15Vdc & 10A Power Supply Design for Electroplating

[lloydi12345]

Hi, I was asked by my colleague to design a power supply with an input of 220Vac and an adjustable output of 0Vdc to 150Vdc with a current adjusting directly proportional to the voltage and a maximum of 150A. I only know how to design a simple power supply that could convert 220Vac to 30Vdc adjustable to 0Vdc. Can someone point me on the right direction on how to start calculating this? I know this sounds hazardous so a lot of help would be greatly appreciated.

Thanks

 

[kubeek]

I think you should start with some more numbers, mainly, what current do you want at 150Vdc? Is the supply supposed to be current limited such that into short it delivers only 150A?

 

[ronsimpson]

So we need 75A at 220V from the wall.
Question: single phase or 3 phase?
Hope you understand this is not a simple project.

 

[lloydi12345]

Thanks for your responses kubeek and ronsimpson, a while ago I talked to my colleague that I think it would be a really tough project if 150A would be the desired current output since I think it's an overkill anyway. We agreed to limit the project's current first at 40A.

So.. I think ideas for designing adjustable 150Vdc rated at 40A would be the specific requirement as of now. Should I use same rectifier bridge again for rectifying AC to DC? Type of transformer involved?

 

[tcmtech]

How clean of power does this need and what duty cycle?

 

[lloydi12345]

How clean of power does this need and what duty cycle?

pardon for some ignorance but what do you mean by duty cycle? I know it's related to PWM but what is its use? Also what is a clean power?

 

[Nigel Goodwin]

So.. I think ideas for designing adjustable 150Vdc rated at 40A would be the specific requirement as of now.

These are still crazy figures - 150V at 40A is 6KW, a UK mains socket is only capable of providing 3KW, and that's higher than the majority of countries.

What EXACTLY are you trying to do?, is it a practical project, or just part of a course? - and has your colleague just 'invented the numbers' without the slightest understanding of what they are?.

 

[tcmtech]

pardon for some ignorance but what do you mean by duty cycle? I know it's related to PWM but what is its use? Also what is a clean power?

You're in way over your head.

Clean power references to how much or how little AC line frequency ripple is tolerable. A little or a lot.
Duty cycle is how long does this power supply have to provide what ever power level for. Continuous duty for hours on end or a few minutes at at time out of every hour or less.

More importantly what is the load this is supposed to power?

 

[alec_t]

What is your budget for parts for this project? Components and hardware for a 6kW supply won't be cheap.

 

[ClydeCrashKop]

I worked on an automatic variable transformer on a boat. It's output was 230 V AC even if the input was 208 V. It was good for over 100 amps. Inside, it looked like a giant rheostat about 2 ft diameter with heavy windings.

 

[ronsimpson]

How about a 0-150V 10A supply and then parallel as many as you need?

 

[4pyros]

I dont understand why 0 to 150 Volts, but you could get 150 volts by rectifying mains voltage.

 

[kubeek]

Nope, 220Vac which the OP stated doesn´t give you 150Vdc after rectification.

 

[tomizett]

Further to tcmtech's question, does it need to be a regulated supply - that is, maintaining exactly 150V whether the load is 0A or 40A - and how much ripple (variation either side of the set voltage at the line or switching frequency) is acceptible?
If neither of these things are critical then a variable transformer plus heavy rectifier and massive caps would certainly be the simplest and most reliable, albeit an expensive and massive system.
I take it size and weight are not an issue?
If you're lucky you might be able to find secondhand a DC welder as a basis.

Please do elaborate on what you're planning to use it for though!

 

[ronsimpson]

Nope, 220Vac which the OP stated doesn´t give you 150Vdc after rectification.

220 X 1.414 =311 (300VDC)

 

[4pyros]

220 X 1.414 =311 (300VDC)

and half that is?

 

[4pyros]

Nope, 220Vac which the OP stated doesn´t give you 150Vdc after rectification.

That depends!

 

[ronsimpson]

That depends!

Depends on what?

 

[4pyros]

Depends on what?

The kind of rectification.

 

[ronsimpson]

The kind of rectification.

Draw a schematic.