Substation Design

Physical & Technical

Considerations

I. Objectives

II. Substation Design Introduction

III. General Design Considerations

Outline

Revision 00

To be able to know:

The general considerations in designing a distribution

substation

The physical layout considerations in developing a

substation.

Objectives

I. Meralco Electric System & Planning

Criteria

II. Use of Gas Insulated Switchgear Substation

Substation Design Introduction

Meralco Electric System

Planning Criteria

All substations shall have at least 2 subtransmission feeds.

Limit maximum normal loading of power transformers to OA rating(FA1 for switching flexibility and FA2 during adjacent transformer failure)

Improvement of reliability of existing substations.

Substations must be near the load center depending on the load density of the substation service area

Substation configuration must be single bus, ring bus, or breaker-and-a-half scheme

Transformer capacity must be 83 MVA for 115-34.5 kV and 33 MVA for 69kV-13.8 kV or 115kV-13.8 kV

USE OF GIS SUBSTATION The conventional substation is normally being used

in substation development. However, in highly urbanized area where land is scarce and very costly, the use of GIS substation is considered. To justify this, the cost of the land should be at least Php 105,000 per sq.meter.

In addition, some selected odd-voltage substations within Metro Manila are also programmed for conversion into major 115 kV substation by using either GIS equipment or a one bank/one line scheme. The rational is that their locations are already within the load center, and it is difficult to find and buy lots to be used as substation site within such developed areas.

I. Geographical / Site Considerations

II. Environmental Considerations

III. Maintenance Considerations

General Design

Considerations

1. Drainage and soil conditions

2. Cost of earth removal, earth addition, and earthmoving

3. Space for future as well as present use

4. Proximity to earthquake fault lines and floodplains

5. Public concern; avoidance of schools, daycare centers, and

playgrounds

6. Atmospheric conditions: salt and industrial contamination

7. Location of present and future load center

8. Location of existing and future sources of power

9. Availability of suitable right of way and access to site by overhead and underground sub-transmission and distribution circuits

10.Location of existing distribution lines

Geographical / Site Considerations

Revision 00

AMADEO 230kV-115kV-13.8kVDELIVERY POINT SUBSTATION

Revision 00

1. Appearance

2. Noise

3. Effluent

4. Electrostatic and electromagnetic

effect

5. Public Safety

6. Weather

Environmental

Considerations

Revision 00

AESTHETICS / APPEARANCE

Revision 00

MALIBAY 115KV-34.5KV SUBSTATION

AESTHETICS / APPEARANCE

MANDALUYONG 115KV 34.5KV SUBSTATION

Revision 00

LEGAZPI 115KV-34.5KV GIS SUBSTATION

AESTHETICS / APPEARANCE

Legazpi 115KV 34.5KV

GIS Substation

Revision 00

SUBSTATION NOISE

Revision 00

SUBSTATION NOISE

Sources of audible noise within a substation include transformers, voltage regulators, circuit breakers, other intermittent noise generators.

Among the sources, transformers have the greatest potential for producing objectionable noise.

The design engineer should consideraudible noise reference documents and regulations

Revision 00

SUBSTATION NOISE

At 550kV BIL,

OA/FA1/FA2

OA 76dB 50000

FA1 79dB 66667

FA2 80dB 83333

Revision 00

SUBSTATION NOISE

At 550kV BIL,

OA/FA1/FA2

OA 76dB 50000

FA1 79dB 66667

FA2 80dB 83333

MERALCO POWER TRANSFORMER SPECIFICATION ON

Revision 00

Minimum Noise Level

1 METER

69 dB

1 METER

63 dB60 dB ( INCLUSIVE OF STREET NOISE )

10 METERS

POWER

TRANSFORMER

CONCRETE

WALL

BARRIER

CONCRETE

WALL

BARRIER

ROCKWELL SWITCHGEAR

BUILDING

SUBSTATION NOISE

Revision 00

EFFLUENT

Revision 00

EFFLUENT

IEEE STD 980-1994 (R2001) IEEE Guide for Containment and

Control of Oil Spills in Substations

RUS Bulletin 1724E-300 Design Guide for Rural Substation

Water Quality Guidelines and General Effluent Standards

of 2008, Revising DAO 34 and 35, Series of 1990

Effluent refers to discharges from known source, which is passed into a

body of water or land, or wastewater flowing out of a manufacturing plant,

industrial plant including domestic, commercial, and recreational facilities.

Revision 00

ELECTRO-MAGNETIC FORCE (EMF)

Exposure (60 Hz) Electric field Magnetic field

Occupational 8.3 kV/m 4.2 G (4,200 mG)General Public 4.2 kV/m 0.833 G (833 mG)

International Commission on Non-Ionizing Radiation Protection (ICNIRP) is anorganization of 15,000 scientists from 40 nations who specialize in radiationprotection.Source: ICNIRP, 1998.

ICNIRP Guidelines for EMF Exposure

Revision 00

ELECTRO-MAGNETIC FORCE (EMF)

Electro-Magnetic Force (EMF) way below allowed international

standard of 833 milli-Gauss

0

10

20.8mG - Colored TV

45mG - Aircon

5.76 mG - Meralco Hillcrest Substation

- taken March 7, 2003

236mG - Hair Dryer

Milli-Gauss

5

20

40

50

200

300

1000International Limit=833mG

11.6mG - Computer

Revision 00

PUBLIC SAFETY

Revision 00

PUBLIC SAFETY

Revision 00

DOORS WITH WARNING SIGN

PUBLIC SAFETY

METAL FENCEDOORS WITH APPROPRIATE

GROUNDING

GATE WITH CAUTION SIGN

Revision 00

WEATHER

Revision 00

WIND

It is important that

substations operate

more reliably in

extremes of weathers.

As a minimum, substations

should be resistant to wind

velocities as shown.

Revision 00

RAINFALL / FLOOD

A substation

should be designed to be

operable under predictable

conditions of rainfall.

should have sufficient

drainage to exhibit little

standing water within a few

hours after a heavy rainfall.

The level of the substation

site should be higher

than the 1 in 50 year

flood level.

Maintenance procedures should have minimal impact on

the operation of the substation

Adequate clearances provided for maintenance

personnel, equipment and procedures are considered

Maintenance

Considerations

TEMPLATE: RING BUS SUBSTATION

AREA=4,180 SQ. METERS

LAGUNA BEL-AIR 115KV-34.5KVRING BUS SUBSTATION

AREA=3,294 SQ. METERS

Revision 00

TEMPLATE: SINGLE BUS SUBSTATION

AREA=3,000 SQ. METERS

Revision 00

AREA=3,000 SQ. METERS

SANTOLAN 115KV-34.5KVSINGLE BUS SUBSTATION

For inquiries, email us: efaraullo@meralco.com.ph