Ability to plug into multiple power sources

Have you looked at your computer power supply lately? Most are designed to take the entire range of voltages and frequencies you've specified. So to a limited extent this can and is already being done today. However, this cannot be done for every and all loads because many loads, particularly induction motors are optimized for one power grid parameters or another.

As Redfred said (rhymes!), if it's an electronic device it might be easy. But the fact that you said there is a panel board implies that there are other loads. So it's going to be difficult for us to help without sufficient information.

As a general rule, it is possible to design a system that will work on the lowest possible voltage and use a transformer in the incoming system that will allow a selection of incoming voltage options to provide for a consistent power level to the downstream devices. I have done this for a portable high pressure washing system OEM. It will, however, require the operator to KNOW AND UNDERSTAND what the incoming voltage level is to make the selection. I'm not sure I would trust the average high school student with that. Alternately then, you could spend even more money for a voltage detection system that could go to a controller that would select contactors that change the transformer primary connections automatically. Expensive, but possible.

As to the 50/60Hz issue, it will make a difference in AC motorized machines. Even if you keep the voltage consistent, the difference in frequency changes the speed and in things like pumps and fans, that changes the loading on the motor. So if you are at the design stage, you need to compensate in your motor sizing for the worst case scenario.

A switch mode power supply at the front end of the equipment to be connected will provide you with the necessary primary power source parameter flexibility. No user knowledge or intervention is required.

Alternatively an AVR (automatic voltage regulator) that is set to the desired output voltage and a large enough dynamic range on its input will automatically give you the desired fixed output to power your widget.

What is the equipment? It really does matter.

The equipment is a system of multiple devices (computers, LAN switches, voice equipment, multiplexers, communications subsystems). Is is a tactical shelter with 6 racks of equipment (about 4500W of load); HVAC is handled separately (not on this power scheme).

There are UPS's (single phase) on just about every rack that can be optioned (selectable) for various inputs. As JRaef points out it is important for the "operator to KNOW AND UNDERSTAND" the process of configuring these UPS accordingly.

Another requirement indicates that a junior technician be able to set this up in the field (perhaps a location where an electrical SME is not available.

Another consideration is the power panel. On top of all this, space is very limited; transoformers or other power conversion devices may present a space claim challenge.

The dream is to set this shelter up next to any worl power source; plug and play

Universal converters are feasible with today's technology. It can be done from 120 to 480V AC (50 to 400Hz) and 12VDC to 500VDC at the inlet and give you anything in between at the outlet. The power can be anything between 500W to 500KW. The converter can tell you if your load is approaching the limit for the specific configuration.

The cost is a function of the volume you need.

You must realize that if you need 5KW with 120V in, the input current will be very high (near 50A). When the same converter is supplied from a 480V source, the input current will be less than 12A but the power electronics will (probably) be operating at 600-700VDC in both cases.

So the cost of this flexibility is that you will need big transistors operating at high voltage as opposed to using two optimized converter that would use either small transistors at high voltage or big transistors at low voltage. (Same applies to the other power components)

Therefore, the flexible converter will cost much more and be larger than the optimized version but anybody will be able to use it on any source...

Contact me if you have a budget, these are the problems we solve regularly.