How to Measure ZSV Without Accessing the Neutral Point of the Permanent Magnet Synchronous Machine?, Singapore

Question: How to measure ZSV without accessing the neutral point of the Permanent Magnet Synchronous machine?

Conventional Carrier Signal Model with Zero Sequence Carrier Voltage Detection

Generally, the modelling of carrier signal injection method using a zero-sequence voltage is implemented on the natural reference frame [BRI04] [BRI05]. The balanced resistor network and access to the machine neutral point are required to measure the zero sequence carrier as shown in Fig. 4.1.

Zero sequence carrier voltage response for rotating signal injection

To calculate the zero-sequence voltage for rotating injection method, the three-phase voltage equations shown below are used. For simplicity, the resistance term and the mutual inductances are neglected as well as the back-EMF as the operating speed is ranged between zero to a very low speed [BRI04] [BRI05].