Transmission expansion planning (TEP) plays a vital role in ensuring the reliable and efficient operation of power systems, especially with the growing demand for electricity and the integration of renewable energy so...
Transmission expansion planning (TEP) plays a vital role in ensuring the reliable and efficient operation of power systems, especially with the growing demand for electricity and the integration of renewable energy sources. This paper focuses on applying unconventional high surge impedance loading (HSIL) lines in transmission expansion planning and compares their outcomes with conventional line-based transmission expansion planning. Starting with a 17 bus- 500 kV power system connected by a conventional transmission line, the objective is to connect a new load located in a new bus, bus #18, to the existing 17-bus power system via two approaches: using conventional lines and incorporating unconventional HSIL lines. By comparing the number of lines required for the conventional and unconventional approaches, maintaining almost identical conductor volume per circuit, the effectiveness of unconventional HSIL lines in TEP is evaluated where using only two unconventional HSIL lines is sufficient to connect 1000 MW load demand at bus 18 while three lines are required when using the conventional design.
We focus on the problem of imitation learning from visual observations, where the learning agent has access to videos of experts as its sole learning source. The challenges of this framework include the absence of exp...
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Designing high-power-delivery and low-system-mass electric power systems (EPS) is a major goal to achieve the next generation of electrified aircraft. As one of its major components, cables must be redesigned to obtai...
Designing high-power-delivery and low-system-mass electric power systems (EPS) is a major goal to achieve the next generation of electrified aircraft. As one of its major components, cables must be redesigned to obtain high-power-density and low-system-mass EPS. Among challenges in designing aircraft cables such as arc and arc tracking, partial discharges (PD), and thermal management, the latter is decisive since the thermal properties of the cable determine its maximum ampacity. The maximum permissible current of a cable depends on radiative and convective heat transfers from its surface to the ambient environment. At the cruising altitude (12.2 km) of wide-body aircraft where the air pressure is 18.8 kPa, the convective heat transfer is greatly reduced which results in a reduction in maximum permissible current. Moreover, both radiative and convective heat transfers depend on the surface area of the cable. One way to increase the heat transfers and compensate for the reduction of convective heat transfer from a limited air pressure is to change the geometry of the cable. The cuboid geometry design provides a larger contact area with the ambient environment for the same cross-section area, so it is expected that the heat transfer will increase compared to conventional cylindrical cables, and in turn, the maximum power carrying capacity of the cable will be larger. Here, the question is whether the hypothesis is true, and if so, how much improvement can be expected. The purpose of this paper is to answer these questions and, for the first time, an MVDC (5 kVdc) high power (1 kA) cuboid shape cable is designed for future AEA to increase the maximum permissible current of the cable.
In conventional lines, subconductors are located symmetrically on an identical circle in each phase. The number of subconductors in a bundle, the radius of the bundle circle, and the radius of each subconductor, are c...
In conventional lines, subconductors are located symmetrically on an identical circle in each phase. The number of subconductors in a bundle, the radius of the bundle circle, and the radius of each subconductor, are chosen so that the maximum electric field strength on the sub conductors, $E_{max}$ , is limited to the permissible field strength on the conductor surface, $E_{p r},\left(E_{max } \leq\right. E_{pr})$ , which is determined by the corona discharge limitation requirement. In this paper, we show that by shifting phase configurations and subconductors into unusual/unconventional arrangements that are geometrically optimized within the space, high power density designs can be achieved. A novel bundle and phase arrangement of a 500 kV transmission line is presented in this paper, resulting in higher natural power than conventional design.
Corona discharges cause power loss, audible noise (AN), radio interference (RI), and television interference (TVI), all of which should be considered during transmission line design. Unconventional high surge impedanc...
Corona discharges cause power loss, audible noise (AN), radio interference (RI), and television interference (TVI), all of which should be considered during transmission line design. Unconventional high surge impedance loading (HSIL) lines have been shown to have the potential to produce greater natural power than conventional lines and conventional HSIL lines. More than one conductor is used in conventional extra high voltage (EHV) lines, typically more than 300 kV, to form bundled conductors which reduce the electrical field on the subconductors and, as a result, reduce corona effects. In conventional lines, the number of subconductors symmetrically placed on a circle and bundle radius are determined based on corona effects considerations. Using a larger bundle circle and increasing the number of subconductors lead to greater natural power, resulting in conventional HSIL lines. Therefore, in conventional HSIL lines, bundled conductors are used not only to address corona effects but also to increase natural power. Using smaller conductors for conventional HSIL lines keeps costs close to conventional lines. In conventional HSIL lines, subconductors are still symmetrically placed on a circle while unconventional HSIL lines have subconductors placed at any point in space. Unconventional HSIL lines can lead to more natural power than conventional HSIL lines. In this paper, AN and RI for unconventional HSIL lines are calculated and discussed.
This paper aims to explore the significance of accurately defining the geometry of needle electrodes in gas discharge plasma finite-element simulations and evaluate the sensitivity and responsiveness of simulation out...
This paper aims to explore the significance of accurately defining the geometry of needle electrodes in gas discharge plasma finite-element simulations and evaluate the sensitivity and responsiveness of simulation outputs to different needle electrode shapes. Using a hydrodynamic (drift-diffusion) model and COMSOL Multiphysics software, a comprehensive numerical analysis is performed to investigate the influence of six needle geometries (hyperbolic, elliptic, and circle-with-tangents) with an equal radius of curvature on negative air discharge plasma characteristics. The study aims to establish a comparative understanding of how the defined geometries relate to the behavior of the discharge plasma. Various aspects, including the properties of Trichel pulses, the spatiotemporal evolution of charged species, and the electrical field distribution, are explored.
This paper presents a 17-bus 500 kV test system for transmission expansion planning (TEP) studies. An actual 500 kV transmission line geometry was used for the overhead lines of this system. Although many test systems...
This paper presents a 17-bus 500 kV test system for transmission expansion planning (TEP) studies. An actual 500 kV transmission line geometry was used for the overhead lines of this system. Although many test systems have been introduced for different types of power system analysis, those especially for TEP studies at a transmission voltage level, not distribution voltage level, are few. To the best of our knowledge, the introduced test systems for TEP studies, either those combined with electricity market problems or those used to connect a new load or generation to an existing power grid, consider the studies under only normal condition. However, for TEP studies it is needed that a test system meets voltage drop and line loading limits criteria under normal condition as well as all single contingencies, and in this regard, addressing the latter, all single contingencies, is challenging. This paper addresses this technical gap, introducing a 17-bus test system at a transmission voltage level, 500 kV, that meets requirements under normal condition as well as all single contingencies. In addition to presenting all details of this new test system, load flow results under normal condition as well as the worst single contigency are presented. For studies on the TEP, this test system can be an invaluable resource.
This paper studies the relationship between a graph neural network (GNN) and a manifold neural network (MNN) when the graph is constructed from a set of points sampled from the manifold, thus encoding geometric inform...
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This paper presents a numerical investigation of positive streamers in a liquid-solid composite dielectric system, specifically in the context of wet-mate DC connectors. The study focuses on the influence of different...
This paper presents a numerical investigation of positive streamers in a liquid-solid composite dielectric system, specifically in the context of wet-mate DC connectors. The study focuses on the influence of different materials and relative permittivity values of the solid dielectric on streamer behavior. The study employs a non-dimensionalized electric field-dependent molecular ionization streamer model to describe the initiation and propagation of streamers within a needle-sphere electrode system. A 2D-axisymmetric COMSOL model is utilized, where a solid tube-like dielectric is placed near the needle tip in an electrode system filled with transformer oil. The effects of varying relative permittivity values on the electric field distribution, streamer propagation velocity, ionization and attachment rates, and spatiotemporal evolution of charged species (electrons, positive ions, and negative ions) are studied. By analyzing these aspects, the paper aims to enhance the understanding of streamer dynamics and provide valuable information for optimizing the design and performance of equipment utilizing liquid-solid composite dielectric systems.
Bipolar medium-voltage dc (MVDC) distribution systems are of great interests nowadays due to its high availability and reliability. A bipolar MVDC grid can be established by the installation of power-balancers or dire...
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