Chongqing Jinkang Powertrain New Energy Co., Ltd.

Other

Sf Motors, Inc.

Junzhe Shi

Ying Liu

Saeed Khaleghi Rahimian

Yifan Tang

Jun Hou

Min Tian

Chen-Yen Yu

Wenke Zhang

Sangwoo Han

Mehdi Forouzan

Xingyu Zhou

A physics-based calendar life model for determining the state of health of a lithium ion battery cell. The model accounts for parasitic reactions on anode and cathode particles to accurately determine degradation of a battery. By incorporating electrolyte decomposition in a cathode, the present calendar model can predict capacity retention as well as the substantial rise of cell resistance at high state of charge (SOC) and temperatures. The present calendar model is a simple algorithm, utilizing only three parameters, and determines the capacity retention and resistance rise based on temperature, SOC and time.

Control-oriented physics-based calendar life model for lithium ion cells

Fuzzy-logic based traction control for electric vehicles is provided. The system detects a wheel slip ratio for each wheel. The system receives an input torque command. The system determines a slip error for each wheel based on the wheel slip ratio for each wheel and a target wheel slip ratio. The system, using the fuzzy-logic based control selection technique, selects a traction control technique from one of a least-quadratic-regulator, a sliding mode controller, a loop-shaping based controller, or a model predictive controller. The system generates a compensation torque value for each wheel. The system generates the compensation torque value based on the traction control technique selected via the fuzzy-logic based control selection technique and the slip error for each wheel. The system transmits commands to actuate drive units of the vehicles based on the compensation torque value.

Fuzzy logic based traction control for electric vehicles

Various arrangements for determining the state of health (SOH) of a battery of an electric vehicle are presented. A first OCV of the battery of the electric vehicle may be determined. Coulomb counting on the battery of the electric vehicle may be performed to determine an accumulated capacity value following the first OCV being determined. A second OCV of the battery of the electric vehicle may be determined after performing the coulomb counting. A change in OCV value may be calculated using the determined first OCV and the determined second OCV. A slope value may be determined by dividing the accumulated capacity value by the change in OCV value. The SOH of the battery may then be determined using the slope value.

Battery state of health estimation using open circuit voltage slope

Battery health is determined by estimating a battery anode capacity, battery cathode capacity, and cyclable lithium capacity. Determining electrode and lithium capacity may include determining anode and cathode open cell voltages (OCV) at the beginning of battery life, and estimating the full cell OCV from the individual (half-cell) OCV values. Once the beginning of battery life information is known, the state of charge (SOC) for a battery is measured during battery life. The SOC measurements may be captured at a plurality of different levels. The cathode capacity, anode capacity, and cycle mobile lithium capacity are then determined from the beginning of life OCV data and plurality of SOC data. The capacities can be used to detect degradation, and a battery management system can take steps to reduce further degradation based on the capacity values.

Battery state of health estimation by tracking electrode and cyclable lithium capacities

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Santa Clara, CA, United States of America

Junzhe Shi