Digital Implementation of Single Current Sensor-Based IPMSM Drive With Sampling Error Delay Compensation

Abstract

Single current sensor-based three-phase drives are gaining huge interest from industries for sensitivity mismatch issues and cost reduction. However, the current sampling error caused by multiple sampling points during current reconstruction from various single current sensor (SCS) topologies led to increase in speed fluctuation and torque ripple. In this paper, a computationally efficient and accurate model-based sampling error compensation scheme based on a new SCS with double branch current sampling technique is proposed for an interior permanent magnet synchronous motor (IPMSM) drive. In order to improve of current reconstruction precision, the compensation strategy includes rotor angle compensation of IPMSM and dead-time effect mitigation for reduction of non-ideal behavior of inverter, which does not require major computation. Also, dc-link voltage utilization is improved significantly without any external dc-link control. The efficacy of the proposed compensation strategy is verified by an experimental setup consisting of 1.5 kW IPMSM drive, which shows the effectiveness of proposed current reconstruction technique from SCS by reducing current sampling error with minimum computational burden.