Design of Hybrid Power System for Electric Vehicle and Human Powered Vehicle: Technical Path from Human Power Coupling to Energy Efficiency Optimization

Keywords: electric vehicles, human powered vehicles, hybrid power, human electric coupling, energy efficiency optimization

abstract

Electric vehicles and human powered vehicles (such as India's Tuk Tuk and Southeast Asia's "Tun Tu") need to solve core issues such as power distribution and efficiency balance through the coordinated drive of manpower and electricity. This article analyzes the technical implementation path of mechanical coupling mechanisms, control algorithms, and energy management strategies.

1.1 Hybrid Power System Architecture

Parallel hybrid power:

Structural features: The manual pedal drives the rear wheels through a chain, and the motor outputs in parallel through a planetary gear set (such as the Indian Bajaj Qute model).

Advantages: Human and electrical resources can work independently or collaboratively, with a 50% increase in motor assisted torque when climbing and an 80% retention in human efficiency when cycling on flat roads.

Series hybrid power:

Structural features: The manual pedal drives the generator to generate electricity, and the electrical energy is stored in the battery to drive the motor (similar to an extended range electric vehicle).

Disadvantage: Energy conversion efficiency loss of 15% -20%, suitable for low-speed short distance scenarios (such as campus shuttle buses).

1.2 Human power coupling mechanism

Unidirectional clutch design:

Adopting a overrunning clutch (such as a wedge clutch), the motor rotates freely when manually driven (to avoid reverse drag losses), and automatically locks when electrically driven (torque transmission efficiency>95%).

Electromagnetic clutch control:

By using a Hall sensor to detect pedal speed (accuracy ± 1rpm), the motor assistance is triggered when the speed is greater than 30rpm (such as the Bosch eBike system).

1.3 Power allocation algorithm

Fuzzy logic control:

Input parameters: pedal torque (N · m), vehicle speed (km/h), battery SOC (%), output motor power (kW).

Example of rule library:

If the pedal torque is greater than 50N · m and the vehicle speed is less than 15km/h, the motor output power is 3kW (full load climbing mode).

If SOC<20%, the motor output power is limited to 1kW (energy-saving mode).

Dynamic programming optimization:

Based on historical road condition data (such as slope and traffic flow), pre planning the working range of motors and manpower can reduce energy consumption by 12% (requiring GPS and high-precision maps).

1.4 Energy Recovery Technology

Human power generation recycling:

When braking or going downhill, the generator is driven in reverse through a one-way clutch to convert kinetic energy into electrical energy (with a recovery efficiency of 15% -20%).

Motor regenerative braking:

Using synchronous rectification technology (such as TI TMS320F28379D controller), the braking energy is fed back to the battery, increasing the recovery efficiency by 10% (suitable for frequent start stop scenarios).

1.5 Lightweight and Durable Design

Frame material:

Q345 high-strength steel (yield strength 345MPa) is used, which is 15% lighter than ordinary carbon steel. The stress distribution is optimized through finite element analysis (FEA) (such as the Indian Kinetic Green model).

Bearing lifespan:

Select SKF deep groove ball bearings (rated life>50000 hours), combined with grease lubrication technology, to reduce the friction coefficient by 30% (such as Vietnam VinFast electric rickshaw).

conclusion

Parallel hybrid power is the mainstream solution, which requires intelligent power distribution and energy recovery technology to achieve synergistic efficiency between manpower and electricity.