Only three system parameters need to be input for SmartTune. The three key system parameters are: rated voltage, rated current and rated speed. The definition is listed below:

• Rated voltage: The rated DC supply voltage for the 3-phase BLDC motor. Device VM needs to be set to this rated voltage.
• Rated speed: The maximum rated speed of the 3-phase BLDC motor (in Hz). If the mechanical speed is in RPM (N), convert the value to electrical frequency (f in Hz) using the formula: f = P x N / 120. P is the number of rotor poles.
• Rated current: The rated peak phase current value for the 3-phase BLDC motor when this is driven at rated speed and rated voltage with load.

Typically, you can find the three parameters above in the data sheet. An example of motor data sheet is in shown in Figure 1-3.

Figure 1-3 Snapshot of Dunkermotoren BG 45 Motor's Data Sheet

Figure 1-3 is a snapshot of Dunkermotoren BG 45 motor's data sheet. As you can see, the rated voltage is 12V, the rated speed is 8*3327/120 = 221.8Hz and the rated current is 1.42A. You can input them into SmartTune, and successfully spin the motor by following the tuning steps in Section 2.

But in many cases, users can have different application needs from the data sheet, or sometimes the data sheet is unavailable. In these cases, randomly inputting unknown parameters can lead to faults reported by system and unsatisfying performance of motor. To eliminate faults, Section 3 provides some practical tips for setting SmartTune parameters.