Siemens (Qatar)

In this article, a multilevel inverter (MLI) scheme is proposed for 9-phase pole phase modulated induction motor (PPMIM) drives. The proposed inverter scheme is realized with the help of three 3-phase four-leg inverters. In 3-phase 12-pole mode (3PH-12PO), the proposed MLI supplies a 3-level voltage for each phase winding of the PPMIM drive with an improved harmonic profile, which results in better torque ripple. In this mode, the PPMIM drive performance is analyzed with a level shifted as well as phase shifted carrier based space vector pulse width modulation (SVPWM) techniques. On the other hand in 9-phase 4-pole mode (9PH-4PO), with help of phase grouping concept a 3-phase SVPWM implemented for enhancing the linear modulation of the 9-phase PPMIM drives by 15.4%. The fourth leg present in each 3-phase four-leg inverter is used effectively for suppressing the circulating currents in phase windings during 9PH-4PO operation. The proposed MLI is efficient to operate the PPMIM drive in both normal as well as fault conditions with rated power/torque. The proposed MLI-fed PPMIM drive performance with open circuit/short circuit of switch and source fault conditions are analyzed. The proposed MLI scheme is validated with the Ansys Maxwell finite element method (FEM) as well as laboratory testbed on a 5-hp 9-phase PPMIM drive under normal as well as open circuit switch/source fault conditions.

In this paper, a multilevel inverter (MLI) scheme is proposed for 9-phase pole phase modulated induction motor (PPMIM) drives. The proposed inverter scheme is realized with the help of 3 three-phase four-leg inverters. In 3-phase 12-pole mode (3PH-I2PO), the proposed MLI supplies a 3-level voltage for each phase winding of the PPMIM drive with an improved harmonic profile. This will minimize the amplitude of spatial harmonics in the airgap MMF, which results in better torque ripple in 3PH-I2PO operation. In this mode, for getting the same performance the PPMIM drive in w.r.t torque ripple the conventional 3-level 9-phase MLI's requires 40 switches, while the proposed MLI requires only 24 switches, which means the switch count is reduced by 40%. On the other hand, the phase windings of the 9-phase PPMIM drive are rearranged into 3 sets of three phase winding groups, where each phase group has three balanced 120 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sup> phase displaced windings. This phase grouping will give the flexibility to use the 3-phase space vector pulse width modulation (SVPWM) that enhances the linear modulation of the 9-phase PPMIM drives by 15.4% in 9-phase 4-pole mode (9PH-4PO). The 4 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> leg present in each three-phase four-leg inverter is used effectively for denying the circulating currents in phase windings in 9PH-4PO operation. The proposed MLI scheme is validated with the Ansys Maxwell FEM electromagnetic tool on a 5hp 9-phase PPMIM drive.

This evolution of the electrical grid into a smart grid represents a fundamental shift in power generation, distribution, and consumption. This paper explores the communication frameworks, operational challenges, and benefits. By leveraging advanced metering infrastructure (AMI), distributed energy resources (DER), and real-time data analytics, smart grids enhance reliability, efficiency, and sustainability [1] [2].

A key requirement for silicon debug and continuous monitoring is to detect and isolate functional failures that escape structural tests. This paper will use the case study of an embedded trace system developed based on the Efficient Trace for RISV-V (E-Trace) specification to highlight the central position it occupies in building a comprehensive SLM solution. Results on some industrial benchmarks demonstrate the efficiency of this approach.

A key requirement for silicon debug and continuous monitoring is to detect and isolate functional failures that escape structural tests. This paper will use the case study of an embedded trace system developed based on the Efficient Trace for RISV-V (E-Trace) specification to highlight the central position it occupies in building a comprehensive SLM solution. Results on some industrial benchmarks demonstrate the efficiency of this approach.

On behalf of the Technical Program Committee of the First Workshop on Smart Grid and Renewable Energy (SGRE2015), it is our pleasure to present the proceedings of this workshop held in Doha, Qatar.

Qatar has some major research priorities, targeting; reducing carbon footprints, developing smart cities and smart grids; and these demand high deployment of electric cars in near future. Qatar is an highly progressive country adopting to new evolving technologies at a fast pace. The proposed project is aimed at the development of a robust, highly reliable, efficient and wide speed range multiphase motor drive system that falls within the right context of the current research priorities of the Qatar University and the State of Qatar. The idea here is to use pole phase modulation technique to enhance the speed-torque control region of a multiphase motor drive system so that gear-less opeartion can be achieved in EV. Advantages and Disadvantages of the proposed pole phase modulated IM drives:  In high pole operation, the PPMIM drive is able to supply the high initial torque for fast acceleration and hill climbing.  The rated torque of the PPMIM drive in the high pole is k times greater than the low pole mode. For example, in 3-phase 12-pole mode, the 9-phase PPMIM drive is able to supply 3 times of the rated torque as comparted to 9-phase 4-pole mode.  In low pole mode, the PPMIM drive is able to supply high speed which is k times greater than the high pole mode.  The PPMIM drives are capable to generate 3 or 4 speed and torque variations. So, the mechanical gearbox system in conventional IC Engine based vehicles can be eliminated with the PPMIM drives, which will reduce the size and weight of the vehicle. Even though the PPMIM drives have several advantages (as mentioned above), on the other side they have a few disadvantages also such as:  To achieve the high starting torque in high power applications, the PPMIM drives has to operate in high pole and low phase mode, which magnifies the magnitude of space harmonics in the air gap.  The magnetizing inductance of the machine is inversely proportional to the square of the number of poles, which lowers the power factor.