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Author: AdminEMTP-RV
Type:
Downloaded: 231 times
Date: 2012-06-18

Motor_Protection

Description:
The following circuit presents a protection scheme for an induction motor due to voltage dips.

The voltage dip generator is presented in a masked subcircuit where it is possible to control ... see morethe shape and duration of the voltage dip.

Tag(s): Motor, Protection

Author: AdminEMTP-RV
Type:
Downloaded: 213 times
Date: 2012-06-18

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

Author: AdminEMTP-RV
Type: Document
Downloaded: 250 times
Date: 2012-06-18

On the implementation of a hysteretic reactor model in EMTP

Description:
Authors:
Sébastien Dennetière, Jean Mahseredjian, Manuel Martinez, Michel Rioual, Alain Xémard, Patrick Bastard

Abstract:
This paper presents the implementation of a hysteretic... see more reactor model in a transient analysis package. Themodel is available in a currently developed EMTP (DCGEPRI) version. It is demonstrated how the hysteretic reactor equations can be solved to eliminate topological limitations and allow solving large scale networks efficiently. Numerical robustness aspects and the representation of minor loops are emphasized. The model demonstrates new and not previously available computational capabilities.

Tag(s):

Author: AdminEMTP-RV
Type:
Downloaded: 220 times
Date: 2012-06-18

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.

Tag(s): Example, Motor

Author: AdminEMTP-RV
Type: Document
Downloaded: 464 times
Date: 2012-06-18

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.

Tag(s):