Mitochondrik is an integrated sensorless PMSM/BLDC motor control module for UAV and robotic propulsion systems based on the Telega motor control technology.
The Telega setup process is the same for any implementation. However, some hardware products have additional settings. The additional steps needed to configure Mitochondrik are described below. For additional information, please refer to the datasheet.
Shunt resistor selection
This section describes how to select an appropriate shunt resistor for motor phase current measurement.
The shunt resistance is selected to provide the maximum resolution for measurement. Based on the fact that the maximum differential input voltage on the current measurement inputs of Mitochondrik is 0.3 V, we can determine the resistance as follows:
\begin{equation} \tag{1}
\text{R}_\text{shunt} = \frac{0.3}{\text{I}_\text{max}}
\end{equation}
where \text{I}_\text{max} – maximum amplitude value of the motor phase current.
At the same time, the shunt resistance is constrained by the power rating of the shunt:
\begin{equation} \tag{2}
\text{R}_\text{shunt} = \frac{\text{P}_\text{shunt(max)}}{{\text{I}_\text{RMS(max)}}^2}
\end{equation}
where \text{P}_\text{shunt(max)} – maximum continuous power of the shunt; \text{I}_\text{RMS(max)} – maximum continuous (>2 s) RMS motor phase current value.
The final value of the shunt resistor is the minimum of (1) and (2).
Set the value of vsi.curr_shunt equal to the actual value of the shunt resistance.
Voltage source inverter (VSI) transistors
The following parameters should be set based on the power transistor parameters (sourced from the transistor documentation).
-
vsi.tr_rds_on- drain-source on-state resistance at \text{V}_\text{DS} = 10…12V and nominal motor phase current; -
vsi.tr_ton_ns- turn-on delay time assuming the drain current is close to the nominal motor phase current; -
vsi.tr_toff_ns- turn-off delay time as above.