LLC DC-DC Converter Performances Improvement for Bidirectional Electric Vehicle Charger Application

Electric Vehicle (EV) bidirectional charger technology is growing in importance. It defines the fact of returning the electricity stored in the batteries of EV to Grid (V2G), to Home (V2H), to Load (V2L), or in one word V2X mode. The EV onboard charger is divided into two parts: AC-DC and DC-DC converters. The isolated bidirectional DC-DC LLC resonant converter is used to improve the charger efficiency within both battery power and voltage ranges. It is controlled by varying the switching frequency based on a small signal modeling approach using the gain transfer function inversion method. The dimensions of the DC-DC LLC converter directly affect the charger cost. Moreover, they cause an important control frequency saturation zone, especially in V2X mode, where the switching frequency is out of the feasibility zone. The new challenge in this paper is to design an optimization strategy to minimize the LLC converter cost and improve the control frequency feasibility zone, for a wide variation of battery voltage and converter power, in the charging (G2V) and discharging (V2X) modes simultaneously. For our best knowledge, this optimization problem, in the case of a bidirectional (G2V and V2X) charger, is not yet considered in the literature. An optimal design that considers the control stability equations in the optimization algorithm is elaborated. The obtained results show a significant converter cost decrease and important expansion of control frequency feasibility zones. A comparative study between initial and optimized values, in G2V and V2X modes, is generated according to the converter efficiency.

Download Full-text

Using LLC Resonant Converter for Designing Electric Vehicle DC/DC Converter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1070-1072.1614 ◽

2014 ◽

Vol 1070-1072 ◽

pp. 1614-1620

Author(s):

Tong Li Wu ◽

Ke Hong Wang ◽

Jia Jia Yang

Keyword(s):

Magnetic Structure ◽

Electric Vehicle ◽

Power Density ◽

Switching Frequency ◽

Resonant Converter ◽

Theoretical Derivation ◽

Loss Distribution ◽

Loss Analysis ◽

Llc Resonant Converter

A design of 100 kHz-1350 W electric vehicle DC/DC converter using LLC resonant converter with integrated transformer is presented. The loss analysis based on theoretical derivation is performed to reveal the loss distribution. Integrated magnetic structure is adopted in the design to further increase the efficiency and power density. A 280 V-360 V input, 13.5 V/100 A output prototype is built to verify its advantage, and the efficiency at 320 V input, 13.5 V/100 A output is 91.5% at the switching frequency of 100 kHz.

Download Full-text

Design of Magnetic Integrated Transformer for LLC Resonant Converter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1070-1072.1621 ◽

2014 ◽

Vol 1070-1072 ◽

pp. 1621-1624

Author(s):

Tong Li Wu ◽

Ke Hong Wang ◽

Jia Jia Yang

Keyword(s):

Electric Vehicle ◽

Design Process ◽

Switching Frequency ◽

Resonant Converter ◽

Test Results ◽

Magnetic Components ◽

Series Resonant ◽

Design Values ◽

Llc Resonant Converter ◽

Resonant Inductor

There are altogether three magnetic components in the resonant tank of LLC resonant converter: the series resonant inductor, the parallel inductor and the transformer. The method to realize the magnetic integrated transformer in LLC resonant converter is presented. The design process is provided, and a magnetic integrated transformer is constructed and the test results correspond well with the design values. A prototype of 1350 W, 100 kHz LLC resonant converter type electric vehicle DC/DC converter equipped with the magnetic integrated transformer is built to verify the performance of the magnetic integrated transformer, and the efficiency at 320 V input, 13.5 V/100 A output is 91.5% at the switching frequency of 100 kHz.

Download Full-text

Predictive Control with Battery Power Sharing Scheme for Dual Open-End Winding Induction Motor based Four-Wheel Drive Electric Vehicle

IEEE Transactions on Industrial Electronics ◽

10.1109/tie.2021.3091919 ◽

2021 ◽

pp. 1-1

Author(s):

Utkal Ranjan Muduli ◽

Abdul R. Beig ◽

Ranjan Kumar Behera ◽

Khaled Al Jaafari ◽

Jamal Y. Alsawalhi

Keyword(s):

Induction Motor ◽

Electric Vehicle ◽

Predictive Control ◽

Power Sharing ◽

Battery Power ◽

Sharing Scheme ◽

Wheel Drive ◽

Four Wheel Drive ◽

Open End Winding

Download Full-text

Optimal Design of LLC Resonant DC Transformer under Adaptive Frequency Tracking Strategy

Electronics ◽

10.3390/electronics9122160 ◽

2020 ◽

Vol 9 (12) ◽

pp. 2160

Author(s):

Yu Tang ◽

Dekai Kong ◽

Chenxu Duan ◽

Hao Sun

Keyword(s):

Working Condition ◽

Transmission Efficiency ◽

Switching Frequency ◽

Optimal Operating ◽

Frequency Tracking ◽

Zero Current ◽

Llc Resonant Converter ◽

Dc Transformer ◽

Zero Voltage ◽

Tracking Strategy

In recent years, the LLC (inductor–inductor–capacitor) DC transformer has been widely used in communication and computer power supply because of its advantages of zero voltage conduction of primary switch and zero current turn off concerning the output rectifier diode. To obtain higher transmission efficiency and make the LLC DC transformer always run at the optimal operating point, the switching frequency of the LLC DC transformer should work at the resonance frequency of the circuit. In actual conditions, the optimal operating frequency of the LLC DC transformer will be changed due to the influences of the working condition on the circuit parameters and the load change. Therefore, the LLC DC transformer controlled by the fixed frequency mode will not be in the best working condition. In this paper, an adaptive frequency tracking method is used to control the circuit; when the circuit parameters change, the LLC DC transformer can always be in the best working state. Then, the influence of circuit parameters such as output power and excitation inductor on the optimal working point of the LLC DC transformer is analyzed in detail. Finally, a 1 kW LLC resonant converter prototype is designed under laboratory conditions to verify the feasibility of the control strategy.

Download Full-text

Optimal Dual-Mode Hybrid Electric Vehicle Powertrain Architecture Design for a Variety of Loading Scenarios

Volume 3: 16th International Conference on Advanced Vehicle Technologies; 11th International Conference on Design Education; 7th Frontiers in Biomedical Devices ◽

10.1115/detc2014-34897 ◽

2014 ◽

Cited By ~ 9

Author(s):

Alparslan Emrah Bayrak ◽

Yi Ren ◽

Panos Y. Papalambros

Keyword(s):

Electric Vehicle ◽

Hybrid Electric Vehicle ◽

Fuel Efficiency ◽

Architecture Design ◽

Optimization Strategy ◽

Passenger Cars ◽

Hybrid Electric ◽

Distribution Of Power ◽

Architecture Development ◽

Vehicle Powertrain

A hybrid-electric vehicle powertrain architecture consists of single or multiple driving modes, i.e., connection arrangements among engine, motors and vehicle output shaft that determine distribution of power. While most architecture development work to date has focused primarily on passenger cars, interest has been growing in exploring architectures for special-purpose vehicles such as vans or trucks for civilian and military applications, whose weights or payloads can vary significantly during operations. Previous findings show that the optimal architecture can be sensitive to vehicle weight. In this paper we investigate architecture design under a distribution of vehicle weights, using a simulation-based design optimization strategy with nested supervisory optimal control and accounting for powertrain complexity. Results show that an architecture under a single load has significant differences and lower fuel efficiency than an architecture designed to work under a variety of loading scenarios.

Download Full-text