Gm Global Technolgoy Operations, Inc.

Fang Wang

Tao Wang

Andrew K Chandler

Theodore T Kim

Yue-Yun Wang

Larry T Nitz

Andrew C Baughman

Wei Liu

Anthony P Tata

Peter Andres

Paul W Kelley

Charles Hua

Fiona E Meyer-Teruel

Thomas John Timpf, Jr

Jeffrey Johnson

Jochen Lenz

Richard H Miller

Tamara R Thomson

Brandon M Thayer

Janpreet S Basi

A system for monitoring a battery module having a plurality of cells includes a sensor adapted to obtain respective cell voltages of the plurality of cells. The controller is adapted to receive data from the sensor, the controller having a processor and tangible, non-transitory memory on which instructions are recorded. The controller is configured to sort the respective cell voltages to create a voltage ranking. The voltage ranking is repeated with at least one new set of cell voltage readings obtained at a predefined checking frequency. Differences in the voltage ranking of the plurality of cells are analyzed. The controller is adapted to control operation of the battery module based in part on differences in the voltage ranking. The controller may be adapted to predict likelihood of a thermal runway event based in part on the differences in the voltage ranking.

Monitoring of battery module based on cell voltage rankings

A battery system includes a rechargeable energy storage system (RESS) having battery cells, and a battery controller network configured to execute two-level logic to detect a thermal runaway condition. The network includes RESS-embedded cell monitoring units (CMUs) electrically connected to a respective cell group, and measuring and wirelessly transmitting cell data. A battery control module (BCM) is in communication with the CMUs. Thermal runaway sensors are mounted on the CMUs and/or the BCM. A master controller connected to the BCM includes a thermal runaway detection algorithm configured to detect a thermal runaway condition occurring within the RESS. The BCM uses data from the CMUs and thermal runaway sensors to execute first logic level which determines when to wake up the master controller. The master controller, in response to receipt of a wakeup signal, executes a second logic level to execute the algorithm.

Two-level method for thermal runaway detection

A battery system includes a battery module, an active cell balancing circuit, and a battery controller. Each cell has diametrically-opposed positive and negative cell tabs. The circuit includes voltage sensors and, at each end of the battery module, first and second tiers of switches and an energy storage element. Each voltage sensor is located between a different pair of adjacent cells. The controller receives measured voltages from the sensors indicative of an electric potential between adjacent battery cells. Responsive to the measured voltages, the controller commands the first tier to selectively connect or disconnect designated pairs of cells to the corresponding second tier. The controller also commands the second tier to selectively connect or disconnect the designated cells to a corresponding energy storage element. This action shuttles energy between the designated pairs of battery cells to balance a state of charge.

Battery module with active cell balancing using energy storage element and two tiers of switches

A high-voltage electrical system includes a high-voltage electrical bus, a low-voltage controller performing battery management system (BMS) functions, and a rechargeable energy storage system (RESS) connected to the HV electrical bus. The RESS has contactors connected to the voltage rails, a battery pack, a current sensor outputting a voltage signal indicative of pack current, cell monitoring units (CMUs) connected to designated battery cells that measure corresponding cell voltages, and voltage isolation hardware between the CMUs and the LV controller. The voltage isolation hardware includes the contactors and may include a transformer. The RESS and LV controller are connected via LV serial connections such that the LV controller performs the designated BMS functions, including monitoring the pack current and controlling an open/closed state of the contactors. A powertrain system includes the electrical system, an electric machine, and a coupled load.

High-voltage system with low-voltage control architecture and method

An electrical system includes a battery disconnect unit (BDU) connected to a rechargeable energy storage system (RESS) via a high-voltage bus. The BDU has one or more contactors that close responsive a low-voltage drive current to thereby connect the RESS to the high-voltage bus. A low-voltage drive circuit conducts the drive current to the contactor(s). Opening of a low-voltage connection interrupts the drive current and causes the contactor(s) to transition from the closed state to an open state. The contactor(s) open in response to interruption of the drive current to thereby disconnect the RESS. The contactor(s) may be closed again after a lockout safety procedure, such that reestablishing the electrical connection does not itself re-energize the high-voltage bus. An electrified powertrain includes a transmission, electric machine, power inverter module, and the above-noted electrical system.

Electrical system with high-voltage system lockout function

A system and method of simultaneously calculating an isolation resistance and a y-capacitance of a RESS may include the steps of: injecting a first signal into a RESS; recording an output signal from the RESS in response to the injection of the first signal; multiplying the first signal with the output signal to determine a first product; multiplying a second signal with the output signal to determine a second product wherein the second signal is orthogonal to the first signal; filtering the first product to determine a first constant; filtering the second product to determine a second constant; processing the first constant to determine a y-capacitance value; and processing the second constant to determine an isolation resistance value.

High voltage bus-to-chassis isolation resistance and Y-capacitance measurement

System and methods for detecting electrical leakages in a battery sensing are presented. In certain embodiments, the systems and methods allow a vehicle battery sensing circuit and/or other associated system to detect certain electrical leakages and implement one or more actions to protect vehicle systems from damage resulting from such leakages.

Systems and methods for detecting leakage paths in a battery sensing circuit

A method and apparatus for determining coolant leakage in a vehicular propulsion system battery. An AC isolation resistance test is used to determine whether an isolation fault has occurred within the battery, but can also determine the capacitance of the circuit or system, which can further determine the coolant leakage levels of the vehicular propulsion system battery. This eliminates having an additional device to measure the coolant leakage.

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Troy, MI, United States of America

Fang Wang