Vector-Controlled Permanent Magnet Synchronous Motor Drive with Reduced Current Sensor

This study presents an algorithm for estimating two-phase rotor reference frame currents using a single-current sensor. For proper vector control operation, at least two of three-phase current information is required. The single-current sensor algorithm is presented for vector- controlled interior permanent magnet synchronous motor drive to reduce the cost and increase reliability. dq-axes current formation method evaluates the two-phase currents in the stationary reference frame by sensing only one-phase current and speed/position information. The two-phase stationary reference frame currents, i(beta s) current, are estimated using i(qs)* and i(alpha s), i.e., constructed from single sensor information. D- and q-axes currents are obtained from i(alpha s) and i(beta s)*. These are used to close the current loop in the vector-controlled drive. Three-phase currents can be reconstructed from the estimated two-phase currents. This method is entirely independent of machine parameters and applicable to all kinds of permanent magnet synchronous motor machines. The presented algorithm is validated on MATLAB/SIMULINK platform. Some sample results are shown from an experiment performed on a prototype developed in the laboratory (using dSPACE 1104).