The manufacturer said no one was injured at the incident and an investigation to establish a cause was underway.
"We do know that the prototype was being started up, and therefore not in operation, at the time of the incident," a statement from the manufacturer said.
MHI Vestas said construction and installation timetables for deployment of the model would be unaffected by the incident.
The model is rated at 9.5MW following regular upgrades from an initial 8MW output. It has been at the highest output since late 2016.
While rated at 9MW in December 2016, the prototype achieved a 24-hour generation record producing 216MWh.
Pictures shared on social media show the turbine's nacelle has been entirely burned out.