High Efficiency Series Chopper Power Train for Electric Vehicles Using a Motor Test Bench

Abstract

Many researchers have studied electric vehicles (EVs) for improving their efficiency to increase the driving range. The system design of an electrical power train has significant influence on the total driving range per charge and has been widely researched. A series chopper power train using a buck-boost chopper has been proposed as an electrical power train system. This electrical power train achieves high efficiency due to low and high inverter input voltage in the low and high speed regions, respectively. In previous studies, a high efficiency control optimizing the chopper output voltage was proposed, and a motor test bench with characteristics similar to actual EVs was constructed by using a battery emulation system with voltage variation characteristics, which occur due to the state of charge (SOC) and internal resistance. This paper shows the effects of optimizing the chopper output voltage on the driving range per charge in both efficiency estimation and the motor test bench experiment. This allows the verification of the usefulness of optimizing the chopper output voltage for increasing the efficiency. The results indicate an improvement of 0.9% and 2.7% in the driving range per charge during efficiency estimation and the motor test bench experiment, respectively.

EV Range Extender in a Two-Battery HEECS Chopper-Based Powertrain

“…The output voltage VHEECS and efficiency ηHEECS are approximately expressed as where E1, E2, d, P1, P2, and ηchop represent the voltage of E1, the voltage of E2, the duty ratio, the output power of E1, the output power of E2, and the efficiency of the chopper, respectively. Thus, the overall efficiency of the HEECS is higher than the efficiency of the chopper [5].…”

“…The inverter input voltage is fixed to the battery voltage; thus, the switching loss of the inverter is proportional to the input voltage. For inverter loss reduction, a series-chopper-type powertrain has been proposed [4,5]. In this design, a DC-DC converter is inserted between the battery and inverter, and the inverter input voltage is controlled by the chopper.…”

Range Extension Autonomous Driving for Electric Vehicles Based on Optimal Velocity Trajectory Generation and Front-Rear Driving-Braking Force Distribution

“…( 3 ) For EVs with in-wheel motors, each wheel can be controlled independently. ( 4 ) Motors not only can be used for driving, but also can be employed for regenerative braking. Although EVs have many advantages, they have one problem: the miles-per-charge is relatively short.…”

“…3-9-3, Shin-Yokohama, Kohoku-ku, Yokohama, Kanagawa 222-8507, Japan electric vehicles, expanding high-efficiency regions of motors, and series chopper power train using a buck-boost chopper (2)- (4) . On the other hand, the authors' research group has proposed a series of pure control approaches named Range Extension Control Systems (RECS) (5) (6) , which do not need to change the vehicle structures.…”

Proposal for faster disturbance rejection of boost DC-DC converter based on simplified current minor loop

“…Boost DC-DC converters are used for loads requiring higher output DC voltage than input DC source at high efficiency [1], [2]. These applications often times require sudden change of load current such as when electric vehicles accelerate [1] and others [2]. Such abrupt change of load current causes undershoots/overshoots in the converter output voltage.…”