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Electric power is commonly transmitted from one location to another without interruption through overhead transmission lines. This paper presents the impact of varying the capacitance and load on the performance of the three types of medium transmission lines (end condenser, nominal ‘pi’, and nominal ‘T’) by using the TQ NE9080 transmission line simulator. It also investigates the effects of increasing...
A fully integrated 24.5/35-GHz dual-band T/R/Calibration switch module with Q-enhanced filtering function for a concurrent dual-band phased array system is presented. The proposed T/R/Calibration switch module offers internal calibration function with a quasi-elliptic dual-bandpass filtering which is enabled by a Q-enhanced metamaterial transmission line structure. This switch module architecture...
In this paper, a 60 GHz low noise amplifier (LNA) using a 130 nm SiGe BiCMOS process is designed and presented. Common emitter (CE) and cascode topologies are used in the first and second stages respectively to ensure that minimal noise figure (NF) and maximum gain are achieved. To investigate the performance of the CE in relation to the NF, the mathematical analysis of the NF of the first stage is...
Overcurrent or overvoltage problems caused by DC line faults endanger the security of modular multilevel converter based high voltage direct current (MMC-HVDC) system. To improve the reliability of fault identification for MMC-HVDC transmission lines, a novel pilot protection scheme based on DC power difference is proposed in this paper. Characteristics of the DC power difference between positive...
Alloyed ohmic contacts to GaAs consist of separate alloyed and unalloyed layers beneath the contact metal layer. (A similar situation is metal to silicide to silicon contacts.) Thus there are three distinct layers separated by two interfaces, each layer having a different resistivity and each interface having a different specific contact resistance. Such a multiple layer contact makes the modeling...
The paper presents an example of modeling high-voltage line with classical columns and pillars compacted with the same lines and testing out the model in the programming tool DIgSILENT with actual measured data for Single Line to Ground Fault with the use of ARs. The parameters of the classical and compacted 400 kV transmission line are entered into the model in the example of 400 kV line Tuzla 4...
Constructing multi-terminal high voltage dc (HVDC) systems can effectively make it possible for the large-scale new energy to be integrated into the grid and make up the defects of the existing ac power system. When constructing the multi-terminal dc system, one cannot avoid the problem that how to control the dc power flow effectively. When nodes are increased and structure of dc grids becomes more...
The continuously growing electrical power demand is more and more faced by the increase of generation from renewable energy sources. Given the uneven distribution of those resources in the power system, an increase in the transmission lines current rating (also called ampacity) is expected in the next future, to avoid the formation of bottlenecks. Given the difficulties in building new lines, due...
Installation of Passive Cancellation Loops (PCLs) is an efficient technique to mitigate the magnetic field generated by high voltage overhead lines (OHLs). PCLs were firstly introduced in the late '90s; even if, at present time, they are seldom installed, they are expected to become a widespread solution due to the increasing public attention to EMF exposure. More in detail, they can be a readily...
Earlier, during open — circuited condition of power line at receiving end side, we have only concept of Ferranti effect, which determines that open voltage, i.e. of receiving end side, of power line is always longer than close voltage, i.e. of sending end side, in case of uncompensated or smaller ohmic value of it. But, here with in this paper for the case of purely uncompensated one again over the...
Deteriorated insulators may lead to flashover or power failure in transmission lines, because of degradation in insulators strings' mechanism and insulation level after long periods of performing. By utilizing finite element method, E-field intensity and potential distribution of insulators strings with different resistance in different positions under the same pollution level have been researched...
This paper investigates the influencing factors and mechanism of sub-synchronous resonance (SSR) phenomenon in the doubly fed induction generator (DFIG) based wind turbines to a series compensated transmission system. First, a model of DFIG-based wind power unit interconnected with series compensated networks is developed to analyze the mechanism of induction generator effect (IGE) and sub-synchronous...
In this paper, the design of 4 Gbps, 2.25 mW Scalable Low-Voltage Signaling (SLVS)-type transmitter is described. The analysis of circuit performance is concentrated on the minimization of common-mode voltage disturbances, while providing satisfactory eye diagram parameters and low power consumption. The edge aligner circuit utilization is proposed in order to minimize the time delay between the input...
This paper study the effect of distributed compact series compensators DCSCs parameters on their features and characteristics. This paper provides the analytical expressions for the calculation of the basic technical characteristics of the DCSC. The calculations for finding the main DCSC characteristics is explained. The variants of the working modes are discussed when the value of capacitance is...
Distribution of the geomagnetically induced currents between the neutrals of certain power transformers in the standard configuration power grids is investigated. The allowances at which the quantitative estimates of the geomagnetically induced currents are obtained are formulated. A spatial model that allows considering a geographical arrangement of the power transformers when calculating the geomagnetically...
A rapid estimation of resonant overvoltages has been developed on basis of analysis of resonant circuit of the disconnected phase on extra high voltage transmission line. The influence of mutual induction caused by the design features of the three-phase shunt reactor group on overvoltages has been taken into account. A simulation model of the power transmission line has been developed to simulate...
Ice storms may lead to the icing of the power and ground wires of the transmission lines. To prevent wires' breakage, the ice melting procedure is required. The most common method of the de-icing procedure requires usage of the power rectifier with high voltage thyristors. They are sensitive to external influences such as power line induced voltage. The aim of our work is to develop the calculation...
In order to determine the insulation level of DC transmission line, one UHV DC transmission project is taken as an example in this paper. PSCAD program is used to establish the simulation calculation model. Multiple fault points on the fault line are selected. The induced overvoltage amplitude, distribution along the line and the maximum overvoltage envelope of healthy pole transmission line corresponding...
In this paper, the evaluation of the concept of impedance differential scheme for long transmission line protection is presented. Using the voltages and currents of both line ends, the differential impedance is calculated. Capacitive charging current which constitutes the main drawback of current differential protection is eliminated in presented protection method. What is more, the advantage of presented...
Line commutated converter based high voltage transmission line fault current rises instantly due to the absence of inductance as which is present in ac. In dc currents there is no natural current zero so interruption of current is difficult and therefore the focus of the paper is to identify the fault in less time so that trip command can be initiated to the dc breaker. The dc lines are economical...
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