Mohd Fakhizan Romlie

Optimal Chiller Loading Using Improved Particle Swarm Optimization

Reducing energy consumption is one of the most important for optimal electric-driven chiller operation. Therefore, even small reduction in power consumption will achieve significant energy savings. This paper adopts improved particle swarm optimization (IPSO), which is aiming to reduce energy consumption, and improve the performance of chillers. The method has been validated by real case study, and the results have demonstrated the effectiveness for saving energy and kept the cooling demand at satisfactory level.

Intelligent approach for optimal energy management of chiller plant using fuzzy and PSO techniques

This paper discusses the optimal energy management of chiller plant. Two intelligent approaches have been employed. Fuzzy is used to adjust the set-point and, while PSO is utilized to optimize the objective function after setting by Fuzzy. Moreover, Fuzzy is also utilized to adjust weighting factors in order to find the best values for the PSO local and global. This will improve PSO performance. The proposed method was combined two levels as Fuzzified PSO, and the model has been simulated and validated by a real case study which consists of 5 electric-driven chillers. The results have shown that the effectiveness of the proposed method compared to the conventional one, and it also has demonstrated a better power saving.

A New Strategy for Multiple Chillers Plant Operation Using Fuzzy Inference System

Reducing energy consumption is one of the most important things for optimal operation of the multiple-chillers. The storage system for chilled-water is used for cooling demand and shifting load consumption at peak hours. The case study in this work is based on the existing system for chillers plant in an industrial building. This paper adopts Fuzzy Inference System, in order to adjust the operating points setting for a period of 24 hours to keep the cooling demand satisfied. This is based on a new strategy for the scheduled operation of the chillers. The results have shown the effectiveness for the energy savings and also satisfying the cooling demand. This proposed control system has been simulated in Matlab and the simulation result is compared with the measured data from the existing system.

Battery Storage for the Utility-Scale Distributed Photovoltaic Generations

Batteries are essential for efficiently utilizing the energy from the photovoltaic (PV) modules. However, integration of batteries with PV plants at large scale needs more attention in terms of size, location, and times for the charging and discharging of the batteries. This paper addresses these aspects. It presents a mixed integer optimization using genetic algorithm for determining the optimum size and placement of battery-sourced distributed PV generation (B-SDPVG) in distribution networks. The total energy loss index is formulated as the main objective function and simultaneously, the bus voltage deviations and penetrations of the B-SDPVG are calculated. The yields from the PV plants are estimated using 15 years of weather data modeled with the aid of beta probability density function. Furthermore, a novel charge–discharge control model is developed for determining the choice of the charging and discharging of batteries at each hour. By considering different time varying voltage-dependent load models, the proposed algorithm is applied on the IEEE 33 bus and the IEEE 69 bus test distribution networks. The numerical results of two distribution networks with time-varying loads show the advantages of the proposed methodology. It was revealed that integration of battery storage and intelligent scheduling for charging and discharging of batteries produced much better results and improved the quality of distribution networks. The supply of power from the B-SDPVG during the peak load hours and at night was made possible for each load model. The proposed charge–discharge control model for scheduling the charging and discharging of the batteries was found dynamic. Results of this paper can be of potential importance in planning for the integration of battery storage in distribution networks.

Design and optimization of permanent magnet machine for ceiling fan

This paper presents an analysis on the optimization of the permanent magnet synchronous machine (PMSM) with the implementation of the single rotor double stator that comprises two systems in one machine, the motor and the generator. This machine was developed for ceiling fan application to increase the efficiency of the system. The five optimization designs have different split ratio and pole pitch ratio and Finite Element Analysis (FEA) has been performed to predict the performance of the designs by analyzing the open circuit flux distribution, air gap flux density and the back EMF. The optimal value of the split ratio is identified to be 0.52 and the pole pitch ratio is 0.5. The split ratio simulation verified that the flux distribution, air gap flux density and the back EMF are affected by the air gap radius. On the other hand, the pole pitch ratio optimization analysis proved that the average value of back EMF is decreasing and the flux distribution of the air gap is fluctuated as the arc length angle between the North-pole and South-pole is unbalanced. Overall, good achievement was achieved.

Comparison of tubular and planar design of a micro linear generator for vibration energy harvesting

Vibration sources is available from many appliances such as motors, generators and rotating devices. This vibration can be harvested and converter to electrical energy to power up wireless sensor network and low power electronic devices. An energy harvester is attached to the vibrating source to harvest the energy. The use of micro linear generator comprising of magnet, moving rotor, stator and windings, will enable users to harvest the vibration energy. The generator converts the vibration energy to electrical energy. In this research, a model of a micro linear generator is presented. This paper focuses on comparing a tubular and a planar design of the micro linear generator for vibration energy harvesting. On top of that, the slotted and slot-less designs are also compared. With the Finite Element Analysis (FEA) software, Ansoft Maxwell, the magnetic flux, flux lines, magnetic field and induced voltage of the various designs of the generator are analysed. By evaluating the simulation results, the tubular slotted design is found to be the best design that produced the best output.

Planning of Distributed Renewable Energy Resources Using Genetic Algorithm

Due to the limitations of fossil fuel reserves and environmental issues, distributed renewable energy resources (DRER) have become a good alternative solution for producing electricity.

Sizing and placement of solar photovoltaic plants by using time-series historical weather data

The integration of distribution generation (DG) in distribution networks with improper planning adversely influences the quality of the electrical networks. Conventionally, the outputs from the intermittent DGs, such as solar photovoltaic (PV) plants, are assumed dispatchable. The intermittency of solar irradiance on the outputs of the PV modules has been ignored in most studies on the sizing and placement of DGs. By looking at this problem, this paper presents the sizing and placement of a distributed solar photovoltaic plant (DSPP) by using time series historical weather data. To predict the output from the PV modules, 15 years of solar data were modeled with the aid of a beta probability density function. The total energy loss index was formulated as the main objective function, and the optimization problem was solved by mixed integer optimization by using genetic algorithm. By adopting a time-varying commercial load, the proposed algorithm was applied on IEEE 33 bus and IEEE 69 bus distribution networ...

Design and analysis of a contactless battery charger with planar PCB windings

This paper focuses on the design of a contactless power transfer system using planar PCB windings for battery charging. A 3D Finite Element (FE) electromagnetic modeling approach is carried out to determine the electromagnetic coupling and inductances of the system according to the change of distance. The simulation are carried out using ANSYS Maxwell software. The simulation result is validated by experimental results using a prototype that has been build. The characteristics of the design planar PCB windings are confirmed with measurement and calculation of the prototype. The experimental results demonstrate the air gap will influence the efficiency of the power transfer by affecting the value of mutual inductance and coupling coefficient.

The third harmonic current contribution during three-phase to ground fault

In recent times, the Gas District Cooling (GDC) plant in Universiti Teknologi PETRONAS (UTP) has suffered faults throughout the power system network due to many reasons. It was reported that third harmonic component exists in its fault current. Synchronous generator is one of the triplen harmonic sources and third harmonic is the major component. Therefore, this paper intends to study the contribution of third harmonic produced by synchronous generator during three-phase to ground fault. Lab scale experiments are conducted to investigate the contribution of third harmonic towards overall fault current. The third harmonic current during normal operation is first measured and considered as base data. Then, third harmonic current during three-phase to ground fault is measured and compared with the base data. During three-phase to ground fault, the load impedance is removed from the circuit and the line is connected directly to the ground. It is found out that the contribution of third harmonic during three-phase to ground fault is significantly high compared to normal operation. The third harmonic fault current depends on effective zero sequence impedance of the circuit. During the fault, the effective zero sequence impedance of the circuit reduces and inversely the third harmonic current increases greatly.