109 Results for the search "te":
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.
Protection_Homopolaire_Evol
Description:
This case introduces a typical zero sequence relay tested in a MV network.
This is a contribution of Marc Petit from Supelec in France.
See the comments in the file.
Tag(s): Protection, Components
Pwm_inv_3ph
Description:
This case shows a three-phase full-bridge DC/AC inverter with PWM switching.
Reference: Power Electronics, Mohan, Undeland, Robbins - Ed Wiley - Chapter 8.
Tag(s): Power Electronics
Reactor
Description:
This is an advanced case of a three-phase shunt-rector modeling along with a Cassie-Mayr Modified circuit-breaker arc model.
This design introduces the way three-phase shunt-reactor may be ... see moresimulated in EMTP-RV. Moreover, it introduces an advanced circuit-breaker arc model known as Cassie-Mayr Modified or Advonin arc model.
Tag(s): Example