How do i generate a control for an IGBT switch based on voltage difference?

I want to minimize the effect of fault current in a wind turbine generator connected to a grid. I'm using a series dynamic braking resistor. in my connection i connected the resistor in parallel to an IGBT switch, but i don't know how to use the difference between the normal operating voltage and the fault voltage to control the operation of the IGBT, so that the switch remains closed when the system is normal and opens at fault voltage.

Answer 1

[MULI]

Hi Charles,

Firstly, measure the grid voltage where wind turbine is connected. You need to define what level corresponds to normal voltage based on ratings of system and tolerance level (eg: a significant drop in voltage).

To implement the control logic “Relational Operator” block can be used to compare measured voltage against the pre-defined threshold and the output of the relational operator block is given to gate terminal of IGBT switch to control the switch.

Now the switch will be ON under normal voltage conditions and OFF under faulted condition and the current is forced through the dynamic breaking resistor to limit the fault current. I have attached the reference model regarding its implemtation.