Development of a Damper Control System for Combined Cycle Thermal Gas Power Plant

2014 ◽  
Author(s):  
Amit Kumar Mondal ◽  
Vindhya Devalla ◽  
Vivek Kaundal ◽  
Kamal Bansal
Keyword(s):  
Heat Dissipation ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Solenoid Valve ◽  
Combined Cycle ◽  
Solenoid Coil ◽  
Hydraulic Damper ◽  
Wireless Control ◽  
Damper Control ◽  
Gas Power Plant

This paper addresses a technique to solve the problem of heat dissipation in solenoid coil of the solenoid valve which is controlling the hydraulic damper by using pulse width modulation (PWM) switching technique with low frequency. In addition to this damper controlling is achieved via wireless controlling. By using PWM based low frequency switching technique the gas turbine trip will be protected. PWM is achieved by microcontroller and wireless control is done by ZigBee.

scholarly journals A Systematic Study on the Harmonic Overlap Effects for DC/AC Converters under Low Switching Frequency Modulation

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2811
Author(s):  
Ze Wang ◽  
Zhen He ◽  
Chao Gao
Keyword(s):  
High Power ◽  
Frequency Modulation ◽  
Heat Dissipation ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Industrial Applications ◽  
Voltage Source ◽  
Switching Frequency ◽  
Ac Converters ◽  
Power Capability

In most high power industrial applications, the low switching frequency modulations (LSFM) are usually implemented to reduce power loss and heat dissipation pressure. However, there are some unexpected influences caused by the low order harmonic sinusoidal pulse width modulation (SPWM), such as the imbalanced submodule power in cascaded half-bridge inverter (CHB) and limited output power capability in H-bridge neutral-point-clamped (HNPC) converter. This paper starts by generalizing the basic characteristic of two-level SPWM, then deeply investigates the influences of low-frequency modulation on the operation of the circuits. They are classified into three mechanisms and generally named as harmonic overlap effect (HOE). The corresponding solutions to copy with the mechanisms are proposed and verified in some topologies through high-power simulations in simulations. In addition, a comprehensive summary of the influences and solutions of these effects on typical high power converters is drawn. The design rules of the modulation schemes for multilevel voltage source converters (VSCs) at low switching frequency are also proposed.

Position Control of Hydraulic Actuators Using Fuzzy Pulse Width Modulation (PWM)

2015 ◽  
Vol 735 ◽  
pp. 294-298 ◽  
Author(s):  
Wei Ying Lai ◽  
Nurfarahin Onn ◽  
Collin Howe Hing Tang ◽  
Mohamed Hussein
Keyword(s):  
Fuzzy Logic ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Solenoid Valve ◽  
Operating Conditions ◽  
Hydraulic Actuators ◽  
Non Linear ◽  
Fuzzy Logic Approach ◽  
Logic Approach ◽  
Non Linear System

Hydraulic actuators are widely employed for industrial automation for its high power over weight ratio, functionality in tough operating conditions and low cost. However, the dynamics of hydraulic systems are non-linear and the system subjected to non-smooth and discontinuous non-linearities due to directional change of valve opening, friction, valve overlap and changes of hydraulic pressure acted on valve spool. Taking into account the effect of nonlinear parameter variations such as bulk modulus, compressibility of oil or viscosity of oil, fuzzy logic approach is chosen. Fuzzy control can adapt the inconstant working condition and non-linear system alongside of its robustness. For PWM controlled hydraulic component such as solenoid valve, effective approximation of the flow properties in a solenoid valve is essential. In this paper, the effect of fuzzy logic approach incorporated on pulse width modulation (PWM) controlled hydraulic system is to be investigated and experimentally verified.

High‐power‐factor dimmable LED driver with low‐frequency pulse‐width modulation

2016 ◽  
Vol 9 (10) ◽  
pp. 2139-2146 ◽  
Author(s):  
Hung‐Liang Cheng ◽  
Yong‐Nong Chang ◽  
Chun‐An Cheng ◽  
Chien‐Hsuan Chang ◽  
Yu‐Hung Lin
Keyword(s):  
Power Factor ◽  
High Power ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Led Driver ◽  
High Power Factor ◽  
Frequency Pulse

Heat Dissipation Mechanism at Carbon Nanotube Junctions on Silicon Oxide Substrate

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Liang Chen ◽  
Satish Kumar
Keyword(s):  
Carbon Nanotube ◽  
Heat Dissipation ◽  
Silicon Oxide ◽  
Low Frequency ◽  
Intermediate Frequency ◽  
Oxide System ◽  
Carbon Nanotube Junctions ◽  
Oxide Substrate ◽  
Efficient Coupling ◽  
Dynamics Simulations

This study investigates heat dissipation at carbon nanotube (CNT) junctions supported on silicon dioxide substrate using molecular dynamics simulations. The temperature rise in a CNT (∼top CNT) not making direct contact with the oxide substrate but only supported by other CNTs (∼bottom CNT) is observed to be hundreds of degree higher compared with the CNTs well-contacted with the substrate at similar power densities. The analysis of spectral temperature decay of CNT-oxide system shows very fast intratube energy transfer in a CNT from high-frequency band to intermediate-frequency bands. The low frequency phonon band (0–5 THz) of top CNT shows two-stage energy relaxation which results from the efficient coupling of low frequency phonons in the CNT-oxide system and the blocking of direct transport of high- and intermediate-frequency phonons of top CNT to the oxide substrate by bottom CNT.

Inlet Fogging for a 655 MW Combined Cycle Power Plant: Design, Implementation and Operating Experience

2003 ◽  
Author(s):  
Hemant Gajjar ◽  
Mustapha Chaker ◽  
Ajay Dighe ◽  
Cyrus B. Meher-Homji
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Low Frequency ◽  
Operating Experience ◽  
Combined Cycle ◽  
Plant Design ◽  
Proper Selection ◽  
Combined Cycle Power Plant ◽  
Technical Details ◽  
Selection Of

The design, installation, commissioning and operation of a fogging system for a large 655 MW combined cycle power plant is described. Technical details and practical installation issues are discussed. Special considerations as to how the fogging system could help in the augmentation of power during high temperature and low frequency operation of the gas turbine is discussed. Finally a discussion is made regarding the importance of inlet filtration and the proper selection of blade coatings.

A Novel Magnetorheological Concentric Spiral-Flow Damper

2015 ◽  
Author(s):  
Kai Hsiang Chang ◽  
Jing Long Tong ◽  
Chou Min Chia ◽  
Kuang Yuh Huang
Keyword(s):  
Heat Dissipation ◽  
Experimental Studies ◽  
Low Frequency ◽  
Mr Damper ◽  
Flow Channel ◽  
Spiral Flow ◽  
Damping Force ◽  
Fixed Space ◽  
Novel Design ◽  
High Range

In this article, a novel design of MR damper, concentric spiral flow MR damper, is proposed. It could improve the heat dissipation problem which is usually found in traditional MR damper. The proposed MR damper has a concentric spiral flow channel around the cylinder which not only separates coils from MR fluid, but also increases the length of flow channel in a fixed space. Experimental studies has been conducted to demonstrate the performance of the proposed MR damper, the result shows the MR damper generates the maximum damping force of 188 N without applying magnetic field and 1251 N when inputting 1.5 A at low frequency, which means the damper has high range of adjustable damping force. The CSF-damper can be used to systems or structures with low dynamic response.

Intelligent Control Circuit Integral with Pattern Recognition Techniques for High-Pressure Sodium Lamps

2017 ◽  
Vol 26 (07) ◽  
pp. 1750108
Author(s):  
Yuzhuo Pan ◽  
Chen Lv ◽  
Shanhe Su ◽  
Jincan Chen
Keyword(s):  
Pattern Recognition ◽  
High Pressure ◽  
Intelligent Control ◽  
High Frequency ◽  
Pulse Width Modulation ◽  
Smart Cities ◽  
Control Strategies ◽  
Low Frequency ◽  
Acoustic Resonance ◽  
Working Device

The paper presents the analysis, simulation, and experimental methods to eliminate acoustic resonance in high-frequency high-pressure sodium (HPS) lamps and integrate intelligent control strategies in the working device. Based on the pulse-width modulation (PWM) output generated by the microcontroller, the acoustic resonance in the high-frequency lamp can be successfully eliminated by modulating the high-frequency driving current via a low-frequency signal. Particularly, by implementing the pattern recognition, the control system enables the lamp to have the abilities of accurate timing, gradient dimming, automatic protection, and intellisense. The proposed model will provide useful information for designing intelligent lighting system towards smart cities.

scholarly journals Development of Wireless Control System for Smart Street Lighting using ESP8266

2020 ◽  
Vol 14 (15) ◽  
pp. 68
Author(s):  
Syifaul Fuada ◽  
Trio Adiono ◽  
Lindawani Siregar
Keyword(s):  
Control System ◽  
Pulse Width Modulation ◽  
Low Cost ◽  
Environmental Condition ◽  
Lighting System ◽  
Street Lighting ◽  
Lighting Control ◽  
Turn On ◽  
Wireless Control ◽  
Temperature And Humidity

In this paper, we report a smart street lighting control system using the ESP8266 which is a low-cost Wi-Fi chip with full TCP/IP stack and microcontroller capability. Our system is equipped with a web server developed in HTML code. Hence, our smart street lighting system can be controlled wirelessly to turn ON or turn OFF, and it can be monitored its environmental condition (i.e., temperature and humidity around the system). All sensors used in this system are pure digitally-outputted sensor: DHT11 to monitor the ambient temperature and humidity and BH1750 to adjust the street light intensity automatically. The dimming technique was applied in the control system by using Pulse Width Modulation (PWM). The system was divided into two main parts: Gateway and Node in which these two parts employ the ESP8266. The Gateway as a coordinator will send a message to the node as an end device (in this work, the streetlight act as a Node). Later, the node will send the ACK to the Gateway. As results, each node can send a message to other nodes.

scholarly journals Implementation of 5-Level H-Bridge Inverter with Multicarrier based Modulation Techniques

2020 ◽  
Vol 8 (5) ◽  
pp. 5180-5185
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Reference Signal ◽  
Low Frequency ◽  
Harmonic Spectrum ◽  
Multilevel Inverter ◽  
Modulation Method ◽  
Dc Voltage ◽  
Modulation Technique

Paper Setup must be in A4 size with Margin: Top In the present paper multi carrier sinusoidal modulation technique which is an efficient method of producing control signals is used for a symmetrical inverter with several levels in cascade H Bridge is discussed. The Cascaded H-Bridge performance output levels depend on the DC voltage sources used at the input side. With the help of two DC voltage sources, five level output can be obtained whereas three sources gives levels of seven in output voltage. In this paper, multi-carrier SPWM switching is obtained for switching of multilevel inverter based switches. Two signals are used in this switching method, among which one of the signals is reference which is a low frequency sinusoidal signal and the one is a carrier signal. In case of sinusoidal PWM method of modulation technique, the reference signal is a sinusoidal one and triangular signal can be used as a carrier signal. These types of inverters have the ability to generate inverted output voltage with an efficient harmonic spectrum and reliable output results. This document provides switching signal for H-bridge inverter structure which can improve harmonic performance. The 5-level multilevel inverter is simulated for traditional carrier-based pulse-width modulation (PWM) phase change carrier techniques. The total harmonic performance of the output voltages is analyzed for the two PWM control methods. The performance of the symmetrical PWM CHB is simulated using MATLAB-SIMULINK model. Model results show that THD can be minimized to a limit with level shifted modulation method of the sinusoidal pulse width. The results from the simulations show that the quality of the waveform of the output voltage improves with less loss and with a lower THD.

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