Experimental Study for the Assessment of the Measurement Uncertainty Associated with Electric Powertrain Efficiency Using the Back-to-Back Direct Method

Abstract

Brushless electric motors are used intensively in the industrial automation sector due to the motors low inertia and fast response. According to the International Electrotechnical Commission, IEC 60034-2-1, the efficiency of a three-phase electric machine (excluding machines for traction vehicles) can be determined by direct or indirect techniques. In the case of small traction motors (<10 kW), direct methods are used extensively by manufacturers, even if no standard has been published or scheduled by the IEC. In this paper, we evaluated the accuracy of the (direct) back-to-back method for the estimation of the energy performance of a 3 kW brushless AC electric motor used in a light electric vehicle. We measured the efficiencies of a pair of motors and inverters, as well as the overall efficiency of the entire power train. The results showed that the methodology was sufficiently accurate and comparable with other indirect methods available in existing literature. Moreover, we developed a Simulink model that used the powertrain efficiency map as the input to perform the simulation of a standard urban driving cycle. The simulation was run 500 times to calculate the probability density function associated with the total range of the vehicle, considering the uncertainty of the efficiency that was determined experimentally. The simulation results confirmed the low deviation of the distribution standard compared to the average value of the range of the vehicle.

Social and Technological Impact of Businesses Surrounding Electric Vehicles

“…Several researchers have been studying the details of electric vehicle technology so that their overall efficiency and performance can be improved. Hannan et al reviewed the various aspects of hybrid electric vehicles [8], Du and Ouyang studied policy impact on the growth of the Chinese EV market [9], while De Santis et al simulated the effect of using a back-to-back dual-motor mounting on powertrain efficiency [10]. In a more recent paper by Li et al, the powertrain efficiency of different configurations and resource types was compared [11].…”

Design and Analysis of Magnetic Coils for Optimizing the Coupling Coefficient in an Electric Vehicle Wireless Power Transfer System

“…In recent years, electric vehicles (EVs) have become more and more popular all over the world, and EVs will reduce environmental pollution and CO 2 emission and achieve a high energy efficiency [1,2]. Moreover, the development and improvement of key technologies with respect to batteries and charging infrastructure as well as electric motors and control increase the attractiveness of EVs [3][4][5]. At the same time, the use of EVs as a sustainable and efficient alternative to traditional diesel-and petrol-based vehicles makes the decarbonization of transport possible in the literature [2].…”

“…A review on EV technology development in key fields, such in the battery, charging, the electronic motor, charging infrastructure, and emerging technology, was shown in a literature study [4]. In order to evaluate the efficiency and associated accuracy of the power train of a light electric vehicle, in [5] the authors verified the feasibility of the back-to-back direct method. Some vehicle to grid (V2G) services, such as reactive regulation, motor starting, and transient conditions of renewable sources, were applied in EVs, which confirmed that this service does not engage the battery or require small amounts of battery charge in [6].…”

Innovative Energy-Saving Propulsion System for Low-Speed Biomimetic Underwater Vehicles

“…Power input to the servomotor [40] is determined as a product of the measured voltages (U) and the electric current (I) [41] across the servomotor using the following equation ( 8):…”