Table 1 Comparison of electric drive system types applied in agricultural machinery.

Single-motor system

Replaces diesel engine with a single electric motor and multi-speed transmission.

Follows conventional layout.

Requires mechanical transmission to handle variable load/speed.

Limited scalability for high-power tractors.

^10,11,12,13

Dual-drive (hybrid) system

Combines electric motors and internal combustion engines in series, parallel, or power-split configurations.

Requires additional power coupling transmission and complex control logic.

High cost and storage system limitations.

^{13,14,15,16,17,18,19,20,21,22}

In-wheel motor (IWM) system

Motor and reducer embedded in each wheel.

Mainly for lightweight robots (e.g., spraying, weeding).

Limited torque due to wheel space constraints.

Unsuitable for heavy-duty operations.

^28,29,30,31

Axle-based system

Integrates motor, reducer, and wheel set within each axle.

Enables high traction and independent control.

–

^{23,24,25,26,27}