Search Results (7)

The diverse array of sensors deployed on meteorological observation towers, tasked with the observation of meteorological gradients, requires distinct power supplies and effective power regulation. In this article, a multi-frequency, multi-receiver (MFMR) inductively coupled power transfer (ICPT) system using a time-sharing frequency strategy is proposed, which enables coupled power transfer to multiple nodes through only one cable. The time-sharing frequency control (TSFC) method is introduced to produce time-sharing multi-frequency currents. By incorporating a controllable resonant capacitor array at the transmitter, the system can operate at various resonance frequencies over specific intervals, allowing it to supply power to multiple loads with unique resonance frequencies. First, an in-depth analysis of the power transmission characteristics of MFMR-ICPT systems is conducted, with the three-frequency, three-receiver (TFTR) ICPT system circuit serving as an example. The frequency cross-coupling effects are then analyzed, and the TSFC method is explained. Finally, experiments are conducted on a TFTR-ICPT system. The results demonstrated that independent power regulation of multiple loads could be achieved by adjusting the duty cycle of different frequency input voltages through the time-sharing frequency strategy. The system achieved a total power output of 38.7 W, with an efficiency of 64.8%. Full article

The transition from conventional to electric transportation has become inevitable in recent years owing to the significant impact of electric vehicles (EVs) on energy sustainability, reduction of global warming and carbon emission reduction. Despite the rapidly growing global adoption of EVs in today’s electrical and transportation networks, energy storage in EVs, particularly in regards to bulky size and charging process, still remains a major bottleneck. As a result, wireless charging of EVs via inductively coupled power transfer (ICPT) through coupled coils is becoming a promising solution. However, the efficiency of charging EV batteries via wireless charging is hugely affected by misalignment between the primary and secondary coils. This paper presents an in-depth analysis of various key factors affecting the efficiency of EV battery charging. Finite element analysis (FEA) using Ansys Maxwell^® is performed on commonly used coil designs such as circular and rectangular coils under various misalignment conditions. In addition, various reactive power compensation topologies applied in ICPT are investigated and the behavior of each topology is observed in simulation. It is revealed that circular structures with S–S compensation topology show more robustness in misalignment conditions and maintain the desired efficiency for a wider range of displacement. A critical analysis of coil designs, compensation techniques and the combination of both factors is accomplished and conclusions are presented. Full article

Since the evaporation duct height (EDH) only covers the antenna height of most shipborne microwave radars, mastering the EDH in advance has great significance in achieving long-range target detection. In this paper, a set of hydrological and meteorological sensors based on the gradient meteorological instrument (GMI) were built to monitor the evaporation duct of the South China Sea (SCS). However, the monitoring needed to be interrupted during the battery replacement of the sensor, which could result in the loss of some important data collection. On the basis of the inductively coupled power transfer (ICPT) technology, the resonance principle was used to compensate the inductive reactance on the closed steel ring (CSR), and the energy stored in the super capacitor was introduced for data collection and return. A novel measuring system for the detection of an evaporation duct was proposed. To avoid iterative calculation by setting the initial value of the current evaporation duct models in large-scale and multi time evaporation duct prediction and diagnosis, on the basis of the non-iterative air–sea flux (NAF) model, the EDH was obtained by introducing the K theoretical flux observation method into the atmospheric refractive index equation. Finally, preliminary experimental results are presented for the detection of evaporation duct to demonstrate the feasibility and effectiveness of the proposed system. The communication accuracy rate of the proposed system was 99.7%. The system transmission power reached 22.8 W. The research results of the NAF model adaptability showed that the mean value of the EDH was 8.7 m, which was lower than the mean EDH of the SCS. The EDH calculated by the NAF model in the unstable air–sea stratification state was slightly lower than that calculated by the NPS model. The diagnosis of the EDH by the NAF model was similar to that of the NPS model, but the calculation stability of the NAF model was better. Full article

Conventional inductive contactless power transfer (ICPT) systems have only one energy transmission path, which makes it challenging to meet the power transmission requirements of high-power and reliability. This study proposes a novel multiple-input multiple-output (MIMO) ICPT system. The three-dimensional finite element analysis tool COMSOL is utilised to study various magnetic coupling structures, analyse the influence of cross-coupling between coils on the same side, design the circuit based on this, propose a parameter configuration method for resonance compensation, and, finally, build an experimental platform with small magnetic coupling structures for single-input single-output systems (SISO) and MIMO systems. The results indicate that the co-directional connection of the coils of the E-shaped and UE-shaped magnetic coupling structures has a strengthening effect on the secondary side coupling. The magnetic coupling structure of the E-shaped iron core exhibits the best transmission performance. The transmission power of the MIMO system with the E-shaped magnetic coupling structure as the core device is significantly improved. In addition, the output power is unchanged after a secondary side fault, which verifies the accuracy of the proposed method. Full article

In a traditional inductive coupling power transfer (ICPT) system, the converter and the resonant network are strongly coupled. Since the coupling coefficient and the parameters of the resonant network usually vary, the resonant network easily detunes, and the system efficiency, power source capacity, power control, and soft switching conditions of the ICPT system are considerably affected. This paper presents an ICPT system based on a power converter decoupled from the resonant network. In the proposed system, the primary inductor is disconnected from the resonant network during the energy injection stage. After storing a certain amount of energy, the primary inductor is reconnects with the resonant network. Through this method, the converter can be decoupled from the resonant network, and the resonant network can be tuned under various coupling coefficients. Theoretical analysis was explored first. Simulations and experimental work are carried out to verify the theoretical analysis. The results show that the proposed ICPT system has the virtues of low power source capacity, independent power control, and soft switching operation under different coupling coefficients. Full article

Inductively coupled power transfer (ICPT) systems, which are superior to batteries due to their real-time power supplycapacity have been used in mooring buoys for the purpose of long-term measurements. A multiple-receiver ICPT system for mooring buoys, which contains a mooring cable for transmitting power, is proposed in this paper to obtain the corresponding profile parameters. Series compensation is applied to all three sections, including the transmitter, the mooring cable and multiple receivers. The voltage of an underwater system with arbitrary load can be stabilized. On that basis, high efficiency can be obtained. By adopting Wolfram Mathematica a detailed analysis of both double-receiver and multiple-receiver ICPT systems for mooring buoys is presented. Finally, a prototype ICPT system with three receivers mounted on a 30 m mooring cable was built to verify the theoretical analysis. Experimental results show that the power transfer efficiency exceeds 45%. Both theoretical analysis and experiments indicate that this system is appropriate for measuring ocean profile parameters. Full article

Batteries are commonly used as the power source of present underwater sensors of ocean buoys. However, batteries need to be frequently replaced, which is costly. To implement the real-time power supply for a buoy’s underwater sensor, a new inductively coupled power transfer (ICPT) system that consists of two couplers and a closed cable is proposed in this paper. The special closed cable, which is the both mooring cable and transmission media, is designed to diminish the influence of changes on impedance. A model of the particular ICPT system is established. Optimization of system parameters are carried out based on the model and verified by means of the simulations. Resonant compensation is used to improve the power transfer performance. Finally, many experiments are implemented to compare with the original prototype. It is confirmed that this system can help solve the difficulty of the energy limit to a buoy’s underwater sensor. Full article