7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 1/9

1

การวางแผนระบบไฟฟา

ว โรจน บัวคล ผ  อานวยการกองแผนงานระบบไฟฟา

มถนายน 2556

2

Selection of Distribution Voltage Level

•  According to PEA planning criteria, we haveset up economical loading a feeder and loadreach distance as follow

– 8 MVA for 22kV system, No more than 18 km

– 12 MVA for 33kV system, No more than 27 km

• If any customers use load more than 10 MW,we recommend them to move up to 115 kVsystem

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 2/9

3

115kV Extension vs 22kV Extension

5 MW – 20MW 

4

115kV Extension vs 33kV Extension

10 – 40 MW 

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 3/9

5

Substation Planning

Objective: to find the best solution betweenbuilding new substation and reinforcement of distribution system to serve the future load

The procedure is classified into 2 steps

1. Capacity Analysis

2. Voltage drop and Power losses Analysis

(Support voltage drop) 

CAPACITY ANALYSIS

To analyze the capacity of nearby substations in

case of one substation cannot supply load

(outage).

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 4/9

D

E

B

C

 A 

Note: These substations link together with distribution feeder

 Assume Sub A is outage.Nearby substations of Sub A are sub B-E

Thus, All load of Sub A should betransferred to Sub B-E

Case Study : Singha Nakhon Area

Singha Nakhon District

Ranot Substation

Songkhla Substation

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 5/9

Capacity Analysis : Singha Nakhon

Analysis :

Case 1 : SONGKHLA (EGAT) fails- Load 20.5 MW must be transferred to RANOT(EGAT)- Reserved capacity of RANOT (EGAT) is 41.5 MW

- Load of SONGKHLA (EGAT) can be transferred toRANOT (EGAT)

Case 2 : RANOT (EGAT) fails- Load 22.5 MW must be transferred to SONGKHLA(EGAT)- Reserved capacity of SONGKHLA (EGAT) is 45.45 MW- Load of RANOT (EGAT) can be transferred to SONGKHLA

(EGAT)

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 6/9

Voltage drop and Power Losses Analysis

SLA07

SLA03

ROA01

ROA02ROA06

Feeders whichsupply load in thisarea are :

Peak Load of supplied feeder at year 2005

Feeder Peak load(MW)

ROA1 3.15ROA2 4.07ROA6 6.30

SLA3 6.57SLA7 10.53

13.52 MW

17.10 MW

Assume : Songkhla cannot supply load

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 7/9

ROA1

ROA2

ROA6

SLA3

SLA7Voltage at theend of line

Close Tie Switches

and load wassupplied by RANOTSS

Ranot SS

Songkhla SS

Voltage at theend of line

Voltage drop Analysis (2005)

Add a new line(185 SAC)

 The voltage drop is improved to :

New line added

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 8/9

Voltage drop Analysis (2011)

Add 2 new lines(185sac) The voltage drop is improved to :

Summarize: Voltage drop Analysis

Add 1 feeder in year 2005

Add 2 feeders in year 2011

7/28/2019 Power System Planning-Example(PEA)

http://slidepdf.com/reader/full/power-system-planning-examplepea 9/9

Plan 1 : SubstationConstruction

Plan 2 : Distribution SystemReinforcement

Cost Plan2/ Cost Plan1 =1.19

Solution : Build New Substation

Economic Comparison between Substation

Construction and Distribut ion System

Reinforcement

ขอขอบคณPEA Smart Grid