In this paper, we proposed a novel steady-state multiple parameters estimation method of the two-coil inductive power transfer (IPT) system based on the measurement of the primary-side voltage and current fundamentals. The method is used to estimate key parameters, such as mutual inductance and equivalent load resistance, as well as receiver self-inductance and compensation capacitance values, and the total parasitic resistance of the secondary side. The method also allows the identification of the secondary-side resonant frequency. The parameters estimation procedure involves three operating modes of the IPT system: 1) open-circuit of the secondary side, 2) short-circuit of the secondary side, and 3) load connection. Each of these modes allows the identification of different parameters. To make the system operate in predefined modes, two switches are added to the receiver circuit. These switches are controlled from the secondary side, while the parameters estimation process, including load voltage and/or current control, is fully conducted on the primary side. The experimental tests on the prototype have validated the proposed method and demonstrated its effectiveness. The method can be applied to a new generation of high-performance wireless battery charging systems, where the single transmitter unit can be used to charge the battery pack in different devices.

The most widely adopted category of the mid-range wireless power transmission (WPT) systems is based on the magnetic resonance coupling (MRC), which is appropriate for a very wide range of applications. The primary concerns of the WPT/MRC system design are the power transfer capabilities. Using the scattering parameters based on power waves, the power transfer of an asymmetric WPT/MRC system with the series-series compensation structure is studied in this paper. This approach is very convenient since the scattering parameters can provide all the relevant characteristics of the WPT/MRC system related to power propagation. To maintain the power transfer capability of the WPT/MRC system at a high level, the scattering parameter $S_{21}$ is used to determine the operating frequency of the power source. Nevertheless, this condition does not coincide with the maximum possible power transfer efficiency of the system. In this regard, the WPT/MRC system is thereafter configured with a matching circuit, whereas the scattering parameter $S_{21}^{\prime }$ S21’is used to calculate and then adjust the matching frequency of the system. This results in the maximum available power transfer efficiency and thereby increases the overall performance of the system. Theoretical investigations are followed by numerical simulation and experimental validation.

Wireless power transfer between electric vehicles, based on magnetic coupling, have been proposed and patented by ZF Friedrichshafen AG and Daimler AG. In this system of wireless power transfer, which is categorized as dynamic, the estimation of coupling factor is essential for maximum efficiency tracking. In this paper a novel approach for estimation of coupling factor is proposed. It is based on the coil geometry properties and distance measurement between the electric vehicles.

In this paper, the enhanced nonlinear magnetic model of the low voltage interior permanent magnet synchronous machine (IPMSM) is developed using the frozen permeability (FP) technique in finite element analysis (FEA) FEMM 4.2 software. The magnetic model is derived by obtaining flux saturation maps for a wide range of dq stator currents. Furthermore, the FEA FP technique accounts for the corresponding offset in the flux maps due to the excitation of the permanent magnets, and well as for fitting the coefficients for the curve-fitting procedure. In order to demonstrate the usefulness of the proposed magnetic model, a nonlinear control strategy based on the maximum torque per ampere (MTPA) optimal algorithm for IPMSM is employed. The magnetic model and the MTPA control strategy are validated through a variety of computer simulations based on FEMM 4.2 and MATLAB R2023a software, as well as on a real IPMSM electric vehicle (EV) traction drive experimental setup.

In inductive power transfer (IPT) systems, the relative position between the primary and secondary side assemblies affects the self-inductance of the coils and their mutual inductance. Additionally, the aging effect of capacitors influences the value of compensation capacitors. It is, therefore, necessary to determine a minimum set of key IPT system parameters when implementing a constant-current (CC) / constant-voltage (CV) battery charging algorithm without real-time communication. This paper presents a method for implementing the CC/CV battery charging algorithm in an LCC-S IPT system without requiring real-time communication or all system parameters. Using only measurements from the primary side, the method is based on the phasor estimation of the primary-side electromotive force (EMF). Estimated parameters include the mutual inductance, the primary-side coil self-inductance and its parasitic resistance, and the secondary-side circuit resonant frequency. The first three parameters are estimated before the battery charging process starts, whereas the secondary-side circuit resonant frequency is identified during the charging process without influencing it. To verify the validity of the proposed method, an IPT prototype with 48 V charging voltage and 4 A charging current is implemented. Experimental results indicate that the estimated parameter set provides fast and accurate output voltage and current control.

In this paper, the enhanced auto-tuning technique based on the injection of two sinusoidal test signals of different frequencies applicable on the low voltage induction motor self-commissioning process is presented. The main feature of the proposed technique resides in the advanced signal processing of measured IM voltage and current signals based on the cascaded delay signal cancelation structure. This processing algorithm enables the filtering of the symmetry-related fundamental harmonic from the non-symmetrical test signal excitation typical for the self-commissioning process. Based upon the steady-state response from the proposed filtering block, the simple yet effective calculation method derives the complete parameter set of the IM equivalent circuit. The technique is validated through the variety of computer simulations and experimental tests on the digitally controlled low voltage IM traction drive.