Signal-Injection Sensorless Control of Synchronous Reluctance Machines for Overload Operation

Signal-injection sensorless control for low speeds region are usually assisted with compensation techniques to support the heavy load operations beyond rated conditions. For the standard $d$-axis pulsating voltage injection, this article analyzes the prospect of using $q$-axis current-model flux instead of the $q$-axis current for decoupled position estimation. Through convergence analysis, the feasibility of operation at overload is evaluated for the decoupled scheme against the state-of-art compensation technique and is shown to be a promising candidate for its simplicity and the lack of preprocessing of flux-map. All claims are experimentally validated on a 1.1 kW synchronous reluctance machine test-bench.