Hi Praveen,

I don't know how it will work on dspace, but perhaps you know that in a practical hardware realisation, the two grounds must be kept separate ? So if you can do the same way in simulation, then certainly that would be realistic.

-Sanjay

Dear Praveen,

I'm not familiar to the term RPS except for Rounds Per Second - which doesn't make sense :-)

Still I have to disagree with Sanjoy Roy's answer.

In low-power drives that feature output power of few kW only, it is common to have one ground connecting power (DC-), logic ground and the supply for the low-side gate driver circuitry while the high-side drivers are supported by bootstrap capacitors.

This is mainly done for cost reduction.

As you are working on DTC which hopefully means Direct Torque Control, using bootstrap is not a valid option, the high-side drivers need to have individual, isolated supplies each.

From electrical point of view, it is possible to connect power-ground, ogic-ground and low-side gate driver supply ground.

Practically, you end up in safety issues regarding isolation requirements for safe operation as well as EMI-issues as your logic and driver parts will suffer from the distortions injected by the high-voltage influence.

It therefore is recommended to separate logic from power and also provide proper isolated supplies for all gate driver units.

In the lab, it is highly recommended, not to connect your development environment galvanically to any external power source as failure in the system may not only damage the inverter but also may destroy the expensive dSpace hardware.

Cheers - Martin

Thank you, for valuable answer

Dear Martin Schulz.....

Dear Mr.Praveen, 

I also agree with Mr.Martin. In hardware implementation, the power circuit and signal circuit must be properly isolated in order to avoid any power quality issues occur and spoil the power circuit. Otherwise, if any short circuit occurs on source side that will destroy the load side components. So it is advisable to have separete ground.

S.Alli