What does a frequency converter do?

Frequency Converter is an electronic device to convert fixed frequency (50Hz / 60Hz), fixed voltage (110/120V, 208-240V, 380V-480V, and customized voltages) to variable frequency (50 Hertz, 60 Hertz or 400 Hertz adjustable) and variable voltage to compatible with different countries' power system, in order to protect the electric appliances from damage while running them on different frequency power systems.

Here list some cases that we got from our customers, which have been solved by using a GoHz frequency converter.

Case 1, Saving cost by using a GoHz frequency converter instead of generator
I work for a marine engineering company, manufacture and test equipment for military vessel predominantly in the UK but also do a lot of overseas work as well. I am working with a team putting together a proposal for a test site upgrade for testing hydraulic power units. Majority of military vessel have a 3-phase, 60Hz supply on board. When it comes to testing this equipment, the customer will generally want to see 60Hz supplied to the units.
Currently to provide a 60Hz supply, we use diesel generators to do this. However, after doing some calculations I have found that the running costs of a generator compared to using mains supply is 41% more expensive than mains supply. Therefore I would like to try and reduce the use of generators down. I have a number of questions that I will list below:

  1. Do you have a frequency converter that converts 3-phase power from 440V, 50Hz to 440V 60Hz?
  2. The largest HPU we will currently test is 60kW full load, do you have a frequency converter that large? If so could you provide me with a quote so I can compare this to generator costs etc.
  3. If you do not have a converter that can cope with that load, what is the maximum power rating of your frequency converters in the range listed in the first question?

Case 2, Converting 3-phase 440v/60Hz to 400v/50Hz for the vessel

We have a possible challenge regarding installation of a new cooling plant on a vessel. The power supply on the vessel is 440V/60Hz, and our supplier of the new refrigeration machinery says that this is not acceptable for their machinery. They need to be supplied with 400V/50hz. Can we solve this problem with Static Frequency Converters, as shown on this block diagram?
GoHz frequency converter for vessel

Case 3, Converting single phase 240v 50Hz to 60Hz in New Zealand
We have received an industrial Hot Foil Stamping Machine from overseas, that has been supplied with 240V (NZ runs 240V power supply) Single Phase 60Hz power system.
We should have received a 240V Single Phase 50Hz power system; hence our enquiry a frequency converter to turn 60Hz in to 50Hz for single phase power system.
Needing to convert from 60Hz to 50Hz; the unit runs a 4hp 3kw Single Phase 18.2A 60Hz motor; we believe the initial starting current is likely to be 80-90A – possibly even a little higher (?)
There are also 2 meters / timers used for adjusting temperature and feed rate – digital gauges in 60Hz.
For this option we suspect we would need a 5 - 8 KVA Frequency converter to adequately handle the load? (Hopefully the detail above is enough for you to advise just what would be needed, and what cost would be)
Needing to convert from 60Hz to 50Hz ; the motor and 2 meters/ timers ( same detail as noted above ) , PLUS also the heating bank in the machine ; heating bank is rated @ 2800W.
The motor has (as above) 18.2A loading, with the heating bank @ 12A; total loading of 30.2A
For this option we suspect we would need a 10-15 KVA Frequency converter to adequately handle the load? (As with above, we are asking for your guidance on best solution and cost, based on data supplied)

Case 4, Working for your home appliance
I just purchased a family hub refrigerator from the USA which is 115V and 60 Hz. I live in the Caribbean where we use 220V and 50 Hz but my house is wired for both 110V and 220V. My main transformer is 110v and 50Hz. My electrician advises that I purchase an electrical frequency converter (single phase) in order to get the fridge to work because the fridge comes on then cools to the required temperature and then heats up again. He says it is due to the lack of a frequency converter and that this will solve the heating problem. It is only needed to power the refrigerator.

Case 5, Step-down / Step-up the voltage
I am moving from Germany to the US, am currently starting to build a house here and would like to bring a kitchen across for various reasons.

While ovens etc. over there all work on 230V 50Hz and should work without problems with the 2 phase 240V (the frequency difference might cause some fans in the oven to run faster but so be it; my friend over here from Switzerland has lots of Swiss stuff like a Jura coffee machine, or a Miele washing machine working here), the issue are the cook-tops. Most cooktops over in Germany utilize the 400V 3-phase power so the question is, is there a way to get those to work.

I am getting a new connection from Duke Power in North Carolina, and the transformer they are going to put in just 200ft from my house will be new as well, so I guess I might be able to specify what I get. Can I step up from 3 phase wye 208V to 400V or step down from 3 phase wye 480V, what would be more economical?


Related reading: how to choose a frequency converter?


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