Inductively Coupled Power Transfer System Research Articles

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%.

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.

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.

Implementation of ZVS for Double-Sided LCC Inductive Coupled Wireless Power Transfer System Under Constant Current/Constant Voltage Operation Mode

The soft-switching characteristics of double-sided LCC wireless power transmission systems are susceptible to system parameter disturbances. In order to improve the stability of zero voltage switches in constant-current and constant-voltage charging modes, this paper synthesizes eight resonant conditions which make the system realize constant-current/constant-voltage and Zero Phase Angle. The influence of compensating capacitance parameter disturbance on system impedance angle is studied under constant current/constant voltage operation mode. The parameter configuration methods of compensated capacitance realized by zero voltage switches under the influence of third-order harmonic in constant current/constant voltage operation mode are also given. The system’s experimental prototype verifies the theoretical analysis’s accuracy with capacitive and inductive input impedance.

Robust H ∞ Control for ICPT Process With Coil Misalignment and Time Delay: A Sojourn-Probability-Based Switching Case

In this paper, the robust <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$H_{\infty }$ </tex-math></inline-formula> control problem is studied for the inductively coupled power transfer (ICPT) process with coil misalignment, energy bounded interference and time-varying delay. The problem of coil misalignment between the primary and secondary coils are considered, and the time varying coupling coefficient are described in a sojourn-probability-based switch model. A set of random variables are utilized to describe the sojourn probabilities of the finite modes of the coil misalignment. It should be pointed out that the sojourn probability of the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$i$ </tex-math></inline-formula> th subsystem is obtained by the off-line statistical test instead of prescribed by hand, which is of more closer physical significance due to its engineering practice. Corresponding to the proposed switching systems, a set of controllers with time-varying delays are constructed. By resorting to the Lyapunov stability theory, the matrix analysis, and the stochastic analysis tools, the delay-dependent sufficient criteria with less conservatism are derived to guarantee the mean square stability of the ICPT system and the given interference attenuation level <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> . The feedback gains of the desired controller can be readily obtained by using the control toolbox in Matlab software. Three cases of the illustrative examples without exception verify the effectiveness of the suggested modeling method and control scheme.

Reliable [formula omitted] filtering for the SP resonant ICPT system with stochastic multiple sensor faults

The inductively coupled power transfer (ICPT) system is one of the most important system in the wireless power transfer field. In this paper, the reliable H∞ filtering problem is considered for the ICPT system based on the series–parallel (SP) resonant compensation network. A more general SP resonant ICPT system model is proposed with considering external disturbances and multiple sensor faults. The sensor faults are assumed to happen in a random way, which are described by a set of stochastic variables satisfying certain statistical features. The main purpose of the addressed problem is to design an H∞ filtering scheme such that the filtering error dynamics are asymptotically mean-square stability (AMSS). For this purpose, a generalized state-space averaging (GSSA) model is built to characterize dynamical behaviors of the SP resonant ICPT system first. Then the filtering-error system with stochastic sensor faults is established via the GSSA model. By virtue of an extended Lyapunov function, a sufficient condition is given to achieve the AMSS of the system and H∞ performance requirement. Subsequently, the H∞ filtering gains are obtained by solving a set of linear matrix inequalities. Finally, a simulation example is provided to verify the availability and reliability of the proposed filtering scheme.

Segmented Power Supply Preset Control Method of High-Speed Rail Contactless Traction Power Supply System considering Regenerative Braking Energy Recovery

For high-speed rail with high energy consumption, the recovery and utilization of regenerative braking energy is essential to improve the energy consumption of high-speed rail. As a technical link, the energy bidirectional feed inductively coupled power transfer (ICPT) system can realize the regenerative braking energy recovery of the contactless traction power supply system. Furthermore, considering that the braking energy of the high-speed rail is the largest when entering the station during the whole line operation, the braking section of the station is mainly considered. This paper proposes a preset control method for segmented power supply of the energy bidirectional feed ICPT system considering regenerative braking energy recovery. By establishing the steady-state mathematical model of the bidirectional ICPT system, the influence of the internal phase-shift angles φ1 and φ2 and the external phase-shift angle γ on the operating state of the system is analyzed. To realize system synchronization under the operation of EMUs, a train braking model is established through force analysis, and a power preset controller is designed to realize the synchronous control of the power flow of the bilateral system. According to the braking process of the train entering the station, the switching control method of the segment coil under the different conditions of the single train entering the station and the multitrain entering the station is proposed to ensure the reliability and flexibility of the train power supply. The simulation results of the 350 kW ICPT system simulation model show that the system can operate stably when the power transmission simulation is switched, and the transmission efficiency can reach 89%, which proves the feasibility of the control method. Energy-saving estimates show that a single train can recover about 200–300 kWh of electric energy during single braking. The comparison with the measured data verifies the accuracy of the modeling in this paper.

H∞ mixed sensitivity robust control method of relay ICPT system for output voltage regulation

Aiming at the problem that the output voltage of relay inductive coupled power transfer (ICPT) system is susceptible to changes due to the influence of system load changes, frequency perturbations, and input voltage fluctuations, an H∞ mixed sensitivity robust control method is adopted to relay ICPT system to regulate the output voltage. First, the working principle of the relay ICPT system is analyzed. Then, the GSSA model of the relay ICPT system is established. By constructing the S/R/T mixed sensitivity function, a suitable weighting function is selected from the frequency domain perspective and converted into H∞ standard control problem to get a robust controller. Finally, an experimental platform is built to verify the control effect of the controller on the system output voltage. Experimental results show that the designed controller in this paper stabilizes the system output voltage and obtains good tracking performance, suppression parameter perturbation performance, anti-interference performance, and improves system robustness simultaneously.

Simultaneous Wireless Power and Information Transfer Based on Phase-Shift Modulation in ICPT System

Compared to traditional simultaneous wireless power and information transfer (SWPIT) technologies, communication technology utilizing the output harmonic component of an inverter as a signal carrier can achieve high-performance signal transmission without affecting power transmission. The SWPIT technology based on phase-shift modulation in inductively coupled power transfer (ICPT) system is proposed in this article. By changing the phase angle of the inverter, a trapezoidal wave current is generated on the primary coil, and a frequency selection circuit is added on the secondary side to separate the fundamental and harmonic currents. The fundamental component current is used for wireless power transfer while the harmonic current is used to transmit the signal. Firstly, the structure and working principle of SWPIT system based on phase-shift modulation in ICPT system are analyzed. Then, a system equivalent model is established and the reactive power is analyzed in depth. Next, the phase angle variation range is determined by crosstalk analysis. Finally, the correctness and effectiveness of the proposed technology are verified with an experimental platform at 50 W. The experimental results demonstrate that the power and information can be transmitted stably with output voltage fluctuation less than 3%, and the signal transmission rate up to 6 kbps.

An Improved Pulse Density Modulation of High-Frequency Inverter in ICPT System

Pulse density modulation (PDM) is often applied in inductively coupled power transfer (ICPT) systems to improve high-frequency inverter (HFI) efficiency. However, the PDM may cause the inverter output current fluctuation, even interruption for light load or low-quality factor system. This may result in the difficulty for the implementation of soft switching in ICPT. In this article, an improved PDM (IPDM) strategy is proposed by optimizing the distribution of switch sequences. Through the current fluctuation numerical analysis and Fourier decomposition, IPDM can reduce the current fluctuation and improve the system efficiency. The experimental results on a 20 kW ICPT system prototype show that the proposed IPDM strategy reduces the HFI output current ripple coefficient is 40% to 65% lower than PDM, and the efficiency is also improved.

Integrated control method for constant output voltage and maximum efficiency tracking of bilateral LCL compensation ICPT system

Inductive coupled power transfer (ICPT) systems are now more desired to provide constant output voltage with the highest efficiency, which will be affected by source (input voltage) and load (load resistance) conditions. To address this issue, an integrated control method is proposed in this study, which is realised by using the active impedance matching technology based on the buck -boost circuit on the load side and the robust H ∞ control technology on the inverter side. This control scheme allows both two technologies to be applied simultaneously and independently operated. The bilateral inductor -capacitor -inductor ICPT compensation system is used here to test the proposed method, which is representative, and it is also applicable to other typical compensation topologies and has a certain universality. Finally, an experimental platform is established. Experimental results show that the system can achieve 24 V constant output voltage and 84.53% efficiency tracking under the condition of simultaneous 20% input voltage disturbance and 50% load change, which shows the effectiveness of the proposed integrated control method.

Hybrid modeling and control of ICPT system with synchronous three-phase triple-parallel Buck converter

AbstractAiming at the influence of coupling coefficient variation on the output voltage of a high-power LCC-S topology inductively coupled power transfer (ICPT) system, a synchronous three-phase triple-parallel Buck converter is used as the voltage adjustment unit. The control method for the three-phase current sharing of synchronous three-phase triple-parallel Buck converter and the constant voltage output ICPT system under the coupling coefficient variation is studied. Firstly, the hybrid model consisting of the circuit averaging model of the three-phase triple-parallel Buck converter and the generalized state-space average model for the LCC-S type ICPT system is established. Then, the control methods for three-phase current sharing of the synchronous three-phase triple-parallel Buck converter and constant voltage output of ICPT system are studied to achieve the multi-objective integrated control of the system. Finally, a 3.3 kW wireless charging system platform is built, the experimental results have verified the effectiveness of the proposed modeling and control method, and demonstrated the stability of the ICPT system.

Modeling, Analysis, and Implementation of Series-Series Compensated Inductive Coupled Power Transfer (ICPT) System for an Electric Vehicle

This paper focuses on the modeling and implementation of an Electric Vehicle (EV) wireless charging system based on inductively coupled power transfer (ICPT) technique where electrical energy can be wirelessly transferred from source to vehicle battery. In fact, the wireless power transfer (WPT) system can solve the fundamental problems of the electric vehicle, which are the short battery life of the EV due to limited battery storage and the user safety by handling high voltage cables. In addition, this paper gives an equivalent electrical circuit of the DC-DC converter for WPT and comprises some basic components, which include the H-bridge inverter, inductive coupling transformer, filter, and rectifier. The input impedance of ICPT with series-series compensation circuit, their phases, and the power factor are calculated and plotted by using Matlab scripts programming for different air gap values between the transmitter coil and receiver coil. The simulation results indicate that it is important to operate the system in the resonance state to transfer the maximum real power from the source to the load. A mathematical expression of optimal equivalent load resistance, corresponding to a maximal transmission efficiency of a wireless charging system, was demonstrated in detail. Finally, a prototype of a wireless charging system has been constructed for using two rectangular coils. The resonant frequency of the designed system with a 500 × 200 mm transmitter coil and a 200 × 100 mm receiver coil is 10 kHz. By carefully adjusting the circuit parameters, the implementation prototype have been successfully transferred a 100 W load power through 10 cm air gap between the coils.

Passivity-Based Control for Movable Multi-Load Inductively Coupled Power Transfer System Based on PCHD Model

A passivity-based control strategy for movable multi-load inductively coupled power transfer (ICPT) system based on PCHD (Port-Controlled Hamiltonian Dissipation, PCHD) model is proposed, which can effectively suppress mutual inductance and load interference. During the movement of the secondary coil of the movable multi-load ICPT system, due to the change of mutual inductance and the randomness of the multi-load, it will cause the transmission power and efficiency to oscillate and generate harmonics. Firstly, in view of the above problems, this paper analyzes the ICPT system under movable multiple loads. The DQ transformation method was used to establish the large-signal mathematical model of the system, and PCHD mathematical model in the DQ domain was established to decouple the active and reactive power. Secondly, the passivity-based controller (PBC) is designed by using the principle of interconnection and damping assignment passivity-based control (IDA-PBC). After that, the second method of Lyapunov function is used for stability analysis, and further verifies the asymptotic stability of the closed-loop system. Finally, the proposed method was verified by MATLAB/Simulink simulation. The simulation results show that the passivity-based controller has stronger robustness in both steady and movable states compared with the PI controller, which effectively suppresses the oscillation and total harmonic distortion caused by the change of mutual inductances and the randomness of the loads.

Design and Analysis of a Noninsert Wet Mateable Connector for Underwater Power and Data Transfer

AbstractCompared with traditional metal contact wet mateable connectors, a noninsert wet mateable connector (NWMC) costs much less and is simpler and safer to plug underwater and can operate steadily for a long duration. This article proposes a newly designed NWMC that can transfer power and data simultaneously in deep-sea conditions. Design and analysis methodology of a small volume and stable output inductive coupling power transfer (ICPT) system that combines calculation, simulation, and measurement methods are proposed. The operating parameters are monitored in real time through the communication path, and the heat is dissipated through the end cap. According to the experimental results, this system is able to maintain an output voltage of up to 48 V, transfer up to 130 W power, and simultaneously obtain 73 Mbps full-duplex noncontact communication.

Research on Energy Distribution of Regenerative Braking in Station for Contactless Traction Power Supply System Based on Bidirectional Energy Interaction ICPT System

The regenerative braking energy of high-speed railway accounts for about 10% of traction energy consumption, which will be higher under special conditions. The regenerative braking energy feedback of the contactless traction power supply system needs to be realized by dynamic bidirectional inductively coupled power transfer (ICPT). A novel regenerative braking energy distribution method for the contactless traction power supply system based on dynamic bidirectional energy ICPT (DBEI-ICPT) technology is proposed. Then, the mathematical model of the dynamic bidirectional ICPT technology is established; and the variation of transmission power is analyzed; Theoretical analysis of the system energy distribution and its feedback methods. The relationship between the energy flow and the train running state during braking is carried out. After that, an improved train braking curve and control method based on the ICPT technology is proposed, which can satisfy the requirements of the regenerative braking process before the train enters the station by controlling three phase shift angles of the ICPT technology. The control strategy with feedforward control is introduced into the energy storage system to suppress the bus voltage fluctuation. Besides, a nonlinear disturbance observer (NDO) is introduced to solve the shortcomings of the traditional feedforward control methods that require remote measurement. Finally, the effectiveness of the proposed power supply system as well the control strategy is verified by simulation. Results show that the current feedforward bus voltage regulation control is more suitable for this system for its shorter sampling time and stability.

Experimental Investigation and Optimal Air Gap Selection for Electric Vehicles Wireless Charging System

The interest for Electricals Vehicles (EV) wireless charging system has been increasing due to its simplicity of operation, robustness, and safety. The focus of this paper is on the presentation of an equivalent electrical circuit of the inductively coupled power transfer (ICPT) system. This paper proposes a new method to obtain an easier calculation of the ICPT system output power. The present method is based on the Thevenin equivalent circuit. For improving the performance of ICPT system, a relationship between the mutual inductance, the resonance frequency and the equivalent load resistance has been demonstrated in detail. This formula has been used to select the optimal air gap among transmitter and receiver coils. A prototype of a wireless charging system has been built using two rectangular coils. The resonant frequency of the designed system with a 50×20 cm transmitter coil and a 20×10 cm receiver coil is 10 kHz, and the maximum efficiency of the system is 86% at optimal air gap. Finally, the experimental results of the proposed system are presented and analyzed.

Review of inductively coupled power transfer for electric vehicle charging

Inductively coupled power transfer (ICPT) is a technology that is implemented to charge electric vehicles (EVs) wirelessly. Some developments from the past years indicate that this promising charging method has the potential to replace wired charging methods. Thus, some aspects of designing ICPT need to be discussed and considered to develop an optimal system. However, most reviews from the previous articles focused on the developments of ICPT systems in the scope of EV charging. This study not only reviews current developments and topical issues and challenges in high-power ICPT systems, but also presents several techniques for analysing the system as well as further developments for wireless EV charging adapted from the other electromagnetic field applications. This study will assist readers to analyse any proposed ICPT systems using current methods of analysis and to tackle highlighted topical issues presented from the previous technical papers.

Stability and control of uncertain ICPT system considering time‐varying delay and stochastic disturbance

SummaryThis paper studies the problem of robust exponential stability for uncertain inductively coupled power transfer (ICPT) system considering time‐varying delay and stochastic disturbance. Firstly, the model of the system is set up via a time domain method. Secondly, based on the Newton‐Leibnitz formula and stability theory, a new stability analysis of the ICPT system with uncertain parameter and time‐varying delay or stochastic disturbance is presented respectively. The proposed approach can be applied for analyzing other similar systems, and the obtained results can be also used for estimating convergence rate and region of stability. Thirdly, based on the Lyapunov‐Krasovskii functional (LKF) approach and the stochastic stability theory, robust exponential stability criteria in the mean square are derived and the relevant controller is designed. The proposed method can further reduce conservatism. Finally, the correctness and effectiveness of the obtained results are verified by an example and simulations indicate that the larger time delay, the slower attenuation. Simultaneously, the uncertain parameter and the stochastic disturbance have a significant influence on the region of stability. In addition, in respect of reducing conservatism, the effectiveness of the proposed method is demonstrated by comparing with other papers. In addition, the designed controller shows better performance for the ICPT system with the parameter uncertainty, the time‐varying delay, and the stochastic disturbance.