I am trying to put together a power stage for the Lebowski controller that can output a short duration maximum of ~18 kW from a ~60 V nominal 16s high capacity battery pack. The resulting peak (as in occasional, short duration) current is going to be about 70% of the maximum battery discharge rate.
This is going to drive a Heinzman PMS120 motor rated at 7 kW continuous S1 duty and, according to the Heizmann datasheet, able to deliver 18 kW and 45 Nm of torque for a 'short duration'. The motor is an axial flux motor with center rotor and coils heat-sinking against the case halves. Weighing in at 27 lbs this motor certainly feels like it has sufficient thermal mass for short bursts of the maximum 18 kW power. It was originally used in the Brammo Enertia motorcyle.
There are plenty of MOSFETs advertising currents sufficient to drive this motor to its maximum output. However, most of the datasheets mention in the fine print that the package leads can sustain a significantly lower current than the silicon can handle. For the TO-247 case 75 A RMS continuous is mentioned and for the SOT-227 somewhere around 200 A.
Do I have to be concerned that the few seconds of maximum current the motor can handle may be too much for the leads with their very low thermal mass?
On paper, 8 FET per phase in the TO-247 case should carry more lead limited current than 2 FET per phase in the SOT-227 packaging. How does this coincide with your experience?
This is going to drive a Heinzman PMS120 motor rated at 7 kW continuous S1 duty and, according to the Heizmann datasheet, able to deliver 18 kW and 45 Nm of torque for a 'short duration'. The motor is an axial flux motor with center rotor and coils heat-sinking against the case halves. Weighing in at 27 lbs this motor certainly feels like it has sufficient thermal mass for short bursts of the maximum 18 kW power. It was originally used in the Brammo Enertia motorcyle.
There are plenty of MOSFETs advertising currents sufficient to drive this motor to its maximum output. However, most of the datasheets mention in the fine print that the package leads can sustain a significantly lower current than the silicon can handle. For the TO-247 case 75 A RMS continuous is mentioned and for the SOT-227 somewhere around 200 A.
Do I have to be concerned that the few seconds of maximum current the motor can handle may be too much for the leads with their very low thermal mass?
On paper, 8 FET per phase in the TO-247 case should carry more lead limited current than 2 FET per phase in the SOT-227 packaging. How does this coincide with your experience?