http://web.stanford.edu/group/efmh/jacobson/Articles/I/JDEnPolicyPt1.pdf

Providing all global energy with wind, water, and solar power, Part I: Technologies, energy resources, quantities and areas of infrastructure, and materials

This paper presents evaluations among the most usual maximum power point tracking (MPPT) techniques, doing meaningful comparisons with respect to the amount of energy extracted from the photovoltaic (PV) panel [tracking factor (TF)] in relation to the available power, PV voltage ripple, dynamic response, and use of sensors. Using MatLab/Simulink and dSPACE platforms, a digitally controlled boost dc-dc converter was implemented and connected to an Agilent Solar Array E4350B simulator in order to verify the analytical procedures. The main experimental results are presented for conventional MPPT algorithms and improved MPPT algorithms named IC based on proportional-integral (PI) and perturb and observe based on PI. Moreover, the dynamic response and the TF are also evaluated using a user-friendly interface, which is capable of online program power profiles and computes the TF. Finally, a typical daily insulation is used in order to verify the experimental results for the main PV MPPT methods.

Evaluation of the Main MPPT Techniques for Photovoltaic Applications

Power quality problems associated with distributed power (DP) inverters, implemented in large numbers onto the same distribution network, are investigated. Currently, these power quality problems are mainly found in projects with large penetration of photovoltaics (PV) on rooftops of houses and commercial buildings. The main object of this paper is to analyze the observed phenomena of harmonic interference of large populations of these inverters and to compare the network interaction of different inverter topologies and control options. These power quality phenomenons are investigated by using extensive laboratory experiments, as well as computer modeling of different inverter topologies. A complete network simulation study on an existing residential network with large penetration of PVs, is included.

Harmonic interaction between a large number of distributed power inverters and the distribution network

This paper reviews state of the art maximum power point tracking (MPPT) algorithms for wind energy systems. Due to the instantaneous changing nature of the wind, it is desirable to determine the one optimal generator speed that ensures maximum energy yield. Therefore, it is essential to include a controller that can track the maximum peak regardless of wind speed. The available MPPT algorithms can be classified as either with or without sensors, as well as according to the techniques used to locate the maximum peak. A comparison has been made between the performance of different MPPT algorithms on the basis of various speed responses and ability to achieve the maximum energy yield. Based on simulation results available in the literature, the optimal torque control (OTC) has been found to be the best MPPT method for wind energy systems due to its simplicity. On the other hand, the perturbation and observation (P&O) method is flexible and simple in implementation, but is less efficient and has difficulties determining the optimum step-size.

A review of maximum power point tracking algorithms for wind energy systems

Artificial intelligence (AI) techniques, particularly the neural networks, are recently having significant impact on power electronics and motor drives. Neural networks have created a new and advancing frontier in power electronics, which is already a complex and multidisciplinary technology that is going through dynamic evolution in the recent years. This paper gives a comprehensive introduction and perspective of neural network applications in the intelligent control and estimation for power electronics and motor drives area. The principal topologies of neural networks that are currently most relevant for applications in power electronics have been reviewed including the detailed description of their properties. Both feedforward and feedback or recurrent architectures have been covered in the description. The application examples that are discussed in this paper include nonlinear function generation, delayless filtering and waveform processing, feedback signal processing of vector drive, space vector PWM of two-level and multilevel inverters, adaptive flux vector estimation, and some of their combination for vector-controlled ac drive. Additional selected applications in the literature are included in the references. From the current trend of the technology, it appears that neural networks will find widespread applications in power electronics and motor drives in future

Neural Network Applications in Power Electronics and Motor Drives—An Introduction and Perspective

This paper proposes a novel solution to the problems that exist in the conventional hill climb searching (HCS) maximum power point tracking (MPPT) algorithm for the wind energy conversion system. The presented solution not only solves the tracking speed versus control efficiency tradeoff problem of HCS but also makes sure that the changing wind conditions do not lead HCS in the wrong direction. It intelligently adapts the variable step size to keep up with the rapid changes in the wind and seizes the perturbation at the maxima to yield 100% control efficiency. For this purpose, a novel peak detection capability has been devised which, in contrast with conventional peak detection, can work robustly under changing wind conditions. The proposed MPPT performs self-tuning to cope with the nonconstant efficiencies of the generator-converter subsystems-a phenomenon quite rarely discussed in research papers so far. In addition, a smart speed-sensorless scheme has been developed to avoid the use of mechanical sensors. The experimental results confirm that the proposed algorithm is remarkably faster and more efficient than the conventional HCS.

A Novel Algorithm for Fast and Efficient Speed-Sensorless Maximum Power Point Tracking in Wind Energy Conversion Systems

Maximum power point tracking (MPPT) is a very important necessity in a system of energy conversion from a renewable energy source. Every year a number of publications appear in various journals and conferences claiming to offer better and faster MPPT techniques for wind energy conversion system (WECS). This research paper provides a concise yet comprehensive critical analysis of these techniques with an in-depth review of their strengths and drawbacks. This review is unique as there has been no other research paper so far that offers such a complete and up-to-date investigation of MPPT techniques in WECS. Therefore this research paper can serve as a precise reference for the future research on MPPT for WECS.

Review and critical analysis of the research papers published till date on maximum power point tracking in wind energy conversion system

Maximum power point tracking (MPPT) is a very important necessity in a system of energy conversion from a renewable energy source. Many research papers have been produced with various schemes over past decades for the MPPT in photovoltaic (PV) system. This research paper inspires its motivation from the fact that the keen study of these existing techniques reveals that there is still quite a need for an absolutely generic and yet very simple MPPT controller which should have all the following traits: total independence from system's parameters, ability to reach the global maxima in minimal possible steps, the correct sense of tracking direction despite the abrupt atmospheric or parametrical changes, and finally having a very cost-effective and energy efficient hardware with the complexity no more than that of a minimal MPPT algorithm like Perturb and Observe (P&O). The MPPT controller presented in this paper is a successful attempt to fulfil all these requirements. It extends the MPPT techniques found in the recent research papers with some innovations in the control algorithm and a simplistic hardware. The simulation results confirm that the proposed MPPT controller is very fast, very efficient, very simple and low cost as compared to the contemporary ones.

An improved and very efficient MPPT controller for PV systems subjected to rapidly varying atmospheric conditions and partial shading

This paper presents a new magnetic circuit model of an interior permanent magnet (IPM) motor for use in SPICE, which is the general-purpose circuit-simulation program. The magnetic circuit model consists of reluctances and permanent magnet magnetomotive-force sources. In the SPICE simulation, a magnetic circuit model of the IPM motor and its driving circuit are coupled by a proper circuit. Using the proposed model, we can calculate dynamic characteristics of the IPM motor easily.

Dynamic analysis of interior permanent magnet motor based on a magnetic circuit model

This paper deals with a numerical model of the switched reluctance generator (SRG) for use on a general-purpose circuit simulation program "SPICE". In the model, the electric circuit and magnetic circuit are coupled by proper controlled sources. Using the numerical model, we can readily calculate the dynamic behavior of the SRG. The method presented here is useful for circuit analysis and design optimization of the SRG.

Osamu Ichinokura

Papers

A Novel Algorithm for Fast and Efficient Speed-Sensorless Maximum Power Point Tracking in Wind Energy Conversion Systems

Review and critical analysis of the research papers published till date on maximum power point tracking in wind energy conversion system

An improved and very efficient MPPT controller for PV systems subjected to rapidly varying atmospheric conditions and partial shading

Dynamic analysis of interior permanent magnet motor based on a magnetic circuit model

Dynamic simulation model of switched reluctance generator