I am building a model in simulink with variable frequency, and I am having trouble with generating a gate signal to the thyristors. It is an isolated system, with an induction generator feeding a resistive load. A capacitor bank is providing reactive power. To control the frequency, a thyristor controlled resistive dump load is used.

I wish to find the zero-crossing point for the voltage, and use this to generate a gate signal for the thyristors. Does anyone have an idea of how to do this i simulink?

Thank you!

 

Could you attach the schematic(as 800x600 jpg or gif file) and the file of model then our helper will be more easier to do a judgement?