This page has only limited features, please log in for full access.
Current-perpendicular-to-the-plane giant magnetoresistance (CPP-GMR) read sensors based on Heusler alloys are promising candidates for ultrahigh areal densities of magnetic data storage technology. In particular, the thickness of reader structures is one of the key factors for the development of practical CPP-GMR sensors. In this research, we studied the dependence of the free layer thickness on the stability of the Co2(Mn0.6Fe0.4)Ge Heusler-based CPP-GMR read head for an areal density of 1 Tb/in2, aiming to determine the appropriate layer thickness. The evaluations were done through simulations based on micromagnetic modelling. The reader stability indicators, including the magnetoresistance (MR) ratio, readback signal, dibit response asymmetry parameter, and power spectral density profile, were characterized and discussed. Our analysis demonstrates that the reader with a free layer thickness of 3 nm indicates the best stability performance for this particular head. A reasonably large MR ratio of 26% was obtained by the reader having this suitable layer thickness. The findings can be utilized to improve the design of the CPP-GMR reader for use in ultrahigh magnetic recording densities.
Pirat Khunkitti; Apirat Siritaratiwat; Kotchakorn Pituso. Free Layer Thickness Dependence of the Stability in Co2(Mn0.6Fe0.4)Ge Heusler Based CPP-GMR Read Sensor for Areal Density of 1 Tb/in2. Micromachines 2021, 12, 1010 .
AMA StylePirat Khunkitti, Apirat Siritaratiwat, Kotchakorn Pituso. Free Layer Thickness Dependence of the Stability in Co2(Mn0.6Fe0.4)Ge Heusler Based CPP-GMR Read Sensor for Areal Density of 1 Tb/in2. Micromachines. 2021; 12 (9):1010.
Chicago/Turabian StylePirat Khunkitti; Apirat Siritaratiwat; Kotchakorn Pituso. 2021. "Free Layer Thickness Dependence of the Stability in Co2(Mn0.6Fe0.4)Ge Heusler Based CPP-GMR Read Sensor for Areal Density of 1 Tb/in2." Micromachines 12, no. 9: 1010.
Solving the optimal power flow problems (OPF) is an important step in optimally dispatching the generation with the considered objective functions. A single-objective function is inadequate for modern power systems, required high-performance generation, so the problem becomes multi-objective optimal power flow (MOOPF). Although the MOOPF problem has been widely solved by many algorithms, new solutions are still required to obtain better performance of generation. Slime mould algorithm (SMA) is a recently proposed metaheuristic algorithm that has been applied to solve several optimization problems in different fields, except the MOOPF problem, while it outperforms various algorithms. Thus, this paper proposes solving MOOPF problems based on SMA considering cost, emission, and transmission line loss as part of the objective functions in a power system. The IEEE 30-, 57-, and 118-bus systems are used to investigate the performance of the SMA on solving MOOPF problems. The objective values generated by SMA are compared with those of other algorithms in the literature. The simulation results show that SMA provides better solutions than many other algorithms in the literature, and the Pareto fronts presenting multi-objective solutions can be efficiently obtained.
Sirote Khunkitti; Apirat Siritaratiwat; Suttichai Premrudeepreechacharn. Multi-Objective Optimal Power Flow Problems Based on Slime Mould Algorithm. Sustainability 2021, 13, 7448 .
AMA StyleSirote Khunkitti, Apirat Siritaratiwat, Suttichai Premrudeepreechacharn. Multi-Objective Optimal Power Flow Problems Based on Slime Mould Algorithm. Sustainability. 2021; 13 (13):7448.
Chicago/Turabian StyleSirote Khunkitti; Apirat Siritaratiwat; Suttichai Premrudeepreechacharn. 2021. "Multi-Objective Optimal Power Flow Problems Based on Slime Mould Algorithm." Sustainability 13, no. 13: 7448.
Power quality disturbance (PQD) is an influential situation that significantly declines the reliability of electrical distribution systems. Therefore, PQD classification is an important process for preventing system reliability degradation. This paper introduces a novel algorithm called “adaptive salp swarm algorithm (SSA)” as an optimal feature selection algorithm for PQD classification. Feature extraction and classifier of the proposed classification system were based on the discrete wavelet and the probabilistic neural network, respectively. The classification was focused on the 13 types of power quality signals. The optimal number of selected features for the proposed classification system was firstly determined. Then, it demonstrated that the optimally selected features resulted in the highest classification accuracy of 98.77%. High performance of the proposed classification system in the noisy environment, as well as based on the real dataset was also verified. Furthermore, the proposed SSA indicates a very high convergence rate compared to other well-known algorithms. A comparison of the proposed classification system’s performance to existing works was also carried out, revealing that the proposed system’s accuracy is on a high-range scale. Hence, the adaptive SSA becomes another efficient optimal feature selection algorithm for PQD classification.
Supanat Chamchuen; Apirat Siritaratiwat; Pradit Fuangfoo; Puripong Suthisopapan; Pirat Khunkitti. Adaptive Salp Swarm Algorithm as Optimal Feature Selection for Power Quality Disturbance Classification. Applied Sciences 2021, 11, 5670 .
AMA StyleSupanat Chamchuen, Apirat Siritaratiwat, Pradit Fuangfoo, Puripong Suthisopapan, Pirat Khunkitti. Adaptive Salp Swarm Algorithm as Optimal Feature Selection for Power Quality Disturbance Classification. Applied Sciences. 2021; 11 (12):5670.
Chicago/Turabian StyleSupanat Chamchuen; Apirat Siritaratiwat; Pradit Fuangfoo; Puripong Suthisopapan; Pirat Khunkitti. 2021. "Adaptive Salp Swarm Algorithm as Optimal Feature Selection for Power Quality Disturbance Classification." Applied Sciences 11, no. 12: 5670.
The optimal siting and sizing of battery energy storage system (BESS) is proposed in this study to improve the performance of the seventh feeder at Nakhon Phanom substation, which is a distribution network with the connected photovoltaic (PV) in Thailand. The considered objective function aims to improve the distribution network performance by minimizing costs incurred in the distribution network within a day, comprising of voltage regulation cost, real power loss cost, and peak demand cost. Particle swarm optimization (PSO) is applied to solve the optimization problem. It is found that the optimal siting and sizing of the BESS installation could improve the performance of the distribution network in terms of cost minimization, voltage profile, real power loss, and peak demand. The results are investigated from three cases where case 1 is without PV and BESS installation, case 2 is with only PV installation, and case 3 is with PV and BESS installations. The comparison results show that case 3 provided the best costs, voltage deviation, real power loss, and peak demand compared to those of cases 1 and 2; system costs provided by cases 1, 2 and 3 are USD 4598, USD 5418, and USD 1467, respectively.
Panyawoot Boonluk; Sirote Khunkitti; Pradit Fuangfoo; Apirat Siritaratiwat. Optimal Siting and Sizing of Battery Energy Storage: Case Study Seventh Feeder at Nakhon Phanom Substation in Thailand. Energies 2021, 14, 1458 .
AMA StylePanyawoot Boonluk, Sirote Khunkitti, Pradit Fuangfoo, Apirat Siritaratiwat. Optimal Siting and Sizing of Battery Energy Storage: Case Study Seventh Feeder at Nakhon Phanom Substation in Thailand. Energies. 2021; 14 (5):1458.
Chicago/Turabian StylePanyawoot Boonluk; Sirote Khunkitti; Pradit Fuangfoo; Apirat Siritaratiwat. 2021. "Optimal Siting and Sizing of Battery Energy Storage: Case Study Seventh Feeder at Nakhon Phanom Substation in Thailand." Energies 14, no. 5: 1458.
Power quality disturbance (PQD) is an important issue in electrical distribution systems that needs to be detected promptly and identified to prevent the degradation of system reliability. This work proposes a PQD classification using a novel algorithm, comprised of the artificial bee colony (ABC) and the particle swarm optimization (PSO) algorithms, called “adaptive ABC-PSO” as the feature selection algorithm. The proposed adaptive technique is applied to a combination of ABC and PSO algorithms, and then used as the feature selection algorithm. A discrete wavelet transform is used as the feature extraction method, and a probabilistic neural network is used as the classifier. We found that the highest classification accuracy (99.31%) could be achieved through nine optimally selected features out of all 72 extracted features. Moreover, the proposed PQD classification system demonstrated high performance in a noisy environment, as well as the real distribution system. When comparing the presented PQD classification system’s performance to previous studies, PQD classification accuracy using adaptive ABC-PSO as the optimal feature selection algorithm is considered to be at a high-range scale; therefore, the adaptive ABC-PSO algorithm can be used to classify the PQD in a practical electrical distribution system.
Supanat Chamchuen; Apirat Siritaratiwat; Pradit Fuangfoo; Puripong Suthisopapan; Pirat Khunkitti. High-Accuracy Power Quality Disturbance Classification Using the Adaptive ABC-PSO as Optimal Feature Selection Algorithm. Energies 2021, 14, 1238 .
AMA StyleSupanat Chamchuen, Apirat Siritaratiwat, Pradit Fuangfoo, Puripong Suthisopapan, Pirat Khunkitti. High-Accuracy Power Quality Disturbance Classification Using the Adaptive ABC-PSO as Optimal Feature Selection Algorithm. Energies. 2021; 14 (5):1238.
Chicago/Turabian StyleSupanat Chamchuen; Apirat Siritaratiwat; Pradit Fuangfoo; Puripong Suthisopapan; Pirat Khunkitti. 2021. "High-Accuracy Power Quality Disturbance Classification Using the Adaptive ABC-PSO as Optimal Feature Selection Algorithm." Energies 14, no. 5: 1238.
In this work, optimal siting and sizing of a battery energy storage system (BESS) in a distribution network with renewable energy sources (RESs) of distribution network operators (DNO) are presented to reduce the effect of RES fluctuations for power generation reliability and quality. The optimal siting and sizing of the BESS are found by minimizing the costs caused by the voltage deviations, power losses, and peak demands in the distribution network for improving the performance of the distribution network. The simulation results of the BESS installation were evaluated in the IEEE 33-bus distribution network. Genetic algorithm (GA) and particle swarm optimization (PSO) were adopted to solve this optimization problem, and the results obtained from these two algorithms were compared. After the BESS installation in the distribution network, the voltage deviations, power losses, and peak demands were reduced when compared to those of the case without BESS installation.
Panyawoot Boonluk; Apirat Siritaratiwat; Pradit Fuangfoo; Sirote Khunkitti. Optimal Siting and Sizing of Battery Energy Storage Systems for Distribution Network of Distribution System Operators. Batteries 2020, 6, 1 .
AMA StylePanyawoot Boonluk, Apirat Siritaratiwat, Pradit Fuangfoo, Sirote Khunkitti. Optimal Siting and Sizing of Battery Energy Storage Systems for Distribution Network of Distribution System Operators. Batteries. 2020; 6 (4):1.
Chicago/Turabian StylePanyawoot Boonluk; Apirat Siritaratiwat; Pradit Fuangfoo; Sirote Khunkitti. 2020. "Optimal Siting and Sizing of Battery Energy Storage Systems for Distribution Network of Distribution System Operators." Batteries 6, no. 4: 1.
A non-destructive technique to inspect a scratch on all magnetic disks in the beginning process of hard disk drive (HDD) manufacturing by using CD and DVD pick-up heads as the detector is proposed. It requires a 100% disk inspection of micrometer-sized scratches in a quick measurement with low cost inventing. Most of the previous studies were in static state but this is the first time to be done in dynamic study using the microcontroller in order to promptly serve for industrial utilization. The size, position, and shape characteristic of scratches are examined using light reflection technique. The results show that, when the laser beam is targeted on a magnetic disk in a position, either scratch or non-scratch, the reflected light intensity differs. The DVD pick-up head can detect the width and the surface characteristic of the scratches, which is similar to the results from scanning electron microscope (SEM) for all scratches sizes less than 100 µm. It is also found that using a DVD pick-up head provides a better resolution of shape characteristic and roughness of scratches surface than a CD pick-up head. Hence, the scratch size of 10s µm scale on the magnetic disk can be accurately characterized by this proposed technique, which can be further utilized for magnetic disk inspection in the hard disk drive manufacturing process.
Achinee Polsawat; Warunee Tipcharoen; Apirat Siritaratiwat. Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller. Applied Sciences 2020, 10, 6897 .
AMA StyleAchinee Polsawat, Warunee Tipcharoen, Apirat Siritaratiwat. Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller. Applied Sciences. 2020; 10 (19):6897.
Chicago/Turabian StyleAchinee Polsawat; Warunee Tipcharoen; Apirat Siritaratiwat. 2020. "Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller." Applied Sciences 10, no. 19: 6897.
The doubly salient permanent magnet (DSPM) machines are very attractive for low-speed power generation. In this work, we propose a design technique to improve the output power of the DSPM generator by an adjustment of pole configuration. The number of stator and rotor poles, split ratio, as well as the stator pole arc of the generator, were proposedly adjusted and optimized. The output characteristics of the generator including the magnetic flux linkage, electromotive force, harmonic, cogging torque, electromagnetic torque, output voltage and output power were analyzed through finite element analysis. The symmetrical magnetic field distribution of all generators was firstly verified. Then, the results indicated that this particular generator was optimized at 18 stator poles and 12 rotor poles, while the split ratio and the stator pole arc should be set as 0.78 and 6.15 degrees, respectively. The proposed optimal generator could provide a significant improvement in the output voltage and the output power compared to the conventional structure. The output power of 1.28 kW can be reached by the optimal structure, which was two times higher than that of the conventional structure. The physical explanation regarding to the structural modification was also given. The proposed design technique can be applied for improving the output power of the DSPM machines.
Warat Sriwannarat; Pattasad Seangwong; Vannakone Lounthavong; Sirote Khunkitti; Apirat Siritaratiwat; Pirat Khunkitti. An Improvement of Output Power in Doubly Salient Permanent Magnet Generator Using Pole Configuration Adjustment. Energies 2020, 13, 4588 .
AMA StyleWarat Sriwannarat, Pattasad Seangwong, Vannakone Lounthavong, Sirote Khunkitti, Apirat Siritaratiwat, Pirat Khunkitti. An Improvement of Output Power in Doubly Salient Permanent Magnet Generator Using Pole Configuration Adjustment. Energies. 2020; 13 (17):4588.
Chicago/Turabian StyleWarat Sriwannarat; Pattasad Seangwong; Vannakone Lounthavong; Sirote Khunkitti; Apirat Siritaratiwat; Pirat Khunkitti. 2020. "An Improvement of Output Power in Doubly Salient Permanent Magnet Generator Using Pole Configuration Adjustment." Energies 13, no. 17: 4588.
Sirote Khunkitti; Suttichai Premrudeepreechacharn; Apirat Siritaratiwat; Neville R. Watson. Power System Voltage Stability Enhancement Based on Line Voltage Stability Indices in Heavily Loaded and Line Outage Contingency Situations. International Journal of Engineering Research and Technology 2020, 13, 1 .
AMA StyleSirote Khunkitti, Suttichai Premrudeepreechacharn, Apirat Siritaratiwat, Neville R. Watson. Power System Voltage Stability Enhancement Based on Line Voltage Stability Indices in Heavily Loaded and Line Outage Contingency Situations. International Journal of Engineering Research and Technology. 2020; 13 (7):1.
Chicago/Turabian StyleSirote Khunkitti; Suttichai Premrudeepreechacharn; Apirat Siritaratiwat; Neville R. Watson. 2020. "Power System Voltage Stability Enhancement Based on Line Voltage Stability Indices in Heavily Loaded and Line Outage Contingency Situations." International Journal of Engineering Research and Technology 13, no. 7: 1.
Pattasad Seangwong; Siripat Somchit; Kanokphon Kaisoda; Phuson Srikhumphun; Kornchanok Suwanpaiboon; Warat Sriwannarat; Apirat Siritaratiwat; Pirat Khunkitti. An Improvement of Electromotive Force in Switched Flux Permanent Magnet Generator by using Multi-Tooth Technique. International Journal of Engineering Research and Technology 2020, 13, 1 .
AMA StylePattasad Seangwong, Siripat Somchit, Kanokphon Kaisoda, Phuson Srikhumphun, Kornchanok Suwanpaiboon, Warat Sriwannarat, Apirat Siritaratiwat, Pirat Khunkitti. An Improvement of Electromotive Force in Switched Flux Permanent Magnet Generator by using Multi-Tooth Technique. International Journal of Engineering Research and Technology. 2020; 13 (3):1.
Chicago/Turabian StylePattasad Seangwong; Siripat Somchit; Kanokphon Kaisoda; Phuson Srikhumphun; Kornchanok Suwanpaiboon; Warat Sriwannarat; Apirat Siritaratiwat; Pirat Khunkitti. 2020. "An Improvement of Electromotive Force in Switched Flux Permanent Magnet Generator by using Multi-Tooth Technique." International Journal of Engineering Research and Technology 13, no. 3: 1.
Electric vehicles (EV) replacing the internal combustion engine vehicle may be the solution for the particulate matter (PM) 2.5 pollution issue. However, the uncontrolled charging of EVs would challenge the power system operation. Therefore, it is necessary to implement some level of control over the EV charging procedure, especially in the residential network. In this paper, an optimization of EVs charging scheduling considering energy arbitrage and the distribution network cost of an urban village environment is presented. The optimized strategy focuses on decreasing the loss of EV owners’ energy arbitrage benefit, introduced as the penalty cost. Also, peak demand, power loss, and transformer aging are included in the estimation of the cost function for the distribution network. The optimization problem is solved using the genetic algorithm. As a case study, data from the urban village in Udon Thani, Thailand, are utilized to demonstrate the applicability of the proposed method. Simulation results show a reduction in the loss of energy arbitrage benefit, transformer peak load, power loss and the transformer loss of life. Therefore, the application of the optimized EV charging can prolong transformer lifetime benefiting both the EV owner and the distribution system operator.
Chitchai Srithapon; Prasanta Ghosh; Apirat Siritaratiwat; Rongrit Chatthaworn. Optimization of Electric Vehicle Charging Scheduling in Urban Village Networks Considering Energy Arbitrage and Distribution Cost. Energies 2020, 13, 349 .
AMA StyleChitchai Srithapon, Prasanta Ghosh, Apirat Siritaratiwat, Rongrit Chatthaworn. Optimization of Electric Vehicle Charging Scheduling in Urban Village Networks Considering Energy Arbitrage and Distribution Cost. Energies. 2020; 13 (2):349.
Chicago/Turabian StyleChitchai Srithapon; Prasanta Ghosh; Apirat Siritaratiwat; Rongrit Chatthaworn. 2020. "Optimization of Electric Vehicle Charging Scheduling in Urban Village Networks Considering Energy Arbitrage and Distribution Cost." Energies 13, no. 2: 349.
This work aims to maximize the benefit of the low-voltage (LV) level distribution system with high photovoltaic (PV) penetration by using an optimal installation of a battery energy storage system (BESS) and capacitor. The 41-bus practical distribution system located in Thailand was focused on. The comprehensive objective function regarding the focused system was proposed. The Salp Swarm and Genetic Algorithms were applied to solve the optimization problem. The total net present value (NPV) of utility was performed as a beneficial indicator, and it was determined by the overall costs and benefits of BESS installation and capacitor placement. A comparison of total NPV in the cases of centralized BESS installation, BESS installation with LV capacitor placement, and decentralized BESS installation was indicated. The results showed that all cases of BESS installation could increasingly flatten the load on the transformer; meanwhile, the voltage profile of the system was significantly improved. Optimal installation of centralized BESS simultaneously with LV capacitor placement provides higher NPV than the case with only centralized BESS installation. In particular, the highest NPV was obtained in the case of installing decentralized BESS. The results can be utilized to maximize the benefits of the utility in the distribution system at a high PV penetration level.
Nathphol Khaboot; Chitchai Srithapon; Apirat Siritaratiwat; Pirat Khunkitti. Increasing Benefits in High PV Penetration Distribution System by Using Battery Enegy Storage and Capacitor Placement Based on Salp Swarm Algorithm. Energies 2019, 12, 4817 .
AMA StyleNathphol Khaboot, Chitchai Srithapon, Apirat Siritaratiwat, Pirat Khunkitti. Increasing Benefits in High PV Penetration Distribution System by Using Battery Enegy Storage and Capacitor Placement Based on Salp Swarm Algorithm. Energies. 2019; 12 (24):4817.
Chicago/Turabian StyleNathphol Khaboot; Chitchai Srithapon; Apirat Siritaratiwat; Pirat Khunkitti. 2019. "Increasing Benefits in High PV Penetration Distribution System by Using Battery Enegy Storage and Capacitor Placement Based on Salp Swarm Algorithm." Energies 12, no. 24: 4817.
Pirat Khunkitti; Anan Kruesubthaworn; Arkom Kaewrawang; Apirat Siritaratiwat. Unstable Playback Response of CPP-GMR Read Head Induced by Electromagnetic Interference: Structural Dependence. IEEE Transactions on Magnetics 2019, 55, 1 -6.
AMA StylePirat Khunkitti, Anan Kruesubthaworn, Arkom Kaewrawang, Apirat Siritaratiwat. Unstable Playback Response of CPP-GMR Read Head Induced by Electromagnetic Interference: Structural Dependence. IEEE Transactions on Magnetics. 2019; 55 (12):1-6.
Chicago/Turabian StylePirat Khunkitti; Anan Kruesubthaworn; Arkom Kaewrawang; Apirat Siritaratiwat. 2019. "Unstable Playback Response of CPP-GMR Read Head Induced by Electromagnetic Interference: Structural Dependence." IEEE Transactions on Magnetics 55, no. 12: 1-6.
Electric vehicle (EV) replacing the internal combustion engine may be the solution to the PM2.5 pollution issues. However, uncontrolled increase of EVs would challenge the power-distribution-system operation, which includes the reduction of distribution transformer lifetime. Therefore, it is necessary to implement some level of control over EV charging procedure, especially in the residential network. In this paper, we present an optimization method for EV charging considering a transformer aging factor in an urban village environment. The optimized strategy focuses on the reduction of the charging cost, power loss and peak load power. The optimization problem is solved using the Genetic Algorithm (GA) in MATLAB. As a case study, we have used data from the village in Udon Thani, Thailand to demonstrate the applicability of the proposed method. Simulation results show a reduction in the charging cost, power loss cost and peak demand power. In addition, the application of the proposed method prolongs the transformer lifetime, which can benefit both EV owner and distribution system operator (DSO).
Chitchai Srithapon; Prasanta Ghosh; Apirat Siritaratiwat; Rongrit Chatthaworn. Optimized Electric Vehicles Charging in an Urban Village Network Considering Transformer Aging. 2019 IEEE Electrical Power and Energy Conference (EPEC) 2019, 1 -6.
AMA StyleChitchai Srithapon, Prasanta Ghosh, Apirat Siritaratiwat, Rongrit Chatthaworn. Optimized Electric Vehicles Charging in an Urban Village Network Considering Transformer Aging. 2019 IEEE Electrical Power and Energy Conference (EPEC). 2019; ():1-6.
Chicago/Turabian StyleChitchai Srithapon; Prasanta Ghosh; Apirat Siritaratiwat; Rongrit Chatthaworn. 2019. "Optimized Electric Vehicles Charging in an Urban Village Network Considering Transformer Aging." 2019 IEEE Electrical Power and Energy Conference (EPEC) , no. : 1-6.
The partitioned stator doubly salient permanent magnet generator (PS-DSPG) with asymmetrical-pole configuration has been widely applied for producing electrical power due to their high reliability, high flux linkage and high electromagnetic force (EMF). Therefore, we aim to improve the performance of this generator an asymmetrical-pole structure technique applied to outer stator pole. The phase flux linkage and phase EMF were characterized by finite element method. It was verified that the flux linkage and EMF were increased when increasing the number of outer stator. Especially, the 30/8/14-pole (outer stator/rotor/PM-pole) of PS-DSPG structure with asymmetrical-pole technique produced high symmetric EMF waveform. the arc variation of rotor iron piece of all proposed structures was investigated. It was found that the 30/8/14-pole of the proposed asymmetrical-pole PS-DSPG structure provides EMF about 61.29% higher than the conventional structure at expanded rotor arc of 140%. Hence, the 30/8/14-pole asymmetrical-pole PS-DSPG structure can be utilized for electrical generation in low-speed applications.
W Sriwannarat; A Janon; Apirat Siritaratiwat; P Khunkitti. Performance improvement of asymmetrical-pole partitioned stator permanent magnet generator by optimizing stator teeth number. IOP Conference Series: Earth and Environmental Science 2019, 322, 012010 .
AMA StyleW Sriwannarat, A Janon, Apirat Siritaratiwat, P Khunkitti. Performance improvement of asymmetrical-pole partitioned stator permanent magnet generator by optimizing stator teeth number. IOP Conference Series: Earth and Environmental Science. 2019; 322 (1):012010.
Chicago/Turabian StyleW Sriwannarat; A Janon; Apirat Siritaratiwat; P Khunkitti. 2019. "Performance improvement of asymmetrical-pole partitioned stator permanent magnet generator by optimizing stator teeth number." IOP Conference Series: Earth and Environmental Science 322, no. 1: 012010.
An optimal stator design technique of a three-phase doubly salient permanent magnet generator (DSPMG) for improving the output power is proposed. The stator configuration was optimally designed by adjusting the stator pole depth and stator pole arc. The trapezoid outer stator tip was also designed. Then, the output characteristics of the designed DSPMG including the flux linkage, electromotive force (EMF), harmonic, cogging torque, efficiency, magnetic flux distribution and voltage regulation were characterized by using the finite element method. Results were compared to the original structure in the literature. It was found that the flux linkage, EMF, cogging torque, and efficiency of the proposed DSPMG were significantly improved after the stator pole depth and stator pole arc were suitably modified. Further details of optimal stator pole depth and stator pole arc are presented. The EMF produced by the optimal proposed structure was 47% higher than that of the conventional structure, while 56% cogging torque improvement and 20% increased efficiency were achieved. The EMF generated by the proposed structure was classified in the high-range scale compared to the other existing models. The symmetrical magnetic flux distribution of all structures was indicated. The voltage regulation of the modified structure was also significantly improved from the conventional model. The proposed design technique can be utilized to maximize the electromagnetic performance of this particular generator type.
Vannakone Lounthavong; Warat Sriwannarat; Apirat Siritaratiwat; Pirat Khunkitti. Optimal Stator Design of Doubly Salient Permanent Magnet Generator for Enhancing the Electromagnetic Performance. Energies 2019, 12, 3201 .
AMA StyleVannakone Lounthavong, Warat Sriwannarat, Apirat Siritaratiwat, Pirat Khunkitti. Optimal Stator Design of Doubly Salient Permanent Magnet Generator for Enhancing the Electromagnetic Performance. Energies. 2019; 12 (16):3201.
Chicago/Turabian StyleVannakone Lounthavong; Warat Sriwannarat; Apirat Siritaratiwat; Pirat Khunkitti. 2019. "Optimal Stator Design of Doubly Salient Permanent Magnet Generator for Enhancing the Electromagnetic Performance." Energies 12, no. 16: 3201.
Spin-transfer torque magnetic random-access memory (STT-MRAM) based on a single-barrier magnetic tunnel junction (SBMTJ) and a double-barrier magnetic tunnel junction (DBMTJ) has evolved along with a low switching current and low energy consumption to obtain a high areal density and a fast switching speed. The increment of initial temperature, ${T}_{{\text {in}}}$ , in STT-MRAM can achieve low switching energy, ${E}_{{\text {SW}}}$ . However, this leads to an unavoidable decrease in $\Delta $ and switching efficiency. In this paper, SBMTJ and DBMTJ were analyzed in terms of the switching efficiency factor with ${E}_{{\text {SW}}}$ reduction by increasing the ${T}_{{\text {in}}}$ . The switching temperature, ${T}_{{\text {SW}}}$ , was investigated using a finite-element method simulation. The results show that the DBMTJ(A) and SBMTJ with the same MgO layer thickness of 0.9 nm provide a higher switching current, ${I}_{{\text {C}}}$ , than the DBMTJ(B) with a MgO layer thickness of 1.3 nm. The ${T}_{{\text {SW}}}$ in a DBMTJ(A) is higher than that in an SBMTJ, while ${T}_{{\text {SW}}}$ for a DBMTJ(B) is the smallest because of its low ${I}_{{\text {C}}}$ . The DBMTJ(A) and DBMTJ(B) can be applied in a higher temperature range than the SBMTJ at a $\Delta $ of 40. In addition, the STT efficiency factor, $\Delta /{I}_{{\text {C0}}}$ , for a DBMTJ is better than the factor for an SBMTJ. Although the temperature increment would cause an undesirable reduction in $\Delta $ , it can reach a low ${E}_{{\text {SW}}}$ for the requirement of a fast write access time. Therefore, the control device for increasing the ${T}_{{\text {in}}}$ in the MTJs is attractive and should be promoted in the advancement of memory technology.
B. Teso; A. Siritaratiwat; A. Kaewrawang; A. Kruesubthaworn; A. Namvong; S. Sainon; C. Surawanitkun. Switching Performance Comparison With Low Switching Energy Due to Initial Temperature Increment in CoFeB/MgO-Based Single and Double Barriers. IEEE Transactions on Electron Devices 2019, 66, 4062 -4067.
AMA StyleB. Teso, A. Siritaratiwat, A. Kaewrawang, A. Kruesubthaworn, A. Namvong, S. Sainon, C. Surawanitkun. Switching Performance Comparison With Low Switching Energy Due to Initial Temperature Increment in CoFeB/MgO-Based Single and Double Barriers. IEEE Transactions on Electron Devices. 2019; 66 (9):4062-4067.
Chicago/Turabian StyleB. Teso; A. Siritaratiwat; A. Kaewrawang; A. Kruesubthaworn; A. Namvong; S. Sainon; C. Surawanitkun. 2019. "Switching Performance Comparison With Low Switching Energy Due to Initial Temperature Increment in CoFeB/MgO-Based Single and Double Barriers." IEEE Transactions on Electron Devices 66, no. 9: 4062-4067.
Solving the Unit Commitment problem is an important step in optimally dispatching the available generation and involves two stages—deciding which generators to commit, and then deciding their power output (economic dispatch). The Unit Commitment problem is a mixed-integer combinational optimization problem that traditional optimization techniques struggle to solve, and metaheuristic techniques are better suited. Dragonfly algorithm (DA) and particle swarm optimization (PSO) are two such metaheuristic techniques, and recently a hybrid (DA-PSO), to make use of the best features of both, has been proposed. The original DA-PSO optimization is unable to solve the Unit Commitment problem because this is a mixed-integer optimization problem. However, this paper proposes a new and improved DA-PSO optimization (referred to as iDA-PSO) for solving the unit commitment and economic dispatch problems. The iDA-PSO employs a sigmoid function to find the optimal on/off status of units, which is the mixed-integer part of obtaining the Unit Commitment problem. To verify the effectiveness of the iDA-PSO approach, it was tested on four different-sized systems (5-unit, 6-unit, 10-unit, and 26-unit systems). The unit commitment, generation schedule, total generation cost, and time were compared with those obtained by other algorithms in the literature. The simulation results show iDA-PSO is a promising technique and is superior to many other algorithms in the literature.
Sirote Khunkitti; Neville R. Watson; Rongrit Chatthaworn; Suttichai Premrudeepreechacharn; Apirat Siritaratiwat. An Improved DA-PSO Optimization Approach for Unit Commitment Problem. Energies 2019, 12, 2335 .
AMA StyleSirote Khunkitti, Neville R. Watson, Rongrit Chatthaworn, Suttichai Premrudeepreechacharn, Apirat Siritaratiwat. An Improved DA-PSO Optimization Approach for Unit Commitment Problem. Energies. 2019; 12 (12):2335.
Chicago/Turabian StyleSirote Khunkitti; Neville R. Watson; Rongrit Chatthaworn; Suttichai Premrudeepreechacharn; Apirat Siritaratiwat. 2019. "An Improved DA-PSO Optimization Approach for Unit Commitment Problem." Energies 12, no. 12: 2335.
Nowadays, the changes of economic, environment, and regulations are forcing the electric utilities to operate systems at maximum capacity. Therefore, the operation and control of power system to improve the system stability has been receiving a great deal of attention. This paper presents an approach for enhancing the static voltage stability margin and reducing the power losses of the system with voltage security-constrained optimal power flow (VSC-OPF) that is based on static line voltage stability indices. The control approaches incorporate the voltage stability criteria into the conventional OPF. The minimization of the summation of fast voltage stability index (FVSI), line stability index (Lmn), and line voltage stability index (LVSI) is used as the objective functions. The performance and effectiveness of the proposed control approaches are evaluated on the standard IEEE 30-bus, 57-bus, and 118-bus test systems under normal and contingency conditions. The comparison analysis is carried out with different cases including minimization of generation cost. The proposed control approaches indicate the promising results and offer efficient countermeasures against the voltage instability of the system.
Natakorn Thasnas; Apirat Siritaratiwat. Implementation of Static Line Voltage Stability Indices for Improved Static Voltage Stability Margin. Journal of Electrical and Computer Engineering 2019, 2019, 1 -14.
AMA StyleNatakorn Thasnas, Apirat Siritaratiwat. Implementation of Static Line Voltage Stability Indices for Improved Static Voltage Stability Margin. Journal of Electrical and Computer Engineering. 2019; 2019 ():1-14.
Chicago/Turabian StyleNatakorn Thasnas; Apirat Siritaratiwat. 2019. "Implementation of Static Line Voltage Stability Indices for Improved Static Voltage Stability Margin." Journal of Electrical and Computer Engineering 2019, no. : 1-14.
In this paper, the magnetic equivalent circuit (MEC) modeling of partitioned stator doubly salient permanent magnet machines (PS-DSPM) is presented. An analytical methodology is proposed to model the air-gap flux in piecewise intervals, and the stator and rotor steel are modeled as fixed permeances. The MEC model is then implemented and executed in a time-stepped simulation. The magnetic flux characteristics and phase EMF of an example PS-DSPM are compared with finite element analysis (FEA). Especially, the two sizes of PS-DSPM machine are investigated to compare the MEC and FEM. The results obtained by MEC and FEA are in good agreement. The modeling MEC of PS-DSPM machines can be utilized for designing the same machine.
Warat Sriwannarat; Nuwantha Fernando; Apirat Siritaratiwat; Pirat Khunkitti. Magnetic Equivalent Circuit Modeling of Partitioned Stator Doubly Salient Permanent Magnet Machines. 2019 IEEE International Electric Machines & Drives Conference (IEMDC) 2019, 1959 -1965.
AMA StyleWarat Sriwannarat, Nuwantha Fernando, Apirat Siritaratiwat, Pirat Khunkitti. Magnetic Equivalent Circuit Modeling of Partitioned Stator Doubly Salient Permanent Magnet Machines. 2019 IEEE International Electric Machines & Drives Conference (IEMDC). 2019; ():1959-1965.
Chicago/Turabian StyleWarat Sriwannarat; Nuwantha Fernando; Apirat Siritaratiwat; Pirat Khunkitti. 2019. "Magnetic Equivalent Circuit Modeling of Partitioned Stator Doubly Salient Permanent Magnet Machines." 2019 IEEE International Electric Machines & Drives Conference (IEMDC) , no. : 1959-1965.