The first objective of this work is to determine some of the performance parameters characterizing the behavior of a particular photovoltaic (PV) panels that are not normally provided in the manufacturers’ specifications. These provide the basis for developing a simple model for the electrical behavior of the PV panel. Next, using this model, the effects of varying solar irradiation, temperature, series and shunt resistances, and partial shading on the output of the PV panel are presented. In addition, the PV panel model is used to configure a large photovoltaic array. Next, a boost converter for the PV panel is designed. This converter is put between the panel and the load in order to control it by means of a maximum power point tracking (MPPT) controller. The MPPT used is based on incremental conductance (INC), and it is demonstrated here that this technique does not respond accurately when solar irradiation is increased. To investigate this, a modified incremental conductance technique is presented in this paper. It is shown that this system does respond accurately and reduces the steady-state oscillations when solar irradiation is increased. Finally, simulations of the conventional and modified algorithm are compared, and the results show that the modified algorithm provides an accurate response to a sudden increase in solar irradiation.

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Modeling of Photovoltaic System with Modified Incremental Conductance Algorithm for Fast Changes of Irradiance

Modified efficient perturb and observe maximum power point tracking technique for grid-tied PV system

Pumping of water requires excessive energy for its operation by consuming a massive amount of diesel, gasoline, electric power etc. The more promising alternative energies to perform the same operation without any energy cost are solar photovoltaic (PV) and wind. These fastest growing renewable energies are more reliable and well suitable for remote villages where there is no possibility of extending transmission lines. Furthermore, these systems are optimal for conditions like only small amount of water needed to be pumped for a particular time. Unlike conventional energy sources of electric power, the renewable energy sources are not dispatchable its power output cannot be controlled. In that case, it involves power conversion stages so that it would necessitate to design an advanced control strategy technique. Those control strategies greatly avoid and protects the system from detrimental operating conditions by monitoring input voltage, water flow, torque, power, pressure, speed and motor vibration etc. Henceforth the use of efficient control strategy not only increase the performance of system it also helps to increase the number of operational hours of solar PV and wind energy systems. In this manuscript, the research work of various control strategies carried out in solar PV and wind energy-based water pumping systems are presented. Additionally, this paper intends to discuss the energy management strategies applied for renewable energy fed water pumping system when the system assisted with third energy system (battery bank, fuel cell, etc). These benefited systems ensure good design, guarantees the control speed required for the motor, regulates the flow of water, assuring accurate operation for all conversion and finally, it maintains precise balance in between the renewable energy generated and power required by the load (pump).

Control and energy management strategies applied for solar photovoltaic and wind energy fed water pumping system: A review

Analysis and implementation of high step-up DC-DC converter for PV based grid application

Maximum power point tracking (MPPT) is necessary to achieve an optimal exploitation of photovoltaic (PV) system. This paper presents a novel voltage-oriented MPPT (VO-MPPT) method, where the conventional perturb and observe (P&O) algorithm is combined with the proposed external voltage control based on an adaptive integral derivative sliding mode (AIDSM). It is designed with new sliding surface, in addition, the derivative and integral terms are chosen to eliminate the overshoot during fast changes in solar irradiation and to minimize the steady-state fluctuation. Furthermore, an adaptation mechanism is joined to adjust the controller gains under each irradiation level. The proposed MPPT is tested and compared with the most widely used MPPT methods by simulations using MATLAB/Simulink TM and real time hardware in the loop (HIL) implementation. The results obtained with the proposed MPPT show excellent dynamic performance under fast irradiation changes.

An improved MPPT scheme employing adaptive integral derivative sliding mode control for photovoltaic systems under fast irradiation changes.

Photovoltaic maximum power point tracking under fast varying of solar radiation

Improvement in the antenna gain is usually achieved at the expense of bandwidth and vice versa. This is where the realization of this enhancement can be made through compromising the antenna profile. In this work, we propose a new design of incorporating periodic metasurface array to enhance the bandwidth and gain while keeping the antenna to a low-profile scheme. The proposed antenna was simulated and fabricated in order to validate the results in the operating frequency range from 10 MHz to 43.5 GHz. Computer simulation technology (CST) microwave studio software was used to design and simulate the proposed antenna, while LPKF prototyping PCB machine was utilized to fabricate the antenna. Results showed that the antenna generated a gain and bandwidth of 14.2 dB and 2.13 GHz, respectively. Following the good agreement between the numerical and measurement results, it is believed that the proposed antenna can be potentially attractive for the application of satellite communications in Ku-band electromagnetic wave.

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A Low-Profile Antenna Based on Single-Layer Metasurface for Ku-Band Applications

This paper presents the design, simulation, fabrication, and measurement of a circular spiral microstrip antenna embedded in distilled water bolus. The antenna is mainly designed to operate at 434 MHz ISM band to be used for a hyperthermia applicator. The performance of the antenna is compared to a conventional patch antenna also embedded in water bolus. The results show that spiral antenna has significant narrower radiation pattern and is capable to operate at multiple frequencies as well. Narrow beam of the antenna is desired to design a multiantenna arrangement with less coupling and a better focusing resolution which can be crucial for deep regional hyperthermia applications. The option of other frequencies is desirable to have a better control over the penetration depth versus focusing depending on the application region.

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A Compact Microstrip Spiral Antenna Embedded in Water Bolus for Hyperthermia Applications

A hyperthermia applicator is designed for the treatment of breast cancer with 24 directive microstrip spiral antennas forming a hemispherical array at 434 MHz. All individual antennas are directed towards a target region and their phases are adapted to focus all the fields at the targeted region. The measurements are performed by submerging uniform liquid solutions inside the applicator which completely stand inside distilled water. By exposing uniform liquid solutions to focused waves we observed temperature distribution with respect to time.

A directive antenna array applicator for focused electromagnetic hyperthermia treatment of breast cancer

This paper presents the adequateness of a rectangular spiral shaped patch antenna and a Vivaldi antenna having narrow beam width to use for antenna arrangements in microwave hyperthermia applications. The results obtained from simplified leg model show the adequateness of the small size spiral antenna due to its capability to operate at multi frequencies and narrow beam width. In addition its small lateral size is promising to use it in multi antenna configuration system for microwave hyperthermia application for cancer treatment.

Omer Isik

Papers

Photovoltaic maximum power point tracking under fast varying of solar radiation

A Low-Profile Antenna Based on Single-Layer Metasurface for Ku-Band Applications

A Compact Microstrip Spiral Antenna Embedded in Water Bolus for Hyperthermia Applications

A directive antenna array applicator for focused electromagnetic hyperthermia treatment of breast cancer

Antenna arrangement considerations for microwave hyperthermia applications