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The circular Rogowski coil with a rectangular section is the most common and basic measuring unit of current. However, in some situations, a noncircular Rogowski coil is more suitable because of the limited space to be embedded in and the demand for decreasing the size of the Rogowski coil. Circular Rogowski coil is usually wound uniformly to guarantee the positional accuracy and anti-interference ability considering the very good symmetry. However, for noncircular Rogowski coil, the turns arrangement is usually designed based on experience due to the lack of theoretic direction. This article first proposed a method of turns arrangement of the noncircular Rogowski coil with a rectangular section, which the positional accuracy and anti-interference ability can be achieved at the same time. By establishing the equivalent relation between mutual inductance and electric potential, the turns density of the noncircular Rogowski coil can be acquired by solving the charge density on its equivalent electrodes. The turns density is proven to be unique. For a given turn number, the turns arrangement of the noncircular Rogowski coil can be obtained by discretizing the turns density. As an example of the method, a square Rogowski coil, which can be used in chip current measurement in Press Pack insulated gate bipolar transistors (IGBTs), is particularly designed and contrasted with the traditional square Rogowski coil with turns equidistantly arranged to verify the great positional accuracy and anti-interference ability. The results of the calculation and experiment show that this method is very effective. [ABSTRACT FROM AUTHOR]

In this work, we present a detailed analysis on the observed streamer characteristics of PEEK (polyetheretherketone) surface in nitrogen at atmospheric pressure driven by positive repetitive pulse voltage, including the forward discharge streamer and the back discharge streamer. Fast oscilloscopic technique and digital photographic technique were employed to observe the streamers of surface discharges, and current pulse waveform analysis technique and image analysis technique were used to analyze the characteristics of the observed streamers. The experimental results show that the current pulse of forward discharge streamer has a shorter rise time, a higher current amplitude, a faster current rising rate, a shorter fall time, a faster current falling rate and a smaller charge quantity than those of back discharge streamer at the same voltage amplitude. Besides, the forward discharge streamer has a longer stopping length, a faster propagation velocity and a stronger maximum light intensity than back discharge streamer at the same voltage amplitude. Furthermore, the correlation between the electrical characteristics and optical characteristics of the streamer was analytically derivated, and the current rising rate of the streamer is proportionally correlated to the product of the streamer stopping length and the streamer velocity square. [ABSTRACT FROM AUTHOR]

With the growing public awareness of environmental protection, the dc ground-level total electric field (TEF) is attracting increasing attention. Especially in high-altitude areas, it has become a key technical factor in deciding conductor types and the height of the transmission line. To determine the altitude effect and correction of the ground-level TEF for HVdc transmission lines, four short bipolar test lines with bundle conductors with the same parameters were built in China at altitudes of 50, 1700, 3400, and 4300 m. Using the test facilities, the dc ground-level TEF was measured over a long period of time, from Jan. 2010 to Nov. 2015. Through a statistical analysis of a large amount of data, the ground-level TEF characteristics of short bipolar test lines at different altitudes were obtained. By comparing the statistical results from different altitudes, it is determined that the dc ground-level TEF and corona inception field strength are linearly dependent on the altitude. Finally, the ground-level TEF and corona inception field strength altitude correction formulas of HVdc transmission lines are proposed. [ABSTRACT FROM AUTHOR]

Magnetic field energy could be calculated by means of inductance, magnetic field intensity, or vector potential A, respectively. However, the former two methods may not reach an agreement in open loop problems. Partial inductance is calculated through A, whereas magnetic field intensity is also related to A. This letter analytically derives the difference between the former two methods. It is necessary that displacement current have to be carefully considered in open loop problems. A numerical example is given out for validation. [ABSTRACT FROM PUBLISHER]

Ionized field strength on the ground level is one of the fundamental electromagnetic environment parameters of ultrahigh voltage direct current (UHVdc) transmission lines. An algorithm of an upstream boundary element method is presented in this paper to calculate the ionized field on the boundary with a high accuracy. The ionized field is generated and measured in an experimental platform with an HV conductor to a grounded cylindrical corona cage. The relations between ionized field strength and applied voltage, conductor position, and conductor diameter are investigated. Calculations show that the relative error of the ionized field on the HV electrode could be reduced to 0.1% when compared with the analytical solution. Ionized field distribution under the typical ±1100 kV UHVdc transmission lines is also analyzed as the application. [ABSTRACT FROM AUTHOR]

Calculation of magnetic vector potential A is fundamental in the partial element equivalent circuit method, which directly affects the value of inductive part, called partial inductance. All of the existing methods for partial inductance are based on Lorenz gauge. This paper presents an analytical method for calculation of partial inductance with Coulomb gauge in quasi-static field. The difference lays on the calculation of A, which has an obvious impact in open loop problems. Some analytical results of conductor segments are derived for comparison of two different gauges, and show the difference between the proposed method and existing methods. Numerical experiments of the self- and mutual-partial inductances of conductor segments in open loop problems are also given. The results illustrate that the proposed method is consistent with the energy method, whereas the existing method gives different values, especially for short conductor segments whose difference might reach 50%. The proposed method may also be applied to closed loop problems and give same results with existing method. [ABSTRACT FROM AUTHOR]

This paper aims to investigate time-domain characteristics of the audible noise caused by single corona source under positive corona discharge. The obtained time-domain waveform of the audible noise consisted of a series of bipolar sound pressure pulses. After the background noise was successfully removed, the characteristics of audible noise pulses, such as amplitudes of each pulse, pulse rate and apparent duration time, were analyzed in this paper. Using the applied voltage and the onset voltage as variables, empirical formulas were derived from the measured results to predict the pulse rate and the amplitudes of the pulses. Furthermore, a typical waveform in the form of segmented double exponential function was developed to simulate the audible noise pulse. The rationality of the typical waveform was confirmed both in time domain and in frequency domain. Finally, some qualitative explanations for the generation of the bipolar pulse waveform of audible noise were given. Based on the remaining space charges characteristics, the influences of the applied voltage on the amplitude and pulse rate of the audible noise pulses were studied qualitatively. [ABSTRACT FROM AUTHOR]

The corridor of the high-voltage direct current transmission lines in China is very complex and there may be buildings near the lines. The conductivity of the building material may influence the electric field in the building. In this paper, based on the upstream FEM, a method is proposed to solve the coupled problem of the ion flow field in the air and the current field in the building model. The numerical results coincide with the analytic results and measurement results. The electric field in and on the building model is analyzed considering different conductivities. [ABSTRACT FROM PUBLISHER]

The power distribution network (PDN) impedance of 3-D-through silicon vias (TSVs) interposer layer is modeled by considering the metal-oxide-semiconductor (MOS) structure effects. The Lambert W function is proposed to simulate the change of depletion width with the bias voltage in the static field, and the high-frequency MOS capacitance is obtained while considering the charges at the semiconductor–insulator interface. Furthermore, based on the depletion width and the insulating dielectric layer assumption, the electrical model of power-ground TSVs pair is presented by combining the MOS capacitance with TSVs parasitic RLGC (resistance-inductance-capacitance-conductance). Finally, the PDN impedance characteristics of the 3-D-IC integrated system with multiple TSVs are performed by using the proposed multitransmission line and model reduction methods, and the importance of the capacitance is presented. [ABSTRACT FROM AUTHOR]

The analytical model based on Poisson–Boltzmann equation in a cylindrical coordinate system is developed for simulating the electrical parameters of the three-dimensional Through Silicon Via (TSV) interconnection. Considering the effects of bias voltage, the accurate charge distribution and the high-frequency capacitance in the depletion layer of the semiconductor is obtained. Moreover, the resistance and inductance parameters of TSV are extracted by using the partial element equivalent circuit method. Finally, the full resistance–inductance–capacitance–conductance electrical model of TSV interconnection is presented first time with the semiconductor behaviour, and the transmission characteristics of signal-ground TSV structure are studied. [ABSTRACT FROM AUTHOR]

Electromagnetic interference on the underground metal pipelines in parallel with the faulted power transmission lines includes two parts: inductive and resistive coupling. Based on the multiconductor transmission line model consisting of overhead power lines and underground pipeline, the tower grounding resistance is, respectively, modeled by the lumped-parameter processing and distributed-parameter equivalent method. Then, the formulas of voltages and currents along the transmission lines are derived combined with the constraints of voltages and currents at the transmission line's ends and the location of grounding fault. Regarding the earth-fault currents along the towers as the excitations, the method of moment is used to investigate the resistive coupling voltage on the nearby underground metal pipeline. Compared with the results of commercial software CDEGS employing the electromagnetic field analysis, the proposed method is proved to be correct and effective. The simulations also show that the results by the lumped-parameter processing method are more accurate than those by the distributed-parameter equivalent method during the tower grounding resistance modeling. Finally, the proposed method is applied to investigate the influence of parallelism length, separation distance, soil resistivity, tower grounding resistance, insulation coating resistivity, grounding fault location, and fault currents from the substations on the pipeline's coating stress voltage. [ABSTRACT FROM PUBLISHER]

As ultra-high-voltage direct current (UHVDC) projects are constructed in China, the electromagnetic environment problem is widely concerned. One of the most important problems is the ion-flow field including the human body under the UHVDC lines. But it has not been analyzed sufficiently. In this paper, the 3-D upstream finite-element method, a new method to analyze the 3-D ion-flow field under HVDC lines is proposed and verified by experiments. Then, the method is used to calculate the ionized electric field and the ion current of the human body model under the UHVDC lines. The ionized electric field is significantly distorted by the human body. According to the results, the ionized electric field and the ion current of the human body remarkably increase with the height of the human body model. The results could provide a reference for evaluating the electromagnetic environment and the personal feeling test under the UHVDC lines. [ABSTRACT FROM PUBLISHER]

An improved method to simulate the ion-flow field generated from the corona discharge on HVDC transmission lines is proposed. To remove the oscillations in simulation of charge conservation law, an upwind weighting function is adopted in the finite-element method. The Poisson's equation and the charge conservation law are solved simultaneously through Newton's method of iterations, which accelerates the convergence of the algorithm. A rule for charge density on boundary in the bipolar problem is proposed in this paper, which ensures the stability of the iterations. The computation time, convergence rate, and accuracy of the proposed method are analyzed. The proposed method is verified by analytical and experimental results, and then it is applied to the prediction of the ion-flow field from a \pm1100-kV HVDC transmission line. [ABSTRACT FROM AUTHOR]

The ionized field under HVDC transmission lines is actually a 3-D field with considering the influence of wires sag, towers, up-and-downs on the ground, surrounding buildings and other situations and little of its calculation method has been reported. In this paper, a method to calculate the 3-D ionized field under HVDC transmission lines is proposed based on Deutsch's assumption which is simple, fast, and easy to use and the computation cost of which is low. After the validity of the method is testified, some examples are analyzed and some conclusion are given. [ABSTRACT FROM PUBLISHER]