Stability Improvement of Dynamic EV Wireless Charging System with Receiver-Side Control Considering Coupling Disturbance

Abstract

Receiver-side control has been a reliable practice for regulating the transferred energy to the batteries in the electric vehicle (EV) wireless power transfer (WPT) systems. Nonetheless, the unpredictable fluctuation of the mutual inductance in dynamic wireless charging brings extreme instability to the charging process. This overshoot that appears in instant vibrations may largely increase the voltage/current stress of the system, and even cause catastrophic failure in the battery load. In addition, the speed of the vehicles may lead to untraceable steady-state operation. However, existing solutions to the above two issues suffer from either long communication time delay or significantly compromised output regulation. In this paper, the slow dynamics and the overshoot issues of the WPT system are elaborated in theory, and the small-signal model mainly considering mutual inductance disturbance is established. A simple feedforward control is proposed for overshoot damping and fast system dynamics. Experimental results validate that the overshoot can be reduced by 13% and the settling time is improved by 50% in vehicle braking or acceleration. In constant speed driving, the battery charging ripple is decreased by 12% and ensures better system stability.

Review on Key Technologies and Development of Magnetic Coupling Resonant-Dynamic Wireless Power Transfer for Unmanned Ground Vehicles

“…Currently, MCR-DWPT technology has made outstanding progress in electric vehicles [4], consumer electronics [5], medical devices [6], wireless sensor networks [7,8], and other civilian fields [9]. For MCR-DWPT of UGVs, most studies focus on the operating environment of city roads and factory transportation with the purpose of realizing MCR-DWPT of UGVs with transmitters buried in the ground.…”

Design and Performance Analysis of New Coupling Magnetic Core Structure for Dynamic Wireless Charging System of Electric Vehicle

“…The transmitting end is laid on the road to realize the high-frequency conversion of electric energy and transmission, and the pickup end is placed on the bottom of the vehicle to complete the signal pickup and energy output. [6][7][8][9][10][11][12][13][14][15] However, the transmitting coil and the pickup coil are physically separated, presenting a loosely coupled structure, [16] which leads to a certain degree of magnetic leakage, reduces the efficiency of energy transmission and leads to larger electromagnetic radiation. [17][18][19][20] Therefore, most of the existing research has been conducted to reduce the distribution of magnetic lines of force in the spatial medium by improving the structural layout of the core, so that as many magnetic lines of force as possible flow with the core to form a closed loop, which is used to attenuate the intensity of electromagnetic radiation in the air [21][22][23][24][25] and to increase the energy transfer power and efficiency.…”

Sensitivity Analysis of a Double-Layer Coupling Structure for an Electric Vehicle Wireless Power Transfer System

“…However, in the event of relative motion between the transmitter and receiver, especially in the case of wireless charging between two traveling EVs, the transmitting coil and receiving coil are prone to be in random relative motion, causing the position between these two coils to randomly change. Such cases have been investigated by many scholars, showing that the relative position between the transmitting coil and receiving coil strongly affects the power level and transfer efficiency of the WPT [5][6][7]. Several works on WPT for EVs have been proposed.…”