Electrical Engineering Department, National Institute of Technology Calicut Year 2004

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EE 324 L SIMULATION LABORATORY

Experiment No. 9

FAULT ANALYSIS OF A SIMPLE AC SYSTEM USING PSCAD

Objective: Simulate the given power system network for L-L, L-L-G, L-L-L and L-L-L- G faults. Determine the voltage and current profiles under each fault.

Software used :EMTDC/PSCAD (Ver. 3.7.3) Power System: given below

PROCEDURE:

To create a PSCAD project.

1. From the windows start menu choose PSCAD folder and then the

PSCAD.EE shortcut to start PSCAD.

2. From the file menu, point to Create New Project and choose Case.

3. From the view menu select project. (Select Project Tree and clicking on message in

view menu opens message tree where the error messages are displayed).

4. Open the new file (noname [psc]) by double clicks.

5. Save the project.

Va

Vb

Vc

10.0

10.0

10.0

0.2

0.2

0.2

Ea

Eb

Va

Vb

Vc

Ea

Eb

Ec

TL1

1

TL2

1

TL1

1

TL1

Ia

Ib

Ic

Ec

TL2Ic

Ib

TL2

1

TimedFaultLogic

A

B

C

1.0

Ia

A

B

CFAULTS

AB->G

Electrical Engineering Department, National Institute of Technology Calicut Year 2004

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To place the parts (general)

1. Open the project tree from view menu.

2. Open the master library.

3. Open the appropriate sub page.

4. Copy the required component.

5. Paste it in the project file.

To place the source

1. From the master library, main page, choose the sub-page sources.

2. Select 3 phase grounded voltage source.

3. Copy the part from the master library and paste in design window

4. Right click on the part and rotate it appropriately.

5. Double click on the part to define its parameters as

a) Configuration

Source name : (optional)

Source impedance: Resistive

Phase shift: 0.0

Voltage input: Internal

Frequency: Internal

b) Resistance

Resistance: 1.0 ohm

c) Voltage

Magnitude: 230 [kv]

Ramp up time: 0.05 sec

6. Click OK

To place the transmission lines

1. Select Tlines from the master library main page.

2. Place transmission line interfaces and transmission line as per the instructions given in

the package.

Electrical Engineering Department, National Institute of Technology Calicut Year 2004

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3. Double click on the transmission line (not interface) and edit the parameters as.

Line Name: LT1

Frequency: 50 Hz

Length of Line: 50km

No. of conductors: 3

4. Choose the edit menu.

5. Right-click on the opened window Transmission Line TL1 and point to Tlines.

6. Select the third option, 3 Line constants 3 condutors delta tower.

7. Right click on the conductor arrangement and choose its physical parameters

appropriately.

8. Close the window Transmission Line TL1.

9. Double click on each transmission line interface and edit the parameters as

Name: TL1

No. of equivalent conductors: 3

To place the wire/resistor/inductor/ground /connection node .

1. Right click and point to add.

2. Choose the part needed.

3. Double click the part to edit its parameters.

To place the fault

1. From the fault page in master library choose the components in the diagram.

2. Copy and paste the part.

3. Double click Timed Fault Logic to set time to apply fault as 0.1sec and 0.05sec.

4. Click OK.

5. Double click FAULTS to edit fault parameters as

a) Configuration

Fault Type Control: Internal

Clear possible if current

flowing: No

b) Fault Resistance Fault On resistance: 0.01 ohm Fault OFF resistance: 1.0E6 ohm

Electrical Engineering Department, National Institute of Technology Calicut Year 2004

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c) Fault type

Is phase A in Fault: Yes

Is phase B in Fault: No

Is phase C in Fault: No

Is the fault to neutral: Yes

(Now the fault type is L-G)

To place the meters

1. Right click and point to add, then to meters and select appropriate one, say

voltmeter to ground.

2. Place the meter chosen, say in the A phase of the supply.

3. Double click on the meter and name the meter, say Va.

4. From add choose data label and channel.

5. Double click on the data label and edit signal name, as Va(should be same as

that used for the corresponding meter).

6. Double click the channel and edit the title. ( this title is the one, which is

displayed on the graph).

7. Connect the data label and channel using a wire.

8. Repeat the same for remaining two phases B & C.

To plot Curve/Graph

To create new plot.

1. Right click on the channel select Input/Output references and choose create new plot.

2. Double click on the graph to edit its parameters like Title, axes properties etc.

To add a curve to existing plot

(This can be used when it is need to plot more than one curve on a single graph like 3 phase voltages) 1. Right click on the channel corresponding to the curve to be added.

2. Point to Input / Output references and choose add as curve.

3. Right click on the existing graph where the curve to be added and choose

paste curve.

Electrical Engineering Department, National Institute of Technology Calicut Year 2004

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To Execute

1. Open the project window.

2. Right click on the file name and Set as Active.

3. Click on the green play icon to start simulation.

Questions: Part A

1 What is a fault? Is it possible to protect the system from complete faults? 2 How reliability is related with protection? 3 What is grounding? 4 How the simulation time separated from fault clearing time? 5 Which type of fault is common to Indian Power System? 6 Which type of fault is severe w.r.to cascading? 7 Give your comments on the results.

Questions: Part B

1 Discuss the major features and capabilities of the software used for the simulation. 2 Can we use any other packages for the same experiment? 3 Explain briefly the solver options and time step for the simulation in the package. 4 Develop a programme (codes) by yourself for the problem with a suitable front end.