scholarly journals A Fundamental Time-Domain and Linearized Eigenvalue Analysis of Coalesced Power Transmission and Unbalanced Distribution Grids using Modelica and the OpenIPSL

2019 ◽  
Author(s):  
Marcelo de C. Fernandes ◽  
Luigi Vanfretti ◽  
Janaína G. de Oliveira ◽  
Maxime Baudette
Keyword(s):  
Time Domain ◽  
Power Transmission ◽  
Eigenvalue Analysis ◽  
Distribution Grids

Subtraction of powerline harmonics from geophysical records

Geophysics ◽  
1993 ◽  
Vol 58 (6) ◽  
pp. 898-903 ◽  
Author(s):  
Karl E. Butler ◽  
R. Don Russell
Keyword(s):  
North America ◽  
Magnetic Fields ◽  
Fundamental Frequency ◽  
Time Domain ◽  
Seismic Data ◽  
Power Transmission ◽  
Power Lines ◽  
Electric And Magnetic Fields ◽  
Harmonic Noise

Harmonic noise generated by power lines and electric railways has plagued geophysicists for decades. The noise occurs as electric and magnetic fields at the fundamental frequency of power transmission (typically 60 Hz in North America) and its harmonics. It may be recorded directly during time‐domain measurements of electric and magnetic felds, or indirectly, by geophone cables during the acquisition of seismic data.

Design of HVDC and SVC Coordinate Damping Controller Based on Wide Area Signal

2006 ◽  
Vol 7 (4) ◽  
Author(s):  
Yong Chang
Keyword(s):  
Power System ◽  
Time Domain ◽  
System Performance ◽  
Eigenvalue Analysis ◽  
Previous Experience ◽  
Wide Area ◽  
Flexible Control ◽  
Facts Devices ◽  
Control Principle ◽  
Damping Controller

HVDC and FACTS devices have been widely applied in power system for their excellent and flexible control ability. Their contributions to the damping of system oscillations are of great importance for achieving satisfactory system performance. However, previous experience has shown that there may be negative interactions among FACTS devices whose supplementary controllers are designed separately. This may deteriorate system performance and even make system unstable. The interactions of HVDC and SVC during system oscillation were analyzed in this paper. The coordinate supplementary damping controller for HVDC and SVC were then designed based on projective control principle. The criterion of synthetic residue is adopted in choosing the proper input wide area signals. Eigenvalue analysis and time domain simulations were performed on a two-area system and the results demonstrated the effectiveness of the proposed controller.

Design and simulation of the electromagnetic heating of a biological tissue

2017 ◽  
Vol 36 (2) ◽  
pp. 408-416 ◽  
Author(s):  
Mykola Ostroushko ◽  
André Buchau ◽  
Wolfgang Rucker
Keyword(s):  
Immune Response ◽  
Time Domain ◽  
Thermal Ablation ◽  
Power Transmission ◽  
Heating System ◽  
Content Type ◽  
Ablation Therapy ◽  
Electromagnetic Heating ◽  
The Time Domain ◽  
Inductive Power Transmission

Purpose The purpose of this paper is to present the design and the numerical calculation of the electromagnetic heating system for the ablation therapy. Hence, the heating of the tumor cells must be processed very carefully to achieve a localized coagulative necrosis and to avoid too high temperatures inside the tissue. Design/methodology/approach The non-invasive method of the ablation therapy is implemented due to the inductive power transmission between the generator and implant. The ferromagnetic implant has a small size and can be placed intravenously into tumor cells. High-frequency driving currents are necessary to obtain high induced eddy currents within the ferromagnetic implant. Findings Finite element analysis has been used for the design and numerical calculation of the electromagnetic heating system. The electromagnetic analysis is done in the time domain due to the nonlinearity of the ferromagnetic implant. Magnetic fields are computed based on a magnetic vector potential formulation. The thermal analysis is done in the time domain as well. The temperature computation in biological tissue is based on a heat balance equation. Research limitations/implications This paper is focused on the design and simulation of the inductive system for the ablation therapy. Practical implications The designed system can be practically implemented. It can be used for the clinical study of the immune response by the thermal ablation therapy. Originality/value The common method of thermal ablation is combined with an inductive power transmission. It enables a repetitive application of this method to study the immune response.

scholarly journals Applications of Triple Active Bridge Converter for Future Grid and Integrated Energy Systems

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1577
Author(s):  
Van-Long Pham ◽  
Keiji Wada
Keyword(s):  
Power Transmission ◽  
Control Strategies ◽  
Energy Systems ◽  
Pollutant Emissions ◽  
Renewable Energy Systems ◽  
Grid Systems ◽  
Integrated Energy Systems ◽  
Transmission Design ◽  
And Control ◽  
Distribution Grids

Renewable energy systems and electric vehicles (EVs) are receiving much attention in industrial and scholarly communities owing to their roles in reducing pollutant emissions. Integrated energy systems (IES), which connect different types of renewable energies and storages, have become common in many applications, such as the grid-connected photovoltaic (PV) and battery systems, fuel cells and battery/supercapacitor in EVs. The advantages of all energy sources are maximized by utilizing connection and control strategies. Because many storage systems and household loads are mainly direct current (DC) types, the DC grid has considerable potential for increasing the efficiency of distribution grids in the future. In IES and future DC grid systems, the triple active bridge (TAB) converter is an isolated bidirectional DC-DC converter that has many advantages as a core circuit. Therefore, this paper reviews the characteristics of the TAB converter in current applications and suggests next-generation applications. First, the characteristics and operation modes of the TAB converter are introduced. An overview of all current applications of the TAB converter is then presented. The advantages and challenges of the TAB converter in each application are discussed. Thereafter, the potential future applications of the TAB converter with an adaptable power transmission design are presented.

Reducing Fatigue Loading due to Pressure Shift in Discrete Fluid Power Force Systems

2016 ◽  
Author(s):  
Anders Hedegaard Hansen ◽  
Henrik C. Pedersen
Keyword(s):  
Time Domain ◽  
Power Transmission ◽  
Fatigue Loading ◽  
Current Paper ◽  
Fluid Power ◽  
Pressure Oscillations ◽  
Force System ◽  
Force Systems ◽  
The Time Domain ◽  
Pressure Overshoot

Discrete Fluid Power Force Systems is one of the topologies gaining focus in the pursuit of lowering energy losses in fluid power transmission systems. The cylinder based Fluid Power Force System considered in this article is constructed with a multi-chamber cylinder, a number of constant pressure lines and a valve manifold. The valve manifold is used to control the connections between the cylinder chambers and the pressure lines and hereby the resulting force form the cylinder. The valve manifold is equipped with fast on/off valves. However, shifting between pressure lines may yield pressure oscillations in the cylinder chamber, especially for systems with long connections between the cylinder and the valve manifold. Hose pressure oscillations will induce oscillations in the produced piston force. Hence, pressure oscillations may increase the fatigue loading on systems employing a discrete fluid power force system. The current paper investigates the correlation between pressure oscillations in the cylinder chambers and valve flow in the manifold. Furthermore, the correlation between the pressure shifting time and the pressure overshoot is investigated. The study therefore focus on how to shape the valve flow in the manifold to reduce the added fatigue loads. A simple transmission line model is developed for the analysis. Two inputs are given in the Laplace domain and the time domain solution of the cylinder pressure to the given inputs are derived through inverse Laplace transformation. Based on the time domain solutions the pressure overshoot for various pressure shifting times is investigated. With the two input functions defined by the pressure shifting time, T, the main results of the current paper show the correlation between the minimum shifting time and the pressure overshoot in a given cylinder chamber with a given line connection.

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