1,720,985 research outputs found
Design and Analysis of EMI Shielding Method using Intermediate Coil for Train WPT System
No full textIn this paper, we proposed an intermediate coil to reduce third harmonic EMI component, which is the highest harmonic EMI component in wireless power transfer (WPT) system. WPT system transfers power wirelessly from Tx coil to Rx coil. When Tx part driving power, unwanted harmonic components are generated from inverter of Tx part and rectifier of Rx part. The proposed intermediate coil can effectively lower third harmonic component without degrading the WPT system efficiency. Three-dimensional electromagnetic simulation and circuit simulation are used to verify the effect of the proposed intermediate coil. Thus, we finally achieved the optimal intermediate coil, which reduce third harmonic component nearly 3 dB with 2% increase in system efficienc
Low EMF Design of Cochlear Implant Wireless Power Transfer System using a Shielding Coil
Full text linkWireless power transfer (WPT) technology is widely used for various applications because of convenience and safety. Especially, medical implant devices such as a cochlear implant are one of the typical applications of the WPT technology. However, WPT systems have problems with electromagnetic field (EMF) leakage, which can cause electro-magnetic interference (EMI) issues in the human body. In this paper, we propose an additional shielding coil for the effective suppression of EMF radiation of a WPT system. The proposed method reduces the EMF leakage in operating frequency range. We verified that the proposed shielding coil reduced the EMF leakage by 5.1 dB using 3D EM simulation. Also, the power transfer efficiency (PTE) and link gain stability of the proposed cochlear implant WPT system are designed to work well with proposed shielding coil
Core-Shared-Repeater (CSR) Coil Scheme for Low EMI and Efficient WPT System in Ultra-Thin Digital TV
No full textDesign and Analysis of On-package Inductor of an Integrated Voltage Regulator for High-Q Factor and EMI Shielding in Active Interposer based 2.5D/3D ICs
No full textOn-package inductor, a promising type of filter inductor for integrated voltage regulator (IVR) requires low loss and shielding structure for high IVR efficiency and vertical noise coupling. In this paper, we proposed a novel on-package inductor of an integrated voltage regulator for high-Q factor and EMI shielding in active interposer based 2.5D/3D ICs. The proposed on-package inductor is composed of 4 parallel spiral loops and a shielding loop. The proposed inductor is verified with simulation and measurement in frequency domain. It achieves both high-Q factor and high shielding effectiveness using the package re-distribution layers only. With its shielding structure, vertical magnetic noise coupling to a noise sensitive circuit block on active interposer is successfully suppressed by 25.5 dB and normal operation of circuit is ensured
Design, Simulation and Measurement of Flexible PCB Coils for Wearable Device Wireless Power Transfer
No full textIn this paper, we design and analyze flexible wireless power transfer (WPT) coils for flexible wearable devices. The 3 cm by 3 cm flexible coils are designed using polyimide substrate. The coil is designed as thin as possible to achieve higher Q-factor and power transfer efficiency (PTE). Furthermore, we analyzed the mutual inductance between the coils with a bending radius of a receiver (Rx) coil of infinite, 26 mm and 13 mm by considering the curvature of the human wrist. As the results, the simulation results of the flexible coil are verified with the measurement results using Z-parameter analysis in the frequency range from 1 MHz to 50 MHz. In conclusion, we verify the mutual inductance simulation results with the measurement results within the average error of 2.85%
고효율 및 저자기장 향 무선전력전송 시스템 최적화 디자인을 위한 심층 결정적 정책 경사법 기반 강화학습 방법론
No full text학위논문(박사) - 한국과학기술원 : 전기및전자공학부, 2024.2,[iii, 37 p. :]In this article, we proposed a deep deterministic policy gradient-based reinforcement learning methodology for the optimal design of wireless power transmission systems, aiming to achieve high efficiency and low electromagnetic field (EMF). Designing wireless power transfer systems necessitates consideration of the size of the leakage magnetic field to meet the high-efficiency and magnetic field specifications between the transmitter and receiver coils. However, modeling the characteristics is challenging due to the application of materials with nonlinear properties, such as ferrite, and the difficulty in accurately deriving resistance values using simulations, which poses a significant obstacle to optimization design. Therefore, by precisely modeling the parameters required to determine the efficiency of wireless power transmission systems and applying them to reinforcement learning, we can achieve the optimal design.Among many deep reinforcement learning methods, we employed deep deterministic policy gradient (DDPG) -based reinforcement learning when dealing with systems having parameters in continuous spaces. This approach is known for its strong learning capabilities in continuous space systems, leading to optimal solutions with significant reductions in computational time and data costs. To validate the proposed methodology, we compared the results with commonly used Bayesian (BO) optimization methods and Particle Swarm Optimization (PSO) methodologies. Ultimately, the proposed methodology outperforms other approaches in terms of optimization performance, computational time, and data costs, marking a pioneering effort in applying reinforcement learning to optimize wireless power transfer systems.한국과학기술원 :전기및전자공학부
Cochlear Implant Wireless Power Transfer System Design for High Efficiency and Link Gain Stability using A Proposed Stagger Tuning Method
Full text linkIn recent years, wireless power transfer (WPT) technology is becoming an increasingly important part of the various applications because of its safety. Especially, medical implant devices such as a cochlear implant are one of the typical applications of the WPT technology. Because of the individual body differences, however, the coupling coefficient of the WPT system can be changed. Therefore, the coupling coefficient-insensitivity is very important design issue. In this paper, we propose a stagger tuning method of a cochlear implant WPT system. The proposed method makes the cochlear implant WPT system stable at the link gain regardless of the coupling coefficient. In addition, the design can be optimized ?vith consideration of the power transfer efficiency (PTE) of the WPT system. We verified that the proposed method increased the PTE of the cochlear implant WPT system by 9 % by mathematical calculation
장거리 무선전력전송 시스템에서 주파수 선택형 중계기 코일을 이용한 전력 전달 효율 증가 및 전자기 간섭 감소 방법
No full text학위논문(석사) - 한국과학기술원 : 전기및전자공학부, 2019.2,[iii, 30 p. :]With the advent of the fourth industrial revolution, wireless power transfer technology is becoming increasingly important. However, one of the biggest limitations of current wireless power transfer technology is that it can not transmit power with high efficiency from long distance. Currently, the wireless charging system has enabled the market for wireless charging pads for short-range charging of low-power electronic devices such as smart phones. However, in the case of high-power electronic devices or electronic devices requiring long-range wireless charging, there is a limit. Also, when a wireless power transfer system is applied, electromagnetic interference problems arise. Electromagnetic interference causes malfunction of sensors. Various solutions have been studied and proposed over the years to overcome these problems. In this paper, we propose a repeater coil that can enhance high efficiency and reduce electromagnetic interference. Analytical equations were derived to analyze the power transfer efficiency and electromagnetic interference reduction rate at a specific resonant frequency of the repeater, and by simulation and measurement to verify this. Through the design and analysis equations presented in this study, it is expected that a repeater coil with a long - distance wireless power transfer system can be designed.한국과학기술원 :전기및전자공학부
Design, Simulation and Measurement of a Flexible Voltage-controlled Oscillator (VCO) Chip with Bending Radius
No full textIn this paper, we designed, simulated and measured an extremely thin flexible LC voltage-controlled oscillator (VCO) with bending radius for flexible electronics. An LC VCO chip is fabricated using a SK Hynix 0.18 mu m process. A silicon substrate of the fabricated VCO chip is grinded to 50 mu m to achieve the flexibility. The flexible VCO chip is bent with a bending device to check voltage output and phase with bending radius. The bending radius is applied from infinite to 20 mm. The results showed that the designed flexible VCO chip is operating properly with the bent structure
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