Wisut Titiroongruang

An Improved PV Output Forecasting Model by Using Weight Function: A Case Study in Cambodia

This paper proposes a new concept to improve accuracy of PV forecasting model. The model was implemented by MATLAB/Simulink software using solar irradiance and module temperature as measurement parameters for calculation. The model was developed by single-diode equivalent circuits (5-p model) for simulated PV module power output and compared with other software programs for validation which showed correct PV characteristics. To achieve high accuracy, the model was improved by weight function using one-year measured data. The accuracy of our developed model was verified by comparison with four commercial simulator software programs and the results from real system which were measured and recorded for 1 year. It was found that the model output was in a good agreement with the measured data. This research can be utilized in another area by adjusting the PV equation with weight function of that area.

CMOS current follower circuits

We design current follower circuits (CF) using the CMOS transistor to substitute for the bipolar transistor circuit. The experimental result which uses Spice program found that the input and output impedance of the circuit are 5 k/spl Omega/ and 76 M/spl Omega/ respectively. Moreover, the bandwidth of the circuit can be used in a wide range from 0 Hz to 4.1 MHz for CF/sup +/ and 0 Hz to 3.4 MHz and the harmonic distortion is less than 4.06% for CF/sup +/ and 4.27% for CF/sup -/. We also implement the circuit by using a commercial MOS transistor 4007, which consists of a dual complement of the CMOS transistor. The implemented circuits show that the electrical characteristics are the same as the analysis results from the Spice program.

Conformal photoresist coating for critical dimension improvement

3D surface topography of read / write head fabrication is difficult for lithography process. Photoresist deposition by using the conventional spin coating method is troubled. Spray coating is a replacement technique that eliminates the problem by producing micro-resist droplets that adhere firmly to the deposition location; thus, spray coating with optimal parameters from designed experiment is a suitable method for photoresist deposition on structures with high aspect ratio. By using proper nitrogen flow rate to spread out AZ4999 resist to be micro-droplet in the same time with proper traveling nozzle speed, the photoresist turbulence will perform good resist coverage over all surfaces. From design of experiment show the optimum condition for conformal deposition is 0.8 Bar at 117mm/s for nitrogen pressure and nozzle speed, respectively. Photoresist thickness was dropped at 30um far away from groove or edge of the head.

Minority Carrier Lifetime Controlling of Mesa Diodes by Electron Beam Irradiation

Mesa diodes were irradiation by electron beam at various doses of 25, 50 and 75 kGy to find optimum dose for controlling minority carrier lifetime. The experiment result shows that electron beam can reduce minority carrier lifetime from 24.3 ns to 14.8, 9.5 ns and 7.9 at dose of 25, 50 and 75 kGy, respectively. However, the result of electron beam is not only reduce the lifetime but also effected to other electrical properties such as increasing in saturation current density about 2-3 times, increasing in reverse leakage current density about 3 times. Dominant cause of reverse leakage is increasing in generation current via center traps which formed by the irradiation.

Effect of exposure energy, focus range, and surface reflection on the photolithography process of contact hole patterning

The patterning the contact holes by photolithography process, in this case polysilicon contacts, is the process to produce electrical connection between metal layer and polysilicon gates or metal layer and source/drain. The photolithography process can control size and shape of the contact hole patterns on photoresist before permanently patterned by etching process and then metallization. The contact holes were specified to have the size of 0.8 micron after the photolithography process. In order to achieve this, the process parameters to be considered are exposure energy, focus length of the lens system, and the effect of light reflecting from the film topography underneath. Since in the previous processing step, the attempt to reduce the film topography was done by planarization using BPSG. By adjusting the exposure energy and focus, the optimal condition, to produce 0.8 micron contact holes, was found to be energy of 305 mJ/cm2 and focus of -1.0 mum.

Subthreshold operation of MOIS devices: boundary of operation

The boundary of MOIS operating in subthreshold is presented in this article. The MOS transistor-like structure is CMOIS (C_omplementary M_etal O_xide I_ntrinsic-like S_emiconductor), which is prepared on gold-doped silicon. This condition causes changes in many essential characteristics of the device. We demonstrate the analytical parameters and the experimental result of the device which are used to determine the subthreshold regime.

Verification of new model by comparison with actual data

This papers shows the results of testing the power output of the solar PV system using silicon crystals used in the test. Then simulate the power output in the form of third-generation model. The first generation model (1D5P) at a second series Weight Function Model and form a third model has been developed. The test system with 28 kWp The results show that the first form (1D5P) error of 14.40%. models the second error of 5.02% in the third form a models that has developed error of 1.05%.

A novel power output model for photovoltaic system

This paper proposed the novel concept model for forecasting the PV power output. The model was used two meteorology to input model which are solar irradiance and module temperature. This model was improve the accuracy of model from simplified model is 1D5P by using the weight function. The proposed model was verified by comparison with measured data. The results showed that the model has high accuracy. The RMSE ranges from 0.02 to 0.07 and average RMSE is 0.04.

The new simulation model for estimating PV power output

This paper proposed the new simulation model for estimate PV Power Output of power plant in Thailand. Our development model were used the solar irradiance and module temperature as input of model. The model has develop by using one year measured data of focus area and verified by comparison with measured data. The results shown high accuracy and error about 1.11 %.

Comparison of PV module power output measurements

This paper describes the objective of the model to produce electricity from solar program. MATLAB / SIMULINK Compared with actual production data from electricity plants. This information is taken from the program PVSYST (crawlers electricity from real factories). The models created from an analysis of the equivalent circuit model of a diode, solar cell, with 5 parameters are the main factors used in the calculations were called 1 D5 P. The comparison takes into account the impact on solar irradiance and module temperature. The result of the comparison. The model has high accuracy and is close to the actual data to generate electricity.