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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: 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: Model
Downloaded: 193 times
Date: 2012-06-18

TCR1

Description:
Example of single phase Thyristor Controlled reactor using TACS control devices. This circuit reproduces the TCR case presented in the EMTP Workbook volume 4 chapter 6.

Example of single ph... see morease Thyristor Controlled reactor using TACS control devices. This circuit reproduces the TCR case presented in the EMTP Workbook volume 4 chapter 6.

The basic static Var system consists of a static switch in series with an inductor. This is normally called a phase controlled reactor, or Thyristor Controlled Reactor (TCR). The TCR is in parallel with a fixed capacitor. Together they interface with the power system at some interconnection point. The control circuit of the TCR can be divided into three parts. There is the gate pulse generator (GPG), the heart of the control system, a voltage regulator and an interface to the power systems which could be simply a RMS voltage meter.

The purpose of the gate pulse generator is to provide firing pulses to the thyristors. The regulator calculates the conduction angle, ?, which is passed to the gate pulse generator as a control signal. It is the function of the gate pulse generator to generate the correct firing pulses to achieve the requested conduction angle, ?. In this example the gate pulse generator is modeled using TACS control devices.

Tag(s): Power Electronics