Optimal design for multiple mode charging station with PI controller using particle swarm optimization

This project proposes a suitable design for charging station (CS) that can produce different charging categories (slow, medium, and high). The CS mode is based on power size, rated voltage levels, number of phases and rated current as well as charging time. The higher charging mode will require less time to complete the charging process as compared to lower charging mode. However, the integration of CS gives negative impact to the distribution system such as power loss and voltage profile. This is due to harmonic that produced from non-linear load of CS. Thus, this research focusing on the analysis of the effect of harmonic on different charging categories (slow, medium and high). The different mode of CS can be obtained by varying the value of pulse width in pulse generator at the buck converter. Next, the suitable universal design for a passive filter is proposed to reduce harmonic distortion based on design CS. A closed loop system is introduced by implementing PI controller in order to reduce the error between the output of CS with output demand. In term of analysis, the values of proportional constant (Kp) and integral constant (Ki) in this project had been obtained by using Particle Swarm Optimization (PSO). All the circuits are designed, simulate and analyses by using MATLAB/Simulink. From the result, it is proved that the installation of single tuned passive filter at 5th order and 7th order can reduce both THDv (2.94%-5.26%) and THDi (4.83%-9.11%). Besides that, closed loop system shows better performance as compared to open loop system in term of THD level and fulfill output demand. The results also fulfill the recommendation of IEEE 519 power harmonic standard

Extraction of dragon fruit (hylocereus polyrhizus) foliage active compound for water treatment

Coagulant plays a significant role in water treatment. It is used to remove the turbidity in raw water. Nowadays, natural coagulants have become interest to many researchers due to the facts that they are in abundance source, cheap, has multifunction, biodegradable and safe for human health. In this study, the potential of dragon fruit foliage (DFF) as natural coagulant was investigated. The experiments were done using standard jar test method. The coagulation process using DFF at various parameters for distilled water extraction method was done. It was found that the parameter such as drying temperature, pH, dosage, initial turbidity, and sedimentation time did have effect on coagulation process using DFF. Then, extraction of DFF active compound using different types of extraction method was carried out. It was found that the best method to extract DFF active compound was using distilled water at 60˚C where 94.4% of turbidity removal can be achieved at the dosage of 10 mg/L. Further application using surface water was found that the performance of DFF in turbidity and TSS removal was comparable with commercial alum. Lastly, the performance of DFF in coagulation process was verified using its active compound. It is believed that the main active compound of DFF is carbohydrate. The analysis for total carbohydrate content was consistent with those results obtained from jar test where extraction using distilled water at 60˚C has the highest soluble carbohydrate content and this explain why it has the highest coagulation efficiency. The result from zeta potential analysis and SEM analysis suggest that adsorption and interparticle bridging mechanism is the main mechanism of DFF in coagulation process. As a conclusion, DFF has a bright future and good potential for application in water treatment

Extraction of dragon fruit foliage as natural coagulant for water treatment.

This study presents the extraction of dragon fruit foliage for application in water treatment. Two types of extraction methods were used which are distilled water and salt extraction method. The experiments were done using jar test method. The finding shows that distilled water extraction method was more effective as compared to salt extraction method in term of turbidity removal. Therefore, distilled water extraction method had been selected for further investigation using surface water study. A comparison study was done by comparing surface water treatment by using dragon fruit foliage against alum to see the capability of dragon fruit foliage in removing turbidity. The results revealed that the turbidity removal for dragon fruit foliage using distilled water extraction was 91.9% at the dosage of 10 mg/L while for alum the turbidity removal was 99.8% at the dosage of 40 mg1L. It was found that the turbidity removal of dragon fruit foliage distilled water extraction was high and almost comparable with commercial alum and the optimum dosage for dragon fruit foliage was 4 times lower than alum. Hence, it can be concluded that dragon fruit foliage deserves evaluation as potential coagulant