Development of a pulse-width modulated power MOSFET-based audio amplifier

This paper presents the design and development of a pulse-width-modulated (PWM) power MOSFET-based audio amplifier. A natural sampled PWM switching strategy is implemented in the development of the amplifier to reduce its harmonic level and increase its efficiency. IRF510 power MOSFETs are used as the amplifier power switching devices. From the results obtained, it is found that the efficiency of the amplifier can be increased to more than 90%

Future strategic plan analysis for integrating distributed renewable generation to smart grid through wireless sensor network: Malaysia prospect

AbstractIntegration of Distributed Renewable Generation (DRG) to the future Smart Grid (SG) is one of the important considerations that is highly prioritized in the SG development roadmap by most of the countries including Malaysia. The plausible way of this integration is the enhancement of information and bidirectional communication infrastructure for energy monitoring and controlling facilities. However, urgency of data delivery through maintaining critical time condition is not crucial in these facilities. In this paper, we have surveyed state-of-the-art protocols for different Wireless Sensor Networks (WSNs) with the aim of realizing communication infrastructure for DRG in Malaysia. Based on the analytical results from surveys, data communication for DRG should be efficient, flexible, reliable, cost effective, and secured. To meet this achievement, IEEE802.15.4 supported ZigBee PRO protocol together with sensors and embedded system is shown as Wireless Sensor (WS) for DRG bidirectional network with prospect of attaining data monitoring facilities. The prospect towards utilizing ZigBee PRO protocol can be a cost effective option for full integration of intelligent DRG and small scale Building-Integrated Photovoltaic (BIPV)/Feed-in-Tariff (FiT) under SG roadmap (Phase4: 2016–2017) conducted by Malaysia national utility company, Tenaga Nasional Berhad (TNB). Moreover, we have provided a direction to utilize the effectiveness of ZigBee-WS network with the existing optical communication backbone for data importing from the end DRG site to the TNB control center. A comparative study is carried out among developing countries on recent trends of SG progress which reveals that some common projects like smart metering and DRG integration are on priority

Analysis of Thrust Constant, Electrical and Mechanical Time Constant for Slot-Less Moving Magnet Linear Oscillatory Actuator

This paper present the analysis of thrust constant, electrical and mechanical time constant for slot-less moving magnet linear oscillatory actuator (LOA) using Permeance Analysis Method (PAM) by changing various parameter of LOA structure. The results show that LOA structure has high impact on the thrust constant, electrical and mechanical time constant. A prototype of LOA was designed and developed. Based on its result analysis, the measurement result shows good agreement with the analysis result

Photon fuelled electric power plants

Most of the underdeveloped countries have abundant sunlight to solve their basic electric power needs. Using natural sunlight and available conventional energy conversion technologies they can produce a huge amount of electricity to volte-face the global energy crisis. This work explores the possibility of implementing the entirely sunlight fuelled photovoltaic power systems, solar thermal power plants, laser ignited fusion power plants and sun powered laser triggered atmospheric electricity. Direct sun- light excited high energy solid state lasers, photovoltaic fed flash-lamp pumped solid state lasers, diode pumped solid state lasers and air laser systems are reviewed for applications in laser induced fusion to envisage sunlight powered electric power system operation. Methods of electricity generation described in this paper rely only on the sunlight as a natural free fuel

IRFOC induction motor with rotor time constant estimation modelling and simulation

Purpose– To provide a new and simple inverse rotor time constant identification method which can be used to update an indirect rotor field oriented controlled (IRFOC) induction motor algorithm.Design/methodology/approach– Two different equations are used to estimate the rotor flux in the stator reference frame. One of the equations is a function of the rotor time constant, rotor angular velocity and the stator currents. The other equation is a function of measured stator currents and voltages. The equation that uses the voltage and the current signals of the stator serves as reference model, however, the other equation works as an adjustable model with respect to the variation of the rotor time constant. Voltage signals used in the reference model equation are obtained from the measured DC bus voltage and the inverter gating signals. The proposed scheme is verified using a MATLAB/SIMULINK model for two different motors and experimentally using a DSP development tool (MCK 243) supplied by Technosoft S.A.Findings– The proposed estimator was able to successfully track the actual value of the inverse rotor time constant for different load torque and speed operating conditions. Increased oscillations in the estimated inverse rotor time constant appeared at lower speeds (below 10 per cent of rated speed) due to drift in a PI regulator (used at the estimator side), which was tuned under rated operating conditions and using parameters nominal values.Research limitations/implications– This estimation scheme is limited when near zero speed operation is demanded; otherwise it gives a simple and practical solution. A suggested way out of this, is to provide a self‐tuning controller that can automatically adjust even for zero speed operation, or to automatically disconnect the estimator and take the most updated value as long as the operating speed is below a predetermined value.Originality/value– This paper presented a new inverse rotor time constant estimator for an IRFOC induction motor application and in conjunction rotor flux was estimated without voltage phase sensors

DC-link capacitor voltage control for single-phase shunt active power filter with step size error cancellation in self-charging algorithm

This study presents an improved self-charging algorithm by introducing a new feature known as step size error cancellation for better performance of DC-link capacitor voltage control in single-phase shunt active power filter (SAPF). Previous works of self-charging algorithms were focused only for steady-state operation by using either proportional-integral (PI) or fuzzy logic control (FLC). However, in a certain operation of any power system, dynamic operation may also happen. Thus, by introducing step size error cancellation as an additional feature to the self-charging algorithm, both steady state and dynamic operations can be covered. For evaluation and comparison analysis, self-charging with PI and FLC algorithms have been developed too. All the algorithms were simulated in MATLAB-Simulink, respectively, together with the single-phase SAPF. For hardware implementation, the proposed algorithm was programmed in TMS320F28335 digital signal processing board. The other two conventional self-charging algorithms were also programmed for comparison purposes. From the results and analysis, the proposed self-charging with step size error cancellation shows the best performance with high accuracy, fast response time and less overshoot and undershoot. It performs well in both steady state and dynamic operations as compared with both previous self-charging techniques which only work well in steady-state operation