Converting AC mains to DC with the same voltage

rob_bluhm

Feb 27, 2010
4
I want to change 240 volt AC current to 240 volt DC currrent without loosing any of the current? The devise is a EV controller that accepts DC current and I dont want to use batteries due to being to heavy. Any answers?

Resqueline

Jul 31, 2009
2,848
Running only on mains will seriously limit the available power output. What power level do you need?
Commercial products like the 1500W Vicor LoPAC Family (AC-DC Switcher Power Supplies) could do the job but may be costly.
Do you have any more detailed specifications on the EV controller?

rob_bluhm

Feb 27, 2010
4
Input
Throttle Control Battery Pack Low Voltage Cutback
0 - 5 kohm 96 - 144 V 65 V

Output
Current Limit Frequency ofOperation Voltage Drop @ 100 Amps
15 kHz 0.30

2 Minute 5 Minute Continuous
500 A 375 A 225 A

Resqueline

Jul 31, 2009
2,848
It seems the controller is made for 120V so I don't understand your request for 240V. The Vicor module can deliver 120V as well btw..
But running on mains will only allow bench-testing an EV motor, up to 1/10th of the controller rating.
What are you trying to do, and what means are at your disposal to accomplish it?

rob_bluhm

Feb 27, 2010
4
Maximum nominal input voltage range for batteries: 72 to 300 volts nominal, 375 volts maximum
Maximum motor current at 50 C heatsink temperature: 1000 Amps for Z1K
Maximum Battery Current at 200V: 950 Amps for Z1K
Maximum Battery Current at 300V: 885 Amps for Z1K
Continuous motor current @ 50 C coolant temp & 100% Duty Cycle: 300 Amps for Z1K
Maximum Motor Current 1,000 Amps
Peak Power: 320,000 Watts for Z1K
PWM frequency 15.7 kHz
Power devices IGBT
Voltage Drop: < 1.9 volts at maximum current.

Resqueline

Jul 31, 2009
2,848
Well, if the last spec's are the right ones then you could just rectify and smooth the mains, giving 340V nominal and 373V max.
You'll need a decent sized capacitor being up for the ripple current rating needed, and an NTC as an inrush current limiter also rated for the needed current.
You're not being very "talkative" here so I can only guess you're in UK and is intending to run this off a 13 Amp outlet. Anyway, that's the current you'll be rating the NTC, rectifier, & cap' from.

rob_bluhm

Feb 27, 2010
4
I ma new to this and still in the learnig stages. but thanks for the help. What is a NTC, and I am from the US

Resqueline

Jul 31, 2009
2,848
Ok, so you're in an area having 240V then.
An NTC is a Negative Temperature Coefficient Resistor. It's disc shaped and has a higher resistance initially - then it will reduce it's resistance as it's heated by the current, thereby limiting it's loss so it doesn't overheat.
You want an initial series resistance so the charging of the capacitor doesn't blow the fuse when you turn it on.

55pilot

Feb 23, 2010
434
The first spec you posted is for a 10 lead acid battery based EV controller.

The second spec is something much bigger. 320KW is 420 horse power. That is not something that is designed to work exclusively with batteries. It is most probably out of some vehicle that works like a diesel electric locomotive, though it is too small to be out of a locomotive itself.

So which spec is correct? Initially you wanted to run 240V, then when it was pointed out that your specs showed you had a 120V controller, you changed your spec. Whic controller do you really have?

On your second spec, the IGBT is dropping 1.9V at 1000A, or 1.8KW just in the one IGBT. That has to be one huge device and such a device will need to be liquid cooled.

It will be helpful to know what exactly you are dealing with, what exactly you are trying to do and what kind to abilities and resources are at your disposal to accomplish that.

As some of us had to point out to another poster a couple of days ago about his project, you too are dealing with some powerful stuff that can kill you or others. If you do not appreciate the risk or lack the knowledge, skill and resources to do it safely, better quit while you and others around you are still alive and unhurt.

---55p

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