Thinking out-of-the-box

For simplifying a problem - we all assume certain things. After solving it successfully, we forget our initial assumptions - as if we had not assumed anything. This is where that certain problem becomes more complicated. At the end of the day, we forget the problem and standardise the solution. So that people always remember a solution and NOT the problem for which it's created...

The better cliche about the above thought is, when people wanted to write in the outer space where the gravity was very low- Americans invented a zero-gravity pen spending millions of dollars and years of time. The Russians proposed that we can use a lead-pencil.

Now we will come to the subject. we all know that power systems have a frequency of 50Hz (or 60 Hz) and say the transmission voltage is 33kV(or may be 66kV). We fix these variables quite nicely and forget about these when problems arise. After all they believed to be constant!

What if these variables are manipulated to gain advantage at the expense of consumers? why a utility might want to manipulate those?

For example, instead of keeping the system frequency at 50 Hz (keeping in mind the natural tolerance limits, for e.g. 49.5Hz ~ 50.5Hz), what if we can reduce the frequency intentionally, say to 47Hz? Here we assume that the under-frequency tripping of circuit breakers are below 47Hz so that we can keep the system running without tripping. at the same time we have manual controls so that we can adjust the speed governing so that it does not automatically settle at 50Hz.

What will be the effects of running the system at lower than 50Hz. As we all know that in most cases , a power system is inductive in load. Thus remembering the relationship Reactance X=L*w=L*2pi*f. This ends up in saying that if the system frequency is reduced- inductance will become lower in magnitude. Which means we can MANIPULATE the reactive power requirement. But the active energy supplied will not change.(no change in energy units)

This has additional effects in electrical apparatus of consumers as they are designed to operate in standard 50Hz frequency.

The same case is applicable to the line-line volatge. If we can manually reduce the line voltage of a 33kV line to about 32kV, what will happen. Surely we know that certain loads can not operate because of the voltage drop such as ACs, UPSs. but what can be gained from this manipulation. normally if the voltage of each generator is adjusted a bit lower than standard voltage, the power factor indicated in each generator will improve. This means that now each generator is supplying less reactive power requirement - and this in turn reduces the overall line voltage. This has implications in fuel efficiencies in case of a diesel generator. in case of hydro generators too this has certain FAVOURABLE effects to the operators of the power system.