Introduction to electric drive systems:

Small and portable power compressors and spindles require ultra high speed and low power electric drives. In this paper we will discuss a drive system which operates at 500000 rpm and output power of 100w. The proposed design has a bidirectional power capability and drive controller. This drive system can be directly connected to mesoscale gas turbines.

Drive system overview and design:

To design such high speed and low power portable models, machine and power electronics are to be considered together other one factor may influence the other factor. Depending upon the size of the design the torque and speed varies. Micro gas turbine systems have an direct connected permanent magnets which generate output power in the range of 10 to 100 watts. The power electronics allow the ac currents of the machine in a bidirectional power flow. A dsp processor is used to implement a drive control system which allows the drive to communicate with the other control systems. For gate drivers dsp and other control drives an additional auxiliary power supply is provided. The drive control is designed by using a position sensor and is monitored in software platform. To achieve the speed of 500000 rpm high speed ball bearings are used and which are of small size and have high robustness. Static air bearings or dynamic air bearings are used to generate air pressure in the rotor and these have very low fiction and a long life time.

Power electronics selection and operation:

The power electronics interface becomes very complex for the drives with low motor inductance of small designs with high fundamental frequency. For such selection the machine design and the number of passive components and position of rotor and speed sensing factors are to be considered. For such drives sensor less position estimation is the best approach because of space restrictions. Synchronous position motor gives the rotor position information so that we can provide proper communication to the phase currents. Thus we can conclude that such small drives are designed by undergoing various complexities.

Download Ultra High Speed Low Power Electric Drive System Project Report.