Khanchai Tunlasakun

Solar powered EL traffic police vest

The paper is present the design and development of solar powered electroluminescent lamp traffic police vest use for safe the traffic policeman from an accident on the road at night. The prototype of this paper was designed on a PIC12F675 microcontroller and used the photovoltaic panel for energize energy to the system. The electroluminescent lamp is illuminate by use DC-AC inverter circuit and controls the lamp for on, off and blinks by microcontroller. The prototype was tested by traffic policeman, it worked satisfactory.

A microcontroller based islanding detection for grid connected inverter

This paper presents the development of a microcontroller based islanding detection for grid connected inverter with very simple under/over voltage and under/over frequency islanding detection algorithms. The system based on a microcontroller from Microchip Technology Inc. PIC family. A PIC microcontroller searches the under/over voltage and under/over frequency from utility grid and processed the value of voltage and frequency for turned on-off relay between grid connected inverter and utility grid.

CPLD-based islanding detection for mini grid connected inverter in renewable energy

This paper presents the development of a CPLD-based islanding detection for mini grid connected inverter in renewable energy with very simple under/over voltage and under/over frequency islanding detection algorithms. The system was implemented on a single XC9572 complex programmable logic device (CPLD) chip using schematic based and VHDL based synthesis model The CPLD monitor the under/over voltage and under/over frequency of utility grid and processed the value of voltage and frequency for turned on-off relay between mini grid connected inverter and utility grid.

A Study of the Mutual Coupling between a Three-Phase Power Line 115 kV and a Parallel Telephone Line By using ATP/ EMTP : Case Study Distribution Line in Thailand Alarm

This paper deals with the unwanted mutual coupling of a three-phase power line 115 kV to a parallel telephone line. This phenomena naturally occurs whenever a line is energized. As a result, a adjacent line is linked with both electric and magnetic field. 115 kV distribution system in Thailand is selected in this study. ATP/EMTP is a powerful tool which is utilized for modeling a three phase power and telephone line that are assumed as a solid line with the restricted program. That means that the insulation effect from the telephone cable is negligible. The simulation result is verified with field tests. The comparison of results shows a good agreement of 10.53 V averaged induced voltage on telephone line which is excessive compared with mutual coupling standard for ADSL applications. In addition, the induced voltage effect when considering the following factors: the height of telephone line above ground, the length of telephone line in each section and the amplitude of current in power line is investigated

FPGA-based islanding detection for grid connected inverter

This paper presents the development of a FPGA based islanding detection for grid connected inverter with simple under/over voltage and under/over frequency islanding detection algorithms. The design is based on the Xilinx chip XC4005E field programmable gate array (FPGA). The FPGA is used for all system logic function. This allows software development, testing, implementation and modification of logic circuitry without hardware modification. The FPGA monitor the under/over voltage and under/over frequency of utility grid and processed the value of voltage and frequency for turned on-off relay between grid connected inverter and utility grid. The results are provided to demonstrate the effectiveness of the design.

System identification with cross validation technique for modeling inverter of photovoltaic system

In this paper, modeling of one type of grid connected single phase inverter commercially available in Thailand is carried out. An inverter of a grid-connected photovoltaic system has been tested and its model determined. The inverter operates in six steady state conditions and its modeling is done using nonlinear system identification approach with Hammerstein Wiener Model. The models with no cross validation and cross validation data of six steady state conditions have been experimented. The results comparison on modeling by using cross validation and no cross validation data has been analyzed by model order, model accuracies and model error. The average percentage accuracy of system identification with cross validation data and no cross validation is 81.89 and 63.83 respectively.

PIC implementation of carbon monoxide alarm for indoor parking car

The purpose of this paper is design and construct of a PIC implementation of carbon monoxide alarm for indoor parking car. The prototype of this paper was designed on a single PIC16F877 microcontroller that performed the acquisition, processing and display of carbon monoxide (CO) data from MiCS-5132 automotive pollution gas sensor and displayed the CO data on 7 segment displays. The system was tested using carbon monoxide from car exhaust fumes and it worked satisfactory.

Modeling of Photovoltaic Grid Connected Inverters Based on Nonlinear System Identification for Power Quality Analysis

Photovoltaic systems are attractive renewable energy sources for Thailand because of high daily solar irradiation, about 18 MJ/m2/day. Furthermore, renewable energy is boosted by the government incentive on adders on electricity from renewable energy like solar PV, wind and biomass, introduced in the second half of 2000s. For PV systems, domestic rooftop PV units, commercial rooftop PV units and ground-based PV plants are appealing. Applications of electricity supply from PV plants that have been filed total more than 1000 MW. With the adder incentive, more households will be attracted to produce electricity with a small generating capacity of less than 10 kW, termed a very small power producer (VSPP). A possibility of expanding domestic roof-top grid-connected units draw our attention to study single phase PV-grid connected systems. Increased PV penetration can have significant [1-2] and detrimental impacts on the power quality (PQ) of the distribution networks [3-5]. Fluctuation of weather condition, variations of loads and grids, connecting PV-based inverters to the power system, requires power quality control to meet standards of electrical utilities. PV can reduce or improve power quality levels [6-9]. Different aspects should be taken into account. In particular, large current variations during PV connection or disconnection can lead to significant voltage transients [10]. Cyclic variations of PV power output can cause voltage fluctuations [11]. Changes of PV active and reactive power and the presence of large numbers of single phase domestic generators can lead to long-duration voltage variations and unbalances [12]. The increasing values of fault currents modify the voltage sag characteristics. Finally, the waveform distortion levels are influenced in different ways according to types of PV connections to the grid, i.e. direct connection or by power electronic interfaces. PV can improve power quality levels, mainly as a consequence of increase of short circuit power and of advanced controls of PWM converters and custom devices. [13] Grid-connected inverter technology is one of the key technologies for reliable and safety grid interconnection operation of PV systems [14-15]. An inverter being a power

Comparison between FPGA-Based and dsPIC-Based islanding detection for grid connected inverter in a photovoltaic system

This paper presents the comparison between FPGA-based and dsPIC-based islanding detection for grid connected inverter in photovoltaic (PV) system with under/over voltage and under/over frequency islanding detection algorithms. The comparison is based on the XC4005E field programmable gate array (FPGA) and the dsPIC30F2010 high-performance digital signal controller. The prototypes of the FPGA and the dsPIC are monitor the grid voltage and grid frequency at the point of common coupling (PCC) between the grid connected inverter, the local load and the distribution transformer and processed the value of voltage and frequency for turned off the relay between the grid connected inverter and the utility grid. The results of study, the prototypes can turn off the relay when the voltage is change under 200 V or over 240 V and frequency is change under 48 Hz or over 52 Hz. The FPGA-based is turn off the relay faster than the dsPIC-based but the cost of design and implement is higher.

MCS51 - Based Carbon Monoxide Alarm

This paper presents the design and development of a MCS51-based carbon monoxide alarm. The system was designed on a single T89C51AC2 microcontroller that performed the acquisition, processing and display of carbon monoxide (CO) data from MiCS-5132 automotive pollution gas sensor and displayed the CO data on 7 segment display. The system was tested using carbon monoxide from car exhaust fumes and it worked satisfactory