14 Results for the search "Source":
Author: gerinlajoie.luc
Type: Model
Downloaded: 123 times
Date: 2012-11-23
Pseudo Aleatory Volt/Ampere source
Description:
Pseudo Aleatory Volt/Ampere source single and three phases devices. Build with Base Line Wander generator. Useful for Spectrum Analysis
nota bene: ts must be a multiple of dt.
Tag(s): Source
Author: gerinlajoie.luc
Type: Model
Downloaded: 196 times
Date: 2012-11-23
Random control generators
Description:
Four control sources are included:
Baseline Wander
Normal distribution
Uniform distribution
Lorenz Chaos
Tag(s): Components
Author: AdminEMTP-RV
Type: Model
Downloaded: 375 times
Date: 2012-06-18
Ferro_hyst_Zno
Description:
Simple ferroresonance case. In this case the switching of a part of the network comprised of a cable connected to a no-load transformer is carried out. A pole of the breaker fails to open and an impor... see moretant and stable ferroresonance phenomena appears.
The ferroresonance problem, whether in a general circuit or in a power-system circuit, is usually tackled in one of two ways : circuit configuration (i.e series and/or parallel) or nonlinearities (i.e saturation and hysteresis of transformers). A fundamental factor to the occurence of ferroresonance is the nonlinear magnetizing characteristic of the transformer and the capacitive coupling.
In this case a 250 kVA, 20/0.4 kV transformer is used. This transformer is represented by the hysteresis transformer model. The hysteresis element has been used as the magnetization branch of the one-phase transformer model. A 200 m cable is used for the study. This cable is modelled by a PI-section. The short circuit power of the source is about 150 MVA.
In order to reduce overvoltages caused by ferroresonance, surge arresters are installed. Two questions have emerged : will the arresters mitigate ferroresonance, and will they fail during ferroresonance ? Simulations in different transient regimes can be carried out in order to determine the maximal current, overvoltages (voltage at the end of the cable for instance), energy absorbed by the arresters
Tag(s): Protection
Author: AdminEMTP-RV
Type:
Downloaded: 454 times
Date: 2012-06-18
Cross_Bonded_Cable
Description:
Insulation coordination - 225 kV cross bonded cable - protection of the sheath.
In the configuration a 225 kV cross-bonded cable is connected at both ends to an otherhead line. The sheath is prot... see moreected by star-connected arresters.
The modelling used is adapted for the study of Fast-Front-Overvoltages (see IEC 60071)
A current source, with a CIGRE concave shape (See CIGRE 63 document), representing a lightning stroke has been connected to a tower close to the cable.
The case includes the modelling of the different elements of the configuration (cable, spans, arresters...).
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.