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The Compact Fluorescent Lamps (CFLs) are widely adopted in residential and commercial sector. This adoption is proposed following the energy conservation and environmental protection efforts. Despite, the CFLs consume low power, many users using these loads can cause a harmonic impact depending of the Attenuation-Amplification Effect. For instance, if this Effect is neglected (e.g., using Harmonic...
In order to analyze non-sinusoidal modes of power supply systems, an accurate determination of parameters for these modes is required. Effective values of currents and voltages are among these parameters. The work is based on the wavelet transform, which allows the values for these parameters depending on each harmonic component to be accurately defined without losing data in the time domain. The...
Models for active devices operating in a nonlinear regime are an indispensable tool for modern RF-circuit design. A popular class of large signal models are X-parameters which offer an accurate description of nonlinear devices. However, they require a specialized measurement setup. Typically nonlinear vector network analyzers (NVNA), are used to conduct the measurements required for an X-parameter...
A method for the symbolic calculation of the harmonic distortion components of op-amp based memristive amplifiers is presented. The resulting fully-symbolic expressions are obtained by using an analytical model for the Hewlett-Packard memristor. The symbolic harmonic analysis allows us to provide more insight on the memristive transfer of the amplifiers. In addition, numerical evaluations are achieved...
In a magnetically coupled resonant (MCR) wireless power transfer (WPT) system, adding repeating coils is an effective way to lengthen transmission distance and improve the transferred power in a wide range. This paper investigated a 3-coil MCR WPT system. Based on fundamental harmonic analysis on the equivalent circuit model, the relationship between the transmission characteristics and the spatial...
This paper presents a design methodology with uncertainty quantification to estimate the required margin for two main design variables in a modular multilevel converter (MMC). In this methodology, the minimum required design margins are calculated by quantifying all sources of uncertainty in the modeling and simulation of MMCs. To this end, an enhanced modeling framework is presented to take into...
An inter-turn fault significantly affects the electromagnetic properties in electric machines, and its propagation may quickly lead to the shutdown of the machines within a few seconds. To build the prediction or detection techniques of the fault, a fault analysis should be carried out. Generally, most faults are analyzed by a method using negative-sequence components obtained from symmetrical coordinate...
The advantages of the Modular Multilevel Converter (MMC) as a Voltage Source Converter (VSC) is well known. These includes scalability, increased reliability, lower Total Harmonic Distortion (THD) in output variables, fault tolerance and so forth. The MMC has found its most application in High Voltage DC (HVDC) systems again because of the stated advantages. In the analysis of such systems, because...
This paper investigates the influence of converter-fed operation on magnetic forces and radial vibration in a hydrogenerator. Flux density distribution is computed using time-stepping finite element (FE) analysis and used to calculate force density distribution based on Maxwell stress tensor. Both temporal and spatial characteristics of selected flux density and force density waves are studied. Important...
As insulators play an important role in supporting power transmission and distribution system, ensuring their condition in order to keep working properly have become an unequivocally essential task to do. There are many ways that can be attained to monitor the state of insulators, which one of them is by observing the leakage current (LC) characteristics. Experiments of LC measurement on six field-aged...
This paper proposes a method for zero-crossing approximation of a band-limited sinusoidal signal embedded by a white Gaussian noise-like distortion. It consists of passive low-pass filter and dynamic-hysteresis comparator circuits. Simplicity and wide dynamic range are the main goal of the proposed approach. Theoretical calculations were formulated to select proper circuit components values. Simulation...
VIENNA rectifier with simple structure, which is widely used in charging systems for electric vehicle, realizes the operation of unit power factor and low harmonic. However, grid voltage unbalance will aggravate the dc-link voltage ripple and input current THD. A novel control scheme is presented to solve the impacts of three unbalanced grid voltage for VIENNA rectifier in this paper. The enhanced...
Arcing fault has been a challenge problem in power network, and it is difficult to be detected by traditional protection devices because of its low fault current level. This paper presents a method to model and detect arcing fault in a power system with renewable energy generation in Matlab/Simulink. All-phase FFT is adopted to detect and identify the arcing fault. It has been shown that all-phase...
This paper analyzes ratio and phase displacement errors produced by commercial capacitive voltage transformers (CVT) under non-sinusoidal waveforms, as exist in power networks. As power quality measurements in high voltage systems are performed at the low voltage side, it is relevant to know the incidence of the CVT in the results. Additionally, a preliminary proposal to compensate those errors is...
This work presents a proposal to represent electrical grounding systems directly in the time domain. The advantage in using this type of representation is that voltage and current are better understood in this domain and the model can easily be inserted into conventional software such as the Alternative Transient Program (ATP) and Electromagnetic Transient Program (EMTP). The proposed method is applied...
This paper describes an accurate circuit model that accounts for the working principles behind the operation of a recently demonstrated planar resonant blazed grating. The strictly planar grating is a simple array of metal strips printed on a conductor-backed substrate. The circuit model provides an analytical description of the perfect blazing caused by resonance in an infinite grating of this kind...
In this paper, a broadband fourth-harmonic mixer based on gallium arsenide (GaAs) Schottky barrier diodes working at 80–100GHz is designed. This fourth-harmonic mixer is simulated and attains low conversion loss below 14dB in the whole band. The design process and simulation results are explained in detail.
The X-parameter model is designed for modeling weakly nonlinear devices in an approximately impedance-matched environment. Load dependent X-parameter models were proposed to overcome this, practically very relevant, limitation and model a nonlinear device in a highly mismatched environment. However, the applicability of load dependent X-parameter models for DUTs operating in deep saturation like in...
This paper provides conclusions on design and laboratory tests of a hybrid rectifier prototype which employs the newest generation of SiC transistors and diodes. For the presented hardware prototype the AC-DC efficiency is about 98%. Based on simulation analysis and the practical realization pros and cons of this topology were identified. It should be noted that hybrid rectifiers importance is growing...
Shunt active power filters (SAPF) generally compensate harmonic current of centralized non-linear loads, which may cause undesired economical burden for networks with distributed harmonic sources. This paper proposed an SAPF predictive control method based on online impedance measurement which can suppress the network-wide harmonics systematically in an optimized way.
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