Islamic University of Gaza

Faculty of Engineering Electrical Engineering department

Electric Machine Lab

Eng. Mohammed S. Jouda

Eng. Amani S. abu reyala

Experiment 1

Introduction to Lab-volt virtual laboratory (LVVL)

OBJECTIVE:

To be familiar with the LVVL simulation.

To be familiar with various subject in LVVL program.

Overview of the Lab-Volt virtual laboratory and Equipment:

The lab-volt virtual laboratory (LVVL) is a three-dimensional classroom laboratory

displayed on a computer screen. Various subject such as hydraulics, pneumatics,

electromechanically systems , and digital telecommunication can be studied using this virtual

equipment.

The virtual equipment sets form complete training systems which are faithful three-

dimensional reproduction of actual lab-volt training systems. They have the same physical

appearance and behave in the same way as the actual training systems. Figure 1 shows an

example of the virtual classroom laboratory.

Figure 1: Virtual classroom laboratory with equipment for studying electrical system.

This Experiment is designed to get you familiar with the various computer-based

instruments (Metering- window, Oscilloscope, Phasor Analyzer, etc) included in the actual

and virtual Lab-Volt Electromechanical Training Systems. It is divided into some sections:

I. Familiarization with the Metering Window and the Data Table:

This familiarization exercise consists of procedure that shows how to use the Lab-Volt

computer-based Metering window and Data Table. The exercise can be performed using either

the actual or virtual Lab-Volt Electromechanical System (EMS).

PROCEDURE:

1. Ensure that the power supply (unit 8821-25) is switched off.

2. Connect the LOW POWER INPUT of the Data Acquisition Interface (DAI) module

to the 24 V - AC output of the Power Supply.

3. Connect the equipment as shown in Figure I-1 & Figure I-2 .

Figure I-1: Simple resistive AC circuit.

Figure I-2: Connect the Simple resistive AC circuit by LVVL program.

4. open the Metering window, set meter E1 as an AC voltmeter and meter I1 as an AC

ammeter as shown in Figure I-3.

Figure I-3: Metering window.

5. Open the Data Table window by choosing the corresponding command in the Tools

menu or by clicking the corresponding button in the Tools bar.

6. For each voltage step, record in the Data Table window the values displayed by the

meters in the Metering window. Observe that a new row in the Data Table window is

filled up with data whenever a record data command is performed.

Set the Power Supply voltage control knob to the 0 position as shown in Figure I-4.

Figure I-4: Data Table window.

7. In the Graph window, plot a graph between the voltage and the current delivered to

resistor R1, To do so, select voltage E1 as the y-axis and I1 as the x-axis. and Colors

help topics to obtain additional information about the Graph window, as shown in

Figure I-5.

Figure I-5: Graph window.

II. Familiarization with the Oscilloscope:

This familiarization exercise consists of procedure that shows how to use the Lab-Volt computer-

based Oscilloscope.

PROCEDURE:

1. Ensure that the power supply (unit 8821-25) is switched off.

2. Connect the LOW POWER INPUT of the Data Acquisition Interface (DAI) module to

the 24 V - AC output of the Power Supply.

3. Connect the equipment as shown in Figure II-1 & Figure II-2 .

Figure II-1: Simple resistive-inductive circuit.

Figure II-2: Connect Simple resistive-inductive circuit by LVVL program.

4. Start the Oscilloscope by choosing the corresponding command in the Instruments

menu or by clicking the corresponding button in the EMS Instruments toolbar.

5. Make the following settings on the Oscilloscope:

Channel 1 Input (observed parameter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . E1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 V/div Input Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DC Channel 2 Input (observed parameter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 A/div Input Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DC Time Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ms/div Trigger Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ch 1 Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0 V Slope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . positive (+) Channel 3 Input (observed parameter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P1 Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 W/div Input Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DC

Observe that a third sinusoidal waveform appears on the Oscilloscope screen.

This waveform shows the power delivered by the AC power source, and is obtained from

the voltage and current measured at inputs E1 and I1of the DAI module as shown in

Figure II-3.

6. On the Power Supply, you can turn the voltage control knob until reach to the value,

While doing this, observe that the waveforms on the Oscilloscope screen are refreshed

at regular intervals to reflect the change in the AC power source voltage.

7. On the Oscilloscope, select the continuous display refresh mode.

Figure II-3: Oscilloscope window.

III. Familiarization with the Phasor Analyzer:

This familiarization exercise consists of procedure that shows how to use the Lab-Volt computer-

based Phasor Analyzer.

PROCEDURE:

1. Ensure that the power supply (unit 8821-25) is switched off.

2. Connect the LOW POWER INPUT of the Data Acquisition Interface (DAI) module to

the 24 V - AC output of the Power Supply.

3. Connect the equipment as shown in Figure III-1 & Figure III-2 .

Figure III-1: Simple resistive-inductive circuit

Figure III-2: Connect Simple resistive-inductive circuit by LVVL program

4. Start the Phasor Analyzer by choosing the corresponding command in the Instruments

menu or by clicking the corresponding button in the EMS Instruments toolbar.

5. Make the following settings on the Phasor Analyzer:

Voltage Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 V/div

Current Sensitivity . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 0.2 A/div

6. On the Phasor Analyzer, select voltage E1 (source voltage).

7. On the Phasor Analyzer, select voltages E2 (voltage across resistor R1) and E3 (voltage

across inductor L1).

Observe that the phasor related to voltage E2 appears at an angle of 0, because the

voltage across a resistor is in phase with the circuit current (phasor I1).

Observe that the phasor related to voltage E3 appears at an angle of about 90, because

the voltage across an inductor leads the circuit current (phasor I1) by 90, as shown in

Figure III-3.

Figure III-3: Phasor window

Exercise :

1. Connect the equipment as shown in Figure 2 by using LVVL program.

2. Set meter E1& E2&E3 as an AC voltmeter and meter I1 as an AC ammeter

and measure the equivalent impedance in this circuit.

3. Record the data in the Data Table window, and plot a graph between the

voltages and the current.

4. Make the settings on the Oscilloscope, obtained from the voltages and current

measured at inputs E1& E2&E3 and I1.

5. Make the following settings on the Phasor Analyzer, select voltage E1 (source

voltage) then comment the result.

Figure 2: Simple resistive-capacitive circuit