Grounding in IGBT Control of Brushed DC Motor

[yousif]

igbt dc motors driver

I use a uC, Optocoupler, MC33153 IGBT Driver IC, and 600V 70A HGTG40N60B3 IGBT to Control A 2HP Brushed DC Motor

How to Connect the Following Grounds in this Diagram?
In MC33153 Datasheet GND1 and M+ are Connected How is this ?
and if I connect GND1 and M+ , should I connect GND2, GND3 also ?
Please I need some Explanations and what type of Driver is this one ?

 

[FvM]

Hello,

I don't understand, why you connect the IGBT with floating emitter, you could as well connect motor M+ to rectifier+ and motor M- to IGBT collector. Then IGBT emitter, that must be connected to driver(GND1) and driver supply (GND2) ground at any case, wouldn't carry high switching voltage (if motor has PWM control).

GND2 and GND3 could be tied together, if the processor don't need isolation from mains supply. Then opto coupler could be omitted.

But the processor circuit then no longer would benefit from safe low voltage and needs the same shock-proof protection as mains voltage itself. Furthermore the processor circuit would be fully exposed to switching transients from the IGBT circuit ground. Control circuits directly connected to mains voltage can be often found with household equipment for cost saving.

Regards,
Frank

 

[Siniša]

I will assume that both 18V and 5V power supplies (rectifiers as you call them on the schematic) are isolated from mains and "250Vdc" is not. Controling M+ or M- does not make much difference in this case.

Most likely option is that driver operates normally (not in bootstrap mode) and GND1 and GND2 are tied to M+. Power supply 18V should have 800V-1000V isolation capability between primary and secondary side!

GND3 is at ground level for safety.