The vector evaluated particle swarm optimisation (VEPSO) algorithm was previously improved by incorporating nondominated solutions for solving multiobjective optimisation problems. However, the ...obtained solutions did not converge close to the Pareto front and also did not distribute evenly over the Pareto front. Therefore, in this study, the concept of multiple nondominated leaders is incorporated to further improve the VEPSO algorithm. Hence, multiple nondominated solutions that are best at a respective objective function are used to guide particles in finding optimal solutions. The improved VEPSO is measured by the number of nondominated solutions found, generational distance, spread, and hypervolume. The results from the conducted experiments show that the proposed VEPSO significantly improved the existing VEPSO algorithms.
•Conventional MPPT methods are vastly used in the industry compared to other methods.•Adaptive conventional MPPT methods attempt to alleviate the common drawbacks of the conventional method.•A single ...adaptive MPPT algorithm fails to mitigate all the common drawbacks of a conventional method.•Various MPPT applications demand numerous types of performance criteria.•The proposed review article can identify the best-performing adaptive conventional MPPT methods based on the distinguished criteria.
This paper thoroughly discusses the design features and operating procedures of six popular conventional MPPT methods. Accordingly, the corresponding modifications of the conventional MPPT methods are analyzed and reviewed. A comprehensive comparative analysis of the twenty-eight adaptive MPPT algorithms is performed based on the tracking time, steady-state oscillations, conversion efficiency, algorithm complexity, implementation cost, capability to perform on the partial shading conditions, etc. The performances of the selected methods are illustrated on the radar graph diagram. The radar graph diagram's contour area helped select the best-performing methods. The summary of this paper will demonstrate a straightforward approach to the readers to select the suitable MPPT methods.
Solar energy exposed its prominence to diminish the growing energy demands. But the formation of multiple peaks under partial shading conditions causes the conventional maximum power point tracking ...controllers to fail to track the global maximum power point (GMPP). Scanning the whole power-voltage curve to locate the GMPP takes extreme time and reduces algorithm effectiveness. Thus, the proposed method devotes the skipping and scanning mechanism incorporated with the perturb and observe (P&O) algorithm to reduce the scanning area drastically. The skipping mechanism skips over the scanning areas between successive peaks based on a specific formula that narrows down the scanning zone. Along with a buck-boost converter, the system includes a voltage control loop controlled by a proportional-integral controller. The proposed algorithm's effectiveness is tested in both simulation and experimental environments on discretized partial shading patterns while GMPP is deployed at different locations. According to the experimental outcomes, the proposed algorithm outperforms the modified maximum power trapezium, skipping fast GMPP, modified cuckoo search, and the conventional P&O algorithm with an average convergence time of 1.02 sec and average efficiency of 99.44 percent.
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•Solar energy’s contribution to the grid is increasing as itsapplications expand.•The term ‘Flexible Power Point Tracking’(FPPT) encompasses the improved functionalities of ...grid-connected systems.•Depending on grid requirements, the FPPT algorithm can function as either FPPT or MPPT.•Employing FPPT in partial shading conditions presents challenges.•The proposed FPPT method is designed to operate in both uniform and partial shading conditions.
Flexible power point tracking (FPPT) terminology has recently emergedto support additional functionality for grid-connected systems. Despite having a well-developed operation under uniform irradiance conditions, the FPPT algorithm's operation under partial shading conditions(PSC) reveals substantial challenges. The presented article introduces a global FPPT (GFPPT) algorithm that can operate under the PSC with a fast-trackingspeed. The proposed GFPPT algorithm employs the conventional search-skip-judge global maximum power point trackingmethod and the essential strategic scheme. The method conducts on the left side of the power-voltage curve to avoid the less robust nature ofthe right-sideoperation. Simulation and experimental tests are employed to validate the adequacy of the proposed approach. The simulation and experimental study adopted an indirect control approach using a proportional-integral controller and a buck-boost dc-dc converter. The uniform irradiance condition and PSC patterns with various peaks are chosen, and the presented GFPPT method is applied underdistinct criteria. The proposed method's effectiveness has been adequately validated based on the simulation and experimental outcomes.
This brief proposes a model-free deadbeat predictive controller (MF-DPC) for voltage source inverters. The proposed control scheme does not require knowledge of the system parameters for its correct ...operation. This is performed using an auto-regressive with exogenous input (ARX) model with a recursive least squares (RLS) estimation algorithm for parameter identification to represent the physical system. A state-space predictive model using the identified parameters and the past data measurements is established to calculate the inverter voltage reference using the deadbeat control principle and generate it using space vector modulation (SVM) allowing fixed-switching operation. In addition, the inherent sensitivity of the deadbeat controller to parameter mismatches is avoided. Simulation and experimental results confirm the validity of the proposed model-free control approach in terms of tracking accuracy and waveform quality.
Ablution area is one of the facilities used by most Muslims in all categories. There are numbers of design guidelines for praying facilities but lack on ablution area specification. Therefore, this ...study was conducted to design an ergonomic ablution area for the M uslim's disabled and elderly based on their preferences and anthropometric dimension. Kano questionnaires and user evaluation form, was used to investigate the preferences of elderly and dis abled in ablution area to 20 respondents at Masjid Bulat, Petaling Jaya and Masjid Kampung Kerinchi,Pantai Dalam, Kuala Lumpur in 2015. Anthropometric dimension of elderly and disabled people was measured. Besides, dimensions of two existing ablution units at selected mosques were evaluated using "Ablution Unit Dimension Eval uation' form. New ablution area design was developed based on elderly and disabled people anthropometric dimension and user preferences as well as user satisfaction survey. This study can be considered as preliminary study for the d evelopment of ergonomic ablution unit design. It is hoped that the findings and recommendations from this research will be referred by the stakehol ders to determine the best solution to increase the level of comfort and accessibility for elderly and disable d at mosques in M alaysia.
A tremendous growth in installed photovoltaic (PV) capacity and widespread use makes solar energy an important renewable energy source today. Voltage fluctuations and power quality problems are ...becoming more and more of a problem as the integration of PV power plants expands. In response, grid-connected PV systems' operational issues and the fluctuation of PV power generation have been addressed via the development of flexible power point tracking (FPPT) solutions. This review study provides a comprehensive analysis of FPPT strategies for PV power generation systems. It categorizes and describes various FPPT methods, studying their tracking performance under different working conditions and analyzing their underlying principles. One key advantage of FPPT strategies lies in their ability to operate PV systems below their maximum power point, thereby allowing for better control and active power reserve. Additionally, these strategies can provide essential grid support services, such as voltage control and frequency support. The work provides a baseline for scientists and researchers looking to adopt appropriate FPPT approaches. This research reveals common trends and efficient procedures for future investigations by contrasting methods based on their properties, such as their operating region selection and performance under partial shading circumstances.
•Describing the operation of different FPPT algorithms.•Analysing the pros and cons of different techniques.•Comprehensive comparative analysis of 33 FPPT algorithms for PV systems.•Segregating the algorithms into distinct categories for recommending the best one.•Guidelines for selecting the most suitable FPPT algorithm for specific applications.
This paper presents a wheelchair navigation system based on a hidden Markov model (HMM), which we developed to assist those with restricted mobility. The semi-autonomous system is equipped with ...obstacle collision avoidance sensors and it takes the electrooculography (EOG) signal traces from the user as commands to maneuver the wheelchair. The EOG traces originate from eyeball and eyelid movements and they are embedded in EEG signals collected from the scalp of the user at three different locations. Features extracted from the EOG traces are used to determine whether the eyes are open or closed, and whether the eyes are gazing to the right, center, or left. These features are utilized as inputs to a few support vector machine (SVM) classifiers, whose outputs are regarded as observations to an HMM. The HMM determines the state of the system and generates commands for navigating the wheelchair accordingly. The use of simple features and the implementation of a sliding window that captures important signatures in the EOG traces result in a fast execution time and high classification rates. The wheelchair is equipped with a proximity sensor and it can move forward and backward in three directions. The asynchronous system achieved an average classification rate of 98% when tested with online data while its average execution time was less than 1 s. It was also tested in a navigation experiment where all of the participants managed to complete the tasks successfully without collisions.
Nowadays, distributed generation (DG) has become an indispensable part for meeting the growing power demand in electrical power generation and distribution. However, one of the drawbacks of DG is ...unintentional islanding phenomena, which has become a safety issue for both human and equipment connected to the system. To prevent this hazardous condition, according to IEEE 1547 standards, this islanding condition must be detected within 2 s. This paper proposed an approach to develop a hybrid islanding detection method (IDM) to prevent the damages caused by this islanding condition. The proposed hybrid IDM is a combination of three different IDMs, two passive and one active; that is, rate of change of active power (ROCOAP) and rate of change of reactive power (ROCORP) are passive IDMs where load connecting strategy (LCS) is active. To differentiate islanding conditions with similar occurrences, different case studies are taken into account with photovoltaic (PV) and synchronous generator (SG) working as distributed generators on PSCAD/EMTDC platform. The simulation results confirm that proposed IDM is more favorable compared to other IDMs due to simplicity and fast islanding detection time when its performance is tested on the 11‐kV Malaysian distribution system for various cases.
Hybrid Islanding Detection Method for Power Distribution Network
The increasing installed capacity of distributed energy resources (DERs) allows prosumers to have a more flexible and proactive role in power system operation. At the same time, it may affect the ...stability of the power grid. To reduce the DERs penetration in the main grid and maximize the profit of the end-users, a new energy trading paradigm called peer-to-peer (P2P) energy trading emerges in the area of the local community microgrid. However, few of the previous works combine types of energy generation and storage equipment to the microgrid framework and propose a throughout distributed optimization solution to this scalable framework considering the impact of battery degradation cost. In this paper, a novel parallel market clearing mechanism is proposed for P2P energy trading with end-users in a highly scalable residential community microgrid. The proposed mechanism takes into account a variety of realistic factors such as household privacy, user preferences, peak shaving services, community power grid-related usage fees, point-to-point bilateral transaction weights, and battery degradation costs. To make the microgrid more scalable, each household in the community is designed with different household energy generation and storage appliances including photovoltaic panels, wind turbines, plug-in electrical vehicles, and various household batteries with different capacities. A distributed approach based on the alternating direction method of multiplier (ADMM) algorithm is presented to solve the energy pricing problem while guaranteeing the privacy of all participants. The designed comparative case studies take into consideration the types of users, grid transaction methods, the influence of peak shaving fee, the impact of energy storage equipment, and the effect of battery degradation costs. The results show a significant reduction of both the cost of each user and the total cost in the P2P energy market while considering the degradation cost of home energy management systems and plug-in electric vehicles. The case studies also present that prosumers have greater advantages than consumers in P2P energy transactions. Peak shaving service and home energy storage devices can distribute and utilize energy more efficiently.
•A residential community microgrid framework with high scalability is designed.•Based on this microgrid framework, an ADMM algorithm is proposed that can be combined with the charging and discharging strategies of PEVs and HESSs.•The proposed algorithm takes into account a variety of realistic factors such as household privacy, user preferences, peak shaving services.•The designed comparative experimental case takes into consideration the types of users, grid transaction methods, the impact of energy storage equipment, and the impact of battery degradation costs.
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