Sunday, July 19, 2009

Transmission lines

Generating stations are placed outside the populated area due to main reasons. Few among them is availability of resources, pollution factor, safety factor. In that case transmission of electrical power to the public is necessary. This can be done using transmission line. Generation of electrical power may be in the range of 12 KV, 36 KV or varies depending upon the generating stations. But before transmitting it should it should be step upped using transformer. Most of the generating stations have step up transformer. This is to minimise transmission losses. Power can be transmitted only at high voltages as it has many factors. To avoid eddy current losses the current level in transmission lines always be minimised.
It can be transmitted in two ways which is above the ground, later is under ground transmission. Proper insulators are places in towers to avoid any electrical short cut. High Voltage Direct Current transmission can be used only when need to transmit for high distances. Types of transmission can be seen in upcoming posts.

Wednesday, July 15, 2009

Principle of motor

Electrical machines run under induction principle. That is, when current carrying conductors are placed inside the magnetic field these conductor experiences some forces which is perpendicular to the conductors as well as field. Due to this force the motors starts rotating. This speed mainly depends on the following factor. The current flowing through the armature, the number of windings in the armature, field strength, and the external load connected to this armature. In an electrical motor this magnetic field is created by either placing permanent magnets or by providing external supply to this field coils.
The armature which carries conductor placed inside the field coils and the commutator and brush assembly is placed at the end of the rotor. External supply is given to the rotor windings via commutator and brush assembly. Once current flows through this conductors it experiences some force which is perpendicular to the field. Due to this force it start rotating. Commutator and brush assembly differs depends upon the type of motor.

Sunday, July 12, 2009

Construction of electrical machine

Electrical machine has almost same construction irrespective of the application. There are various parts in machine construction. Lets see each in detail. Outer layer of machine is called it acts as protection to entire set up. It is made up some hard metal to withstand vibration while machine is running and protect inner parts from outside disturbances. Then, there are two main parts. Those are named stator which is stable all the time, whereas rotor is rotating part of a machine.
Coils which is used for induction placed in two parts. Coil placed in stator is called field coil, where supply is given when machine is act as motor. Rotor coils are normally armature coils which gets supply due to induction. Commutator and brush assembly is placed in dc machines where it is used to collect the current from the machine. Armature and field terminals are taken out and placed in the yoke so that we can get the output from the machine.

Friday, July 10, 2009

Electrical Machines

Machines used for conversion purpose. It can covert one form energy into another form. It can be classified under two categories. Machines which convert electrical energy into mechanical rotations are known as motors, whereas machines which can covert mechanical rotations into electrical form is know as Generator.
Depending upon the input given, these are classified into two major types. First one is single phase where single phase supply is given at input terminals. Later is three phase machines which gets three phase supply at their input terminal.
Depending upon the supply further these machines are classified as AC machines and DC machines. Where AC and DC stands for Alternating Current, Direct Current respectively. It works under induction principle. AC machines are mostly used in all industries as it is effective in many ways.
Now a days use of machines are used in almost all places from micro application to train, plane, escalator and so on. We will discuss each and every part of machines in upcoming posts.

Tuesday, July 7, 2009

Electrical Measurements

Current, Voltage, resistance, power, and all other can be measured using equipments. Let us how to do that. Flow of electrons is called current which can be measured in many ways. Easiest way to measure is just keep a conductor which carries current in a device. This device has digital meter which gives the amount of current flowing through that conductor in Ampere. Voltage - Volt meter can be used to measure voltage, he you need to connect to terminal which has potential difference. The display clearly shows the voltage.
Resistance can be measured in many ways. If we find the current flow and the voltage at particular conductor then there is formula R=V/I. This can be measured in terms of ohm.
Power can be measured by multiplying current and voltage. Conductivity is the reciprocal of resistance. The unit of conductivity is mho. Multi meter can be used to measure current, voltage, power.

Sunday, July 5, 2009

Basic elements of electrical engineering

More complex in this world is electrical engineering. It is very difficult to get to know each and every aspect of this field. Here are some basic elements of electrical engineering and the meaning of them. There are two types of charges. Positive charge is named as proton where as the negative charge is called electron. When electron and neutron joins the net is neutral that is zero point. Current is nothing but flow of electrons. Electrons flow only if there is potential difference between two points. This potential difference is named as Voltage. If Voltage of one point is 240 means that the potential difference between that point and ground is 240 measured in terms of volt. Resistance is nothing but electrons cant flow in a conductor freely. There is some disturbances for electron flow this is called resistant. It may differ from one metal to other. Insulator is the material which doesn't allow the flow of electrons. Metal which allows flow of electrons is called Conductor.

Thursday, July 2, 2009

Introduction Electrical Engineering

Electrical Engineering - Its easy to say this word but it is really hard to understand the exact meaning. You can not imagine a day with out electrical. It has different fields like generation, transmission, and distribution. In this site we are going to discuss about each and every part of electrical world. As we know, electric power is mandatory for human life. But to reach our place it has to be generated and needs to be transmitted. Apart from this we are using so many electrical apparatus like television, radio, heater, air controller, and so on.
The work behind this product we really don't know. This is where an electrical engineer stand. Invention of technology keep going from the day Thomas Alva Edison found electric bulb. we developed lot but still need to do more.
Here you can find everything you need to know about power engineering. If you have any doubts about our posts please open your heart and give comments. We are here to serve you..