Development and Simulation of an Electric Motor-Driven Oil Pump with PWM-Based PI Speed Tracking Control for Continuously Variable Transmission (CVT) Applications

Conventional Continuously Variable Transmissions (CVTs) employ mechanically driven hydraulic oil pumps that operate continuously with the engine, resulting in unnecessary power consumption, reduced transmission efficiency, and limited flexibility in hydraulic pressure regulation. To overcome these limitations, this paper proposes a novel electric oil pump (EOP)-based CVT controlled by a Pulse Width Modulation (PWM)-based Proportional–Integral (PI) speed tracking controller. The proposed system replaces the conventional mechanically driven pump with an independently controlled EOP, enabling hydraulic pressure generation according to the instantaneous transmission demand. A comprehensive model of the EOP-CVT system was developed in MATLAB/Simulink and evaluated using the four European driving cycles (ECE 15, EUDC, EUDC for low power vehicles, and NEDC). The simulation results demonstrate high-speed tracking performance, with a tracking accuracy of more than 99.7%, maximum mean absolute error of 0.19 km/h, and maximum overshoot of 3.28%, while the max settling time was 2.18 s. The CVT ratio range was 0.4–2.4, and the EOP maximum speed was 3344 rpm. Compared with the conventional pump, the proposed EOP requires 47% less energy. These results demonstrate the potential of independently controlled EOP operation to reduce simulated hydraulic power demand while maintaining accurate vehicle-speed tracking, providing a practical foundation for further experimental validation and advanced transmission control.