NEDO/MagHEM's test bench for the new ultra-high-efficiency motor with magnetic bearings uses the HBM eDrive testing system, including the highly dynamic GEN7tA power meter, for electrical efficiency measurement. In conventional systems, synchronous measurement was difficult because it was done with a torque meter, a power meter, and multiple measuring instruments, depending on the measurement parameters. Synchronizing the measurements of all measured parameters by introducing the eDrive GEN7tA system makes measuring substantially easier. In addition, real-time computation enables simultaneous observation of measured waveforms such as magnetic flux and torque waveforms as well as computed waveforms such as iron loss separation, thereby significantly improving test efficiency.
Since iron-loss separation requires data in the switching frequency range of the inverter, high-speed sampling is necessary. However, with the conventional power meter, the sampling was relatively slow and it was impossible to capture the phenomenon in the relatively high-speed regions in order to investigate torque ripple or switching frequency related issues. Only the HBM eDrive system can measure voltage and current signals with high-speed sampling of 2 MS/s and provide 1/2 cycle power measurement calculation. (However, since the maximum speed of motor rotation is 20,000 rpm and the switching frequency is 20 kHz, further high-speed measurement is required for high frequency component measurement.)
With the conventional power meter, only analysis based on the averaged calculation results was possible, but since HBM eDrive processes all the raw data (instantaneous data) at high speed, both the speed and the accuracy of the analysis have greatly improved. A high voltage of 600 V can be measured directly by using the Genesis HighSpeed 1000 V input card. It is also more convenient; there is no need to switch between the time-axis display and the FFT display, so the researchers can check the output on the same screen.
(*) The NEDO/MagHEM researchers are now focusing on developing new high-performance magnets, together with the results of the development of soft magnetic materials and motor evaluation technology in the first phase, aiming to develop magnetic materials that can reduce its energy loss and increase its power density by 40% compared to conventional electric motors. The specific development goals of each research and development item shall be in accordance with the research and development plan of the separate sheet.