35 Results for the search "line":
Line_Coupling
Description:
The following example demonstrates the coupling effect between 3 adjacent transmission lines.
The case study consists of the implementation of a third transmission line next to two existing... see more lines. The data of the geometrical configuration are entered in the DATA LINE module and are stored in the "line_couplin_CP.lin". The generated model was obtained using the CP option and are loaded to the CP m-phase module using the data included in the "line_coupling_CP_rv.csv" file. The results are very close to the measurements provided in "H.W. DOMMEL ET AL, CASE STUDIES FOR ELECTROMAGNETIC TRANSIENTS, P.1,1991".
Non_Linear_Benchmark
Description:
Benchmark case for testing the nonlinear solution method of transients simulation packages.
This case shows the superior capability of EMTP-RV to handle simultaneous solutions of three very... see more nonlinear elements: Circuit-breaker arc , Hysteretic characteristic of transformers and Zinc-Oxide arresters.
Tag(s): Example
PM_subcircuit
Description:
Example of a user defined model. In this case a line-start permanent magnet synchronous machine is connected to a simple power network. This machine, working as a generator, has been modeled by contro... see morel elements. This user defined model is not recomme.
The line-start permanent magnet motor is a high-efficiency synchronous motor with self starting capability when operating from a fixed frequency voltage source. The permanent magnets embedded in its rotor provide the synchronous excitation and the rotor cage provides the induction motor torque for starting. The difference in permeability between the magnet and rotor core also results in significant magnetic saliency and reluctance torque at synchronous speed. At asynchronous speeds, the dc excitation and saliency of the permanent magnets will cause pulsating torque components. When the field strength of the magnet is too strong, a line-start permanent magnet motor may fail to synchronize because of the excessive pulsating torque component from the dc-excitation of the magnet.
The objective of this case is to create a user defined model of a permanent magnet synchronous machine. With this model the user can explore the behaviour of the torque components during a starting run of the generator from standstill. In particular, we will examine the ability of the motor to synchronize with various values of magnet field strength, mechanical loading and rotor inertia.
This case also shows the capabilities of EMTP-RV to create user defined models. This model assembled with control elements is particularly clear. I needed 4 hours to create this model and to validate it with an existing Simulink model ! The user can see the whole model with its equations on one page (see Figure below)
This model is given as an example of user defined model and should not be used for other purposes.
Presentation of an approach based on EMTP for the calculation of lightning induced overvoltages
Description:
Authors:
A. Xémard, P. Baraton, B. Bressac, N. Qako, J. Mahseredjian, G. Simard, J. Ribeiro, R. Tarafi, A. Zeddam.
Abstract:
LIPS (Lightning Impact on Power Systems) is a toolbo... see morex based on EMTP (DCG version) and devoted to the calculation of the failure rate of apparatus due to lightning. This software covers direct and induced lightning. It has been developed in a partnership project between France Telecom, Hydro-Québec and électricité de France. The induced lightning nearby the electrical system. It is based on the following computational steps:
1) For each overhead line and underground cable of the electrical system, two equivalent current sources are calculated in the frequency domain, representing the illumination of the conductors by external electrical field due to lightning. These sources are evaluated in the frequency domain, taking into account the variation of the parameters of lines and cables with frequency. The conductivity of the ground is taken as finite. The modal theory is applied in the case of multi-conductor cable or line.
2) The equivalent sources are converted into time-domain and then included in an EMTP representation of the system allowing a time-domain transient computation. this approach and follow by comparisons between induced overvoltages calculated by LIPS and results from the literature.
Self_Exc_ind
Description:
Simulation case of the self-excitation of induction motors during startup on a series compensated radial line.
This case reproduces the results published in the book of Anderson and Farmer ... see moreentitled 'Series Compensation of Power Systems', PBLSH publisher, 1996.
Although approximate data are used, results compare surprisingly well with the figures in chapter 7.
Tag(s): Motor