Efficiency analysis of a continuously variable transmission with linear control for a series hybrid electric vehicle

Threshold-changing control strategy for series hybrid electric vehicles

“…The electrical dynamics of the PMSM (as well as of the PMSG in the PS) are modeled in the d-q rotating reference frame by two nonlinear differential equations of direct and quadrature axis components of stator current [35], with all the relevant parameters given in Tables 2.1 and 2.2 in [31]. A toroidal CVT that can vary the final drive ratio is used to connect the PMSM to the rear wheels, to regulate beneficially by a separate linear control law [36] the efficiency of the PMSM as it drives the wheels at any speed. The car model describes the longitudinal motion and it includes a 3 degree of freedom vehicle body, spinning wheels with tire shear forces and vertical compliance, front and rear suspension, aerodynamic forces and regenerative braking.…”

Dynamic modeling platform for series hybrid electric vehicles

“…, to achieve operation of the motor in its most efficient operating region, according to the scheme described in Shabbir and Evangelou (2014a). k CV T is a constant and ω wc is the wheel rotational speed.…”

Impact of Optimally Controlled Continuously Variable Transmission on Fuel Economy of a Series Hybrid Electric Vehicle

“…However, the investigation of CVT for series HEV powertrains is still limited. Recently, the performance of a linearly controlled CVT system is evaluated in a hybrid electric vehicle of series architecture for given drive cycles [6]. The control algorithm is designed such that the motor is operated along a straight line passing through the origin and the point of peak efficiency in the motor efficiency map with respect to the speed and torque.…”

“…Therefore, the solution is only suboptimal and the optimality degrades as the accuracy of the linear approximation drops. The benefit of this CVT system in [6] is characterized by the increase in the motor efficiency instead of overall fuel economy because the CVT control is isolated from the energy management strategies.…”

“…In contrast with [6], the present paper deals with an optimal control methodology for combined and global optimization of the CVT gear ratio, the power share and the driving speed in terms of fuel consumption. Therefore, the necessity of knowing a priori the driving cycle that is usually not available in real-world driving is removed.…”