How to enable brake chopper pwm signal ?

[simon123]

I am trying to enable brake chopper pwm signal in GCT and it Works as long as I don't connect motor to the drive. BC pwm signal doesn't switch when three output pwm for motor are switching.

Anyone can help me please?

thanks

[PetrS]

Hi

The BC function generates the DC-bus break control signal based on the actual DC-bus voltage.

So the u_dc_bus_ON and u_dc_bus_OFF thresholds have to be properly set and also actual DC-bus voltage have to be measured and passed to BC function following BC update. Check if all above is done properly.

The usage of the BC eTPU function is demonstrated  in the application “BLDC Motor with Speed Closed Loop and DC-Bus Break Controller”. For a detailed description of the demo refer to AN2954 (http://cache.freescale.com/files/32bit/doc/app_note/AN2954.pdf).

Regards,

Petr