http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Model predictive control (MPC) has a number of desirable attributes which are difficult to achieve with classical converter control techniques. Unfortunately, the nature of power electronics imposes restriction to the method, as a result of the limited number of available converter states. This, combined with the spread spectrum nature of harmonics inherent with the strategy, complicates further design. This paper presents a method for removing this characteristic without compromising the desirable functionality of predictive control. The method, named modulated MPC, is applied to a two-level three-phase converter and compared with a number of similar approaches. Experimental results are used to support theoretical analysis and simulation studies.

/pdf/modulated-model-predictive-control-for-a-three-phase-active-2deyp01mjf.pdf

Modulated Model Predictive Control for a Three-Phase Active Rectifier

Multilevel converters are known to have many advantages for electricity network applications. In particular, cascaded H-bridge converters are attractive because of their inherent modularity and scalability. Predictive control for power converters is advantageous as a result of its applicability to discrete system and fast response. In this paper, a novel control technique, named modulated model predictive control, is introduced with the aim to increase the performance of model predictive control. The proposed controller addresses a modulation scheme as part of the minimization process. The proposed control technique is described in detail, validated through simulation and experimental testing, and compared with dead-beat and traditional model predictive control. The results show the increased performance of the modulated model predictive control with respect to the classic finite control set model predictive control in terms of current waveform total harmonic distortion (THD). Moreover, the proposed controller allows a multi-objective control, with respect to dead-beat control that does not present this capability.

Modulated Model Predictive Control for a Seven-Level Cascaded H-Bridge Back-to-Back Converter

A modulation-based method for generating pulse waveforms with selective harmonic elimination is proposed. Harmonic elimination, traditionally digital, is shown to be achievable by comparison of a sine wave with modified triangle carrier. The method can be used to calculate easily and quickly the desired waveform without solution of coupled transcendental equations

Modulation-Based Harmonic Elimination

Vehicular drive system which is small-sized and/or improved in its fuel economy. A power distributing mechanism 16 , which is provided with a differential-state switching device in the form of a switching clutch C 0 and a switching brake B 0 , is switchable by the switching device between a differential state (continuously-variable shifting state) in which the mechanism is operable as an electrically controlled continuously variable transmission, and a fixed-speed-ratio shifting state in which the mechanism is operable as a transmission having a fixed speed ratio or ratios. The power distributing mechanism 16 is placed in the fixed-speed-ratio shifting state during a high-speed running of the vehicle or a high-speed operation of engine 8 , so that the output of the engine 8 is transmitted to drive wheels 38 primarily through a mechanical power transmitting path, whereby fuel economy of the vehicle is improved owing to reduction of a loss of conversion of a mechanical energy into an electric energy. The mechanism 16 is also placed in the fixed-speed-ratio shifting state during a high-output operation of the engine 8 , so that the required electric reaction of first electric motor M 1 can be reduced, whereby the required size of the first electric motor M 1 , and the required size of the drive system 10 including the electric motor M 1 can be reduced.

Vehicular drive system

A significant innovation effort in ground vehicles' technology is represented by the replacement of the traditional mechanical-hydraulic systems with all-electric systems, termed by-wire systems, for the transmission and execution of the driving commands. According to the experience in the aerospace environment, such replacement is expected to give appreciable benefits, even though it poses several problems. This paper provides an overview of the key components of by-wire systems, i.e. the electric actuators and the communication networks, especially for steering and braking operations.

Drive-by-wire systems for ground vehicles

Nowadays, advanced applications of motion control often require a coordinated management of several mechanical degrees-of-freedom (DoF). This is conventionally achieved by using suitable mechanical devices and a separate actuator per each DoF. Electric actuators able to directly manage multiple DoF may provide appreciable benefits in terms of performances, volume, weight and cost. This paper aims to provide an overview of several configurations of multi-DoF electromechanical actuators considered in the recent technical literature and presently under study.

Electromagnetic Actuators Featuring Multiple Degrees-of-Freedom: a Survey

The theoretical derivation of equivalent circuits by analytically modeling the internal electromagnetic phenomena constitutes a classical approach for analyzing electric machines. Anyway, textbooks often tend to address it adopting a limited approach focused on specific common cases, thus introducing not strictly necessary hypotheses that turn into a reduced insight of the matter. On the other hand, papers focused on the derivation of analytical expressions of fields often adopt a much detailed approach resulting unwisely complex for circuital modeling. This paper proposes an intermediate circuit-oriented analysis that is more general and rigorous than usual while keeping a reasonable level of complexity of the treatment, thus resulting also suited for educational purposes at graduate level and above.

A mid-complexity analysis of long-drum-type electric machines suitable for circuital modeling

The combination of a rotary and linear motion along the same axis is used in several applications, including tooling machines, robotics, automation etc. It may be also used to conveniently manage pairs of basic functions of active wheels in electric and hybrid vehicles. In such cases, rotary-linear machines may represent an interesting alternative to the usual employ of a separated actuator per each basic motion. Anyway, such machines often rely on a structure that is either not suited to be conveniently realized using common materials and manufacturing techniques, or exhibits a complex behavior not permitting an effective decoupled control of force and torque. This paper presents some results concerning the structure, theoretical modeling, FEM analysis, magnetic circuit modeling and drive control for an isotropic brushless machine recently proposed.

A low-complexity rotary-linear motor useable for actuation of active wheels

This paper proposes and investigates an innovative methodology that can have a significant impact on the market potential of wound field, small–medium size synchronous generators (SGs). The technique proposed here is aimed at removing the need for the traditional stator skewing that is so commonly used in SGs to achieve acceptable values of voltage total harmonic distortion. To do this, a nonstandard damper cage configuration is proposed that comprises modulation of the damper bars’ positioning. An off-the-shelf, 400-kVA generator is used as a benchmark machine. Its rotor is optimized and modified according to the proposed technique. The results of the final machine are then compared to the benchmark machine highlighting the excellent advantages that can be achieved through this technique. A full-scale prototype of the modified generator is then built to experimentally validate the concept. Finally, a detailed analysis on all the performance aspects of the prototype is carried out, to guarantee that the proposed technique has no negative impact whatsoever on the generator's performance.

/pdf/a-methodology-to-remove-stator-skew-in-small-medium-size-ii74ua78px.pdf

Paolo Bolognesi

Papers

Drive-by-wire systems for ground vehicles

Electromagnetic Actuators Featuring Multiple Degrees-of-Freedom: a Survey

A mid-complexity analysis of long-drum-type electric machines suitable for circuital modeling

A low-complexity rotary-linear motor useable for actuation of active wheels

A Methodology to Remove Stator Skew in Small–Medium Size Synchronous Generators via Innovative Damper Cage Designs