Efficiency Analysis of PWM Inverter Fed Three-Phase and Dual Three-Phase High Frequency Induction Machines for Low/Medium Power Applications

A performance analysis of three-phase and dual three-phase (DTP) induction pulsewidth modulation (PWM) inverter-fed motor drives is conducted in this paper. The focus is on the efficiency performance of high-frequency DTP machines compared to their three-phase counterparts in low/medium power applications. For this purpose, a DTP machine, having two sets of stator three-phase windings spatially shifted by 30 electrical degrees (asymmetrical six-phase winding configuration), was tested for both six-phase and three-phase winding configurations under the same magnetic conditions. Simulation and experimental results are presented to evaluate the efficiency performance of three-phase and dual-three induction motor drives employing PWM voltage source inverters

A Novel Matrix Transformation for Decoupled Control of Modular Multiphase PMSM Drives

When multiphase drives are used for specific applications, the modular solutions are preferred as they use consolidated power electronics technologies. The literature reports two modeling approaches for multiphase machines having a modular configuration of the stator winding. The first approach is the vector space decomposition (VSD) that models the energy conversion as for an equivalent three-phase machine. The main alternative to the VSD is the multistator (MS) modeling that emphasizes machine modularity in terms of torque production. Both approaches have advantages and disadvantages for multiphase machines with a modular structure. Therefore, this article aims to combine the VSD and MS approaches, defining a new matrix transformation and, hence, developing a new modeling approach for multiphase machines with a modular structure. The proposed transformation allows a decoupled and independent torque control of the sets composing the machine, preserving the torque regulation's modularity. Together with a new vector control scheme, it has been applied to a modular permanent magnet synchronous machine (PMSM) with a nonstandard spatial shift between windings. Experimental results are presented for a nine-phase PMSM prototype with a triple-three-phase stator winding configuration

A space vector PWM algorithm for a three-level asymmetrical six-phase motor drive

A space vector pulse-width modulation (SVPWM) algorithm for a three-level asymmetrical six-phase drive based on vector space decomposition (VSD) approach is presented in this paper. A modification in zero plane of the transformation matrix is proposed in order to meet the requirement that the realisation of sinusoidal output phase voltages can be obtained through the chosen output leg voltage space vectors. Furthermore, a method of choosing the switching sequences based on all possible one-level transitions of the leg voltages, i.e. a permutation method, is introduced. The algorithm is then validated experimentally and obtained results show that the developed method successfully achieves the desired fundamental phase voltage, although low order harmonics are present due to uncompensated inverter dead time. Last but not least, the performance of the proposed SVPWM algorithm is compared to several carrier-based PWM algorithms including in-phase disposition with ‘double min-max injection’ (PD-DI). This is a little known type of injection, which is verified to obtain identical performance as the presented multilevel algorithm

Direct-Flux Vector Control of induction motor for light traction

The paper presents a Direct-Flux Vector Control (DFVC) scheme suitable for induction motors employed in light traction applications. In such applications, deep flux weakening is required, and the maximum torque production must be obtained under current and voltage constraints. The mathematical model of the control scheme is discussed and the implementation issues are analysed. Experimental results are presented for a small power induction motor, showing the feasibility of the proposed control, with a particular focus on the robust flux-weakening operation

The IEEE IES Technical Committee Cluster of Energy

The IEEE Industrial Electronics Society (IES) Technical Committee (TC) Cluster of Energy was established at the 44th Annual Conference of the IEEE Industrial Electronics Society, 21-23 October 2018, in Washington, D.C. The worldwide challenges of energy shortage and global warming urgently require innovations in the energy field [1]. Applicationoriented multidisciplinary approaches are the key to addressing challenges and developing cutting-edge solutions. The IES is positioning itself as a leader in the energy field thanks to its wide coverage of expertise and the multidisciplinary nature of the Society

Zero-/Low-Speed Operation of Multiphase Drive Systems With Modular Multilevel Converters

Modular multilevel converter (MMC)-based AC motor drives are emerging trend-research. They ease medium-/high-voltage handling in high-power applications with reduced footprint and life-cycle costs. A known challenge concerning their operation is the zero-/low-speed operating condition. The recent techniques proposed to improve operation during that interval, implement complex hardware/software approaches. To cope with this issue, this paper proposes multiphase machines for MMC-based AC-drives. Among several advantages regarding the power splitting, multiphase machines provide additional degrees of freedom compared with their three-phase counterparts. Novel exploitation to these additional degrees of freedom is proposed in this paper by injecting a secondary current component in the load current with specific magnitude and frequency during zero-/low-speed intervals enabling the motor to function duly. Since the control of these secondary components is already inherited in the current controller structure of any multiphase machine, no additional algorithms or sensors will be required. In this paper, a three-level five-phase MMC-based distributed winding induction machine drive system for medium-/high-voltage applications is investigated during low-speed operation as well as starting from standstill to rated speed. Two different control options are proposed using capacitor voltage measurements or under sensorless operation in order to reduce the cost and complexity in the case of a high number of MMC levels. The experimental results have been obtained with a downscaled drive system to verify the proposed solution