Analysis and Design of Hybrid Transmission System

There appears to be a significant gap between the Chinese and international hybrid technologies in terms of vehicle fuel consumption, system integration and cost control. This course has been designed to increase an engineers’ knowledge of hybrid transmission development, hybrid system design, and hybrid vehicle powertrain integration. The course focuses on energy efficiency in electric vehicles (EV) and HEV fuel economy while maintaining and improving engineering for optimal power and performance, cost control, and occupant comfort. The course introduces hybrid electric vehicles (HEV), their working conditions and conversion, configuration classification of hybrid system and hybrid transmissions; the sub-systems and components of hybrid systems (engine, motor, transmission, gear, clutch, synchronizer, etc.). Through the analysis of several typical hybrid transmissions, we will discuss in-depth the issues common in the overall design of a hybrid, including: the Prius power split hybrid system; a power split hybrid system with mode switching; design and analysis of P2/P2.5 hybrid system; deeply integrated P2/P2.5 mechatronics design; and a series-parallel hybrid (including extended range) system.

What Will You Learn

Upon completion of this course, you will be able to:
  • Select the appropriate hybrid system configuration for HEVs (including PHEVs)
  • Design overall structure for hybrid powertrains
  • Optimize the system parameters for hybrid transmissions
  • Develop the functions and control strategies for hybrid transmissions
  • Match engines and optimize the powertrains for hybrid vehicles

Is This Course For You

Design, powertrain, systems, and/or application engineers involved in the design, development and integration of hybrid transmissions and components, improving fuel and energy efficiency of hybrid vehicles, improving hybrid vehicle power performance, and those involved in improving cost efficiency in the design and manufacturing of the hybrid vehicle will benefit by attending.

Materials Provided

This data is not available at this time

Course Requirements


  • Hybrid System and Hybrid Transmissions
    • HEV
    • Hybrid system (classification)
    • Functions of hybrid transmissions
    • HEV operationg modes and and energy-saving approaches
    • Drive/Transmission - Mechanical drive (gear, ratio, range); electrical drive (CVT); drive torque, power and efficiency
  • Components of hybrid systems
    • Engine (characteristics; torque, power, and efficiency; dedicated hybrid engine)
    • Motor (characteristics; Rev, torque, power, and efficiency)
    • Mechanical transmission (AT, CVT, DCT, AMT)
    • Electrical drive/transmission (eCVT)
    • Kinematic and dynamic characteristics of planetary gear set
    • Mechanical drive components (gear, clutch, synchronizers)
  • Power-split hybrid transmission I: the Prius hybrid transmission
    • System structures and evolution: the first to fourth generations
    • Analysis of system dynamics -- EV conditions: REV, output torque and power (low speed, high speed); HEV conditions: Engine ratio control; Output torque and power (medium-low speed, medium-high speed); Analysis of electromechanical system design
    • Fuel economy
    • Compromise and optimizations between power performance (at low speeds) and fuel economy (at high speeds)
  • Power split hybrid transmission II: CHS power split with mode switching
    • System structures and main parameters
    • Analysis of system dynamics -- EV conditions: REV, output torque and power (low speed, high speed); HEV conditions: Ratio, Output torque and power (medium-low speed, medium-high speed)
    • Fuel economy
    • Compromise and optimizations between power performance (at low speeds) and fuel economy (at high speeds)
    • Improvement of power split hybrid system
  • P2 hybrid transmission
    • System structures and functions -- Hybrid module (dynamic coupling; drive route and transformation); Mechanical transmission
    • Transmission design and optimization -- Transmission type: AT, DCT, CVT, AMT; Gear and range; Reduce shaft length; Design of hydraulic system
    • Design of hybrid module - Dynamic coupling (function design: conditions and mutual switching), mechanical design and optimization; Motor system (EV conditions: acceleration capacity, gradeability, maximum speed; HEV conditions: power generation, regenerative braking)
    • P2.5 hybrid transmission – Comparison of power performance and fuel economy; Motor arrangement: parallel or coaxial
  • Optimized system design: mechatronic hybrid transmissions
    • A motor and a planetary gear set form an electric torque convertor (eTC), as well as a hybrid module; eTC provides better launch performance than a hydraulic torque converter and clutch; An application of eTC.
    • Dual-input gearbox for hybrid transmission: Engine shifts gear while motor drives, and vice versa; Motor facilitates synchronization to simplify dual clutches
    • Combination of eTC and dual-input gearbox: increase the number of speed ratios – Graphic method of representing dual-input gearbox ratios; Combination of graphic methods of planetary gear set lever and dual input transmission ratio; Case study: a hybrid transmission with six pairs of gears and 12 speed ratios
  • Series and series-parallel hybrid transmissions
    • System structures and components
    • System design: EV conditions (acceleration capacity, gradeability, maximum speed)
    • System design: HEV conditions, serial drive/ electric drive / CVT
    • Driveline: parallel drive / fixed ratio
    • System design: add mechanical transmission mechanism