*Article* **Real-Time Digital Twin of a Wound Rotor Induction Machine Based on Finite Element Method**

#### **Sami Bouzid** *∗***, Philippe Viarouge and Jérôme Cros**

Department of Electrical and Computer Engineering, Laval University, Quebec, QC G1V 0A6, Canada; philippe.viarouge@gel.ulaval.ca (P.V.); jerome.cros@gel.ulaval.ca (J.C.)

**\*** Correspondence: sami.bouzid.1@outlook.com; Tel.: +1-8197639153

Received: 30 September 2020; Accepted: 12 October 2020 ; Published: 16 October 2020

**Abstract:** Monitoring and early fault prediction of large electrical machines is important to maintain a sustainable and safe power system. With the ever-increasing computational power of modern processors, real-time simulation based monitoring of electrical machines is becoming a topic of interest. This work describes the development of a real-time digital twin (RTDT) of a wound rotor induction machine (WRIM) using a precomputed finite element model fed with online measurements. It computes accurate outputs in real-time of electromagnetic quantities otherwise difficult to measure such as local magnetic flux, current in bars and torque. In addition, it considers space harmonics, magnetic imbalance and fault conditions. The development process of the RTDT is described thoroughly and outputs are compared in real-time to measurements taken from the actual machine in rotation. Results show that they are accurate with harmonic content respected.

**Keywords:** digital twin; doubly-fed induction generator, electrical machines; finite elements method; monitoring; real-time; wound rotor induction machine
