DSpace Collection:
http://dspace.spu.ac.th/handle/123456789/2704
2024-03-28T15:23:42ZVoltage-controlled of photocurrent in silicon planar metal-semiconductor-metal structures
http://dspace.spu.ac.th/handle/123456789/3795
Title: Voltage-controlled of photocurrent in silicon planar metal-semiconductor-metal structures
Authors: Sanya Khunkhao
Abstract: The bias-controllable photocurrent characteristic by using planar MSM structures with both depleted and undepleted regions under dc and ac optical illumination condition has been proposed at the active area. The structure has two co-planar Mo/n-Si Schottky-barrier junctions on silicon of resistivity 9-12 Ω-cm and the electrode separation is 20 m. By introducing an undepleted region between Schottky barriers on both sides, the depleted region width at the front surface under illumination varies with bias applied, where this region would be more sensitive to optical quantity than the undepleted region to generate the photocurrent. Therefore, this structure is expected to show the output photocurrent as the function of not only optical illumination intensity but applied bias due to laterally spreading of space-charge-region (SCR). Making use of planar molybdenum n-type silicon molybdenum (Mo/n-Si/Mo) structures, it has been experimentally demonstrated that such a structure exhibits voltage-controllability of photocurrents whilst maintaining the inherent function converting optical signal into electronic signal. An appreciable improvement in obtaining output photocurrent was confirmed from both dc and low frequency 100Hz-100 kHz photoresponse properties. It was found that this structure shown an appreciable voltage controllability of the photocurrent of this structure.2555-08-05T15:18:17ZMulti-Objective Optimal Power Flow Considering System Emissions and Fuzzy Constraints
http://dspace.spu.ac.th/handle/123456789/3788
Title: Multi-Objective Optimal Power Flow Considering System Emissions and Fuzzy Constraints
Authors: Keerati Chayakulkheeree
Abstract: This paper proposes a fuzzy multi-objective optimal real power flow (FMOPF) with transmission line limit and transformer loading constraints. In the proposed FMOPF algorithm, the total system operating cost, total system SO2, NOx, and CO2 emissions fuzzy minimization objectives are solved simultaneously considering fuzzy line flow constraints, using fuzzy linear programming (FLP). The proposed FMOPF is tested with the IEEE 30 bus system. The simulation results shown that the proposed FMOPF can efficiently and effectively trade off among total system operating cost and total system SO2, NOx, and CO2 emissions.2555-08-05T13:51:45ZApplication of Distributed Slack Bus Power Flow to Competitive Environments
http://dspace.spu.ac.th/handle/123456789/3787
Title: Application of Distributed Slack Bus Power Flow to Competitive Environments
Authors: Keerati Chayakulkheeree
Abstract: This paper presents the mathematical model of distributed slack bus power flow (DSPF) program and its application to competitive electricity supply industry (ESI). The advantage of DSPF is its ability to compute the frequency deviation when the ACE is treated as fixed value. It can represent the automatic generation controls (AGC) for maintaining nominal frequency. More specifically, the proposed method can diversify the power imbalance to voltage controlled buses in the system via participation factor. Therefore, the AGC of the generators can be incorporated in the analysis. The participation factors of the generators are obtained by the weighted average of AGC accepted quantities in ancillary services market. The results shows that the proposed method can satisfactory represent the system behaviour that all generators are response to power imbalance. In addition, the proposed method results in the better justified AGC setting in competitive electricity market than that of using single slack bus power flow. The DSPF is tested with the IEEE 30 bus system and compared to single slack bus power flow solution. Numerical results shown that the method can effectively represent the generation control characteristics to the power flow model and potentially be applied to simulate the competitive electricity markets.2555-08-05T07:32:46ZOptical profiling on lateral spreading of spacecharge-region metal-semiconductor-metal structures
http://dspace.spu.ac.th/handle/123456789/3782
Title: Optical profiling on lateral spreading of spacecharge-region metal-semiconductor-metal structures
Authors: Sanya Khunkhao
Abstract: Optical profiling on lateral spreading of space-chargeregion
properties of Schottky-barrier metal-semiconductormetal
(MSM) structures have been investigated experimentally.
Making use of a planar molybdenum/n-type silicon
/molybdenum (Mo/n-Si/Mo) MSM structure with a wide
electrode separation, one-dimensional (1D) profiling of optical–
beam intensity distribution from a helium-neon (He-Ne) laser
was carried out. It was also confirmed that, in addition to
existing photosensing function, the sensitivity (output
photocurrent) of such a structure could be controlled by an
applying bias via lateral spreading of the surface space-chargeregion
(SCR) at the side of the Schottky-junction reversebiased.2555-08-04T16:19:20Z