Events at Department of Energy Technology

Guest lectures by Professor Jiabin Wang and Professor Radu Bojoi


11.12.2017 kl. 10.00 - 11.12.2017 kl. 12.00


There will be two guest lectures on 11 December 2017 prior to the PhD defence of Yang Feng


High Fidelity Modelling and Control of Interior Permanent Magnet Machine Drives

Guest lecturer

Professor Jiabin Wang, University of Sheffield, Sheffield, UK


10:00 - 10:45


Interior permanent-magnet (IPM) machines, a most common variant of salient-pole permanent magnet machine, exhibit relatively large high order harmonics in phase voltages and high nonlinearity in torque production due to both the presence of reluctance torque and the magnetic saturation in stator and rotor cores. Further, accurate temperature predictions for IPM machines are essential to prevent irreversible demagnetization and undesirable reduction in lifetime. This talk describes a high fidelity and computationally efficient electro-thermally coupled model for interior permanent magnet machines. First, a high-fidelity IPM model accounting magnetic saturation, spatial harmonics, iron loss and temperature effects is presented. The temperature effects on both the d- and q-axis flux-linkages and the torque in the proposed model are quantified. The IPM model with due account of temperature effect is integrated with a state-space lumped parameter thermal model to establish a high fidelity and computationally efficient electro-thermally coupled model for IPMs. Both the steady state and mission specific operations can be simulated with the proposed model. Experimental validation of the proposed model is performed with a 10kW IPM prototype machine. Due to significant voltage harmonics and highly nonlinear machine characteristics, control of IPM drives is a great challenge. The talk will outline novel techniques to achieve maximum torque per Ampere (MTPA) operation in constant torque region and voltage-constrained maximum torque per Ampere (VCMTPA) in field weakening regions, and present their experimental results.

About the lecturer

Jiabin Wang received the B.Eng. and M.Eng. degrees from Jiangsu University of Science and Technology, Zhenjiang, China, in 1982 and 1986, respectively, and the Ph.D. degree from the University of East London, London, U.K., in 1996, all in electrical and electronic engineering. Currently, he is a Professor in Electrical Engineering at the University of Sheffield, Sheffield, U.K. From 1986 to 1991, he was with the Department of Electrical Engineering at Jiangsu University of Science and Technology, where he was appointed a Lecturer in 1987 and an Associated Professor in 1990. He was a Postdoctoral Research Associate at the University of Sheffield, Sheffield, U.K., from 1996 to 1997, and a Senior Lecturer at the University of East London from 1998 to 2001. His research interests range from motion control and electromechanical energy conversion to electric drives for applications in automotive, renewable energy, household appliances and aerospace sectors. He is a fellow of the IET and a senior member of IEEE.



Testing of Power Converters at the end of the Production Line using the Virtual Load Concept with Common Mode Active Filtering Features

Guest Lecturer

Professor Radu Bojoi, the Politecnico di Torino, Italy


11:00 - 11.45


The final testing of power converters for adjustable speed drives is usually performed with the target motor and its mechanical load in the customer applications. This testing represents a standard procedure for power converter prototypes at the end of the development phase of the entire drive control strategy. The production of the power electronics needs an additional testing at the end of the production line to detect early failures by imposing output current and power maximum stress. The presentation focuses on a transformerless scheme for the testing of power converters for variable speed electrical drives at the end of the production line. For this purpose, the converter under test does not supply a real electrical machine but another power electric converter acting as a load emulator that regenerates the power into the grid. The testing platform is intended to emulate all necessary tests needed to stress the converter under test for different operating conditions and also for special identification procedures. The presented system is already operational for the testing of 150 kVA power converters at the end of the production line.

About the Lecturer

Radu Bojoi (SM’10) is a Full Professor of Power electronics and Electrical Drives at the Politecnico di Torino, Italy, where he is the coordinator of the Power Electronics Innovation Center (PEIC@PoliTO). Dr. Bojoi published more than 100 papers in international journals and conferences covering power electronics and electrical drives for transportation electrification, power quality, industrial applications and home appliances. He was involved in many research projects with industry for direct technology transfer aiming at obtaining new products. Dr. Bojoi is the co-recipient of 5 prize paper awards, the last one in 2016 from the Industry Application Society.  Dr. Bojoi is an Associate Editor of the IEEE Transactions on Industrial Electronics.

The guest lectures will take place in pon 111, 1.177 (auditorium), and all are welcome.


Department of Energy Technology


Pontoppidanstræde 111, auditorium 1.177