What are the Effects of Generating Slightly Lower Frequency?

Yes. You will be cheating all your customers.

If your generators are for internal use only, go ahead.

It should bother you that all rotating devices are designed to run on 50 Hz, not 49.5.

You will see a slight reduction in efficiency.

hair brained idea

As Lyn mentioned if you are selling the electricity the clients will be cheated and any equipment damaged by lowering the frequency would be your fault.

As the efficiency drops, the equipment to maintain the operation tend to overheat and you will damage them, so I don't believe your management will be too happy with you.

We are generating for our use. Some times we sale the power, but at that time it is syncronized with grid and we have no control on frequency.

Photo of the plant electrician, making connections to the grid.

Aww! That was one for the 'Caption This' column.

please remember there is no thing is ideal .

Straight across the board is the value of the energy saved greater then the value in the lost of production. Say if you drop the frequency 1% and you save 1% of your fuel consumption. Is this value greater then 1% of lost production.

If it is shut it down all together and have you labor force do everything by hand.

No.

Your plant clocks will run slower and you will have to work longer...

Thanks all contributer.

Now I understud that 50 Hz is idial condition.

What are the effects if the frequency is kept slightly heigher, say 50.2?

So that we can go home earlier and need to work for little less hrs!!

Most plant motors are synchronous motors, which all have a range in which they operate most efficiently. Moving out of this efficient range will result in "inefficiency". Motors will heat up more, this heat is a parasitic load. This means that all the motors will draw more power because they are operating outside of their optimum range. Drawing more power means that you will burn more fuel to run the plant. Changing frequency off of the optimim will result in more fuel being burned to maintain your plant.

Some loads do not care about frequency. Lighting loads for instance. In which case there would still be no savings by varying the frequency off the optimal, either off by going higher or off by going lower.

Dear Mr. satendrakumar,

If the frequency is reduced, the Motor speed will fall by (0.5/50)*100 = 1%. The output of the Equipment will fall. This will have good amount of Impact on the Performance -on the CENTRIFUGAL PUMPS, and CENTRIFUGAL FANS since the capacity is PROPORTIONAL to to the SPEED, HEAD will vary as the SQUARE of SPEED, and the POWER will vary as the CUBE OF THE SPEED.

On Electical side, the Impedence Voltage will fall proportionally as the Inductance effect is proportional to the Frequency, and capacitive reactance will be inversionally proportional to Frequency.

DHAYANANDHAN.S

I think there is tolerance in the frequency but there are limits, in the generators the tolerance is +1 or -1 of the normal frequency

What effect would the reduced frequency have on your electronics? Your instrumentation? Your electrically operated controls? Just what is the nature of your plant that you are generating this electricity for? How about your communication system and your computers? Would you suffer from control malfunctions leading to a disastrous un-controlled shutdown due to electronic aberrations?

And you better correct the frequency before you try to parallel to the grid unless you enjoy watching generators being launched from their foundations.

The minimum frequency according IEC 60034-1 has to be 0.98*50= 49 Hz, but the voltage also has to be limited: not more than 1.03 and not less than 0.95 p.u.

So 49.5 Hz [0.99 p.u.] is still good [with the voltage in above limits].

Good? How? Why not at rated frequency and voltage?

How it affect the profitability of a generating company and a consumer, if frequency and voltage is reduced as per IEC recommendation?

Consider the generation and utilisation of 25 MW.

What was said in the above posts it is-theoretically-right. The synchronous motors and the induction motor will slow down a bit. But, if you could not go down to less than 0.98 p.u. of rated frequency nothing special would happen.

The problem is if you set the frequency nominal up as 49.5 Hz you can maintain the frequency-all the time-above 49 Hz. I don't know how rapid the rpm regulator respond could when the load will suddenly grow up. I think this issue it is only a theoretical one.

By the way, 60 Hz motor will run fair enough on 50 Hz system.

Zanoter4 said:

"By the way, 60 Hz motor will run fair enough on 50 Hz system."

Heres my experience:

we ran 230v 50hz HVAV motors at 208v 60 hz and they now 3 years old and still running fine. imho this is due to:

1. the drop in voltage is compensated for by the increase in frequency. I know this may not conform to theory, and I would like to hear another explanation ??? maybe the motors are cooled enough and just tolerant of variations in voltage and hz.

2. the electronics aren't as problem, since alot of electronics (including the electronics on these HVACs apparently) work on 120-230v AC - DC volts converters internally.