A multiphase inverter with phase-shifted control is proposed for the inductive power transfer (IPT) of EVs where the charging voltage can be regulated by adjusting the angle among the inverter phases. An equivalent circuit model is developed and linearized to analyze the system dynamic characteristics at its operating point. In terms of the high order model, a balanced model reduction method is used to remove the fast modes which are outside the desired system bandwidth and insignificant to controller design. In addition, the model is discretized and the communication delay of the feedback loop is considered in the discretized model. Based on this model, the parameters of a PI controller are designed to achieve the expected performance indexes. A 6.5 kW S-S compensation IPT system prototype with constant voltage control is built and tested to verify the control performance. The experimental results show that the charging voltage can be maintained constant within 6 ms and has no overshoot under disturbances, which verifies that the closed-loop system with PI controller operates properly and efficiently for IPT. Besides, the measured transmission efficiency of the system at a receiving power of 6.5 kW is 95.1%

ToTo prevent the degradation of battery life and reduce switching loss in inductive power transfer (IPT) systems for electric vehicles (EVs), it is vital to realize constant current/voltage (CC/CV) charging and zero-voltage-switching (ZVS) operation. However, due to the existence of couplings between the charging and ZVS operating control loops, the controllers are neither optimal nor robust. In this paper, a model-based decoupled control method is proposed to improve the performance of the charging and ZVS operating controllers. Since the operating point of the CC and CV modes are different, two dynamic models for the corresponding charging modes are built and linearized. Besides, the couplings between the charging and ZVS operating control loops are analyzed, and in turn, decoupled by designing compensators. To optimize the system performance, we chose PI controllers, and their parameters are obtained by calculating the settling time and overshoot of the close-loop dominant poles according to the control performance requirements. In the experiment, a 500-W series-series IPT system prototype is built and tested to verify the improvement of the control performance. Compared with the coupled control method and the traditional closed-loop control feedback method, the recorded response curves and transient waveforms demonstrate that the proposed decoupled control method brings a better performance to the system.

As an important hub equipment in the power system, the power transformer has increasingly higher requirements for its reliability and safety with the rapid development of the power industry. However, the vibrations and noise generated during its operation not only cause a series of issues such as loose windings, core wear, and fatigue of fasteners, but also lead to anxiety and unease among nearby residents, severely affecting their physical and mental health. Therefore, the generation mechanism and control measures of vibration and noise in power transformers have attracted extensive attention from scholars. The magnetostrictive effect of silicon steel sheets is one of the important factors in the causes of transformer vibration and noise. This paper focuses on the magnetostrictive effect of silicon steel sheets. Firstly, the micro mechanism of magnetostriction is introduced. Secondly, based on current research status, the vibration and noise mechanism caused by magnetostriction are summarized, and the influencing factors, measurement, modeling, and noise reduction methods based on magnetostriction are summarized. Finally, based on the current research status and future development trends, prospects are proposed, aiming to provide references for subsequent research on transformer vibration and noise.

A fast diagnosis method for power switch open-circuit faults of half-bridge inverters with different topologies is proposed in this research. To begin with, the inverter dc voltage models of inverters are established based on the consideration of dc side inductance parameters. Next, the current paths of inverter under different switching states are analyzed, and the characteristics of dc voltage waveform during circuit commutation are studied. Then, the effect of the switch open-circuit fault on the voltage waveform characteristics of the inverter is analyzed. Subsequently, a fast diagnosis method for the open-circuit fault of the inverter switch tube is proposed, the method can accurately locate the fault within several switching cycles by comparing the temporal position relationship between the characteristics waveform of dc voltage and the changes of switching control signal. Finally, the feasibility and accuracy of the method are verified by experiments.

In this paper, a dual-channel RF-DC microwave rectifier circuit is designed with a 2:1 power distribution ratio in a Wilkinson power splitter. The rectifier circuit works at 2.45 Ghz. After impedance matching and tuning, the structure is able to broaden the dynamic power range of the rectifier circuit while maintaining maximum rectifier efficiency. Compared with the HSMS2820 rectifier branch, this design enhances the power dynamic ranges of 60% efficiency and 50% efficiency by 4 dBm and 3 dBm, respectively. Compared with the HSMS2860 rectifier branch, for the efficiency of 60% and efficiency of 50%, the power dynamic range is expanded by 5 dBm and 2 dBm, respectively. This shows that the technology is helpful for improving the stability of energy conversion at the receiver end of microwave wireless energy transmission systems. Finally, the rationality of this conclusion is verified by establishing a mathematical model.