Power Losses Minimization for Optimal Operating Maps in Power-Split HEVs: A Case Study on the Chevrolet Volt

Abstract

The power-split architecture is the most promising hybrid electric powertrain. However, a real advantage in energy saving while maintaining high performance can be achieved only by the implementation of a proper energy management strategy. This requires an optimized functional design before and a comprehensive analysis of the powertrain losses after, which could be rather challenging owing to the constructive complexity of the power-split transmission, especially for multi-mode architecture with multiple planetary gearing. This difficulty was overcome by a dimensionless model, already available in the literature, that enables the analysis of any power-split transmission, even in full electric operation. This paper relies on this approach to find the operating points of the internal combustion engine and both electric machines which minimize the total power losses. This optimization is carried out for given vehicle speed and demanded torque, by supposing different scenarios in respect of the battery capability of providing or gathering power. The efficiency of the thermal engine and the electric machines is considered, as well as the transmission mechanical power losses. The aim is to provide a global efficiency map that can be exploited to extract data for the implementation of the most suitable real-time control strategy. As a case study, the procedure is applied to the multi-mode power-split system of the Chevrolet Volt.

The Perspective of Fuel Cell High‐Speed Powerboats

“…Castellano and Cammalleri [16] or Jurkovic, Rahman, Patel, and Savagian. [17] A proper design would deliver the peak efficiency around the point of more common steady operation of the motor/generator in the specific vehicle.…”

“…A typical efficiency map of a motor/generator unit for automotive applications is shown in Figure 3 . Even higher peak values above 0.94, up to 0.95 and 0.97, are proposed in ref., [14,15] Castellano and Cammalleri [ 16 ] or Jurkovic, Rahman, Patel, and Savagian. [ 17 ] A proper design would deliver the peak efficiency around the point of more common steady operation of the motor/generator in the specific vehicle.…”

Energy Management Systems’ Modeling and Optimization in Hybrid Electric Vehicles

“…Depending on the driving conditions, this configuration allows for various operating modes such as pure electric mode, series hybrid mode, and parallel hybrid mode according to power distribution [9,13,17,20,[24][25][26]. It offers advantages such as improved fuel efficiency, performance, and reduced emissions by providing more flexibility in power management and optimization under different driving conditions [14,[27][28][29]. Depending on the driving conditions, this configuration allows for various operating modes such as pure electric mode, series hybrid mode, and parallel hybrid mode according to power distribution [9,13,17,20,[24][25][26].…”

“…Depending on the driving conditions, this configuration allows for various operating modes such as pure electric mode, series hybrid mode, and parallel hybrid mode according to power distribution [9,13,17,20,[24][25][26]. It offers advantages such as improved fuel efficiency, performance, and reduced emissions by providing more flexibility in power management and optimization under different driving conditions [14,[27][28][29].…”

Special Issue on Frontiers in Hybrid Vehicles Powertrain

“…Nonetheless, the high constructive complexity of power-split transmissions requires proper mathematical tools for the analysis and the design. Castellano and Cammalleri [7], taking the Voltec multimode power-split transmission as a case study, described a procedure to evaluate a global efficiency map in various battery scenarios that can be exploited to extract data to implement a real-time EMS. The contribution is based on a universal parametric approach that can be applied to any power-split transmission.…”