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Calculation of Losses in Transmission System in Dependence on Temperature and Transmitted Power
Ladislav Rudolf,
Vladimir Kral,
Milan Bernat
Issue:
Volume 9, Issue 6, December 2021
Pages:
180-185
Received:
28 June 2021
Accepted:
6 August 2021
Published:
24 December 2021
Abstract: Innovations and trends has been significantly increased during modern theory and practical realizations in the field of energetic. In the Czech Republic, the research of predictions of technical losses on the transmission system can be considered as novel and important topic. Using software possibilities can be appropriately utilized in the frame of estimations of the technical losses. While they cannot be eliminated, they may be minimized. Losses can be measured or calculated using transmission-line parameters. This causality is considered in the form of the presented and proposed mathematical equations including real measured data of the atmospheric temperatures achieved on the substations selected in the Moravian-Silesian region. In this contribution, results of proposed calculations of technical losses based only on line parameters taking into account the ambient temperature are being compared in relation to a particular transmission system using prediction software. Particularly, technical losses caused by a configuration change of a selected part of a transmission system are considered related to the operation of Dlouhé Stráně pumped storage hydro power plant. As can be conclude, after the resulted comparisons using by the proposed mathematical models in software and the obtained real measured data, general minimization of the losses is necessary to create the most accurate models of the states that might occur in the future and to propose required modifications of the given part of the transmission system. A future bounded research can be focused on the sensors situated on the transmission lines instead of the substations.
Abstract: Innovations and trends has been significantly increased during modern theory and practical realizations in the field of energetic. In the Czech Republic, the research of predictions of technical losses on the transmission system can be considered as novel and important topic. Using software possibilities can be appropriately utilized in the frame o...
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Fast Parallel FDFD Algorithm for Solving Electromagnetic Scattering Problems
Jianming Wu,
Xinbo He,
Bing Wei,
Xianglin Li
Issue:
Volume 9, Issue 6, December 2021
Pages:
186-193
Received:
25 November 2021
Accepted:
8 December 2021
Published:
24 December 2021
Abstract: The finite difference frequency domain (FDFD) method is very suitable for working out narrowband problems and resonance problems. However, the FDFD method needs to solve a large complex sparse matrix equation. With the increase of computing scale, the dimension of matrix will increase rapidly, which is difficult to simulate. For improving the computational efficiency of solving the large complex sparse matrix equation and extend the application scope of the FDFD method, a fast parallel FDFD method on the basis of message passing interface (MPI) shared memory technology is proposed in this paper, which is used to solve the electromagnetic scattering problems of electrically large targets. Based on the conjugate gradient iterative algorithm, the large complex sparse matrix is reasonably distributed to each process according to the unequal row allocation scheme, so as to guarantee the load balancing of each process. In addition, the intermediate vectors utilized in total processes are stored in the shared memory of MPI, which reduces the communication time and the consumption of computer memory. The proposed parallel FDFD method is employed to solve the bistatic RCS of the PEC sphere, composite Von warhead and an automobile, compared with the serial FDFD method, the parallel FDFD method greatly improves the computational efficiency when the memory is not increased much.
Abstract: The finite difference frequency domain (FDFD) method is very suitable for working out narrowband problems and resonance problems. However, the FDFD method needs to solve a large complex sparse matrix equation. With the increase of computing scale, the dimension of matrix will increase rapidly, which is difficult to simulate. For improving the compu...
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About Calculation the Resistance of Two-dimensional Infinite Grid Systems
Issue:
Volume 9, Issue 6, December 2021
Pages:
194-199
Received:
14 November 2021
Accepted:
7 December 2021
Published:
24 December 2021
Abstract: The paper considers the problem of calculating the resistance between nodes of infinite grid resistor systems with square and triangular cells. There has long been a question about the resistance between the nearest nodes of an infinite grid of resistances with square cells with the same resistance r. Here, earlier, by the method of symmetry and superposition, a result was obtained r/2 that is striking in its simplicity. However, this result is only approximate, although many physicists consider this result to be accurate. New examples are presented proving what the results obtained earlier by the superposition and symmetry method is only approximate. The result r/2 gives only the lower limit of the correct resistance value. In our work, the correctness of using the equivalent resistance method to calculate the resistance between nearest nodes of infinite grid systems is proved. Using this method, for the resistance between the nearest nodes of an infinite grid of resistances with square cells, a result is obtained about 0.5216 r that only slightly differs from r/2. The results differ from the previously obtained values by about 10%. The resistance between the diagonal points of an infinite grid of identical resistors r with square cells is calculated. For the value of this resistance, a value founded about 0.7071 r that differs from the value 2r/π obtained previously by the superposition and symmetry method.
Abstract: The paper considers the problem of calculating the resistance between nodes of infinite grid resistor systems with square and triangular cells. There has long been a question about the resistance between the nearest nodes of an infinite grid of resistances with square cells with the same resistance r. Here, earlier, by the method of symmetry and su...
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Design and Implementation of an Automated Lighting System
Raghavendra Dakuri Venkata
Issue:
Volume 9, Issue 6, December 2021
Pages:
200-206
Received:
17 November 2021
Accepted:
16 December 2021
Published:
24 December 2021
Abstract: A programmable logic controller is a digitally operated system used in an industrial environment that uses a programmable memory to implement specific functions to control through digital or analogue inputs and outputs of various types of machines. This report used a typical application for PLC's lighting control in a building for an office environment. The proposed design must define an appropriate office with various areas or rooms needing lighting with multiple control signals, the lighting controlled by a Siemens LOGO PLC (type 6ED1 052-1MD00-0BA5). The design has four relay outputs and eight digital inputs configured as analogue inputs. The scheme designed must be unique to meet the minimum requirements, including a provision for emergency evacuation if the radiation levels exceed a critical threshold. The system must use both analogue inputs but used for different purposes, and the analogue input level ranges must be significantly different. The relay logic has controlled by rules derived from an original relay logic using an embedded computer system. It optimises the control tasks to perform rugged designs to withstand vibrations, temperature, humidity, and electrical noise designs that allow a vast expansion. This circuit will be developed and simulated using the LOGO comfort software and then implemented on the PLC hardware. It includes diagrams and a description that clearly describes how the system should operate.
Abstract: A programmable logic controller is a digitally operated system used in an industrial environment that uses a programmable memory to implement specific functions to control through digital or analogue inputs and outputs of various types of machines. This report used a typical application for PLC's lighting control in a building for an office environ...
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