Gate Driving for High Voltage System

[sabu31]

Dear All,

I need to make an H-Bridge with DC-Link Voltage of 2.5kV. I am intending to use the device whose datasheet is attached. I would like to know what is the driver IC that can be used for driving the high side of the bridge whose DC-link is 2.5kV. Any reference design or related document will be helpful.

Thanks & Regards,

 

[KlausST]

Hi,

it depends on the circuit.
If used as LOW SIDE switch then the gate drive voltage (V_GE) is just a couple of volts. .. and has nothing to do with 2.5kV.

Show your circuit and we can discuss about it in detail.

Klaus

 

[sabu31]

Hi KlausST,
Thanks for the mail. As mentioned in the post, I need to know options for high side driving.

 

[KlausST]

Hi,

sorry. Indeed I missed the "high side" information.

driving HIGH side causes two major problems:
* power supply (depends on duty cycle range (bootstrap) and, driving power and switching frequency)
* digital control signal (mainly depends on switching frequency and duty cycle range)

Possible solutions:
* In some applications you may use a transformer that combines the power and the signal solution in one part.
* power supply: DCDC converters, HF/NF transformers, bootstrap circuit
* control signal: opto coupler, POF, digital isolators,

Klaus

 

[FvM]

Little room for IC gate drivers with isolation > 2 kV. Infineon is advertising 1ED3x single channel drivers for 2300 V class https://www.infineon.com/cms/en/product/power/gate-driver-ics/high-side-drivers/, but only useable under preconditions. For higher voltage, discrete isolation transformers for power supply and control signals are the way to go.

 

[danadakk]

Isolated gate drivers :

https://www.digikey.com/en/products/filter/isolators-gate-drivers/906?s=N4IgTCBcDaIPYAcAucDGcCuCA2BTATiALoC%2BQA

General HV opto isolators :

https://www.digikey.com/en/products/filter/transistor-photovoltaic-output-optoisolators/903?s=N4IgTCBcDaIPYAcAucDGcCuCA2BTATiALoC%2BQA

Ref material :

https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=33062

https://www.ti.com/lit/ml/slua618a/slua618a.pdf\

https://www.nve.com/Downloads/il6xxCMTI.pdf

Regards, Dana.

 

[Easy peasy]

Isolated high side gate drivers for 2.5kVDC bus do not really exist - as the rating for 2.5kV constant is only a few hundred hours at most

A carefully wound and constructed GD transformer is the only way to go here - same for low side to get the same delays.

You need to consult an experienced power electronics design engineer.

 

[cupoftea]

If you want too use a switching power supply and have 2.5kV bus..then you would really only use an LLC converter for that, as you will know.....because leakage in txformer is big and llc can use that. Also, a slow gate drive can be tolerated by llc because its zero voltage switch on.
But some kind of stacked SMPS sounds like the way here....with balancers to assure that the vin stays equal to each of the stacked SMPS's....then each smps will only see say 500V, if there are 5 of them in the stack.

 

[BradtheRad]

Consider this method of biasing if you only have N-devices, and a low-voltage control to bias them.

Bias the high side NPN On by means of a resistor conducting supply voltage.

Turning it Off is done by pulling its bias to ground by turning On an additional NPN.

In this manner one clock signal is able to operate the half-bridge (or half of the H-bridge).