[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Multilevel converters have been under research and development for more than three decades and have found successful industrial application. However, this is still a technology under development, and many new contributions and new commercial topologies have been reported in the last few years. The aim of this paper is to group and review these recent contributions, in order to establish the current state of the art and trends of the technology, to provide readers with a comprehensive and insightful review of where multilevel converter technology stands and is heading. This paper first presents a brief overview of well-established multilevel converters strongly oriented to their current state in industrial applications to then center the discussion on the new converters that have made their way into the industry. In addition, new promising topologies are discussed. Recent advances made in modulation and control of multilevel converters are also addressed. A great part of this paper is devoted to show nontraditional applications powered by multilevel converters and how multilevel converters are becoming an enabling technology in many industrial sectors. Finally, some future trends and challenges in the further development of this technology are discussed to motivate future contributions that address open problems and explore new possibilities.

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Recent Advances and Industrial Applications of Multilevel Converters

The aim of this paper is to present a review of current control techniques for three-phase voltage-source pulsewidth modulated converters. Various techniques, different in concept, have been described in two main groups: linear and nonlinear. The first includes proportional integral (stationary and synchronous) and state feedback controllers, and predictive techniques with constant switching frequency. The second comprises bang-bang (hysteresis, delta modulation) controllers and predictive controllers with on-line optimization. New trends in current control-neural networks and fuzzy-logic-based controllers-are discussed, as well. Selected oscillograms accompany the presentation in order to illustrate properties of the described controller groups.

Current control techniques for three-phase voltage-source PWM converters: a survey

The authors discuss high-voltage power conversion. Conventional series connection and three-level voltage source inverter techniques are reviewed and compared. A novel versatile multilevel commutation cell is introduced: it is shown that this topology is safer and more simple to control, and delivers purer output waveforms. The authors show how this technique can be applied to either choppers or voltage-source inverters and generalized to any number of switches.<<ETX>>

Multi-level conversion : high voltage choppers and voltage-source inverters

This paper gives an overview of medium-voltage (MV) multilevel converters with a focus on achieving minimum harmonic distortion and high efficiency at low switching frequency operation. Increasing the power rating by minimizing switching frequency while still maintaining reasonable power quality is an important requirement and a persistent challenge for the industry. Existing solutions are discussed and analyzed based on their topologies, limitations, and control techniques. As a preferred option for future research and application, an inverter configuration based on three-level building blocks to generate five-level voltage waveforms is suggested. This paper shows that such an inverter may be operated at a very low switching frequency to achieve minimum on-state and dynamic device losses for highly efficient MV drive applications while maintaining low harmonic distortion.

Medium-Voltage Multilevel Converters—State of the Art, Challenges, and Requirements in Industrial Applications

The theory of variable structure systems with sliding mode control has been used to develop a power conditioning system. An experimental system has been developed, and digital simulation of both the power and control systems has been performed. The good agreement between the analytical study and the experimental and simulation results confirms the validity of the proposed control system.

Experimental study of a power conditioning system using sliding mode control

In ac-supplied traction systems (e.g., 15 kV, 16.7 Hz), the energy supplied by a conventional transformer results in large volume, high weight, and relatively low efficiency. In this paper, an ac-dc multilevel converter is presented that allows the use of a medium-frequency transformer in the input section of a traction drive. The proposed solution seems particularly well adapted to the different requirements (volume, weight, EMC, losses) of the electric traction domain. The system is studied from a theoretical point of view, starting from the basic module up to the entire converter structure. Simulation results and reduced-scale (10-kVA four-stage converter) experimental results are presented.

Multilevel Converter for Traction Applications: Small-Scale Prototype Tests Results

https://arodes.hes-so.ch/record/4010/files/Preprint.pdf

Use cases for blockchain in the energy industry opportunities of emerging business models and related risks

A new method for electrical motor drive self-commissioning, with elastic couplings and backlash, is presented. The heuristic algorithm particle swarm optimization (PSO) has been used for the identification and optimization of parameters. Initially, a model-based identification procedure is performed to evaluate the parameters of the system. Then, the parameters of a proportional–integral–derivative (PID)-based controller are optimized by using a time-domain performance criterion. Experimental results, obtained by testing three different laboratory permanent magnet synchronous motor (PMSM) drive prototypes, are also presented to confirm the validity of the proposed approach.

PSO-Based Self-Commissioning of Electrical Motor Drives

Photovoltaic (PV) systems are widely spread across MV and LV distribution systems and the penetration of PV generation is solidly growing. Because of the uncertain nature of the solar energy resource, PV power forecasting models are crucial in any energy management system for smart distribution networks. Although point forecasts can suit many scopes, probabilistic forecasts add further flexibility to an energy management system and are recommended to enable a wider range of decision making and optimization strategies. This paper proposes methodology towards probabilistic PV power forecasting based on a Bayesian bootstrap quantile regression model, in which a Bayesian bootstrap is applied to estimate the parameters of a quantile regression model. A novel procedure is presented to optimize the extraction of the predictive quantiles from the bootstrapped estimation of the related coefficients, raising the predictive ability of the final forecasts. Numerical experiments based on actual data quantify an enhancement of the performance of up to 2.2% when compared to relevant benchmarks.

/pdf/bayesian-bootstrap-quantile-regression-for-probabilistic-1j7htztnp2.pdf

Mauro Carpita

Papers

Experimental study of a power conditioning system using sliding mode control

Multilevel Converter for Traction Applications: Small-Scale Prototype Tests Results

Use cases for blockchain in the energy industry opportunities of emerging business models and related risks

PSO-Based Self-Commissioning of Electrical Motor Drives

Bayesian bootstrap quantile regression for probabilistic photovoltaic power forecasting