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In this paper, numerical evaluation of ionized field quantities associated with HVDC corona is carried out using charge simulation technique and integral algorithm. And considering the surface charge of each rectangle patches and simulation charge inside the HVDC conductors as unknown variables, a set of quadratic equations are developed on the base of the potential at the boundary, the corona onset...
A comparison of shielded 7 mm coaxial open circuits' capacitance with different center conductor is introduced. With analysis of the measurement results, a kind of special shielded open is suggested to be used as impedance standard for precision coaxial connectors, such as type N, GPC3.5, GPC2.92 in high frequency range.
The transmission lines pass by the high altitude region with low air pressure, which brings many special problems to the design and operation of the transmission lines. The corona cage is widely used to study the corona performance of conductors for its good economy and maneuverability. A computation model is adopted for evaluating the corona inception voltages of conductors in the corona cage, which...
Impact loads from ice shedding and broken conductors are common for transmission lines in accreted ice zone, which can bring threaten to the safe operation of the transmission lines. Dynamic analysis of the conductors in transmission lines under two typical impact loads were carried out. Firstly, a finite element model of seven span conductors in transmission line was established in general software...
In this article local and remote magnetic immission characteristics of electrified 16.7 Hz railway systems are presented. Railway systems with different spatial arrangements of reduction conductors and the magnetic field caused by these systems are compared. Concerning typical maximum operating (traction) currents minimum distances between railway systems and environments dedicated as medical based...
Because the air thermal resistance is high, the current-rating of underground cables in pipes are much lower than the current-rating of direct buried cables. In order to improve the cable current carrying capacities, thermal material is pumped into pipes to improve the situation of duct heat output. Based on the combinatorial coordinates, a complex computer program employing the finite difference...
The reduction of the low frequency electric and magnetic field of electric railways by optimization of the positions of return conductor(s) and feeder(s) is the focus of this paper. Possible optimization criteria are shown and further will be applied to the typical system configuration of a high performance Austrian railway track. The results of the optimization show, that there is a great potential...
This paper describes the actual problem of inductively interfered pipelines due to traction and short circuit currents of electric railways. At first a brief overview about calculation-formulas and standards is given. Furthermore the most important limits for induced pipe potentials regarding short time- (short circuit currents) and long time interference (normal operation traction currents) of the...
The advent of novel sub-micron technologies of IC fabrication led to such a decrease in lead-to-lead separation that it is not possible any more to neglect the influence of these leads on the reliability of the system operation. Both the small lead separation and the application of multilayer interconnecting systems cause parasitic electromagnetic couplings; in the case of a unipolar CMOS technology,...
With the implements of China's Western Development Project and West-East Power Transmission Project, transmission lines will inevitably pass through high altitude regions with complex atmospheric conditions. Air density and air humidity along the line passages will change much, which will affect the corona discharge performance of conductors. Studies about the effect of air density and air humidity...
Both operating experiences and experiments show that the cross-section shape of iced conductor has an obvious influence on ice-melting time, however, it is ignored by almost all the existing ice-melting models which suppose that the iced conductor has a perfect circular cross-section shape. Based on the observed results in the natural icing station, this paper has analyzed the shape characteristic...
This paper takes a comprehensive view of metallic conductors run to outside environments, and explores the physical and electrical protection schemes that must be applied in various regions of the world. Included in this discussion are the protection of AC and DC input power conductors, telecommunication conductors, alarms and signal conductors, and coaxial cabling.
The paper proposes a method to calculate voltage across faulted open port of short circuit fault and open conductor fault in detail. Based on the superposition theory, the formula is deduced to calculate voltage across faulted open port of short circuit fault when the potential values and the phrase angles of generators in power system unequal to each other. On the basis of superposition theory and...
This paper presents a prototype of equipment used to detect faults in conductor cables employed in power transmission lines. It is able to do visual inspection of the external condition of the conductors and to detect internal faults in its magnetic material core (ACSR cables). The equipment is composed by a mobile unit - a robot - which moves on the line conductor, and by a control unit - a notebook...
Lightning induces voltage on a horizontally suspended conductor due to electromagnetic field coupling. If the induced voltage is measured across a matched impedance at both ends, it may be possible to locate the distance and angle of incidence of the lightning. Researches on lightning induced voltages mainly focus on its effect to insulation across the conductor and ground. The situation is modeled...
The Dirichlet problem for Laplace's equation in an area between two arbitrary profiled infinitely long cylinders is rigorously solved by the Method of Regularization. The obtained solution is applied to the accurate analysis of the shielded microstrip line with homogeneous dielectric filling and thick conductor - the structure supporting the transmission of an ideal TEM-wave. Capacitance and characteristic...
The analysis of time varying electromagnetic fields in conductor media can be done by an integral equation in terms of the current density vector. For time domain solutions concerning complex structures, numerical procedures are useful and, for their correct application, stability conditions must be defined. In this paper conditions of applicability are analyzed and simulation examples are shown for...
A novel compact four-port antenna based receiving radar detection system is presented. Emphasis is placed on the antenna and pattern transform algorithms development. The antenna, with size of 113 × 113 × 33.7mm3, operated within 1.0-1.8GHz (s11 <; -10dB) and 5.5dBi single port gain, is designed and integrated successfully in a specific cylindrical stepped conductor. Two different pattern transform...
The paper deals with the Roebel bar losses computation. It was considered the most general Roebel bar structure, including both solid and hollow elementary conductors. One proposes an analytical method for the estimation of the currents in the elementary conductors, as function on the geometrical dimensions and material data. It is possible to emphasize also the current density distribution on the...
Use of high temperature conductors is being considered by more and more electric utilities as a means to increase transmission line capacity. This has raised questions regarding the effect of these increased temperatures on the performance of all components attached to the conductor, including the insulators. This paper presents the results of laboratory studies of several suspension insulator assemblies...
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