Efficiency Measurement of a 3-Phase Inverter for a BLDC Motor

This application note introduces the reader to the SpaceX Hyperloop Pod Competition project and their special demands for the electrical drive train. Common motor technology like brushless motors and their typical control methods widely used in the industry are also discussed within this document.

However, the main focus of this paper is a demonstration of a power measurement method of a three-phase inverter by means of a 4-channel oscilloscope. Not only the theory of the power measurement is presented but also the conducted measurement is presented including tips and tricks to obtain the best measurement results.

The measurement solution provided by Rohde & Schwarz was mandatory for the TUM Hyperloop team to overcome challenges in optimization of the electrical drive train used in the SpaceX Hyperloop Pod Competition project.

Many thanks to Mr. Johannes Ungar and Faruk Centinkaya (TUM Hyperloop) for contributing significantly to this application note. By combining their expertise in electrical drive trains used in the Hyperloop Project and with a Test & Measurement solution from Rohde & Schwarz, we have achieved synergies that will be beneficial for any design and test engineers in the industry.