727 research outputs found
Simulation and Implementation of a High Performance Torque Control Scheme of IM Utilizing FPGA
Thi paper presents a novel approach to design and implementation of a high perfromane torque control scheme i.e. direct torque control with space vector modulation(DTC-SVM) of three phase induction motor using Field Programmable gate array (FPGA). The conventional direct torque control (DTC) is one of control scheme that is used commonly in induction motor control system. This method supports a very quick and precise torque response. However, the conventional DTC is not perfect and has some disadvantages. To minimize the ripples of the electromagnetic torque and flux linkage and to fix the variable switching frequency produced in the conventional DTC, this paper proposes improved DTC-SVM concept. Both simulation and experimental results show that the proposed scheme can dramatically improve the steady state performance while preserving the dynamic performance of the conventional DTC.DOI:http://dx.doi.org/10.11591/ijece.v2i3.20
Reduction of Switches and DC Sources in Cascaded Multilevel Inverter
Harmonics and increasing number of switches and DC sources for increasing level is the major issue in the cascaded multilevel inverter for the application of medium and high voltage power system applications. In this paper several new techniques are used to reduce the switches and DC sources, which overcome the disadvantages of cascaded multilevel inverter. The THD values for various levels (seven & nine) are compared with and without PWM technique
Energy Efficient Approach for Collision Avoidance in Wireless Sensor Networks
One of the main challenges in the wireless sensor network is to improve the performance of the network by extending the lifetime of the sensor nodes. Excessive packet collisions lead to packet losses and retransmissions, resulting in significant overhead costs and latency which in turn makes a need to design a distributed and scalable time slot allocation. A new proposal is proposed which avoids collisions between packets and also provides increased energy efficiency and further prolong network lifetime, in wireless sensor network
Development of a high pressure compressed natural gas mixer for a 1.5 litre CNG-diesel dual engine
[Abstract]: The Computational Fluid Dynamics (CFD) analysis
software was used to study the flow behaviour of compressed
natural gas (CNG) and air in a CNG-air mixer to be introduced through the air inlet of a CNG-Diesel dual fuel stationary engine. The results of the simulation show that the Venturi mixer with more holes gives superior engine performance compared to the 4-hole Venturi mixer. Further analysis is done on the different holes mixer to investigate the effect of engine speed on the mass flow rate of CNG and the equivalence ratio Lambda. The second part of the paper represents a comparison results between the performances of a single cylinder research Compression Ignition CI engine fuelled with CNG-diesel system
and conventional CI engine fuelled by conventional diesel. The engine was equipped with the simulated Venturi mixer, the result showed significant reduction in the exhaust gas emission compared to the conventional diesel engine. The average power output generated by dual fuel engine was slightly higher than that diesel one at different engine speeds
Investigation on D-STATCOM Operation for Power Quality Improvement in a Three Phase Three Wire Distribution System with a New Control Strategy
This paper deals with the issue of modeling and analysis of power controllers, power electronic-based equipment aimed at improving the reliability, stability and quality of power flows in low voltage distribution networks. A new control scheme is proposed to generate the PWM signal based on the measurements of voltage, and no reactive power measurements are required. The operation of the proposed control method is presented for D-STATCOM. Simulations and analysis are carried out in MATLAB/PLECS with this control method for the proposed systems. The reliability of the control scheme in the system response to the voltage instabilities due to system faults or load variations is proved obviously in the simulation results. Keywords: D-STATCOM, PWM, VSC, MATLAB/PLECS
Compensation of Voltage Sag and Swell Using SMES Based Dynamic Voltage Restorer
Conducting Magnetic Energy Storage (SMES) is portrayed by profoundly proficient vitality storage. It has fast reaction and power controllability and is relied upon to add to brilliant intensity of the power grid. SMES innovation can possibly bring genuine power storage trademark and furthermore high power and vitality thickness for momentary reaction. This normal for SMES used to shield buyers from the network voltage variances like sag, swell and interference. This paper examinations the activity guideline of the SMES based DVR and its structure depends on basic PI control technique to repay voltage droops, swell and intrusion. Utilizing MATLAB/SIMULINK, the models of the SMES based DVR is set up, and the re-enactment tests are performed to assess the grid disturbances
Compensation of Voltage Sag and Swell Using SMES Based Dynamic Voltage Restorer
Conducting Magnetic Energy Storage (SMES) is portrayed by profoundly proficient vitality storage. It has fast reaction and power controllability and is relied upon to add to brilliant intensity of the power grid. SMES innovation can possibly bring genuine power storage trademark and furthermore high power and vitality thickness for momentary reaction. This normal for SMES used to shield buyers from the network voltage variances like sag, swell and interference. This paper examinations the activity guideline of the SMES based DVR and its structure depends on basic PI control technique to repay voltage droops, swell and intrusion. Utilizing MATLAB/SIMULINK, the models of the SMES based DVR is set up, and the re-enactment tests are performed to assess the grid disturbances
Larval development — Penaeus semisulcatus de Haan
The larvae of Penaeus semisulcatus reared from eggs spawned in the laboratory are described
and illustrated tor the first tlma. At a rearing tamparatura of 31.0'c the nauplii hatched out
12 to 13 hours after spawning; the duration of tha nauplius, protozoaa and mysis stages was 42
hours, 154 hours and 96 hours respectively. The larvae passed through 6 nauplius substages, 3 protozoea
substages and 3 mysis substages before transforming into postlarva I
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