A novel feedback correction-adaptive Kalman filtering method for the whole-life-cycle state of charge and closed-circuit voltage prediction of lithium-ion batteries based on the second-order electrical equivalent circuit model

The underwater wireless power transfer (UWPT) technology provides a feasible way to solve the problems of the traditional power supply method of the autonomous underwater vehicle (AUV). The magnetic coupler is the most essential component in the wireless power transfer system. Its configuration determines its applicable scenarios, and its parameter design and optimization will directly affect the system's overall output power and efficiency. In this article, an arc-shaped underwater wireless power transfer magnetic coupler is proposed, which is suitable for AUV's curved shell. Especially, the proposed novel magnetic coupler utilizes Fe-based nanocrystalline alloy soft magnetic material as the magnetic core. Both volume and weight of the receiver are reduced compared with the traditional Mn-Zn ferrite material. Fe-based nanocrystalline alloy material provides a novel design idea for the magnetic coupler on electrical equipment with special-shaped shell due to its flexibility. A prototype of the UWPT system for 320 mm diameter AUV is built, and it can transfer 3 kW power in the experiment with a dc–dc efficiency of 91.9% at the forward maximum output power point. Compared with the structure with ferrite core, the volume of the proposed structure is reduced by 41.1%, and the weight is reduced by 42.6%, so that the expected effect has been achieved. 

A Novel Arc-Shaped Lightweight Magnetic Coupler for AUV Wireless Power Transfer

Energy storage plays a fundamental role in balancing the power fluctuations induced by the distributed generation of renewable energy sources. In this scenario, electric vehicles can strongly contribute to exchange power with the grid through their on-board batteries. When the vehicle is parked, the battery can be discharged, injecting active power into the grid, provided that its state of charge will be restored before vehicle utilization. This paper presents a comprehensive step-by-step design of a wireless charger for a Vehicle-to-Home application. The design procedure begins from the constraints disposed by the Italian reference technical rules for Low Voltage utilities and by the standard SAE J2954 for Wireless Power Transfer for electric vehicles. The selection of the output power of the battery is followed by the power sizing of each stage of the bidirectional wireless charger.

https://www.mdpi.com/2624-8921/3/3/25/pdf

Design of a Bidirectional Wireless Power Transfer System for Vehicle-to-Home Applications

Bidirectional ac–dc wireless power transfer (WPT) converters are widely used in grid-connected electric vehicle systems for grid-to-vehicle and vehicle-to-grid applications. They usually apply a two-stage topology with a bidirectional ac–dc power factor correction converter and a bidirectional dc–dc WPT converter. Such a two-stage topology cannot achieve high efficiency and low cost. Recently, single-stage matrix bidirectional ac–dc WPT converters have been proposed. However, the matrix-converter-based topologies do not utilize remarkably lower count of power switches and generate large double-line frequency ripple in the dc-side voltage or current. This article proposes a new single-phase bidirectional ac–dc WPT topology with an integrated power stage to overcome the drawbacks of the matrix-converter-based topologies and retain the advantages of single-stage topologies. Description of the proposed topology with the modulation and control methods, theoretical analysis, and reference design procedure are presented in detail. Finally, a scaled-down laboratory prototype with 500-W output power is implemented with experimental results presented to validate the principle, analysis, and design. 

A Soft-Switched Power-Factor-Corrected Single-Phase Bidirectional AC–DC Wireless Power Transfer Converter With an Integrated Power Stage

This paper proposes an energy shaping controller of a DC/DC converter for automatic guided vehicles (AGVs) wireless power transfer (WPT). A transformer is inserted after the LCC topology to improve the transfer power, and the DC/DC boost converter is added before this topology to obtain desired systematic power dynamically. The system power transfer model is derived based on the idea of voltage transformation and the desired power can be implemented indirectly through regulating desired output voltage of DC/DC converter. With the proposed controller, this WPT system will have a much better dynamic performance and the effective working time can be increased significantly. Furthermore, this paper proposes dynamical regulation strategy for output power to get real time target power according to the charging curve of the battery. Simulation and experimental results verified the control performance of the proposed control scheme. A WPT prototype with power up to 1.65 kW was built, and 92.12% efficiency from DC power source to battery load is achieved, which is 4% higher than that obtained by the conventional PID method.

https://www.mdpi.com/1996-1073/13/11/2959/pdf

Energy Shaping Control for Wireless Power Transfer System in Automatic Guided Vehicles

For the bidirectional wireless power transfer (BWPT) technology, the phase synchronization between the transmitting and receiving converters is very essential and difficult to achieve by wireless communication between two sides because the delay and data transfer interval of wireless communication severely influence the control performance. This article proposes a novel control strategy for BWPT, which can achieve the phase synchronization and maximum efficiency point tracking independent of the real-time wireless communication. To solve the overshoot and oscillation problem incurred by the proposed control strategy and the nature of the system itself, the dynamics of a series–series compensated BWPT system is then analyzed and a small-signal model of this system is derived based on the generalized state space averaging and extended describing function methods. Using the small-signal model, a BWPT control system based on the proposed control strategy is designed and optimized. The validity of the proposed strategy and the performance of the control system are verified experimentally using a 3.3-kW prototype system.

A Bidirectional Wireless Power Transfer System Control Strategy Independent of Real-Time Wireless Communication

The interaction between the resonant wireless power transfer (WPT) component and the dc/dc converter may weaken the system stability, causing overshoot and oscillation in the dynamic process of such WPT system. Nevertheless, both the mechanism and the solutions of the above problems are not fully researched for the WPT systems. This paper first analyzes the small-signal impedance characteristics of such systems and points out the cause of the instability phenomenon. Then, a novel control strategy is proposed to regulate the system impedance characteristics, which can suppress the interaction and improve the system dynamic performance. Small-signal analysis and experiment results demonstrate that the proposed strategy has the advantages of fast response and less overshoot compared with traditional PI control, and is suitable for different operating conditions.

Impedance Shaping Control Strategy for Wireless Power Transfer System Based on Dynamic Small-Signal Analysis

The wireless power supply solution has shown great advantages in rail transit applications, such as maglev trains and trams. However, research works on designing the magnetic coupler for wireless charging system in rail applications, which is a crucial problem, are not sufficient. Considering the high power and lightweight requirements, this article selects the coaxial M-shape magnetic coupler with LCL /S compensation for railway applications, which contains the transmitting rail and the receiving coil wound on an M-shape magnetic core. First, analysis was conducted on the requirements for inductance parameters of the magnetic coupler under the circuit constraints, including transmission power, input and output voltages, and component electrical stress, etc. Then, the influence of the geometric parameters of the coil structure and misalignment on its inductance parameters is analyzed. Based on these analysis results, the design method for the M-type magnetic coupler based on the lightweight principal is proposed. The geometric parameters are designed following a certain sequence to minimize the number of iterations and FEM simulation parameter sweeps, making the design procedure suitable for engineering practice. According to the proposed method, the magnetic coupler for a 360 kW wireless charging tram is designed and implemented. Through simulations and experiments, the magnetic coupler is verified to be feasible for the system with light weight.

Designing an M-Shape Magnetic Coupler for the Wireless Charging System in Railway Applications

Online monitoring for underground power cable insulation has become an urgent need in distribution grids, which can lead to proactive maintenance and avoid severe insulation faults. Insulation capacitance has been selected as an effective insulation condition indicator in many researches, but the variation of insulation conductance is always overlooked, resulting in a limited monitoring range and sensitivity. To solve this problem, a novel online monitoring method for underground power cable insulation based on resonance frequency analysis under chirp signal injection is proposed in this article. An online monitoring scheme based on common-mode chirp signal injection is first designed, realizing online monitoring in a nonintrusive manner. The resonance frequency under the injected signal is then analyzed, providing an effective approach to monitor insulation capacitance regardless of the accompanied insulation conductance variation. Simulations and experiments are carried out, proving the effectiveness of the proposed method for different system operating conditions.

Online Monitoring for Underground Power Cable Insulation Based on Resonance Frequency Analysis Under Chirp Signal Injection

The invention relates to a steady-state modeling and AC/DC hybrid system power flow analysis method for a power router. The method is characterized by comprising the following steps: (1) establishingan AC/DC power flow model of the multi-port power router according to an equivalent circuit topological graph of the multi-port power router; (2) combining the established AC/DC power flow model of the multi-port power router with a power flow model of a conventional AC/DC network and establishing a power flow model of an AC/DC hybrid system comprising the multi-port power router; (3) solving thepower flow model of the AC/DC hybrid system comprising the multi-port power router to obtain a power flow analysis result of the power flow model of the AC/DC hybrid system comprising the multi-port power router. The method can be widely applied to power flow analysis of the AC/DC hybrid system comprising the multi-port power router.

Qiuqiong Lin

Papers

A Bidirectional Wireless Power Transfer System Control Strategy Independent of Real-Time Wireless Communication

Impedance Shaping Control Strategy for Wireless Power Transfer System Based on Dynamic Small-Signal Analysis

Designing an M-Shape Magnetic Coupler for the Wireless Charging System in Railway Applications

Online Monitoring for Underground Power Cable Insulation Based on Resonance Frequency Analysis Under Chirp Signal Injection

Steady-state modeling and AC/DC hybrid system power flow analysis method for power router