Transmisi

the small size of a cross section of wire or conductor cable . this is correspond with relation between voltage and current based on the power formula below :

P=V.I "With the same load or power, the greater the voltage, the smaller the current will be produced, and the smaller the current flowing, the smaller the diameter of the cross section of the current will be needed. Therefore, so that the size or diameter of the electrical conductor cross section needed as a conductor in the Transmission network does not use a very large conductor size, the way is to use a larger electric voltage even reach of thousands hundred voltage

Main station. The main station is an inseparable part of the electricity distribution transmission channel. Where a power system is centered on a place containing transmission and distribution channels, connecting equipment , transfomators, and safety equipment and control equipment. Java Bali Electric Power System in 2010 There were 435 substations with 24 500 kV Extra High voltage substations, 310 GI 150 kV, 101 GI 70 kV. . The main function of the substation: 1. To regulate the flow of electrical power from the transmission line to other transmission lines ,then distributed to consumers 2. As a place of control 3. As a safety operation for the system 4. As a place to reduce the transmission voltage to a distribution voltage Therefore, if viewed in terms of benefits and usability of the substation itself, then the equipment and components of the main station must have high reliability. and quality that is undoubted, or can be said to be optimal in its performance so that the resident as consumers do not feel disadvantaged by its performance. Therefore, something related to the reconstruction of the substation construction must have the applicable conditions and the construction of the main station must be considered load.

So the planning of a substation must meet the following requirements 1. Operations, namely in terms of easy maintenance and repair 2. Flexibility 3. Simple and strong construction 4. Has a high level of reliability and usability 5. Has a high level of security

c. Distribution

The system of distributing electricity from electricity to consumers (load) is an important thing to learn. Considering the distribution of electricity, the process goes through several stages, from an electric power generator producing electricity, channeled to the transmission network ,directly to the substation. From the electric power substation to the primary distribution network , and through the distribution substation directly to the secondary distribution network , electricity is channeled to consumers. Thus the electric power distribution system functions to distribute power electricity to the user via a low voltage network , while a transmission line serves to deliver extra high-voltage electricity to large power load centers (through distribution networks). Electricity Distribution is the process of distributing electricity from the Transmission Network to customers using electricity. This distribution network is divided into two parts, include : 1. Primary distribution network Primary distribution network is distribution netwok from reduced transmission network voltage in main station to medium voltage with 20 KV nominal voltage using step-down transformator 2. Secondary distribution network

Secondary distribution network is distribution network from main station to users . in distribution network started to do dividing electrical power load according to location and needs, and then dividing this distribution network . before arriving in consumer houses , 20.000 volt voltage is reduced again to 380 volt ( phase-phase ) or 220 volt (phase – neutral ), using step down transformer , that electrical voltage will enter consumer houses with low voltage classification ( 220 v or 380 v between phases ). Two types of voltages in the Distribution Network are as follows: 1. Medium voltage distribution network with the power around 6 kv – 20 kv 2. Low voltage distribution network with the power around 380 volt (phases to phases )or 220 volt (phase to neutral )

Different of distribution network with transmission network :

No.

In term of

Distribution

Transmission

1

Network location

In the city

Outside the city

2

System voltage

< 30 kV

> 30 kV

3

Network form

Radial,

loop,

parallel, Radial and loop

interconnection 4

Distribution system

Underground system and in Air system dan under the sea the air system

5

Network construction

More

system

complicated

and More simple

many 6

Network analysis

more complicated

More simple

7

Calculated circuit component

R and L component

R, L, and C component

8

Network supporting

Network poles

Network towers

9

Network

supporting

30 – 200 m

pole Less then 20 m

height 10

Distribution wire

BCC, SAC, AAC, and ACSR and ACAR AAAC

11

Bend wire

With bend wire

12

Network isolator

Pin

type,

post

hanging type , and type

Without bend wire type, Hanging type ring

13

Besarnya andongan

0–1m

14

Function

Distributing

2–5m power

to Distributing power to main

consumers

station

15

Supporting material

Steel , wood and iron

steel

16

Space between poles

40 – 100 m

150 – 350 m

Electric power distribution system An electric power network system is the distribution of electrical energy from a power plant to the consumer (user) at the required voltage level. This electric power system consists of generating units, transmission units and distribution units. Electricity distribution system can be divided into two types, direct distribution system and indirect distribution system. 1. Direct Distribution System Direct distribution system is an electric power distribution system that is carried out directly from the Power Plant, and not through the transmission network. This direct distribution system is used if the Power Plant is located not far from the load centers, usually located in the load service area or on the edge of the city. 2. Indirect Distribution System Indirect distribution system is an electricity distribution system that is carried out if the Electric Power Generation Center is far from the load centers, so that for the distribution of electric power requires the transmission network as an intermediary network before being connected to a distribution network that directly transmits electricity to consumers. Distribution Network Structure Electric power distribution system consists of several parts, include : 1) mainstation or Power Plant Center In this section if the electricity distribution system is carried out directly, the first part of the electric power distribution system is the Electric Power Generation Center. Usually the Power Plant Center is located at the edge of the city and generally in the form of a Diesel Power Plant (PLTD). To deliver electricity to load centers (consumers) is done with the primary distribution network and secondary distribution network. If the electricity distribution system is carried out indirectly, then the first part of the electric power distribution system is the substation which functions to reduce the voltage of the transmission network and deliver electricity through the primary distribution network.