The many different techniques for maximum power point tracking of photovoltaic (PV) arrays are discussed. The techniques are taken from the literature dating back to the earliest methods. It is shown that at least 19 distinct methods have been introduced in the literature, with many variations on implementation. This paper should serve as a convenient reference for future work in PV power generation.

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Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques

Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.

/pdf/a-review-of-single-phase-improved-power-quality-ac-dc-2pm6h4zjxq.pdf

A review of single-phase improved power quality AC-DC converters

Wireless power transfer (WPT) using magnetic resonance is the technology which could set human free from the annoying wires. In fact, the WPT adopts the same basic theory which has already been developed for at least 30 years with the term inductive power transfer. WPT technology is developing rapidly in recent years. At kilowatts power level, the transfer distance increases from several millimeters to several hundred millimeters with a grid to load efficiency above 90%. The advances make the WPT very attractive to the electric vehicle (EV) charging applications in both stationary and dynamic charging scenarios. This paper reviewed the technologies in the WPT area applicable to EV wireless charging. By introducing WPT in EVs, the obstacles of charging time, range, and cost can be easily mitigated. Battery technology is no longer relevant in the mass market penetration of EVs. It is hoped that researchers could be encouraged by the state-of-the-art achievements, and push forward the further development of WPT as well as the expansion of EV.

Wireless Power Transfer for Electric Vehicle Applications

This paper provides a comprehensive review of the maximum power point tracking (MPPT) techniques applied to photovoltaic (PV) power system available until January, 2012. A good number of publications report on different MPPT techniques for a PV system together with implementation. But, confusion lies while selecting a MPPT as every technique has its own merits and demerits. Hence, a proper review of these techniques is essential. Unfortunately, very few attempts have been made in this regard, excepting two latest reviews on MPPT [Salas, 2006], [Esram and Chapman, 2007]. Since, MPPT is an essential part of a PV system, extensive research has been revealed in recent years in this field and many new techniques have been reported to the list since then. In this paper, a detailed description and then classification of the MPPT techniques have made based on features, such as number of control variables involved, types of control strategies employed, types of circuitry used suitably for PV system and practical/commercial applications. This paper is intended to serve as a convenient reference for future MPPT users in PV systems.

A Comparative Study on Maximum Power Point Tracking Techniques for Photovoltaic Power Systems

Acoustic impedance-matched surfaces do not reflect incident waves. Traditional means of acoustic absorption have so far resulted in imperfect impedance matching and bulky structures, or require costly and sophisticated electrical design. Inspired by electromagnetic metamaterials, a subwavelength acoustically reflecting surface with hybrid resonances and impedance-matched to airborne sound at tunable frequencies is now demonstrated.

/pdf/acoustic-metasurface-with-hybrid-resonances-4tunjpntx7.pdf

Acoustic metasurface with hybrid resonances

A novel method of Transmission Line based power processing is suggested. This paper presents the possibility to decompose pulses of high power magnitude and short duration and transform it into pulses of lower magnitude and longer duration or even to a d.c. wave form. The basic idea is to feed the energy into a bunch of Transmission Lines, each of them characterized by a different propagation time, then collect the energy at the output. In such a manner, fractions of the energy that were fed at the input simultaneously, arrive at the output sequentially, thus accomplishing a time averaging.

Current averaging networks based on transmission lines

We propose the application of graphical convolution to the analysis of the resonance phenomenon. This time-domain approach encompasses both the finally attained periodic oscillations and the initial transient period. It also provides interesting discussion concerning the analysis of nonsinusoidal waves, based not on frequency analysis but on direct consideration of waveforms, and thus presenting an introduction to Fourier series. Further developing the point of view of graphical convolution, we arrive at a new definition of resonance in terms of time domain.

https://downloads.hindawi.com/journals/je/2013/414109.pdf

One More Tool for Understanding Resonance and the Way for a New Definition

An adjustable power-factor operation of a boost-based bidirectional AC/DC converter is described. It possesses a bi-directional power flow capability. The converter has a bias capacitor connected in series with the AC source which provides a DC voltage boost at the input. By appropriate control of the bias capacitor DC voltage, an always positive voltage is applied to the input of a boost power-factor corrector. This enables removal of a diode bridge rectifier that is commonly employed in switch-mode rectifiers. A bi-directional DC/DC boost converter allows for power factor adjustment in the full range of 0/spl deg/-360/spl deg/. Hence, the circuit can be used to compensate reactive power of other loads while either consuming active power (as in a battery charger) or providing active power (as in photovoltaic systems). The total harmonic distortion of the converter input current is less than 1.2% for any mode of operation. The operational principle of the proposed circuit was verified by Saber simulations.

A novel rectifier/inverter with adjustable power factor

High energy conversion efficiency of grid tied inverters for renewable energy applications constitutes a prime design goal of these systems. On the other, presently employed PWM techniques seem to set a bound to the efficiency since the associated switching losses are difficult to reduce. This paper introduces a new approach to synthesis of sinusoidal waveform in which the switching frequency is relatively low (in contrast to PWM technique) which yield a major reduction in switching losses. Even though the switching frequency is low, the harmonic content at the inverter's output is extremely low which allow for significant size decrease of the output filter. The method is based on a multiplication like principle, which is described in this paper.

Multiplication based synthesis of grid tied inverters

An objection to teaching resonance exclusively in terms of phasors is expressed.

Doron Shmilovitz

Papers

Current averaging networks based on transmission lines

One More Tool for Understanding Resonance and the Way for a New Definition

A novel rectifier/inverter with adjustable power factor

Multiplication based synthesis of grid tied inverters

The ‘a + b’ Argument for Teaching Resonance