With the exponential growth in global photovoltaic (PV) power capacity, protection of PV systems has gained prodigious importance in last few decades. Even with the use of standard protection devices in a PV system, faults occurring in a PV array may remain undetected. Inspired by the ever increasing demand for a reliable fault detection technique, several advanced techniques have been proposed in literature; especially in the last few years. Hence, this paper carries out an in depth analysis of various fault occurrences, protection challenges and ramifications due to undetected faults in PV systems. Furthermore, with a widespread literature, the paper critically reviews numerous fault detection algorithms/techniques available for PV systems which are proven to be effective and feasible to implement. The proposed study is not only limited to surveying the existing techniques but also analyzes the performance of each technique with an emphasis on its: 1) Approach, 2) Sensor requirements, 3) Ability to diagnose and localize faults, 4) Integration complexity, 5) Accuracy, 6) Applicability and 7) Implementation cost. Overall, this paper is envisioned to avail the researchers working in the field of PV systems with a valuable resource, which will assist them to enrich their research works.

A comprehensive review on protection challenges and fault diagnosis in PV systems

The objective of this paper is to introduce the integration of the diverse factors that affect the performance of Photovoltaic panels and how those factors affect the performance of the system. Those factors include: environmental, PV system, installation, cost factors as well as other miscellaneous factors. Each of these factors is further classified into novel subcategories along with the reduction/increase effects of some factors on the system output. Solar irradiance, module temperature, dust accumulation, shading and soiling factors are some of the environmental concerns that have major effects. Panel's I-V characteristics, inverter, battery and panel efficiencies, panel material, atomic structure and band-gap energy are some of the system factors. As for the installation factors, cable characteristics, angle of inclination, mismatch effects, fixed/tracking PV mechanisms as well as MPPT are crucial to consider. Concerning the cost factors, the cables and the overall system costs are to be taken into consideration especially during payback period calculations. Other miscellaneous factors have a role in affecting the performance of the system such as degradations in the PV panel, panel resistances, performance ratio, maintenance and cleaning, sizing of the system as well as the surface area of the panel. The study results shall help both practitioners and researchers in having an inclusive overview about the several factors that can have an effect on the performance of the PV panels by removing the burden of having to search several studies under each category of factors. Moreover, researchers can build on this study by researching new ways to decrease the effect of certain factors which can further enhance the performance of the system. On the other hand, practitioners can introduce new systems that can be physically implemented in our daily lives to hinder the effect of factors negatively affecting PV panels’ performance.

An integrated review of factors influencing the perfomance of photovoltaic panels

The mitigation of environmental effects on clean-energy technology is an area of increasing interest. Photovoltaic (PV) modules have been widely used in small and large-scale applications for many years. However, they are not yet competitive with other electrical energy-generation technologies, especially in environments that suffer from dust, airborne particles, humidity and high ambient temperatures. This paper presents a review of the effect of climatic conditions on PV module performance, in particular, the effect of dust fouling. Research to date indicates that dust deposition has a considerable effect on PV module performance as it reduces the light transmissivity of the PV module surface cover. Studies on the ways in which dust is deposited on PV module surfaces are reviewed, as understanding this process is essential to develop effective mitigation approaches. Module performance is also adversely affected by high ambient temperature, humidity and lack of rainfall. The current review summarizes the past, current and promising future approaches towards mitigating environmental effects, in particular dust fouling. Electrostatic cleaning methods and micro/nanoscale surface functionalization methods both have the potential to counteract the negative effects of dust deposition, with the combination of the two methods showing special efficacy, particularly in arid regions.

The effect of environmental factors and dust accumulation on photovoltaic modules and dust-accumulation mitigation strategies

The topic of soiling of photovoltaic module (PV) and concentrated solar power (CSP) collectors has recently gained increasing attention due to its impact on solar power production, especially in arid and semi-arid areas with high concentrations of airborne dust. Soiling describes the deposition of dust and other contaminants on surfaces, reducing solar irradiation by absorbing or reflecting the sunlight, causing energy yield losses which can exceed 1% per day. The amount of soiling is influenced by complex interactions of many factors which can vary significantly from site to site. In this study we provide a detailed overview of macroscopic and microscopic factors influencing soiling. This includes a global analysis of key parameters including airborne dust concentrations, dust characteristics (mineral composition, size distribution), and particle deposition rates. A theoretical model for relevant particle adhesion and removal forces is presented to achieve a microscopic understanding of wind cleaning effects. Further, it was found that dew occurs frequently on PV modules in many soiling affected areas and that this can significantly increase particle adhesion. Therefore, a detailed analysis and model of the dew-driven soiling mechanisms of cementation, particle caking, and capillary aging are given on the basis of microstructural material and dust characterization of outdoor exposed glass samples. Furthermore, we study the complex interplay and dynamics of different environmental parameters (relative humidity, ambient and module temperature, airborne dust concentration, wind speed) and their correlation to dust accumulation, and provide explanations with the help of the developed models. Overall the study aims to provide a useful, in-depth but also global overview and fundamental understanding of soiling processes on PV modules down to the microscale, which could be used to develop appropriate soiling mitigation strategies.

Fundamentals of soiling processes on photovoltaic modules

The objective of this literature review and survey is to provide a compilation and assessment of recent published reports for solar-electric device soiling R&D, to extend and update the compendium covering 2012–2015 we published last year. This review provides a comprehensive listing of the publications with references for 2016—with some preliminary 2017 publications that have appeared at the time of this writing. Photovoltaics (PV) and concentrating solar (thermal) power (CSP) technologies are covered. To guide the reader, tabulated information on the investigative focus of the studies, the location, the duration (if pertinent), the solar-device type, key findings and other useful information within the report is presented.

Solar energy dust and soiling R&D progress: Literature review update for 2016

Electricity generation from solar energy has a great potential since it relies mainly on an abundant and clean source. However, there are many alterable and unalterable factors that can govern a PV module's efficiency. Dust is one of the location-dependent environmental factors that falls under the unalterable factors group. It can degrade the efficiency of a PV panel by causing physical damages, by attenuating the incoming solar radiation and by causing temperature rise, which results in changes in panel's electrical characteristics. Degree of degradation depends mainly on the deposition density, which is governed by various factors. Dust accumulation of 20 g/m2 on a PV panel reduces short circuit current, open circuit voltage and efficiency by 15–21%, 2–6% and 15–35% respectively. This work reviews, elaborates and summarizes the effects of dust on solar panel efficiency and the factors governing dust deposition on PV panel.

Dust as an unalterable deteriorative factor affecting PV panel's efficiency: why and how

Permanent magnet synchronous motors (PMSMs) are known as highly efficient motors and are slowly replacing induction motors in diverse industries. PMSM systems are nonlinear and consist of time-varying parameters with high-order complex dynamics. High performance applications of PMSMs require their speed controllers to provide a fast response, precise tracking, small overshoot and strong disturbance rejection ability. Sliding mode control (SMC) is well known as a robust control method for systems with parameter variations and external disturbances. This paper investigates the current status of implementation of sliding mode control speed control of PMSMs. Our aim is to highlight various designs of sliding surface and composite controller designs with SMC implementation, which purpose is to improve controller’s robustness and/or to reduce SMC chattering. SMC enhancement using fractional order sliding surface design is elaborated and verified by simulation results presented. Remarkable features as well as disadvantages of previous works are summarized. Ideas on possible future works are also discussed, which emphasize on current gaps in this area of research.

https://www.mdpi.com/1996-1073/12/9/1669/pdf

Robust Speed Control of PMSM Using Sliding Mode Control (SMC)—A Review

This paper investigates speed regulation of permanent magnet synchronous motor (PMSM) system based on sliding mode control (SMC). Sliding mode control has been vastly applied for speed control of PMSM. However, continuous SMC enhancement studies are executed to improve the performance of conventional SMC in terms of tracking and disturbance rejection properties as well as to reduce chattering effects. By introducing fractional calculus in the sliding mode manifold, a novel fractional order sliding mode controller is proposed for the speed loop. The proposed fractional order sliding mode speed controller is designed with a sliding surface that consists of both fractional differentiation and integration. Stability of the proposed controller is proved using Lyapunov stability theorem. The simulation and experimental results show the superiorities of the proposed method in terms of faster convergence, better tracking precision and better anti-disturbance rejection properties. In addition, chattering effect of this enhanced SMC is smaller compared to those of conventional SMC. Last but not least, a comprehensive comparison table summarizes key performance indexes of the proposed controller with respect to conventional integer order controller.

/pdf/application-of-fractional-order-sliding-mode-control-for-4ftiu9wkks.pdf

Application of Fractional Order Sliding Mode Control for Speed Control of Permanent Magnet Synchronous Motor

A fractional order sliding mode control with PID sliding surface design (FOSMC-PID) is proposed in this research. This controller incorporates fractional calculus which has a slower energy transfer compared to integer order calculus in order to suppress the chattering. Stability of this controller is analyzed using Lyapunov stability theorem. Simulation results proved that the proposed FOSMC speed controller performs as a robust and fast anti-disturbance controller to regulate the speed of a PMSM and proven its advantages against SMC controllers. The proposed sliding surface design also improves the FOSMC in terms of torque ripple reduction, chattering reduction and anti-disturbance properties, compared to FOSMC with PI or PD sliding surface.

Fractional Order SMC for Speed Control of PMSM

The wide use of machine and machinery in the construction industry can reduce the dependency on foreign workers. The Construction Industry Development Board is formulating a strategic plan to promote the use of machine and machinery in the construction industry. Therefore, this study aims to study the level and status of the usage machine and machinery among the G7 contractors at construction sites. The instrument used in the study consist of questionnaire and interviews. Based on the literature findings, there are 9 types of machine and 9 types machinery used in the construction industry. The percentage use of machine and machinery as well as the level of mechanisation for each phase of construction is at level 1, where the machine and machinery is still driven by the operator and do not involved high technology. The main recommendation in this study is to provide training on the latest information on machine and machinery and CPD (Continue Professional Development) training to promote the use of machine and machinery. In addition, the offering better incentives such as tax breaks and loan facilities should be awarded and provided by the government to activate the economic growth.

Fardila Mohd Zaihidee

Papers

Dust as an unalterable deteriorative factor affecting PV panel's efficiency: why and how

Robust Speed Control of PMSM Using Sliding Mode Control (SMC)—A Review

Application of Fractional Order Sliding Mode Control for Speed Control of Permanent Magnet Synchronous Motor

Fractional Order SMC for Speed Control of PMSM

Status dan Tahap Penggunaan Jentera dan Mesin di kalangan Kontraktor G7 di Malaysia