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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...
High frequency harmonics from a frequency converter causes additional losses in a deep-bar induction motor. The harmonics have their own amplitude and phase with respect to the fundamental signal, but the harmonic loss is only dependent on the amplitude of harmonics. A deep-bar induction motor can be modelled by a triple-cage circuit to take skin effect into account. The triple cage circuit having...
This paper presents a new connection method of triple two-level PWM converters to provide multi-level output waveform to a motor/transformer which has triple independent sets of three-phase winding. By simply changing the connection between the PWM converters and the windings of the motor/transformer, the level of winding voltage can be increased without any hardware modification. With triple 2-level...
Divide-by-three frequency dividers, based on a parallel injection, are analyzed and the actual locking phenomenon underlying their operation is shown. Analytical results allow us to predict the output steady-states and the locking range in terms of the circuit parameters, thus obtaining useful design insights. The derived results are shown to be very close to SPICE simulation results for a 0.13μm...
Simulation model of inverter is established in MATLAB/SIMULINK on the basis of the given concepts of system, simulation and models in this paper. We studied the output harmonic characteristics of the inverter, analyzed the influence on output waveform caused by different carrier ratio and modulation depth. The results of simulation show that SPWM (sine pulse width modulation) can effectively suppress...
In this paper a method for the control of the stability of nonlinear circuits under large-signal conditions, including an analysis of the transient regime, is presented. It is based on the calculation of the conversion matrix, computed both from standard harmonic balance at steady-state large-signal regime and from a transient envelope simulation. This allows the direct design of the passive networks...
Each type of device causing harmonics has a particular shape of harmonic current and voltage (amplitude and phase displacement). This work provides a methodology for analyzing the distortion from the data record of digital fault recorders in order to quantify the distortion in current and voltage. This can be done by decomposing the signal into its constituent components in the frequency domain, because...
In a HVDC transmission system, faults occur in the AC system can result in the variation of impedance-frequency characteristic of the HVDC converter. In this paper, an advanced switching function model of HVDC converter, which considers the effect of the interactions between the AC and DC system and the unbalanced operating conditions of the converter, is presented. Based on this model, a method for...
Parametric instabilities are a common phenomenon in nonlinear circuits such as power amplifiers, frequency multipliers, etc. In spite of this fact, the analysis of this phenomenon is not usually covered in the curricula of Telecommunication Engineering. In this paper we present a software tool for the understanding of the basics of parametric oscillations, which are due to the nonlinear behavior of...
In this paper, low frequency AC (LFAC) to high frequency AC (HFAC) power conversion system conditioning and processing circuit without DC smoothing. Capacitor filter link from the voltage grid of utility frequency AC power supply source is proposed and introduced. The operating principle of utility frequency AC-high frequency AC power frequency conversion circuit defined as high frequency cycloinverter...
This paper discusses the design of a 60 GHz low noise amplifier (LNA) using a standard low power SOI CMOS process from ST Microelectronics. First, we outline the technology as well as the mm-wave design challenges. Using recent work on coplanar waveguide (CPW) modeling, we describe how it's possible to use parametric, 3D electromagnetic simulation to complete or replace analytical models of on-chip...
SUNRAY-1D code for large signal analysis of a helix TWT was developed. Effect of circuit loss, sever loss, backward and reflection waves are considered in this model. Higher order harmonics, spurious signals and intermodulation components are also considered in this model. This is fast and it takes less than one minute to find out saturation drive on a P-IV computer. It is also validated with experimental...
A high intercept points, cost-effective, and power-efficient switching FET double balanced mixer (DBM) is reported. The Switching FET DBM demonstrated in this work offers input intercept points (IIP3) and conversion loss typically 44 dBm and 8.5 dB respectively with 15 dBm LO power for the frequency band (RF: 900-2150 MHz, LO: 850-1950 MHz, IF: 50-200 MHz). The measured interport isolation is typically...
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