Load Flow Example 1

ETAP Workshop Notes ©1996-2009 Operation Technology, Inc. Page 1 of 7

1. Build the following system

Element Parameters Type Element Parameters

MOV MOV3, MOV5 Initial Status = Throttle

Lump Load Lump2 PF=85%, Constant kVA Load = 50%, Rated kV = 13.8

Lump4 & Lump 6 PF=85%, Constant kVA Load = 80%, Rated kV = 0.46

Static Load Load1, Load6, Load8 kV = Bus Nominal kV, PF=80%

Load3, Load5 kV = Bus Nominal kV, PF=100%

Capacitor CAP1 kV=4.16, kvar/Bank = 150 kvar, # of Banks = 2

Syn Motor Syn1 PF @ 100% Load = 80%, FLA = 403.5

Syn2, Syn4 PF@100% Load =91.71%, FLA = 220.1

Load Flow Example 1

ETAP Workshop Notes ©1996-2009 Operation Technology, Inc. Page 2 of 7

Load Flow Example 1

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2. Run Load Flow. Results are displayed below.

Load Flow Example 1

ETAP Workshop Notes ©1996-2009 Operation Technology, Inc. Page 4 of 7

Load Flow Example 1

ETAP Workshop Notes ©1996-2009 Operation Technology, Inc. Page 5 of 7

I. Exercise 1 – Create Configurations

1. Create new configurations and study cases

New Configurations

Name Configuration

Normal Open Tie-Breaker CB3 and CB4 and close all other CBs.

Load Shift Close tie- breaker CB3 & CB4 and open both side CBs of T5 and Cable5

T3 Down Based on Normal configuration, close CB3 and open both side CBs of T3.

T4 Down Based on Normal configuration, close CB4 and open both side CBs of T4.

TieCBClosed Both Tie- Breaker CB3 and CB4 are Closed.

New Study Cases

Name Configuration

DesignLoad Use Design load without diversity factor.

Use Design for generation category.

Use default values for Adjustment Page.

Loading and generator overexcited alert: Critical = 100%, Marginal =

95%.

90%Load Use global diversity factor to set all load to 90

Use the default setting for Adjustment.

All Loading and generator overexcited alert: Critical = 100%, Marginal

= 95%.

II. Exercise 2 – Check System Voltage Condition

1. Check System Voltage Condition

Run different cases to see if there is voltage problem.

If there is any problem, fix it.

III. Exercise 3 – Use LF Calculation to Check Equipment Rating

1. Check Cable 2 Rating (Use Revision)

Run different cases to see if Cable2 is over/under sized.

Consider different operating conditions.

Use derated ampacity based on default Tray setup (ICEA P54-440, H=6, W=18, Fill=30%, No

cover, cumulative effect and fire protection).

2. Check Cable 5 & Cable 7 Rating (Use Revision)

Run different cases to see if Cables 5 & 7 is under over/under sized.

Consider all possible configurations.

Use derated ampacity based on default Tray setup (ICEA P54-440, H=6, W=18, Fill=30%, No

cover, cumulative effect and fire protection).

3. Check XFMR T4 and T5 Rating

For all cases under consideration, are T4 and T5 under/over sized.

What size would be more adequate?

Check system voltage condition again.

Load Flow Example 1

ETAP Workshop Notes ©1996-2009 Operation Technology, Inc. Page 6 of 7

4. Determine Rating For Bus8, Bus12, CB8 and CB9

Operating conditions to be considered: configuration, loading, compatibility with upper stream

elements.

Consider the condition when one transformer (T4 or T5) is down.

III. Exercise 4 – Maximize Generator Output

1. Fully utilize co-gen capability

Let generator output 10 MW.

Check if there is any problem with system voltage, utility operating PF, etc.

III. Exercise 5 – Voltage Regulation

1. Operating without co-gen

See if high voltage buses can maintain V >= 98%.

Use transformer tap to correct voltage problem. Does it cause over voltage condition when

generator is in?

Try LTC or use LTC tool to determine tap position.

IV. Exercise 6 – Element Sizing

1. Size Cable 2 (Use Revision)

2 by 2 conduit

Ta=25, Tc=90, Rho = 95

2. Size Cable 5 & 7 (Use Revision)

A/G Tray with Height = 6, Width = 20, Fill = 25%

Tray Ta = 30, Tc=90

Use ICEA method.

3. Size equipment cable for Mtr4

Set up Ampacity page data: Ta=35, Tc=90, NEC, A/G Tray with top cover.

Size requirements: Vd (2%), Vst(80%), Ampacity (Mtr4 with MF), and SC (26kA, 0.06 second).

Use library: ICEA, Rubber, Magnetic installation, 100% insulation level, 0.6kV, 3/C, CU

conductor, 200ft.

Load Flow Example 2

ETAP Workshop Notes ©1996-2009 Operation Technology, Inc. Page 7 of 7

1. Open the ETAP project LFExample-2

2. Run Load Flow

3. You will notice a large number of under voltage conditions throughout the system

4. Correct these under voltage conditions in the system

5. For a solution to this problem please select the following

Revision = Solution

Configuration = Solution-CFG

Or run Load Flow Example-2 Scenario