Vol.:(0123456789) Transactions of the Indian National Academy of Engineering https://doi.org/10.1007/s41403-020-00184-w 123 REVIEW ARTICLE A Novel Modeling Approach for a Switched Reluctance Machine for Multi‑Quadrant Operation Swagata Mapa 1  · G. Bhuvaneswari 1 Received: 4 July 2020 / Accepted: 27 October 2020 © Indian National Academy of Engineering 2020 Abstract Switched reluctance machine (SRM) is robust in nature as its rotor is devoid of permanent magnets and rotor windings. It is capable of operating in a wide range of speeds and ofers an excellent dynamic response when appropriate power converters and control techniques are employed for its operation. These qualities make SRM, one of the best choices for electric vehi- cle (EV) applications. Due to its extremely non-linear characteristics, accurate modelling of an SRM is a challenging task. This paper frst discusses an experimental technique to determine the parameters of the SRM accurately and subsequently presents precise modeling of the machine using these experimentally obtained parameters. Two methods of modeling an SRM are discussed along with an objective comparison brought out clearly not only between the two models but also with the performance of a laboratory prototype. A novel modifcation has been incorporated, to accommodate the saturation phenomenon of the machine, while developing the linear model for the SRM. Detailed analysis of the two types of models in the same operating zones is carried out, and their results are compared with the actual experimental results to ascertain the accuracy of the developed models. Keywords Non-linear model · Linear model · Variable inductance · Switched reluctance machine Introduction The transportation sector is at the outset of a major revolu- tion because of the increasing oil prices and carbon diox- ide induced climate change afecting the globe adversely (Du and Ouyang 2013). This is the reason why research on electric vehicles (EVs) is progressing in a focused manner. Any EV should satisfy primarily two requirements, namely, extremely good efficiency and excellent controllability. Switched reluctance motors ft the bill exactly because of their high torque to inertia ratio, exceptional reliability owing to fault-tolerant structure, good controllability due to the availability of power converters and maintenance-free operation caused by the rugged rotor structure (Miller 2001; Mihic et al. 2017; Lee et al. 2017; Kachapornkul et al. 2007; Pindoriya et al. 2018; Bukhari et al. 2019). SRM is smaller in size (for a given kW rating as com- pared to the other conventional electrical machines) and is capable of operating in a wide range of speed; so, it is the natural choice in the feld of aerospace and automotive systems. Owing to its constructional features and due to its being mostly operated in the magnetic saturation region to obtain higher torque output and efciency, SRM behaves in a highly non-linear manner. Thus, to model, analyze, and understand its performance, accurate estimation of its static electromagnetic characteristics is necessary, which is normally accomplished using fnite element (FE) analysis (Arumugam et al. 1985; Sun et al. 2019). But, for carrying out FE analysis, accurate knowledge of the internal dimen- sions of the machine, such as stator pole arc length, rotor pole arc length and width of the airgap, are essential, apart from knowing the magnetic property of the material of the core and the number of turns in each of the phase wind- ings. Determining the fux linkage characteristics of an SRM experimentally is very involved (Krishnan and Materu 1989; Sharma et al. 1999). As the fux linkage characteristics play a vital role in the capability of an SRM, its magnetic circuit design is of paramount importance. Electric transportation sector is highly competitive which makes it important to estimate the system performance realistically. When the performance is to be evaluated, it * Swagata Mapa swagata17.iitd@gmail.com 1 Electrical Engineering Department, Indian Institute of Technology Delhi, New Delhi 110016, India