Dynamic Prime Mover Management for Enhanced Energy Efficiency in Electric Tractors

Electric tractors present unique opportunities for efficient power management by decoupling traction and auxiliary loads. In the proposed system, two independent electric motors are employed: one dedicated to vehicle traction and the other to drive the power take-off (PTO) and hydraulic functions, including steering and auxiliary attachments like loaders. Hydraulic flow demand directly impacts operational productivity; traditionally, hydraulic flow is linked to engine speed, requiring frequent manual adjustments. This paper proposes an innovative dynamic control strategy that optimizes motor speed based on real-time application demands, introducing three distinct modes: Low Idle Mode, Loader Mode, and PTO Mode. The Vehicle Control Unit (VCU) at the heart in coordination with the Farm Machinery Control Unit (FMCU) and Motor Control Unit (MCU), dynamically selects the appropriate mode based on user inputs such as PTO activation and joystick controls Low Idle Mode minimizes energy usage during driving by reducing hydraulic flow to meet steering requirements alone. Loader Mode enhances performance during frequent, high-demand loader tasks. PTO Mode ensures stable operation for rotary implement-driven applications. Validation under field conditions demonstrated up to a 50% reduction in motor current during Low Idle Mode, resulting in significant improvements in range and operational efficiency. This approach not only enhances energy efficiency but also reduces operator fatigue by minimizing the need for frequent manual adjustments. The paper presents the control strategy, system architecture, and validation results, emphasizing the potential for scalable adoption across future electric tractor platforms.