Coupled Power Transfer Research Articles

Power stabilization control of wireless charging system based on LCL‐P compensation structure

AbstractTo enhance the stabilizing function and boost the output power of the inductive coupling power transfer (ICPT) system, a power stabilization control method based on LCL‐P resonance compensation for a wireless energy transmission system is proposed. “L” represents inductance, “C” represents capacitance, “LCL” refers to the primary‐side compensation structure, and “P” indicates that the secondary side is compensated in parallel . Firstly, this paper synthesizes the modeling principle of the gyrator equivalent model of the resonant circuit and coupled inductor, graphically analyzes the resonant compensation structure, and derives the circuit characteristics of the LCL‐P compensation structure. Then, this paper proposes an improved control strategy for the Maximum Power Point Tracking (MPPT) algorithm to dynamically track the output power and thus obtain the optimal operating point through frequency conversion. Lastly, using MATLAB/Simulink software to build the simulation model of the wireless charging system through parameter design, the impact of the conventional DC/DC power control method is contrasted with the algorithmic control suggested in this paper. The results demonstrate that: the device can realize power transfer of 2.7 KW level, the energy transfer efficiency reaches more than 90%, the inverter realizes soft‐switching operation, and the improved MPPT algorithmic control strategy proposed in this paper is utilized to achieve better closed‐loop control of the system. The excellent characteristics of the LCL‐P compensation structure in high‐power transmission applications, as well as the correctness and feasibility of the control algorithm proposed in this paper, are demonstrated through simulation and practical experiments. This is a significant step towards improving the wide‐range adaptation of the wireless charging system, which is based on the LCL‐P resonance compensation to the changes in the load and coupling.

Dual-frequency modulation based mutual inductance and load identification method for inductively coupled power transfer systems

Dual-frequency modulation based mutual inductance and load identification method for inductively coupled power transfer systems

Development of Electric Impact Driver Integrated with Inductively Coupled Wireless Power Transfer

Development of Electric Impact Driver Integrated with Inductively Coupled Wireless Power Transfer

Improving the Critical Transmission Distance of Inductively Coupled Wireless Power Transfer Having Parity-Time Symmetry

Improving the Critical Transmission Distance of Inductively Coupled Wireless Power Transfer Having Parity-Time Symmetry

Performance Investigation of HFR Full-bridge Inverter in Resonant Inductive Coupled Power Transfer System for an Electric Vehicle

Inductive WPT of the resonant category is generally employed for medium and high-power transmission applications like electric vehicle charging due to it contributes excellent efficiency. The high-frequency resonant full-bridge inverter using series-series resonant topology is proposed. The design of the high-frequency resonant inverter is simulated and verified by MATLAB/SIMULINK software. The charging scheme which is available in the AC-DC as well as in the DC-DC converter should operate with the two steps to achieve a duty cycle-based voltage control and hysteresis current control. The resonant frequency of the proposed system has a frequency range of 65 kHz with a DC voltage of 12V. The simulation has been carried out successfully and transmitted a 5KW power load of constant current and voltage control. The Performance chart of with the existing method is carried out in terms of parameters and the efficiency can be achieved by 95%.

Improved Design of PCB Coil for Magnetically Coupled Wireless Power Transfer

In recent years, wireless power transfer (WPT) has progressed rapidly in both theory and commercialization. However, existing research into WPT coil design for low-power devices to mitigate the coil offset is limited. A dual-layer printed circuit board (PCB) structure is proposed in this paper to mitigate the coil offset while retaining manufacturing simplicity for practical uses. Specifically, the impacts of key geometric parameters on the coil quality factor and coupling coefficient are analyzed through models and simulations. Equivalent PCB coils were formed for mutual inductance models, and four basic compensation circuits were analyzed. The impacts of changes in coil thickness, line width, turn spacing, and number of turns on the quality factor of PCB coils were analyzed with a fixed outer diameter of the coil. Eleven types of PCB coils were manufactured to verify the simulation results. The offset transmission efficiency can reach 46.6% with an output power of 14.4 W. The PCB coil with improved design could offer remarkable improvements in the WPT system for low-power electronic devices.

Transmission characteristics of the mobile inductively coupled power transfer system for dual transmitters and pickups based on PSpice

Transmission characteristics of the mobile inductively coupled power transfer system for dual transmitters and pickups based on PSpice

Analysis and Implementation of Underwater Single Capacitive Coupled Simultaneous Wireless Power and Bidirectional Data Transfer System

Analysis and Implementation of Underwater Single Capacitive Coupled Simultaneous Wireless Power and Bidirectional Data Transfer System

Undersea Capacitive Coupled Simultaneous Wireless Power and Data Transfer for Multi-Load Applications

Undersea Capacitive Coupled Simultaneous Wireless Power and Data Transfer for Multi-Load Applications

Novel Inductively Coupled Wireless Power Transfer System Based on Modified Birdcage Coils for Torso Implanted Medical Devices

Novel Inductively Coupled Wireless Power Transfer System Based on Modified Birdcage Coils for Torso Implanted Medical Devices

T–S Fuzzy Model-Based Fault Detection for Inductively Coupled Power Transfer Systems With Coil Misalignment

T–S Fuzzy Model-Based Fault Detection for Inductively Coupled Power Transfer Systems With Coil Misalignment

Event-triggered model predictive control for series–series resonant ICPT systems in electric vehicles: A data-driven modeling method

This paper investigates the event-triggered model predictive control (MPC) for the series–series (SS) resonant inductive coupling power transfer (ICPT) system in electric vehicles (EVs). Different from most existing literature in ICPT systems, a data-driven modeling approach based on input–output data is proposed to describe the system dynamics and achieve constant voltage output in the presence of load variations. In the traditional MPC control strategies, the optimal control input should be calculated at each time instant to achieve the desired output voltage, which causes great computational burden. To tackle this issue, an event-triggered MPC mechanism is therefore developed to effectively alleviate the computational burden, which will generate the optimal control input only when the norm of the state error exceeds a predefined threshold. The effectiveness and reliability of the proposed event-triggered MPC control strategy are successfully verified by the experimental results.

Comparative Analysis of SS, SP, PP and PS Topologies for Magnetic Coupled Wireless Power Transfer System Composed of the Negative Resistor

In recent years, the concept of the negative resistor (NR) has been proposed and applied in the magnetic coupled wireless power transfer (MC-WPT) system to improve the stability of power transfer. However, it remains a fundamental challenge to find the characteristic differences and applications of the four basic NR-based MC-WPT topologies. In this paper, the circuit models of the four basic NR-based MC-WPT topologies: series-series (SS), series-parallel (SP), parallel-parallel (PP), and parallel-series (PS) are established, and their characteristics are analyzed and compared by using circuit theory, which enables engineers to determine and select topologies to suit different applications and requirements. Theoretical analysis shows that the compensation methods of the transmitter and receiver of the NR-based MC-WPT system would affect the operating frequency and output characteristics of the system. Moreover, by comparative analysis, the conditions and applicable ranges for a stable output of different topologies were provided. Finally, the experimental prototypes are set up by using the power electronic inverter and operational amplifier, and the voltage gain ratios of the four basic NR-based WPT topologies under the variations of transfer distance and load are observed. The experimental results validate the correctness of the theoretical analysis.

An inductive power transfer approach to power and signal synchronous transmission using binary frequency shift keying communication

AbstractTo satisfy the requirements for transferring signals in an inductively coupled power transfer system, a novel power and signal composite modulation strategy is proposed using the binary frequency shift keying technology. The information‐carrying inverter control signal is generated by the logical combination of a signal carrier and the inverter control pulse using AND operation. Then a binary frequency shift keying method is used to modulate the signal carrier, and the resulting voltage ripples are injected to the bus at the output side as the signal carrier, to realize the signal and power synchronous transmission. At the signal receiver side, the output voltage ripple is sampled and filtered, and fast Fourier transform (FFT) is adopted for signal demodulation. The experimental test reveals that the proposed synchronous transmission method can achieve signal modulation and injection by modulating the frequency of power switches, and the transmitted signal can be demodulated by using FFT method with small time delay. This research can provide a new method for realizing power and signal synchronous transmission in an inductively coupled power transfer system.

Body-based capacitive coupling and conductive channel power transfer for wearable and implant electronics

Wearable and implant electronic devices have been widely utilized for healthcare and medicine. However, powering these devices for long duration with stable performance is extremely challenging. Here, we propose a body-based capacitive coupling and conductive channel power transfer (BC4PT) technology for this application. The BC4PT could unintentionally harvest the 50/60 Hz electricity using daily electronic devices. Large stray capacitances exist between electronic device such as phones and hand. When a person uses a plugged-in device, a high amount of 50/60 Hz electricity could be coupled to the hand, and transferred to wearable devices via the body conductive channel. The BC4PT could light up a 120 LEDs array directly, charge a 1mF capacitor to ∼ 23 V in 10 min. The harvested energy is utilized to power a wireless multivariable physiological sensor chip continuously or an implant device via the resonance-coupled wireless power transmission. The technology has a great application prospect for the self-powered wireless wearable and implant systems.

A Quadrupole Receiving Coil With Series-Connected Diode Rectifiers for Interoperability of Nonpolarized and Polarized Transmitting Coils

Non-polarized and polarized coils are utilized in an electric vehicles (EV) wireless charging system. These coils are decoupled from each other at the central position, leading to interoperability issues. This letter proposes a new decoupling method and a quadrupole receiving coil with series connected diode rectifiers for interoperability purposes. Decoupling windings are added to achieve decoupling of the four receiving poles. The total mutual inductance between the transmitting coil and the quadrupole receiving coil is the summation of the absolute values of the mutual inductances between the transmitting coil and the four receiving poles. In this way, the proposed quadrupole coil can be tolerant with not only the non-polarized transmitting coil, but also with the polarized transmitting coils along two perpendicular directions. The experimental results confirm that a large coupling and efficient power transfer can be achieved with the non-polarized coil and the polarized coil placed at two perpendicular directions with good misalignment tolerance.

Concave Ferrite Core for Wireless Power Transfer (WPT)

High-efficiency wireless power transfer (WPT) systems can present a perfect solution for fast-charging autonomous guided vehicles (AGV) to improve working hours in high-tech warehouses. Stationary charging stations reduce separation distance, improving coupling factor and power transfer efficiency. Analysis and design of the WPT system focused on maximum power at the load with a SS compensation circuit to reach high efficiency while applying the theory of power transformers design to maximize the power handleability with the physical dimensions. The proposed concept fits small AGVs. This paper proposes a unique ferrite structure for the transmitter ferromagnetic core. This novel shape introduces horizontal angular misalignment resistance due to the transmitter’s omnidirectional concave disc ferrite core combined with an E-core ferrite at the receiver side. The proposed WPT system can output 200 W at 100 kHz. A realistic 3D model has been designed into a symmetrical equivalent to reducing complexity and computational effort. The visualization of the magnetic flux distribution demonstrated that the proposed design has a better path to flow without concentrating flux in small regions, reducing heating losses.

An Efficient and Stable Embedded Multi-U-Shaped Column Rotary Transformer

Inductively Coupled Power Transfer (ICPT) technology can be used to solve the problems of high friction loss, overheating and low stability caused by conductive slip rings on rotating power supply equipment. An improved Embedded Multi-U-Shaped Column Rotary Transformer (EMUCRT) based on the ICPT and spliced core structure is proposed in this paper. It has a higher coupling coefficient and can transmit power more efficiently and stably due to the primary magnetic core is embedded inside the secondary magnetic core. Compared with the one-piece core structure, the spliced type is more flexible due to its loose magnetic core arrangement. Its primary coil can still transmit energy stably after offset by a certain distance, so the structure has good anti-misalignment ability. On the basis of analyzing its magnetic core arrangement and magnetic circuit model, the optimal magnetic core specifications and quantities of primary and secondary side are obtained by theoretical calculation and simulation. In order to verify the high efficiency, rotational stability and anti-misalignment characteristics of the structure, an experimental prototype was built. The results show that EMUCRT can transmit energy efficiently and has good rotational and offset stability.

The development of wireless charging technology in the electric vehicle

Greenhouse gas emissions have caused the global climate to deteriorate, and the consumption of oil resources is becoming less cost-effective. Electric vehicles (EVs) are a good way to reduce this negative impact. However, the energy density of batteries is too low compared with oil, so electric cars need to be recharged repeatedly. This paper provides a comprehensive review of all the wireless charging technologies for EVs. The technology principle of Inductively Coupled Power Transfer (ICPT), Magnetically Coupled Resonant Wireless Power Transfer (MCR-WPT) and Microwave Power Transfer (MPT) are discussed by a comparative analysis between the three technologies. The analysis found that MCR-WPT is the best technology because it has high efficiency and very little radiation. After that, wireless charging is expounded from both static and dynamic perspectives. Next, different national requirements and standards for wireless charging are presented. According to the economic and safety analysis, it is found that wireless charging technology can avoid many security risks, reduce the occupied area and has a longer service life than wired charging.

Efficiency optimization for LCC‐LC compensated inductive coupling power transfer system with load‐independent zero‐phase‐angle and constant voltage output

SummaryHigh‐order compensation for the inductive coupling power transfer (ICPT) system is preferred due to its high design freedom and excellent coil current harmonics suppression capability. Especially, the good harmonics suppression capability is helpful to implement the synchronous wireless transfer of energy and data with a pair of data communication coils integrated into the energy transfer coils. Thus, on basis of THD1 and THD2 comparison for different high‐order compensation topologies, the LCC‐LC compensated ICPT system with load‐independent zero phase angle (ZPA) and constant voltage output is discussed in this paper. Compared with other high‐order compensation topologies with constant voltage output such as LC‐LC, LC‐LCC, and LCC‐LCC, the LCC‐LC has the advantages of ZPA operation with zero voltage switching and less secondary‐side components. For a given magnetic coupler, infinite feasible combinations of compensation parameters can make the system accomplish ZPA and the same output characteristics. Thus, efficiency optimization of the LCC‐LC compensated ICPT system can be investigated by configuring the optimal compensation parameters. To validate the theoretical analysis, especially the efficiency improvement, the experimental platform with 270 V input and 270 V/3 kW output is designed and built. The comparative experimental results for three different the compensation parameters show the optimized system can improve greatly conversion efficiency over the entire load range, especially under light load.