Background and Objectives: The occurrence of ferro resonance is a very complex phenomenon in power systems. In circuits including inductors and capacitors, if the value of zc = zl becomes, an intensification or resonance state is created in the circuit. In circuits and networks that have saturated inductors, nonlinear resonance or ferro resonance is created, Ferro resonance is a nonlinear resonance phenomenon that occurs between the network capacitor and the nonlinear inductance of the transformer during saturation. Ferro resonance at the main frequency and higher frequencies cause insulation problems and at low frequencies causes thermal problems. In the event of this phenomenon, the voltage range increases to a considerable extent and may also be distorted, which due to the structure of the winding connections in transformers can cause damage to electrical installations. Methods: In this paper, we study and simulate the phenomenon of ferro resonance and provide solutions such as using high resistance on the primary side of the transformer and the combination of resistors and inductors on the secondary side of the transformer to damp the ferro resonance in MATLAB software. Furthermore, the utilization of surge arresters is discussed in detail. Results: It is illuminated that utilization of suggested approaches has an acceptable reduction rate on the damping of ferro resonance fluctuations. Especially when using resistor and inductor simultaneously the fluctuations reduce and ferro resonance is damped immediately. Conclusion: It is important to pay attention to the transformer and the amount of capacitors in transmission lines, especially cable lines. Furthermore, asymmetric switching is another important factor. High resistance can reduce fluctuations but causes power losses in the circuit but using Resistance and inductor structure are able to create acceptable damping and reduce fluctuations without loss problems. The presence of a surge arrester can also reduce the overvoltage caused by ferro resonance to an appropriate level.
Herein, we report a novel technique to develop remote assessment and observation for partial discharge events under high voltage cable systems output. Finite element modeling of the cavities bided in the insulators which are the source of Partial Discharge signals occurred in a 3-d section of a typical 230 KV high voltage XLPE 3-phase cable. All electromagnetic related equations are solved using FEM software. The idea is to consider the permittivity constant in cavities as a nonlinear function during the solving process. This function is related to electric field value inside each cavity. This modeling leads to a new approach in simple modeling of PD phenomena in the H. V. apparatus with the big amount of destructive PD cavities. In continue, the obtained waveform is illustrated respecting to the main power line waveform.
The purpose of this paper is to investigate the changes in the electric field intensity due to the presence of dust on the 63 kV porcelain insulators using finite element method (FEM). The investigating Insulators were drawn in three different models (without dust layer as a basic structure, with uniform dust layer and heterogeneous dust layer) using AutoCAD software and in continue are analyzed with utilization of COMSOL software. Finally the derived values are analyzed and discussed in details. It is shown that the dust layer has an adverse effect on the electric field pattern, and the higher the concentration and volume of dust placed on the surface of insulators, results to an adverse effect on the electric field intensity around the porcelain insulator.
Facilities and buildings installed nearby high voltage equipment and electric field exposure is always a serious threat to the health of organisms and can have a significant impact on the functioning of sensitive and vital organs such as the heart and brain. Therefore, it is necessary to study the electromagnetic field value in these areas to control the intensity and restrict the induced value regarding to international recommendations. In this paper, the effects of 230KV transmission line electric fields on the environment are examined by proper FEM software.The model under consideration in this project is a four story building adjacent to the 230KV transmission line.At first, the distance between the building and high voltage transmission lines and its relationship to the intensity of the electric field is examined, and then the intensity of the electric field is compared to the standards of the International Commission on Non Ionizing Radiation Protection (ICNIRP). To continue, in places where the electric field exceeds the standard level value, solutions to reduce the intensity of the electric field to the tolerable value have been proposed.The first solution is to use a metal shield around the building as a Faraday cage, which weakens the potential for electric field value by creating an enclosed surface, the reduction rate is 4700%,both complete cage shape and incomplete cage shapes are considered in this study which reduces the exposure value to 62.5% of its initial value. The second approach to reducing the electric field is to use protective conductor paints against electromagnetic fields. In the following study, the effect of using trees as a barrier against electromagnetic radiation will be examined. Finally, the three proposed solutions are compared in terms of environmental constraints, economic justification, and the reduction in electric field value.
In recent years, the use of wind energy to generate electricity in the world has been accelerating and growing. Wind farms are unstable when dynamic voltage fluctuations occur, especially sudden and sudden changes in load, and show oscillating performance at their output. In this paper, the Unified Power Flow Controller (UPFC) has been simulated and studied by Matlab software to improve the dynamic stability and transient behavior of the wind power plant in the event of sudden load changes. The simulation results show that by controlling the UPFC series inverter, voltage fluctuations in the PCC bus are prevented and the UPFC parallel inverter injects power after changing the load for faster recovery and stability of the PCC bus voltage and thus the stability of the wind farm. The UPFC can control the active and reactive power at the transmission line, and in fact, controls the output of the wind turbine with the generator from both sides to the fluctuations caused by sudden load changes that play a role such as sudden disturbances and oscillating errors. Also, the presence of UPFC in the system reduces power fluctuations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.