A Novel I-f Startup Strategy with Smooth Transition to Sensorless Control for CSI-Fed PMSM Drives Used in Submersible Pumps

This paper proposes a practical startup strategy for current source inverter (CSI)-fed Permanent Magnet Synchronous Motor (PMSM) drives in submersible pump applications, focusing on ensuring a seamless shift to sensorless field-oriented control (FOC). The method effectively manages the transition to sensorless operation without requiring precise current or alignment error calculations, thereby simplifying implementation. By addressing speed and current oscillations directly during the startup and transition stages, the approach significantly enhances overall system stability and responsiveness. Validation through simulation and experimental testing demonstrates the strategy's success in maintaining low oscillation levels across various operating conditions, confirming its reliability for high-performance industrial applications.