Applied Mechanics and Materials Vol. 793

Abstract: A 300 W/ 50 Hz single-phase sine wave with a 555 timer IC controller was designed, simulated, implemented and tested to investigate output AC power quality. An input 12 VDC power supply, which simulates PV-Wind power source, was connected to the inverter circuit and charge-discharge energy storage was also studied. Results of simulation show that as well as the experiment result is obtained.This paper is present the advantage ofhybrid system wind &solar together in power supply system from the integration between time andlocation. It showsthe evolution of wind-solar in single-phase sine wave power inverter and provides the structure of information and communications technology and equipment.Some main techniques such as the circuit topology and operation modes of the key link, algorithm of the intelligent control charging and discharging and so on.

Abstract: This paper focuses on investigation of various voltage controllers which are the Proportional Integration Derivative (PID) control and P-Resonant control in order to observe the efficiency of the low cost microcontroller such as Arduino for the gating signals generation. Both of the controllers have been selected due to the availabality of the block diagrams that can be build in the MATLAB. The MATLAB-Simulink block will be used as the interface between the design controller to the Arduino board before downloaded into Arduino. The results show, the Arduino is able to operate from various controllers but it gives better result when the P-Resonant controller has been used.

Abstract: This paper analyzes effects caused by voltage sag types A, B, C and D on induction motor based on experimental test. The effect can be investigated in term the current peaks and speed variation. The magnitudes depend on magnitude of sag and duration, voltage sag types, during and recovery voltage sag. Several of voltage sag characteristics have been conducted in different magnitude, duration and sag types. The results show that the current peaks generated reach more than 4 times of normal current and it was achieved at recovery voltage instant. Sag magnitude has great influence on the current peak but sag duration is not significantly. Type A voltage sag only can cause the motor stop running and it was achieved when it was subjected to sag magnitude of 10% and 6s in duration. The motor stops running in shorter duration when it was subjected to interruption with sag duration of 4s. Therefore voltage sag of type A lead to more severe on induction motor if compared with other sag type. This is according to number of phase that experience sag. The magnitude and duration of voltage sags have influenced significantly on the motor speed only for low sag magnitude and long sag duration.

Abstract: Three Phase Inverters being used today are based on Field Orientation Control (FOC) and Sine Wave PWM (SPWM) techniques because 120 degree or 180 degree conduction methods produce high value of THD (Total Harmonic Distortion) in the power system. The Indirect Field Orientation Control (IFOC) method is difficult to implement in real systems due to speed sensor accuracy issue. This paper discusses the problem with IFOC and a PWM based 180 degree conduction mode for the three phase inverter. The modified control method improves THD and this paper also compares the results obtained using modified control method with the conventional 180 degree conduction mode.

Abstract: This paper presents the design validation and optimization of a moving-magnet tubular linear permanent magnet motor (TLPMM) with a trapezoidal permanent magnets shape. The design optimization was implemented by two-dimensional Finite-Element Analysis (2-D FEA) and the validation has been established by using Matlab M-file. The proposed motor has been designed to produce 85 W output power which is enough to operate the linear reciprocating compressor of a household refrigerator system. The purpose of optimization is to achieve maximum efficiency and minimum losses, where the angle of PMs (β) and split-ratio (R_m/R_e) after optimization the motor produce the highest efficiency of 93.8 %.

Abstract: This paper proposed a novel single-stage square wave buck-boost inverter (SWBBI). The proposed inverter is designed by using dual buck-boost converters. The input DC voltage of the proposed inverter can be either stepped-down or stepped-up in square output voltage waveform depending on the duty-cycle applied for each buck-boost converter. This characteristic is not found in conventional voltage source inverter where the output voltage is always lower than the input DC voltage. The proposed inverter is analyzed by a series of simulations using MATLAB/Simulink as well as experiments by using different values of duty-cycle. A conclusion about the feasibility of the proposed inverter is given by comparing the simulation and experimental results.

Abstract: An investigation of the several different techniques and method have been suggested in the design of compact microwave filters for the realization of high performance output micromachined microstrip low pass filters and highest attenuation loss is presented in this paper. It is shown that the basis for much fundamental microwave filter theory lies in the real of lumped-element filters, which lumped elements suffers for not suitable use in high frequency, because wavelength will decrease to short and the only distributed elements can practically well and the lumped elements circuit and work efficiently at low frequency or vice versa wavelength of distributed elements become too larger. In this paper, a review of numerous methods of design compact microstrip filters that have been offered over the last years is proposed, including a discussion of topologies and the structures used to make compactness size of microwave filters.

Abstract: In 2012, KTMB launched a new fleet of China-made 6-car electric multiple units (EMUs) to augment their existing 3-car EMUs, the objective being to expand the capacity of its Klang Valley train commuter service from 33,000 to 95,000 passengers during the morning and afternoon peak hours. Due to significant expansion in train traffic density, it was essential to investigate whether the existing 25kV overhead centenary system (OCS) electrical network infrastructure could support the ensuing electrical power demands/loads due to the additional tractive effort of the 6-car trains and increased train traffic density. Traction power simulation study using MM-TRAIN software was conducted for this purpose. This paper illustrates the indispensable tool of traction power simulation software to access the performance of moving rail traction loads under normal (no outage) and under first emergency feeding conditions (n-1 outage contingency)

Abstract: This paper presents the implementation of a microcontroller-based Harmonic Elimination PWM (HEPWM) switching scheme of a Cascaded H-Bridge Multilevel Inverter (CHMI) for renewable energy system. This technique applies Particle Swarm Optimization (PSO) technique to allow computation of HEPWM switching angles. The detail description on the microcontroller-based implementation is provided in this paper. The performance of CHMI employing the control strategy based-on the simulation and experimental results are shown for comparison purposes.

Abstract: Uninterrupted power supply (UPS) sits between a power supply such as wall outlet and devices to prevent undesired feature that can occur within the power source such as outages, sags, surges and bad harmonics from the supply to avoid a negative impact on the devices. This paper presents a photovoltaic (PV) powered UPS using microcontroller PIC16F628A-I/P. It is a standby UPS whereas if the main power source fails to supply power to loads, a battery powered inverter turns on to continue supplying power. The battery is charged by the PV using solar charger and transfer switch controlled by the microcontroller. In this research, AC three-level waveform single phase inverter was developed and created by a microcontroller PIC16F627A-I/P with varied maximum voltage angle from 20⁰ to 180⁰ and tested to a load of 240 V, 20 W AC aquarium water pump, and also analyzed effect of maximum voltage angle on the three-level single phase inverter performance. The result showed that maximum voltage angles of the inverter effected on root mean square value of AC voltage, current and power. If the maximum voltage angle was increased, therefore value of the AC voltage, current and power would increase. The maximum voltage angle would effect on the current total harmonic distortion (CTHD), the lowest CTHD of 15.448% was obtained when the maximum voltage angle was 134⁰.