High Performance Control Techniques for Multiphase eDrives

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Direct Digital Sensing Potentiostat targeting Body-Dust

In this paper, an innovative Direct Digital Sensing Potentiostat integrated circuit for enzymeless blood glucose sensing and direct digitization is proposed to address the requirements of Body Dust. The circuit occupies a silicon area of 460 μm2 in 180nm CMOS and operates down to 0.4V power supply voltage with 4.7nW power consumption. The functionality of the proposed circuit and its performance under typical conditions and under process and temperature variations is tested by post-layout simulations

An eDrive-Based Estimation Method of the Laundry Unbalance and Laundry Inertia for Washing Machine Applications

The estimation of the laundry unbalance and laundry inertia is fundamental in washing machine applications. On the one hand, the estimation and management of the laundry unbalance play a pivotal role in reducing mechanical stress and noise during the spinning phase. On the other hand, the laundry inertia’s estimation, performed at the beginning of the washing cycle, allows for the determination of the proper amounts of water and detergent, the water temperature, and the tumbling time. In this way, good washing performance is obtained, avoiding the waste of energy and resources. Moreover, at the end of the washing cycle, the laundry inertia’s accurate estimation is needed to properly manage the spinning phase. With the aim of optimizing the washing performance, this paper proposes a novel method to estimate the laundry unbalance and laundry inertia. The proposed approach does not require additional sensors, since it uses the already implemented motor control scheme, enhanced by a dedicated position-tracking observer. Experimental results have been carried out on a commercial horizontal-axis direct-drive washer, demonstrating the validity of the proposed solution

Modular Stator Flux and Torque Control of Multi-Three-Phase Induction Motor Drives

direct flux vector control, induction motor drives, modular torque control, multiphase electrical machine

Decoupled and Modular Torque Control of Multi-Three-Phase Induction Motor Drives

In recent years, the development of multi-three-phase drives for both energy production and transportation electrification has gained growing attention. An essential feature of the multi-three-phase drives is their modularity since they can be configured as three-phase units operating in parallel and with a modular control scheme. The so-called multi-stator modeling approach represents a suitable solution for the implementation of modular control strategies able to deal with several three-phase units. Nevertheless, the use of the multi-stator approach leads to relevant coupling terms in the resulting set of equations. To solve this issue, a new decoupling transformation for the decoupled torque control of multi-three-phase induction motor drives is proposed. The experimental validation has been carried out with a modular power converter feeding a 12-phase induction machine prototype (10 kW, 6000 r/min) using a quadruple three-phase stator winding configuration

A Detailed Analysis of the Electromagnetic Phenomena Observed During the Flux-Decay Test

The paper analyses in detail the physical phenomena involved during the flux decay test used for the rotor time constant determination. The analysis has been performed on a 15 kW induction motor and the back e.m.f transient has been critically analysed during its evolution, finding a link between its time-by-time evolution and the physical phenomena that happen in both the stator and the rotor. In particular, the effects due to the lamination saturation, the stator and rotor leakage inductances and the stator iron losses have been associated to the transient evolution of the back e.m.f.

Experimental Identification of Induction Machine Flux Maps for Traction Applications

Nowadays the permanent magnet machines are a widespread solution in the automotive field. However, the induction machine (IM) represents a valid solution as it is rare-earth free and does not have induced stator back-emf in case of inverter turn-off. Regardless of the machine type, identification procedures are needed for torque control calibration and for optimal machine utilization in terms of efficiency and maximum torque production under inverter current and voltage constraints. For synchronous machines, a common and consolidated practice is to obtain the machine flux maps (current-to-flux relationship) in the rotor (d,q) frame using calibrated Finite Element Analysis (FEA) or experimental procedures. However, to the best of the authors' knowledge, the literature does not report an experimental approach able to obtain the flux maps for IMs. Therefore, this paper proposes an experimental procedure to obtain the IM flux maps in (d,q) rotor flux frame for inverter supply and real operating conditions. In addition, the proposed procedure is able to obtain the parameters of the IM equivalent circuit with no need of additional tests. Experimental validation is provided for a 4-poles IM rated 10 kW, 200 Hz

Off-Line Efficiency Mapping of Induction Motors Operated in Wide Torque-Speed Ranges

In the context of a progressive component virtualization for energetic assessments in variable speed and load operations, this paper presents a methodology for computing the efficiency maps of three-phase induction motors. The proposed approach is based on the conventional machine equivalent circuit to quickly obtain a set of efficiency maps at different machine temperatures and supply voltage levels. The well-known no-load and locked-rotor tests are used to determine the motor parameters at different frequencies and voltages, taking into account the machine nonlinearities and the iron losses. The approach has been validated on an 11 kW, 4 poles, 50 Hz induction motor tested in different operating conditions

Fault-Tolerant Torque Controller Based on Adaptive Decoupled Multi-Stator Modeling for Multi-Three-Phase Induction Motor Drives

Among the multiphase solutions, multi-three- phase drives are becoming more and more widespread in practice as they can be modularly supplied by conventional three-phase inverters. The literature reports several control approaches to perform the torque regulation of multi-three- phase machines. Most of such solutions use the vector space decomposition (VSD) approach since it allows the control of a multi-three-phase machine using the conventional control schemes of three-phase drives, thus reducing the complexity of the control algorithm. However, this advantage is practically lost in the case of open-three-phase faults. Indeed, the post-fault operation of the VSD-based drive schemes requires the implementation of additional control modules, often specifically designed for the machine under consideration. Therefore, this paper aims to propose a novel control approach that allows using any control scheme developed for three-phase motors to perform the torque regulation of a multi-three-phase machine both in healthy and faulty operation. In this way, the previously mentioned drawbacks of the VSD-based control schemes in dealing with the faulty operation of the machine are avoided. Moreover, the simplicity of the control algorithm is always preserved, regardless of the machine's operating condition. The proposed solution has been experimentally validated through a 12-phase induction motor, rated 10 kW at 6000 r/min, using a quadruple-three-phase configuration of the stator windin

Accurate Induction Machines Efficiency Mapping Computed by Standard Test Parameters

The extensive electrification process that is taking hold in several applications makes increasingly necessary the virtualization of electric components for energetic and performance assessments during the system design stage. For this purpose, this paper proposes a straightforward methodology for computing the efficiency maps of induction machines operated in wide torque-speed ranges. The modeling approach is based on the induction machine equivalent circuit defined in the rotor dq coordinates. The procedure allows computing a set of efficiency maps at different machine temperatures and supply voltage levels, both for motor and generator operation modes. The equivalent circuit parameters at different frequencies and voltages are determined by means of the well-known no-load and locked-rotor tests, thus including in the modelling the machine nonlinearities, skin effect and the iron losses. The proposed methodology has been validated on a 10 kW, 4-pole induction machine. The comparison between computed and experimental efficiency maps for different operating conditions, confirm the validity of the proposed methodology