Bipolar output using SpeedVal Kit

Ash2002

I am trying to find out if there is any reason why I could not use the following SpeedVal Evaluation Platform configuration to generate a Bipolar output e.g. +800V to -800V and a sinusoidal waveform about 0V.

The EVAL-ADUM4146WHB1Z Gate Drive Module does support Bipolar HV Supplies for a H-Bridge.

See this example from the data sheet, obvously the EVAL board provides Dual Drivers for High and Low Side:

I hope to use the MOD-PWR-MM-C3M0075120J H-Bridge module and

connect HS+ to +800V and HS- to -800V, essentially like this:

I need to connect my PSU ground to the Mid-Point, as shown on the schematic for MOD-PWR-MM-C3M0075120J.

The Mid-point seems to be also called the Switch-Node in the user guide:

On the Motherboard, there is what looks like a screw terminal for the Mid-point.

So finally my question is, using the modules listed above, if I connect a Dual PSU, GND to the Mid-point, +800V to the HS+ (Bus+) and -800V to the HS- (Bus-), would this work? Is it recommend and what other issues might there be? Is there some jumper setting or other config that needs to change?

Many thanks

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

AAnders

Hello Ash2002,

Unfortunately the configuration you have proposed is not possible with a single SpeedVal Kit motherboard. Placing +800 on +Bus and -800 on -Bus would apply 1600V to the DC bus, which exceeds the voltage rating of the capacitors, and would put 1600V of stress across a 1200V MOSFET when the other device is turned on.

One method you could use to achieve a +/-800V peak sine wave output would be to use two motherboards configured as an H-Bridge to allow for a bi-polar output. Supplying both boards with an 800V bus using two 400V power supplies with the mid-point grounded would keep the motherboards and MOSFETs within their rated voltage and be capable of providing a +800 to -800V peak output to the load. A simplified diagram is shown below. Please let me know if you have any other questions.

Thanks,

Adam

TBhatia

Hi, I hope that this answered your question. I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.