Is this possible "sharing load and synchronizing power from a generator and a transformer involves two power sources" if possible how? need practical guideline. which controller i can use for this?

 

@Paul.037,

It would be very helpful if you could provide the entire context and source of the quotation you cited.

If there is one synchronous generator and its prime mover supplying electric power to a load or loads, then it can't--by definition share the load, because it is the only generator supplying the electric power to the load or loads of an AC (Alternating Current) electric power transmission and distribution system (grid). (An electric load is the aggregate sum of all electric loads on an electric power transmission and distribution--all the lights, all the tea kettles, all the refrigerators, all the air conditioners, all the electric water pumps, all the televisions, all the computers and computer monitors and associated equipment. They ALL appear as one single load to one or more synchronous generators synchronized to an electric power transmission and distribution system (grid).)

If there are two synchronous generators and their prime movers, synchronized together supplying electric power to a load or loads connected to an AC electric power transmission and distribution system then these two synchronous generators and their prime movers must share the load--or the alternative is that they will "fight" to provide the power to the load(s) while maintaining the system/grid frequency. And, the fight can be very, very ugly--resulting in serious problems including a system-wide loss of electric power to the load(s). In the same way all the loads on an electric power transmission and distribution system appear as one load, all the synchronous generators and their prime movers all appear as ONE generator supplying the load (loads) of an electric power system. To accomplish this task, ALL the synchronous generators must "play nice" with each other--translation: They must share in producing the electric power required by the load(s) connected to the AC electric power transmission and distribution system. If they don't, the system/grid frequency will be very, Very, VERY unstable.

On an AC electric power transmission and distribution system/grid frequency is almost the single most important parameter to be maintained as close as possible to the rated system/grid frequency (usually 50 Hz or 60 Hz). And when the amount of electric power generation synchronized the system/grid exactly matches the amount of power required by the load(s) on the grid/system--the system/grid frequency is stable, and should be at or very near rated. (Of course, on any electric system/grid, loads are being turned on and off, started, and stopped, loaded and unloaded all the time, all day long, every day of every month of every year of every decade of every century. For that reason, sometimes the system/grid frequency is a few hundredths of a Hertz higher or lower than the nominal system/grid frequency should be--but in the end everything all works fine (on a well-regulated and controlled electric power transmission and distribution system).

When the amount of generation synchronized to the grid (as measured by the amount of load each and every generator and its prime mover is producing (carrying) the system/grid frequency is, or should be, fairly stable. That means that every generator and its prime mover (when there is more than one generator and its prime mover synchronized to the system/grid) needs to produce power stably and participate stably and smoothly with the other generators on the system/grid. THIS is my personal definition of electric power sharing by multiple synchronous generators and their prime movers synchronized to an electric system/grid. So, by (my) definition, there must be more than one generator and its prime mover providing electric power to an electric power transmission and distribution system/grid to power all the load(s) connected to the system/grid.

Now ALL of the above refers to real power: watts; kW (kilowatts); MW (megawatts). Amperes flowing in the synchronous generators armature. Just about EVERY synchronous generator produces electric power at a relative constant generator terminal voltage--11.2 kV; 13.8 kV; 440 Volts; whatever the generator nameplate voltage rating is. In reality, though, most synchronous generators can produce voltage at a level approximately 5% less than nameplate rating, or 5% higher than nameplate rating. But, that's all--for the vast majority of synchronous electric generators.

The real electric power produced by a synchronous generator is (BASICALLY!!!) the product of the generator's terminal voltage multiplied by the generator stator current (for a purely resistive load--zero reactive current (sometimes--and incorrectly--referred to as reactive "power")). For a three-phase synchronous generator, there is also another term in the electric power equation: the square root of 3, which happens to be a constant value of approximately 1.732, which because it never changes--ever--when a synchronous generator is running (or not running...)--we are going to ignore it (because it never changes). SO, the BASIC real electric power equation is: P=Vt*Ia, where P=Electric power (in watts/kW/Mw), Vt is generator terminal voltage (in volts), and Ia is generator armature current (in Amperes).

Now, if the generator terminal voltage can only change by approximately -5% or +5% of nameplate rating, that means that the real power produced by a synchronous generator can only be changed by approximately -5% or +5%--which is very little for most synchronous generators.

So, how does one effectively change the real power produced by a synchronous generator? By changing the amount of amperes flowing in the generator's armature.

A generator (synchronous or otherwise) is an electric device for converting torque into armature amperes. An electric motor (synchronous or induction) is an electric device for converting amperes into torque. (Up until a few decades ago, the overwhelming majority of electric loads on an AC electric power transmission and distribution system/grid were electric motors--powering water pumps, primarily (fresh water, grey water, black water--but moving water from one place to another).) So, to get the armature amperes to increase in a generator, it is necessary to increase the amount of torque being applied to the generator's rotor from the generator's prime mover (a steam turbine, or a combustion turbine, or a hydraulic (hydro) turbine, or a reciprocating engine (burning diesel fuel or heavy fuel oil, or natural gas--or some kind of fossil fuel). Increase the steam or fuel flowing into a synchronous generator prime mover and, when it is synchronized to an electric power system/grid it will result in more amperes flowing in the generator's armature. And, that power is sent out to the electric power transmission and distribution system/grid.

And, that power must be produced stably (smoothly), including when changing load (by changing the amount of fuel or steam or water flowing into the synchronous generator's prime mover. And, when it's done stably and smoothly while two or more synchronous generators and their prime movers are synchronized to an electric power transmission and distribution system/grid they are all "sharing" in powering all the load(s) connected to the system/grid.

That's all I got time for this evening. This should get you started. And, by the way, the same goes for reactive current (VArs, kVArs, MVARs)--also often (incorrectly) referred to as reactive "power." For a synchronous generator to "share" in the production of reactive current--there must be MORE THAN ONE synchronous generator and its prime mover synchronized to the same electric transmission and distribution system/grid.

If you need more information or clarity, you need to provide some more information. Yes; external controllers can be used to manipulate the real power and reactive current to automate the control of real power and reactive power. But, there are other methods, too. Some very simple, that have been around since the beginning of AC electric power production. But, we need to know why you think it's not necessary to have more than one synchronous generator to have it share in the production of real power or reactive current. If you have a candy bar, and no one is near you or no one else near you want any of your candy bar you can't share it. But, if even one other person expresses an interest in your candy bar, it can be shared. Make sense? (Not exactly the same as sharing the production of real AC electric power and reactive current--but something can't be shared unless there is another "entity" to share it with, wouldn't you say?