Power Control Strategies of On-Road Charging for Electric Vehicles

Self Cite

As is common in multi-load wireless power transfer (WPT) systems based on series–series compensation topology, the power received by loads and the efficiency of the process are highly sensitive to changes in the number of loads. To guarantee that the power supplied to a load remains stable when other loads access or leave the system, we propose an improved multi-load system for WPT. The new system uses an LCC/S topology (based on inductor–capacitor–inductor or LCL topology) to keep the power received by the loads stable. By comparing two scenarios (ideal and real models based on LCC/S topology), we aim to eliminate cross-coupling between receiving coils by connecting compensating capacitors in series on the receiving side. In this way, the stability of the power received by loads is further improved. Moreover, a method of optimizing control over the efficiency is proposed based on the effect on the overall efficiency of impedance and number of loads. This allows us to optimize the overall efficiency of the system. Finally, a system to verify our theoretical analysis is established and used to show the validity and effectiveness of the proposed system.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Design and Optimization of a Wireless Power Transfer System Allowing Random Access for Multiple Loads

Tan

Zhang

Wang³

et al. 2019

Self Cite

“…The power cable for charging on the ground may also introduce a hazard, especially when using a cracked, old cable in poor weather, which may expose the user to an electrical shock. To address these problems, wireless power transfer (WPT) charging systems have been adopted for charging the batteries of EVs either on the road [4] or in parking spaces [5]. By WPT, the charging of EVs becomes more convenient, and the battery capacities of EVs with the WPT system can be reduced to 20% or less compared to EVs which rely on the conductive charging system [2].…”

Section: Introductionmentioning

confidence: 99%

Design and Analysis of a Novel Magnetic Coupler of an In-Wheel Wireless Power Transfer System for Electric Vehicles

Hwang

Jang

2020

Electric vehicle (EVs), which use an electric motor, are expected to replace internal combustion engine vehicles. However, to date EVs are not highly attractive to consumers due to their unsatisfactory battery charging characteristics and high cost. In particular, the existing conductive charging method makes it more difficult to spread EVs due to the inconvenience of charging and the risk of electric shock. The wireless power transfer (WPT) system can eliminate all of the charging troubles of EVs. However, the WPT systems in existing EVs have large air gaps between the transmitter coil and the receiver coil, posing a hurdle that prevents success. The large air gap cause issues such as a loose coupling, low efficiency, and troublesome electromagnetic compatibility (EMC). An in-wheel WPT system can serve as a solution to address the issues arising due to the large air gap. In this paper, we propose a magnetic coupler structure of an in-wheel WPT system for EV applications. A design of two coils is introduced, in which the transmitter coil and receiver coil are designed based on a design method. Moreover, the pad structure according to the ferromagnetic core geometry is designed and discussed. The aim of this research is to find a suitable configuration of the magnetic coupler for an in-wheel WPT system. The values of the coupling coefficients according the magnetic coupler structure are determined. This paper is expected to provide a good reference for further research, including work on the manufacturing of a prototype.

“…These include double-sided inductor-capacitor-capacitor compensation, electric-field resonance, and magnetic shielding, all of which relate to the efficiency and safety of the vehicle's wireless charging [2][3][4]. A study [5] investigated the various designs of transmitting and receiving coils for on-road charging systems. Different circuit models were introduced based on the number of charging EVs, and a power-control algorithm was presented to respond to diverse traffic environments.…”

Section: Introductionmentioning

confidence: 99%

Optimal Design of Wireless Charging Electric Bus System Based on Reinforcement Learning

Lee

Cho

2019

The design of conventional electric vehicles (EVs) is affected by numerous limitations, such as a short travel distance and long charging time. As one of the first wireless charging systems, the Online Electric Vehicle (OLEV) was developed to overcome the limitations of the current generation of EVs. Using wireless charging, an electric vehicle can be charged by power cables embedded in the road. In this paper, a model and algorithm for the optimal design of a wireless charging electric bus system is proposed. The model is built using a Markov decision process and is used to verify the optimal number of power cables, as well as optimal pickup capacity and battery capacity. Using reinforcement learning, the optimization problem of a wireless charging electric bus system in a diverse traffic environment is then solved. The numerical results show that the proposed algorithm maximizes average reward and minimizes total cost. We show the effectiveness of the proposed algorithm compared with obtaining the exact solution via mixed integer programming (MIP).