Simplification of halt sequence to suppress increase of DC-link voltage during motor regeneration

This paper proposes an approach to simplify the proposed halt sequence of an inverter without the pole position information of a permanent magnet synchronous motor. When the Back-to-back (BTB) system with a small capacitor is stopped by the grid faults during motor regeneration, the DC-link capacitor voltage is increased rapidly if all gates in the BTB system are turned off at the same time. Therefore, a dynamic brake system is connected in parallel to the DC-link capacitor. The proposed halt sequence can stop the regeneration operation and suppress the rising of the DC-link capacitor voltage without the dynamic brake system. The proposed halt sequence is simplified by detecting the peak of the maximum current in this paper. In the experiment, it is confirmed that proposed halt sequence without the pole position information suppresses the rising of the DC-link capacitor voltage within 12V as well as with the pole position information.