1,721,024 research outputs found
Frequency tuning in inductive power transfer systems
Full text linkInductive power transfer systems (IPTSs) systems are equipped with compensation networks that resonate at the supply frequency with the inductance of the transmitting and receiving coils to both maximize the power transfer efficiency and reduce the IPTS power sizing. If the network and coil parameters differ from the designed values, the resonance frequencies deviate from the supply frequency, thus reducing the IPTS efficiency. To cope with this issue, two methods of tuning the IPTS supply frequency are presented and discussed. One method is aimed at making resonant the impedance seen by the IPTS power supply, the other one at making resonant the impedance of the receiving stage. The paper closes by implementing the first method in an experimental setup and by testing its tuning capabilities on a prototypal IPTS used for charging the battery of an electric vehicle
Application of solid-state transformers in a novel architecture of hybrid AC/DC house power systems
Full text linkThe ongoing diffusion of solid-state DC/DC converters makes possible a partial migration of electric power systems from the present AC paradigm to a future DC scenario. In addition, the power demand in the domestic environment is expected to grow considerably, for example, due to the progressive diffusion of electric vehicles, induction cooking and heat pumps. To face this evolution, the paper introduces a novel electric topology for a hybrid AC/DC smart house, based on the solid-state transformer technology. The electric scheme, voltage levels and converters types are thoroughly discussed to better integrate the spread of electric appliances, which are frequently based on internal DC buses, within the present AC distribution networks. Voltage levels are determined to guarantee high safety zones with negligible electric risk in the most exposed areas of the house. At the same time, the developed control schemes assure high power quality (voltage stability in the case of both load variations and network perturbations), manage power flows and local resources according to ancillary services requirements and increase the domestic network overall efficiency. Dynamic simulations are performed, making use of DIgSILENT PowerFactory software, to demonstrate the feasibility of the proposed distribution scheme for next-generation smart houses under different operating conditions
Optimal design of the compensation networks of an inductive wireless power transfer system
Full text linkPurpose: This paper aims to present an approach to the design of the compensation networks (CNs) based on a genetic optimization algorithm. The algorithm is applied to CNs with T-topology and considers the effects of the parasitic series resistances of their inductive components. The effectiveness of the algorithm is verified using Bode diagrams and simulation results. Design/methodology/approach: The paper at first describes the problem and the approach followed to reach a set of optimal solutions, then explains the optimization algorithm, reports the obtained solutions and selects the optimal CNs. Finally, the actual performance of the wireless power transfer system (WPTS) when the selected CNs are used are checked. Findings: This approach gave interesting results and made available a number of different sizing solutions of complex networks in a very short time. Most of the obtained solutions outperform the widely used series-series compensation. An accurate post processing of the obtained result is mandatory to discriminate the solutions that could be implemented from those that in a real system would originate uncontrolled high frequency current oscillation. Originality/value: This paper offers a rather new approach to solve the problem of sizing the CNs of a dynamic WPTS. This approach makes available a large number of optimal solutions to the problem in a short time, without solving complex system of equations
A Novel Beluga Whale-Jaya Optimization for Effective EV Charge Scheduling in Power Generation
Full text linkWhile considering the provision of the safest environment, it leads to the rapid growth of Electric Vehicles (EVs) that spread over the markets based on features like improvement of charging stations, economy, battery technology, and price. Moreover, the EV charging station placement issues are regarded as facility location issues. In addition, EV charging station placement issues have concerns about the electric distribution systems, the system losses, and the total number of convergences over the traffic network for voltage deviations. The voltage profile enhancement and loss minimization are considered two major issues obtained over the distributed model and are commonly equipped along with the shunt capacitors for reactive power compensations. A novel EV charging model is developed based on hybrid optimization approaches to tackle the issue. The charge level parameters of regional EV charging schedules are tuned with the help of a developed hybrid approach named Beluga Whale-Jaya Optimization (BWJO) derived via Beluga whale optimization (BWO) and JAYA optimization (JA) to attain the minimization of greenhouse gas emission acquired from electricity. Thus, the developed model has offered an enhanced performance rate when contrasted with conventional EV charging schedules schemes
Analysis and experimentation of a novel modulation technique for a dual-output WPT inverter
Full text linkDynamic wireless power transfer systems require to supply many transmitting coils deployed under the road surface and arranged along the so-called track. This layout entails the use of a large number of inverters or of devices that switch the power to the proper coils. This paper presents a technique that uses a single three phase inverter to supply two coils with voltages having different and independently adjustable amplitudes of their first harmonic component. Differently from the well-known phase shift technique, the amplitude and the phase of the voltages are not correlated. Moreover, the presented technique has the ability of inherently reducing the phase difference between the two output currents when the supplied loads are partially reactive. This feature enhances the power transfer capability of the inverter when both the track coils are coupled with the same pickup. After presenting this technique, the paper analyzes the functioning of the dual-output inverter in different load conditions recognizing the boundaries of four different modes of operation. For each of them the analytical expression of the amplitude and phase of the generated voltages are given. The theoretical findings are validated by experiments performed on a prototypal setup that implements the presented modulation technique
Performance analysis of envelope modelling applied to resonant converters
Full text linkResonant converters are often studied using their envelope models, i.e. the transfer functions that relate the envelope of the output quantities to those of the input ones. Transfer functions can accurately represent only the input-output relation of linear systems and hence any method used to develop the envelope model cannot be accurate if the resonant converter processes the envelopes in a non-linear way. This paper works out a general criterion that recognizes whether the envelope processing is linear or not, the type of the eventual non-linearity and its amount. The criterion is expressed in terms of conditions that have to be fulfilled by the input-output Bode diagram of the converter. These conditions are of general validity and do not depend on the converter topology; their applicability is not limited to resonant converters, but it can be extended to any system. The conditions have been derived by reviewing the procedure that leads to the Modulated Variables Laplace Transform method for the development of the envelope models. The theoretical results are verified at first by simulations and then by experimental tests carried out on two different resonant topologies of a prototypal converter that works as wireless battery charger
Design and Experimentation of a Single-Phase PLL With Novel OSG Method
Full text linkDifferent phase-locked loop algorithms applied to three-phase grid voltages implement a closed control loop based on the Park transform to obtain the grid voltage instantaneous phase and frequency. When a single-phase grid voltage must be processed, one of the inputs of the Park transform is generated by a block that, starting from the available voltage, computes an additional signal with the same frequency of the grid voltage and ideally orthogonal to it. This paper introduces a novel method for the orthogonal signal generation and gives a detailed analysis of its functioning. Then, after sizing the control loop of the phase-locked loop, the paper considers different aspects relevant to implementation of the presented orthogonal signal generation and of the phase-locked loop on a digital signal controller, such as the finite numerical resolution, the memory usage and the computation time. Finally, the paper checks the comprehensive performance of the orthogonal signal generation and phase-locked loop pair by experimental tests and compares the obtained results with those available in the literature
A Novel Bi-directional Wireless Power Transfer Design for Smart Homes
No full textThe continuous increase of greenhouse gases has led to the melting of glaciers, rising sea levels, and a decline in rain forests. To reduce the impact of greenhouse gases, we need to reduce the consumption of fossil fuels, which is possible through the use of electric vehicles (EV’s) energy storage systems, in order to interchange the energy between distributed grids or residential electrical appliances supplied with EV’s batteries. Thus, the given paper proposes the design of a bi-directional wireless battery charger (BDWBC) for smart homes. The design complies with the synchronous rectification circuit associated with primary and secondary half-bridge (H-bridge) converters. The proposed system is implemented using MATLAB Simulink and is validated against the existing recent works based on evaluation metrics such as charging power (watts) and efficiency (%). Thus, the given wireless power transfer (WPT) approach leads to distributed energy resource management with maximum charging power and efficiency for smart homes
Modified Series-Series Compensation Topology for WPT Systems
No full textWireless Power Transfer Systems use a wide selection of different compensation topologies to enhance one or the other of their characteristics. Among the simplest topologies, the series-series compensation offers high efficiency in a wide range of transferred power but requires an effective control of the output voltage and of the supply current when used in applications where the load varies substantially in order to protect the system from overvoltage or overcurrent. This paper presents a modified series-series compensation topology that inherently implements this protection at the expenses of a small decrease of the transfer efficiency. At high loads, the modified series-series topology operates as the conventional one, but at low loads its behavior changes limiting the transmitting side current and the output voltage. A preliminary analysis of operations of the proposed topology is performed in the time domain, then it is completed in the phasor domain and, finally, the obtained results are checked against those obtained by simulation implemented in the PSIM environment
Analysis and Comprehensive Comparison of Wireless Power Transfer System Using SS and SP topology for Electric Vehicle Charging
No full textWireless power transfer (WPT) system now becomes one of the most promising innovations that offer the benefits of more safety, ease of usability, and increased charging range of moving electric vehicles (EVs) compared to conventional wired charging. In real-world applications, suitable measures should be taken to make up for the power transfer coils so that the output power increases and the input apparent power rating of the power converter decreases. Using the idea of the coupled inductor, this paper analyses the concepts employed in the series-series (SS) and series-parallel (SP) compensation topologies of the WPT systems to select an appropriate compensation topology for EV charging. With the help of MATLAB/SIMULINK, the link among the effects of mutual inductance, load, and working frequency on the voltage gain has been analyzed and compared respectively. The simulation findings reveal that the SS compensation topology is better for system applications with lower loads, whereas the SP topology is preferable for systems with higher loads. There is the best possible load for a fixed transfer distance that optimizes the voltage gain and system performance. Furthermore, this study analyses the dependencies of the coupling coefficient and the receiving side quality factor on the transmitting side compensation design using SS and SP topologies. Hence, this article could be used as a reference for a developer to determine the best compensation topology of the WPT system based on EV applications
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