My doubt is abstract in nature and has nothing to do with Power System Engg...... it is to reflect the 'physics' behind load sharing between two power sources in general.

The case of 'voltmeter being replaced by additional load' is an over-exaggerated abstract statement by me to posit a theoretical point and not to be taken in the practical sense as such!

 

Perhaps you should review Kirchoff's Laws.

 

Dear Studiot,

As per Thingmaker3’s advice, I applied ‘Superposition Theorem’ to the problem of ‘Load Sharing’ between two power sources A and B (assumed to be DC) connected in parallel and sharing a common load. I observed that if EMF of say power source A is increased, terminal voltage Vt rises…… hence load current I(load) increases……. output power (W or MW) would also increase. But when the ‘Load Sharing’ concept is applied to Generators pertaining to Power System Engg., if input torque of say Gen A is increased…… terminal voltage Vt rises but load current I(load) or output power (MW) appears to remain constant.

I) To posit my point, consider Attachment on Alt Loading; Fig. 5 on Page no. 8, Example 3. Assume terminal voltage ‘Vt’ in place of ‘speed & frequency’ on the Y-axis……X-axis depicting output power or load current I(load) {DC generators can be considered for clarity}. Both G1 and G2 equally share the common load of 10MW i.e;.
G1(5MW) + G2(5MW) = Load output power(10MW).
Now, if the governor speed setting of G1 is increased…… terminal voltage Vt rises, the load sharing between both generators is altered to;
G1(7MW) + G2(3MW) = Load output power(10MW).
As observed, in spite of increased Vt the output Load power still remains constant at 10MW……. albeit with G1 taking up more load. (AVR considered on manual)

So the question now arises, Although Vt increases, Load power (MW) or I(load) remains un-altered? Then how does a voltmeter connected in parallel to the total Load indicate rise in Vt …… as voltmeter current ‘Iv’ remains constant (since ‘Iv’ now becomes integral part of the output load current....... it is in milliamps though) ? This concept still eludes me.

II) In Attachment on generator induced EMF waves, I think amplitude of EMF wave ‘Eb’ ought to increase….. as frequency (and hence speed) of Gen B appears to have increased, since magnitude of induced EMF ‘E’ in stator coils is directly proportional to generator speed. Kindly comment on the same.


Thanks & regards,
Shahvir

 

Perhaps you should review Kirchoff's Laws

post 95

As per Thingmaker3’s advice, I applied ‘Superposition Theorem’

post 96

You will find the path to enlightenment much less bumpy if you actually take proper note of what is said to you.

In all conscience Thingmaker3's post was short and clear enough.

Superposition is not the same as Kirchoff's Laws, which are a sight more fundamental.

Superposition only applies to circuits capable of solution by linear analysis.
Kirchoff's laws apply to both linear and non linear circuits alike as they are basically a statement of the principle of conservation of energy, suitable phrased for electrical calculation.

 

You will find the path to enlightenment much less bumpy if you actually take proper note of what is said to you.
In all conscience Thingmaker3's post was short and clear enough.

I think my dyslexia might have kicked in or it might be a problem related to semantics from my side!

Superposition is not the same as Kirchoff's Laws, which are a sight more fundamental.
Superposition only applies to circuits capable of solution by linear analysis. Kirchoff's laws apply to both linear and non linear circuits alike as they are basically a statement of the principle of conservation of energy, suitable phrased for electrical calculation.

I had applied Superposition Theorem as it conveniently adapts itself to networks containing more than one voltage source, equal or unequal. I had also considered batteries (DC source) and resistances to avoid complexity and which are linear and thankfully, obeys Ohm’s laws.

For further details you may refer to my recent thread on ‘A Peculiar Problem’ in the ‘Physics section’ of this forum……if you wish that is. I have branched out my doubt into a new thread to avoid further confusion!

Thanks & Kind Regards,
Shahvir

 

Superposition is not the same as Kirchoff's Laws, which are a sight more fundamental.

Superposition only applies to circuits capable of solution by linear analysis.
Kirchoff's laws apply to both linear and non linear circuits alike as they are basically a statement of the principle of conservation of energy, suitable phrased for electrical calculation.

Dear Studiot,

I applied Kirchoff's Laws to my electrical network as suggested by you and obtained exactly the same results as when i had applied Superposition Theorem.

This is because i have considered a linear circuit which obeys Ohm's laws.
You can refer to my thread on 'A Peculier Problem' in the 'Physics section' to gain a detailed insight into what i am refering to.

Kind Regards,
Shahvir