, then the by-pass circuit can disconnect the cell or module from other cells or modules electrically coupled in parallel. If a cell or module has a lower capability than another cell or module, then the by-pass circuit can control the current to the cell or module to maximize the performance of the system and prevent the system from creating a walk-home condition.

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Bloomfield, MI, United States of America

John T Guerin