Four control topologies for single-phase uninterruptible power system (UPS) inverters are presented and compared, with the common objective of providing a dynamically stiff, low total harmonic distortion (THD), sinusoidal output voltage. Full-state feedback, full-state command controllers are shown, utilizing both filter inductor current and filter capacitor current feedback to augment output voltage control. All controllers presented include output voltage decoupling in a manner analogous to "back EMF" decoupling in DC motor drives. Disturbance input decoupling of the load current and its derivative is presented. An observer-based controller is additionally considered and is shown to be a technically viable, economically attractive option. The accuracy transfer function of the observer estimate is used to evaluate its measurement performance. Comparative disturbance rejection is evaluated by overlaying the dynamic stiffness (inverse of output impedance) frequency response of each controller on a single plot. Experimental results for one controller are presented.

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Control topology options for single-phase UPS inverters

An induction motor is the most frequently used electric machine in high-performance drive applications. Control schemes of such drives require an exact knowledge of at least some of the induction motor parameters. Any mismatch between the parameter values used within the controller and actual parameter values in the motor leads to a deterioration in the drive performance. Numerous methods for induction machine on-line and off-line parameter estimation have been developed exclusively for application in high-performance drives. This paper aims at providing a review of the major techniques used for the induction motor parameter estimation. The paper is illustrated throughout with experimental and simulation examples related to various parameter estimation techniques.

A review of RFO induction motor parameter estimation techniques

Induction machine drive condition monitoring and diagnostic research—a survey

The application of vector control to a conventional synchronous reluctance motor (VCSynRM) is presented with emphasis on the effects of saturation and iron losses. It is shown experimentally that these parasitic effects can significantly influence the performance of a VCSynRM. A synchronous reference frame steady state model of SynRM including saturation and iron losses is developed. The behavior of a vector-controlled SynRM is analyzed based on the model. It is observed that saturation and iron losses can have a significant effect on the performance of a VCSynRM. To verify the validity of the model for vector control, a digital signal processor (DSP) based vector controller was built for a 7.5 hp SynRM to experimentally evaluate performance. Experimental results concerning optimal torque/ampere and optimal efficiency operation are shown to be in general agreement with the predictions of the model. >

https://chppe.osu.edu/sites/chppe.osu.edu/files/uploads/Publications2/Vector%20Control%20of%20a%20Synchronous%20Reluctance%20Machine%20Including%20Saturation%20and%20Iron%20Loss.pdf

Vector control of a synchronous reluctance motor including saturation and iron loss

http://w3.gazi.edu.tr/~icolak/folders/SinghGK-atif.pdf

Self-excited induction generator research—a survey

This paper presents derivation of the equations which describe field-oriented control of saturated induction machines. Field-oriented control principles are applied on the saturated model of induction machine and new equations are obtained, which differ significantly from the well-known model valid when the main flux saturation is absent or neglected. Rotor flux oriented control of voltage-fed and current-fed saturated induction machines is discussed. New decoupling circuits which are needed under saturated conditions are presented. Simulation results, which show the influence of main flux saturation on transient behaviour of the drive and which verify the theoretical results are included.

Field-oriented control of induction machines in the presence of magnetic saturation

Modifications that are necessary in the structures of rotor flux computers and indirect vector controllers in order to take into account the main flux saturation are considered The schemes discussed are based on measurement of the main flux and stator currents, stator voltages and stator currents, and stator currents and rotor speed Particular attention is given to a calculator based on stator currents and rotor speed as measured variables and to simplified saturated indirect vector controllers Verification of the proposed saturated rotor flux calculators and indirect vector controllers is provided by means of digital simulation One of the schemes is applied in a vector-controlled induction motor drive, and experimental results are included >

Saturation compensation schemes for vector controlled induction motor drives

A cloud-resolving mesoscale model has been used to investigate the effects of cloud seeding by silver-iodide (AgI) if the seeding is performed at cold part of a long-lasting convective cloud. Our motivation for this research was to answer the principle question: where, when and what amount of silver-iodide lead to optimum effects of seeding: rain precipitation enhancement and reduction of hail. The bulk two-moment microphysical scheme and the new software package for silver-iodide are incorporated in the model. The new saturation-adjustment scheme is introduced to include the effect of seeding agent particles as deposition nuclei. Sensitivity tests with respect to seeding agent amount, location, time and dynamics of seeding are performed.

Cloud seeding impact on precipitation as revealed by cloud-resolving mesoscale model

https://tesla.rcub.bg.ac.rs/~dvujovic/atmres.pdf

Vladan Vučković

Papers

Field-oriented control of induction machines in the presence of magnetic saturation

Saturation compensation schemes for vector controlled induction motor drives

Cloud seeding impact on precipitation as revealed by cloud-resolving mesoscale model

The effects of a river valley on an isolated cumulonimbus cloud development

The influence of merging and individual storm splitting on mesoscale convective system formation