Electrical Power Distribution System

-
Electrical Power distribution is an essential part of the electrical power system. Distribution system is Electrical System between substation fed by transmission system and the consumer end. 
According to nature of current Distribution System is classified in to
  1. AC Distribution System
  2. DC Distribution System 
Electrical energy is generated, transmitted and distributed in the form of alternating current. One important reason for the widespread use of alternating current in preference to direct current is the fact that alternating voltage can be conveniently changed in magnitude by means of a transformer.
For certain application DC supply is absolutely necessary. DC supply is necessary where variable speed machinery are used, for electro chemical work also in congested area where storage battery reserves is necessary. 
This Single line diagram shows general layout of Distribution System.
Distribution system employs Feeders, Distributor and Service mains.
Feeder - It is a conductor which connects substations to area where power is to be distributed.
Feeders don't have tapping current is same throughout.
Distributor- It is a conductor from which tappings are taken for supply to the consumers. The current through a distributor is not constant because tappings are taken at various places along its length.
Service Mains- It is a small cable which connects the distributor to the consumers terminals.

AC Distribution system is classified in to,
  1. Primary Distribution
  2. Secondary Distribution
1-Primary distribution:
Primary AC distribution system operates at voltages. Transmission line terminates at the sub-station where voltage is reduced from 33 kV to 11kV, 3-phase, 3-wire. The 11 kV lines run along the important road sides of the city. Power supplied to various substations and Big consumers having more demand at this Voltage. Primary distribution is carried out by 3-phase, 3-wire system.

2-Secondary distribution:
The electric power from primary distribution line (11 kV) is delivered to distribution sub-stations (DS). These sub-stations are located near the consumers localities and step down the voltage to 400 V, 3-phase, 4-wire for secondary distribution.
The voltage between any two phases is 400 V and between any phase and neutral is 230 V. The single-phase residential lighting load is connected between any one phase and neutral, whereas 3-phase, 400 V motor load is connected across 3-phase lines directly.

According to scheme of connection Distribution System classified as,
  1. Radial System
  2. Ring main System
  3. Interconnected System 
1- In Radial system separate feeders radiate from a single substation and feed the distributors at one end.
This is the simplest distribution circuit.
2-In Ring main system, Distribution transformer primary forms a loop, The loop circuit starts from the substation bus-bars, makes a loop through the area to be served, and returns to the substation.
3- In interconnected system the feeder ring is energized by two or more than two source.

Dipashri Patil
Electrical Engineer 

Comments

Post a Comment

Popular posts from this blog

What are the disadvantages of poor power factor?

-
Image
Disadvantages of poor  power factor - 1-Greater Copper Losses As at the low power factor, the load current is greater. Therefore, the large load current causes more I^2* R losses in all the components of the supply system. This in turn results in poor efficiency of the system. 2- Large kVA Rating of Equipment The electrical source equipment such as alternators, transformers, switchgears, etc. are always rated in kVA because the power factor of the load is not known when these equipment are manufactured in the factory. Hence, from the definition of power factor, we get, kVA rating=kW / cosϕ That is, the kVA rating of the equipment is inversely proportional to the power factor. Therefore, the lower the power factor, the higher the kVA rating of the equipment. Hence, at low power factor, the kVA rating the equipment needs to be made more which increases the size and cost of the equipment. 3- Larger Conductor Size For transmitting and distributing a constant amount of power at a constant v
Read more

Recognizing the risks associated with incorrect earthing of diesel generator.

-
Image
Incorrect earthing of a diesel generator can pose several risks: 1. Electric Shock:  Improper grounding can lead to electric shocks, endangering anyone in contact with the generator or its surroundings. 2. Equipment Damage:  Inadequate grounding may cause electrical equipment connected to the generator to malfunction or be damaged due to power surges or improper current flow. 3. Fire Hazard: Poor grounding increases the risk of electrical fires, which can result in property damage and pose a threat to occupants' safety. 4. Non-compliance:  Improper earthing can lead to violations of safety regulations and codes, potentially resulting in legal consequences and liability issues. 5. Operational Issues: Incorrect grounding can cause the generator to operate inefficiently or inconsistently, leading to disruptions in power supply and potential damage to connected devices or systems. It is always safe practice to ensuring proper earthing is essential for the safe and reliable operation of
Read more

Things to consider while buying APFC panels

-
Image
Things to consider when buying APFC panels: 1. Power factor: Power factor is a measure of how efficiently your electrical system is using power. APFC panels are designed to regulate your power factor, improving the efficiency of your system and reducing your energy costs. 2. Size of the panel:  APFC panels come in different sizes, so it's important to choose the right size for your needs. The size of the panel will depend on the size of your electrical system and the amount of power it uses. 3. Cost:  APFC panels can vary widely in price, so it's important to set a budget and choose a panel that fits within your budget. 4. Installation:  It's important to have your APFC panel installed by a licensed and experienced electrician. A qualified electrician can ensure that your panel is installed correctly and safely, and can help you choose the right panel for your needs. By choosing the right APFC panel and working with a qualified electrician, you can improve the efficiency of
Read more