Open Access

ARTICLE

Sensorless Speed Control of Synchronous Reluctance Motor Using an Advanced Fictitious Flux Estimation Including Cross Coupling Effect

Abdin Abdin¹, Nicola Bianchi^1,*, Andrea Voltan², Walter Faedo², Piero Cazzavillan², Alessandro Biason²
1 Department of Electrical Engineering, University of Padova, Padova, 35131, Italy
2 Dana Service and Assembly Center (SAC), Veneto, 35035, Italy
* Corresponding Author: Nicola Bianchi. Email:
(This article belongs to the Special Issue: Energy Transition in the Transport Sector: Challenges and Opportunities)

Energy Engineering https://doi.org/10.32604/ee.2025.073434

Received 18 September 2025; Accepted 24 December 2025; Published online 19 January 2026

Abstract

Synchronous reluctance motors (SynRM) are widely employed in industrial applications due to their high robustness, low cost, and absence of permanent magnets. In recent years, significant research efforts have focused on improving the controllability and efficiency of SynRM. Accurate rotor position information is essential for the controller to generate appropriate current and voltage references corresponding to the desired speed and load torque. Shaft-mounted position sensors are generally undesirable because of their high cost, sensitivity to harsh operating conditions, maintenance requirements, and reduced reliability in environments characterized by high vibration. Consequently, sensorless control techniques that estimate rotor position using measured stator currents and voltages have attracted increasing attention. However, magnetic saturation, parameter nonlinearities, and cross-coupling effects significantly degrade position estimation accuracy and may compromise the stability of sensorless SynRM drives. In this paper, a nonlinear SynRM model is developed using finite element analysis (FEA) to accurately capture magnetic saturation and cross-coupling effects, thereby providing a precise representation of the machine’s electromagnetic behavior under varying load and flux conditions. A series of magnetostatic FEA simulations is performed. To reduce computational complexity, only one motor pole is analyzed by applying anti-periodic boundary conditions along the domain sides and enforcing a zero magnetic vector potential on the external stator boundary. Nonlinear iron material properties are modeled using the appropriate B-H curve. The simulations are carried out by imposing d- and q-axis current components and computing the corresponding flux linkages and electromagnetic torque. Based on these results, both apparent and incremental inductances are extracted and incorporated into the control algorithm. An advanced fictitious flux linkage method combined with a phase-locked loop (PLL) is employed for accurate rotor position estimation. Simulation results confirm that the proposed sensorless control strategy ensures stable operation and high position estimation accuracy over the entire speed range.

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Keywords

Sensorless controller 1; advanced active flux 2; fictitious flux 3; magnetic cross-coupling 4; phase locked loop controller 5

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