Estimation of a Multimass System Using the LWTLS and a Coefficient Diagram for Vibration-Controller Design

Vibration caused by mechanical resonance and time delay caused by signal detection and transmission degrade the control performance of a servo controller for a multimass mechanical system. A precise numerical model that represents resonance characteristics and time delay is necessary to design a desired control system. This paper presents an identification method using the iterative process of the linearized and weighted total least-squares method. The proposed method derives a transfer function without any prior knowledge of resonance characteristics and time delay. The order of the transfer function is determined with a coefficient diagram that shows coefficients of the denominator of the transfer function. Identification results with an experimental setup are shown to demonstrate the performance of the proposed method. A velocity servo controller with vibration-suppression control is designed with the transfer function, and control performance is verified with the experimental setup to validate the transfer function

DDPWM-based power conversion system using three to four phase matrix converter for stand-alone power system

This paper presents a novel stand-alone power system using a three to four phase matrix converter (MC) for use with renewable energy sources such as a micro hydro turbine or a tiny wind turbine with a permanent magnet synchronous generator (PMSG). MCs are able to convert AC power to AC power directly without using DC link capacitors, and AC to DC conversion is also possible because DC is considered to be a type of AC power. Here, two single phase AC outputs with constant frequency and two DC outputs for a battery storage system are described for a fluctuating voltage source. Direct duty ratio pulse width modulation (DDPWM) is used to achieve the desired output because it is easy to expand an ordinary three to three phase MC to produce a three to four phase MC. In addition, fictitious reference iterative tuning (FRIT) is used to design the controller gains. The validity of the proposed method is demonstrated using MATLAB/Simulink simulations

FPGA-Based Implementation of Finite Set-MPC for a VSI System Using XSG-Based Modeling

Finite set-model predictive control (FS-MPC) is used for power converters and drives having unique advantages as compared to the conventional control strategies. However, the computational burden of the FS-MPC is a primary concern for real-time implementation. Field programmable gate array (FPGA) is an alternative and exciting solution for real-time implementation because of the parallel processing capability, as well as, discrete nature of the hardware platform. Nevertheless, FPGA is capable of handling the computational requirements for the FS-MPC implementation, however, the system development involves multiple steps that lead to the time-consuming debugging process. Moreover, specific hardware coding skill makes it more complex corresponding to an increase in system complexity that leads to a tedious task for system development. This paper presents an FPGA-based experimental implementation of FS-MPC using the system modeling approach. Furthermore, a comparative analysis of FS-MPC in stationary αβ and rotating dq frame is considered for simulation as well as experimental result. The FS-MPC for a three-phase voltage source inverter (VSI) system is developed in a realistic digital simulator integrated with MATLAB-Simulink. The simulated controller model is further used for experimental system implementation and validation using Xilinx FPGA: Zedboard Zynq Evaluation and Development Kit. The digital simulator termed as Xilinx system generator (XSG) provided by Xilinx is used for modeling-based FPGA design

Controller design using coefficient diagram methods for matrix converter based unified power flow controllers

This paper presents a new controller design method using the coefficient diagram method (CDM) for matrix converters (MCs). MCs are able to convert AC to AC power directly without DC link capacitors. In this paper MCs are used in unified power flow controllers (UPFCs), which is one of the flexible AC transmission system (FACTS) devices located in the transmission line. The CDM is an effective method for designing adequate gains in a PID controller but is not convenient for solving the complex characteristic polynomials of non-standard systems such as the multiplication of controller gains or multi-input-multi-output systems. We propose to combine CDMs with Particle Swarm Optimization (PSO). PSO is employed for searching the near optimal diagram. Our proposed method is applied to a simple transmission line and the validity of the proposed method is shown using MATLAB/Simulink simulation

Performance Improvement of a Portable Electric Generator Using an Optimized Bio-Fuel Ratio in a Single Cylinder Two-Stroke Engine

The performance of an electrical generator using bio-fuel and gasoline blends of different composition as fuel in a single cylinder engine is presented. The effect of an optimized blend ratio of bio-fuel with gasoline on engine performance improvement and thereby on the electrical generator output is studied. Bio-fuels such as ethanol, butanol and methanol are blended with gasoline in different proportions and evaluated for performance. The effects of different bio-fuel/gasoline blending ratios are compared experimentally with that of the gasoline alone using the output power developed by the electric generator as the evaluation parameter. With a composition of 10% ethanol–gasoline, the engine performance is increased up to 6% and with a blending ratio of 20% butanol–gasoline the performance is increased up to 8% compared to the use of 100% gasoline. The investigations are performed on a portable generator used in palm tree harvesting applications

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

A battery charging system for intermittent generation from a synchronous generator with a novel maximum power point tracking control

This paper proposed a battery charging system for intermittent generation from a synchronous generator with a novel Maximum Power Point Tracking (MPPT) control method. Analyzing the generation with boost chopper by the state space averaging method, the internal voltage of the generator, the output voltage and the resistance of the output of the boost chopper can be estimated by with only single current sensor. Even though the intermittent generation, the proposed the battery charging system is able to charge the battery constantly because of a bi-directional DC/DC converter and an Electric Double-Layer Capacitor (EDLC). The basic principle of the proposed MPPT control method and the proposed charging system are discussed, and then confirmed by digital computer simulation using PLECS. The simulation results reveal that the proposed MPPT controller controls the maximum power point and the proposed charging system is able to charge the battery constantly

Power speed characteristics of a novel double-stator PM generator integrated with a magnetic gear

This paper describes the power speed characteristics of a novel double-stator permanent magnet generator integrated with a magnetic gear (MG) using 2-D finite element method (2D-FEM). The machine is proposed for low-speed applications and it has a novel structure with two iron ring pole pieces and three permanent magnet rotors consisting of an outer field PM, inner field PM and prime PM. A prototype of the proposed machine is constructed and tested experimentally. The power characteristics including voltage, current, torque and speed are analyzed and compared with the measured results. The measured power characteristics are in good agreement with the calculated results but there is limitation on the measured speed characteristics which is primarily due to the constraint on the transmission torque of the magnetic gear. The predicted and measured results validate the proposed machine design

A novel double-stator permanent magnet generator integrated with a magnetic gear

This paper presents a double-stator permanent magnet generator (DSPMG) integrated with a novel magnetic gear structure which is proposed to be used as a direct drive generator for low speed applications. Torque transmission is based on three rotors consisting of prime permanent magnet poles on the middle rotor and field permanent magnet poles on the inner and outer rotors, respectively. The proposed machine combines the function of a triple rotor magnetic gear and electrical power generator. The operating principle of the generator is discussed, and its performance characteristics are analyzed using 2-dimensional finite-element method (2D-FEM). Analysis results about its magnetic gear ratio, transmission torque, cogging torque and electrical power performance are reported. The 2-D finite element analysis results verify the proposed generator design

X-Irradiation at 0.5 Gy after the forced swim test reduces forced swimming-induced immobility in mice

The forced swim test (FST) is a screening model for antidepressant activity; it causes immobility and induces oxidative stress. We previously reported that radon inhalation has antidepressant-like effects in mice potentially through the activation of antioxidative functions upon radon inhalation. This study aimed to investigate the effect of prior and post low-dose X-irradiation (0.1, 0.5, 1.0 and 2.0 Gy) on FST-induced immobility and oxidative stress in the mouse brain, and the differences, if any, between the two. Mice received X-irradiation before or after the FST repeatedly for 5 days. In the post-FST-irradiated group, an additional FST was conducted 4h after the last irradiation. Consequently, animals receiving prior X-irradiation (0.1 Gy) had better mobility outcomes than sham-irradiated mice; however, their levels of lipid peroxide (LPO), an oxidative stress marker, remained unchanged. However, animals that received post-FST X-irradiation (0.5 Gy) had better mobility outcomes and their LPO levels were significantly lower than those of the sham-irradiated mice. The present results indicate that 0.5 Gy X-irradiation after FST inhibits FST-induced immobility and oxidative stress in mice