Synchronous generator, One year later.

As I hopefully started this blog, I thought it could be scientific, funny, and helpful blog. Since then and till now, I've never added anything helpful, maybe something odd, and natural, but helpful? ... I don't think so. This is why as I started my seventh term in Electromechanical Engineering, I started to re-read and re-understand some things that I studied before. This blog will contain a brief explanation of what some of you might've heard of as a generator, or as I will discuss "Synchronous Generator".

A synchronous generator is an energy conversion "something". It converts mechanical energy to electrical, no matter what the mechanical energy is e.g: Wind, Waterfalls, Steam turbine power... etc . Lets start by dividing the generator into two main parts, the Stator, and the rotor. The stator is that stationary part and the rotor is the rotating part, DUH! The thing is there must be something as a stator and something as a rotor. The rotor in this type of generators is always the DC current carrying windings, and the stator is what is called the ARMATURE where voltage is generated. So why is that then? It's because when there is electricity transferred from a rotating "thing"  to a stationary "thing" it's hard to use wires and we end up with some things called carbon brushes and slip rings. Again, WHY is that then? Alright, now the armature is used to transfer the generated voltage to "someplace", this voltage is usually very high. Therefore it is much easier to deal with carbon brushes and slip rings with lower DC voltage that high AC voltages, there's your reason HAPPY now? Anyhow, now we reached the point that ROTOR = DC current and STATOR = induced AC voltage.

Coming to Main Theory of Operation:

Now we manufacture the synchronous generator, so we decide everything. Up until now we settled that ARMATURE=STATOR and DC=ROTOR. When DC current is passed through the Stator, magnetic flux is created. This generator will never work until it's ROTOR is rotated. Okay, it's rotating now, windings or armature are now cutting the magnetic flow lines created by the ROTOR. This magnetic flux induce EMF in the armature, represented by:
             E = 4.44 ɸ  f  Tph Kp Kd (RMS and for one phase)
As you probably can vaguely see now that the generator achieved it's purpose, GENERATING ELECTRIC POWER FROM MECHANICAL POWER. This is the main theory of operation of a generator used to just produce voltage and not using it and imagining it's a piece of heaven that is 100% efficient.

When dealing with a generator we must take into consideration the unexpected bull-crap the always makes us go "How the hell did he/she think of that?". He/She referring to the scientist who started all this. Some of these effects or “unexpected bull-crap" are:

1. Winding effects: The fact that the same wire is cutting the magnetic flux at different times due to being in different positions. (More will be more understandable if you got into Electrical Machines).
2. Chording factor: That sometimes some engineers (ironically that's our goal, torturing ourselves) want to pay less so but shorter wires, leading to a change in the winding.
3. Electrical losses.
4. Mechanical losses.
5. And the biggest bite of the ass, HARMONICS.

Coming up next, the "Generator on load". Right now, and since the first time I was learning about this, I always respond "Ouh, maan". Generally, when you have a generator, generating voltage and it's output terminals are an open circuit there is nothing to worry about, the problem arises when you use this generator to feed a load (The whole point of a generator, DUH!). Now you have a closed circuit when a load is connected with current flow, voltage change and power flow, so what's the problem? The problem is that a generator rated at 100 V output magically changes to 90 V, 80 V or even 20 V when loaded. It's not the value what's bothering, it's the fact that it changed in the first place. In a nut shell, when current is flowing through the load, it is also flowing through the armature and so creating an opposing magnetic field to the one that generated the voltage at the beginning, so reducing the induced voltage, aka 100 volts. Moreover, armature resistance and inductance are neglected. This finally leads to generator efficiency and couple of other annoying terms as Voltage Regulation ... etc.

Basically, you know now how a generator works. You might not fully understand how it works and the details that took me 8 lectures to understand, but hey it's good to know something after all. Just for more stuffing of information, there is some other machine known as Synchronous motor. Easy, work backwards! Instead of using mechanical energy to rotate the rotor, use electrical input energy to rotate the rotor. Instead of giving mechanical to get electrical, give it electrical to get mechanical. Anyhow, I hope you enjoyed the preface about synchronous motors. If you are actually and engineer and more understanding of this than me and would like to comment, feedback me or correct something in this "essay", Please! I made this for the world to benefit and for me too. :). Thanks for your time.