Real-Time Modeling of Electric Machines for Hardware-in-the-Loop Environment: A State-of-the-Art Review

Hardware-in-the-loop (HIL) simulation enables real-time closed-loop testing of electric drive systems by interfacing machine models with physical controllers. This paper presents a review of real-time modeling approaches for electrical machines in HIL environments. Nonlinearities such as magnetic saturation, cogging torque, spatial harmonics, and thermal effects are examined in the context of analytical, finite element analysis (FEA) based methods, and lookup table driven models. The review also evaluates real-time hardware platforms in terms of execution latency, model compatibility, and integration workflows. A comparative analysis highlights that while induction machine and permanent magnet synchronous machine models are extensively validated, switched reluctance machine (SRM) modeling efforts remain limited, particularly in capturing multiphysics behavior. The review explores the current limitations in SRM modeling and motivates the development of high-fidelity, multiphysics approaches compatible with real-time HIL simulation.