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Along with the increasing popularity of smart home, multi-coupling wireless power transfer (WPT) technique has shown significant potentials for portable electric-driven appliances. Accordingly, there existing growing diversity of charging requirements from various household appliances like mobile phones, iPad or laptop, for examples quick charging, the State of Charge (SoC), etc., therefore, the multi-coupling WPT system needs to deal with various charging requests simultaneously. Besides, the security of the wirelessly transmitted energy attracts attentions from researchers as well, especially for multiple WPT receivers coupling with the identical transmitting coil. Previously proposed energy encryption scheme utilized the characteristic of frequency sensitivity to encrypt the transmission channel . Consequently, the key point of delivering the maximum power is to ensure the impedance matching, especially adjusting the resonant capacitor of primary unit while the frequency is regulated randomly. As aforementioned, this paper proposes an optimal-distribution and maximum-power based system which can distribute the limited transmitted power to different receivers simultaneously based on the proposed multi-coupling energy distribution scheme utilizing a novel control algorithm, meanwhile the proposed system is able to compensate the change of capacitance voltage due to the change of resonant frequency on account of various standard of charging equipment. More importantly, the proposed compensation which can extend the range of resonant frequency significantly only need one capacitor with a brand new current injection topology named capacitance buffer rather than the traditional capacitor array, so the system can continuously adjust the impedance to the resonate state to maintain the maximum output power.

This paper proposes a new topology-reconfigurable capacitive compensation network, aiming to achieve the energy encryption of the contactless charging for multiple electric vehicles (EVs). The proposed variable topology of compensation network consists of an M × N capacitor matrix, where capacitors can be connected either in series or in parallel by controlling switches. Then, the proposed capacitor matrix can be formed in the series-parallel and the series-parallel–series-parallel topologies according to the adjustment of the resonant frequency. In such ways, the proposed topology-reconfigurable capacitor matrix can significantly extend the capacitive compensating range while reducing the number of capacitors, thus effectively enhancing the security performance of multiple-objective contactless charging systems. Finally, this paper gives the simulated and experimental results to verify the theoretical analysis, which can further illustrate the feasibility of the proposed topology-reconfigurable capacitor matrix for the energy encryption of EV contactless charging systems.

This paper proposes an improved figure-of-eight coil for transcranial magnetic stimulation (TMS) by using the magnetic resonant coupling (MRC) effect, aiming to improve the treatment effect for psychiatric disorders. The proposed MRC-based figure-of-eight coil consists of two reverse-winding resonance coils, which embraces two series-connected source coils, respectively. Different from conventional figure-of-eight coils, the proposed topology can produce the resonant electromagnetic field to accumulate the stimulation energy. In such ways, the improved TMS system can effectively enhance the stimulation focality and depth while significantly reducing the requirement of the power supply, thus improving the safety as well as facilitating the miniaturization and portability. Last, this paper gives the simulated and experimental results to verify the theoretical analysis, which can further illustrate the feasibility of the proposed MRC-based figure-of-eight coil for TMS systems.

Recently, wireless power transfer (WPT) is getting increasing attentions, for it is able to provide a brand new method for power transmission. The limitations of traditional cable charging method such as tangled and inconvenient power cords, and a limited number of charging interface are well overcome. As for the WPT system, one of the major concern is the power transmission efficiency and the transmitted power influenced by various transmission distance and the variety of loads. Especially in multi-receiver condition, there existing variety of loads with different requirements. Based on the impedance alteration method [1], a comprehensive analysis regarding to the relationship among the equivalent load, output power and efficiency in multi-receiver system is conducted, and a novel load alteration strategy aiming at better satisfying different requirements in different load consistence is proposed based on the aforementioned analysis.

This paper proposes an optimal design of quadrature-shaped pickup to satisfy various demands on performance at special positions for omnidirectional wireless power transfer (WPT). Omnidirectional WPT technology as a brand new way of energy supply has shown great potentials for charging objectives at all directions. In order to ensure the energy can be transmitted to arbitrary spatial directions, the orthogonal structure of three circular transmitting coils has been widely accepted matched with non-identical current control scheme. However, there are still some special positions where the transmitted power drops to the bottom which is not suitable for applications. Accordingly, this paper proposes an optimal design analysis for the quadrature-shaped pickup to satisfy different demands on either power or efficiency at such positions. The simulated analysis and experimental results are both given to verify the enhancement of the proposed quadrature-shaped pickup, which aims to provide a reference to fabricate an appropriate pickup up for utilizations.