Cooling System Energy Consumption Reduction through a Novel All-Electric Powertrain Traction Module and Control Optimization

Abstract

In this work, the problem of reducing the energy consumption of the cooling circuit for the propulsion system of an all-electric vehicle is approached with two different concepts: improvement of the powertrain efficiency and optimization of the control strategy. Improvement of the powertrain efficiency is obtained through a modular design, which consists of replacing the electric powertrain with several smaller traction modules whose powers sum up to the total power of the original powertrain. In this paper, it is shown how modularity, among other benefits, also allows reducing the energy consumption of the cooling system up to 54%. The energy consumption of the cooling system is associated with two components: the pump and the fan. They produce a so-called auxiliary load on the battery, reducing the maximum range of the vehicle. In conventional cooling systems, the pump and the fan are controlled with a thermostat, without taking into account the energy consumption. Conversely, in this work a control strategy to reduce the auxiliary loads is developed and compared with the conventional approach, showing that the energy consumption of the cooling system can be reduced up to 27%. To test the control strategy, numerical simulations have been carried out with a 1-D model of the cooling system. On the other hand, all the thermal loads of the components have been calculated with a vehicle simulator, which is able to predict the vehicle’s behavior under different driving cycles.

Three-Phase 75 kW Brushless Direct Current Motor for Electric Vehicles: Different Power Stage Design, Calculation of Losses, Cooling Techniques, and Comparison

“…Equation ( 13) was used for the diode in these calculations. It is calculated as shown in Equation (14).…”

“…In conventional cooling systems, the pump and the fan are controlled with a thermostat. In new studies, the thermal loads of all components of the vehicle are calculated and, simulated, and control strategies are developed [14].…”

“…An interesting control approach to reduce the motor cooling system energy consumption is proposed in [13], but the considered vehicle is a hybrid electric. There are different studies in the literature, such as those testing the control strategy that reduces the energy consumption of the cooling system, that is, the pump and fan, with numerical simulation in different driving cycles [14]. However, there is no study in the literature comparing three different power stages and cooling system designs, and loss calculations.…”

Design and Analysis of a Permanent Magnet Brushless DC Motor in an Automotive Cooling System

“…As motor drive systems are a primary component of NEVs, their performance has a significant impact on NEVs' performance. A motor drive system will continue to accumulate heat during operation [9], and when the system temperature reaches a certain threshold, the system will be exposed to an increasingly hostile environment, wherein the electromagnetic characteristics of the material used in the motor are altered; the residual flux density and coercivity are reduced [10]; the torque capability of the motor is restricted [11]; the power loss is increased [12]; the system's stability and reliability are decreased [13]; and the performance of the drive system is severely limited [14]. In order to prevent these adverse effects, the performance of the cooling system in the motor drive system becomes a particular issue to address.…”

Electrified Powertrains for a Sustainable Mobility: Topologies, Design and Integrated Energy Management Strategies

“…S. Lombardi et al [2] have tried to tackle the problem of reducing the energy consumption of the cooling circuit for the propulsion system of an all-electric road vehicle through two different approaches: optimization of the control strategy and improvement of the powertrain efficiency. In the first approach, a control strategy to reduce the auxiliary loads of the fan and the pump has been developed and compared with the conventional approach, where the pump and the fan are controlled with a thermostat, while in the second approach a single-motor powertrain has been replaced by smaller traction modules whose powers sum up to the total power of the original powertrain.…”