Background
SAIC-GM has been active in the plug-in hybrid segment for many years. In 2010, GM introduced early plug-in vehicles to the China market. Under current demand conditions, SAIC-GM plans to introduce a new generation smart electric plug-in hybrid system designed to address three core user issues in the plug-in hybrid 2.0 era: reduced performance in charge-depletion, inconsistent driving quality, and battery safety challenges.
Platform and Design Goals
Built around technical priorities of genuine performance, improved smoothness, and enhanced safety, the new system is a highly modular platform intended for iterative upgrades and extended service life. The architecture and control system were developed specifically for the China market and cover several key areas.
Electric Drive Unit
The new-generation plug-in electric drive unit is the system core. It was developed by the Pan Asia Technical Automotive Center (PATAC). The front-drive motor family covers a wide peak power range, while the rear-drive motor provides strong supplemental torque. The Ecotec 1.5T engine has been updated with a deep Miller-cycle high-efficiency combustion strategy to improve fuel economy while delivering competitive hybrid-class power output.
Previously, GM’s North American development focused on power-split architectures, which performed well but were less flexible for rapid iteration. PATAC engineers developed a P1P3 architecture that integrates dual electric controls, achieving a reported 3.35 Wh/kg metric for the integrated system.
Main electric-drive characteristics
- Peak torque density greater than 14.4 Nm/kg; power density greater than 7.8 kW/kg for the motor family.
- Oil-cooling and flat-wire winding techniques, combined with ultra-thin, low-loss silicon steel laminations, yield a peak motor efficiency up to 97.8%.
- Rotor durability developed to a global benchmark of over 250,000 cycles over 0–18,000 rpm.
- Inverter module with one of the highest power densities in the plug-in hybrid field, exceeding 40 kW/L; inverter peak efficiency up to 98.7%; overall electric drive system peak efficiency up to 96.1%.
Data on paper indicates the PATAC engineering team focused on high efficiency and compact power density for the electric-drive subsystem.
Battery Design and Safety
The new-generation plug-in battery follows the Aoteng standard, featuring a dedicated cell formulation and multiple safety protections intended to optimize safety, cycle life, and energy losses. Through extensive testing, the battery demonstrated strong cycle life and safety performance.
The battery is derived from the Aoteng electric-vehicle standard and adapted for plug-in use. It is reported to exceed 3,300 cycles under CLTC.
Main battery features
- Dedicated cell formulation using fine carbon coating and related techniques, supported by extensive high-throughput cell testing (described as 1.6 million hours) covering five usage dimensions and over 100 test items to prevent lithium plating during fast charging over the full lifecycle.
- Battery pack with 360-degree multiple safety protections to form a comprehensive safety barrier for the traction battery.
- Design validated so that, at an ambient temperature of 50°C, thermal runaway does not propagate and no open flame is observed.
An advanced n-Tau battery AI big-data management model is used for accurate state estimation. For lithium iron phosphate cells, state-of-charge (SOC) estimation error is reported at less than or equal to 2%, which reduces the need for frequent full-charge cycles by the user.
Control Algorithms and System Optimization
The plug-in hybrid system employs a three-tier AI control approach: vehicle-cloud integration, collaborative prediction, and dynamic control. This control strategy coordinates multiple energy sources and power flows to improve overall efficiency across all scenarios, operating conditions, and life-cycle stages.
User Experience and Applications
The system is intended to address core user concerns across full-condition performance, driving feel in diverse scenarios, and long-term safety. SAIC-GM plans to deploy the new plug-in hybrid system in two models: the Chevrolet Equinox Plus and the Buick GL8.
Summary
The PATAC-developed next-generation intelligent electric hybrid system emphasizes modularity, improved drive efficiency, and enhanced battery safety and management. The architecture and associated controls aim to support iterative improvement and deployment across multiple vehicle segments within the China market.
