Educational Workshops

Abstract: The model predictive control (MPC) method has shown a successful performance beside the easy implementation in drive applications. In many industries, the sensorless application of the drive system is a necessary demand. Therefore, any successful control method should be easily adoptable for sensorless applications. There are more challenges of sensorless application of model predictive control in compare with the traditional control methods, i.e., field oriented control (FOC), and direct torque control (DTC). The control method is based on the model in the MPC technique and the model of the motor is speed dependent. Thus, the control method is more dependent on the speed. In this tutorial, the tricks and the techniques that have been proposed to overcome this issue will be presented. At first, a short review about the MPC based drives will be presented. Then the sensorless application of the MPC based drives will be reviewed. Afterwards, the challenges and the question points will be mentioned and the solutions for each issue will be covered.

Content:

1. Introduction of model predictive control based drives
2. Introduction of sensorless drives
3. Sensorless application of MPC based drives
   • Observer based speed estimation for the predictive model
   • Adaptive speed estimation for the predictive method
   • Signal injection based speed estimation in predictive methods
4. Challenges in sensorless application of MPC in drives
   • Speed dependent prediction model
   • Sensitivity in low speed performance
   • Parameter variation
5. Solutions for the challenges of sensorless predictive control of AC motors
   • Inherently speed independent prediction model
   • Closed loop prediction model
   • Robust predictive model
   • Finite set position estimation

Abstract: Power quality issues has been an active role player in power systems since the appearance of sensitive loads such as computers systems, industrial processers and even protection systems. Power quality issues, other than customer satisfaction level, will have impacts on protection, operation of metering devices, system components aging as well as creating resonances for the power system.
In a future power system, where a majority of devices are connected via power electronics converters, power quality could become a limiting factor for new connections even before thermal or voltage constraints occur (as defined by G54-1/IEEE 519/IEC 61000). In such a future, power quality will need to be planned for in a similar manner to other connection limits, creating a requirement for targeted modelling, forecasting, monitoring and management techniques.
The main differences between power quality definitions in traditional and modern power systems, include the change in the nature of loads, control and protection systems, increased knowledge of customers about the power quality issue and their rights, new challenges as well as new opportunities in this, introduced by modern power system components. In this workshop, after having a brief introduction to the power quality concept, and power quality improvement devices, there will be a discussion on recently introduced power quality improvement devices/techniques as well as different control methods applied in these applications.
New challenges introduced to power systems by integration of renewable energy systems, electrical vehicle charging infrastructure as well as other low carbon technology devices will also be discussed.
Several case studies on application of new solutions for power quality issues will be discussed, and an insight to the real-world power quality issues will be provided. Finally, a set of conclusions, recommendations as well as results from case studies on opportunities and challenges introduced to power systems by modern components, will be provided based on the experimental/simulation results from different industrial/academic projects.

Abstract: Employing the new generation of power electronic switches named as wide band gap (WBG) devices results in high efficiency and high power density power electronic converters. WBG devices including silicon carbide (SiC) and gallium nitride (GaN) power switches provide lower Rds(ON), higher switching frequency, much lower conduction and switching loss, and higher operating temperature in comparison to the silicon based power switches. These unique features of WBG devices enable power electronic converters to utilize much smaller passive components and cooling system which leads to remarkable increase in power density, efficiency, and reliability of power electronic converters. However, utilizing very high switching frequency in WBG based power electronic converters results in extra electromagnetic interference (EMI) and higher common mode (CM) current and voltage. Hence, in order to overcome these issues in WBG based power electronic converters, advanced and novel methods of EMI reduction techniques are required. Moreover, the mentioned issues can be solved by selecting new optimized inverter configurations and modulation methods. In this workshop, first, a comparison between WBG based and traditional Silicon based power electronic converters will be presented. Second, utilizing WBG devices in some applications such as motor drive, electric vehicles and other applications will be briefly described. Then, EMI in WBG based power electronic converters as well as some examples will be presented. Finally, the state-of-the-art techniques to reduce the EMI in power electronic converters will be discussed and compared.

Content:

• Introduction
• Wide Bandgap (WBG) Devices
• WBG Based Power Electronic Converters
• EMI in WBG Based Power Electronic Converters
• Modelling the EMI in Flyback Converter
• Sample Design of EMI Filter for Flyback Converter
• State-of-the-art Techniques for EMI Reduction in WBG based Power Electronic Converters
  • Concept 1: Decreasing the Amplitude of PWM Voltages: Hybrid Multilevel Inverters
  • Concept 2: Switching Harmonic Clusters Cancelation: New Configurations of Multilevel Converters + Power Electronics Converter Module (PECM) + Advanced Modulation Techniques
  • Concept 3: Hybrid Multilevel Converters + Advanced Filter Configurations
  • Concept 4: Filter-less Multilevel Converters: Voltage Level Multiplier Module (VLMM)
• Conclusion