scholarly journals Design and Analysis of Asynchronous Sampling Duty Cycle Corrector

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2594
Author(s):  
Gijin Park ◽  
Jaeduk Han ◽  
Woorham Bae
Keyword(s):  
Duty Cycle ◽  
Low Frequency ◽  
Operating Conditions ◽  
Cmos Process ◽  
Asynchronous Sampling ◽  
Operation Conditions ◽  
Correction Scheme ◽  
Control Scheme ◽  
And Performance ◽  
Settling Behavior

This paper presents a duty cycle correction scheme based on asynchronous sampling and associated settling analysis. The proposed duty cycle corrector circuit consumes less power and area compared to other corrector circuits due to the low-frequency operation of asynchronous sampling. However, the settling behavior of an asynchronous sampling duty cycle corrector is limited in some operation conditions, which degrades its robustness and performance. This paper, therefore, performs analysis on the settling behavior of the asynchronous sampling in various operating conditions and proposes a control scheme to avoid the lagged settling. To verify the proposed duty cycle corrector and its analysis, a prototype design is implemented in a 40-nm CMOS process and its performance is verified by post-layout simulations. The proposed duty cycle corrector achieved very small duty cycle errors (less than 0.8%) and consumed 540 uW per one DCC unit.

Experimental and numerical investigations of aerodynamic behavior of a three-stage high-pressure turbine at different operation conditions

2011 ◽  
Vol 226 (6) ◽  
pp. 1535-1549
Author(s):  
S Abdelfattah ◽  
M T Schobeiri
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Critical Discussion ◽  
Numerical Results ◽  
Operating Conditions ◽  
Steam Turbines ◽  
High Pressure Turbine ◽  
Numerical Investigations ◽  
Operation Conditions ◽  
And Performance

Using the Reynolds-averaged Navier–Stokes-based numerical methods to simulate the flow field, efficiency and performance of high-pressure turbine components of multi-stage steam turbines result in substantial differences between the experimental and the numerical results pertaining to the individual flow quantities. These differences are integrally noticeable in terms of major discrepancies in aerodynamic losses, efficiency, and performance of the turbine. As a consequence, engine manufacturers are compelled to frequently calibrate their simulation package by performing a series of experiments before issuing efficiency and performance guaranty. The aim of this article is to investigate the cause of the aforementioned differences by utilizing a three-stage high-pressure research turbine with three-dimensional compound lean blades as the platform for experimental and numerical investigations. Experimental data were obtained using interstage aerodynamic measurements at three measurement stations, namely, downstream of the first rotor row, the second stator row, and the second rotor row. Detailed measurements were conducted using custom-designed five-hole probes traversed in both circumferential and radial directions. Aerodynamic measurements were carried out within a rotational speed range of 1800–2800 r/min. Numerical simulations were performed utilizing a commercially available computational fluid dynamics code. A detailed mesh of the three stages was created and used to simulate the corresponding operating conditions. The experimental and numerical results were compared following a critical discussion relative to differences mentioned above.

scholarly journals Comparison of Honey Bee Mating Optimization and Genetic Algorithm for Coordinated Design of Pss and Statcom Based on Damping of Power System Oscillation

2013 ◽  
Vol 64 (3) ◽  
pp. 133-142 ◽  
Author(s):  
Amin Safari ◽  
Ali Ahmadian ◽  
Masoud Aliakbar Golkar
Keyword(s):  
Honey Bee ◽  
Low Frequency ◽  
Performance Comparison ◽  
Optimization Techniques ◽  
Operating Conditions ◽  
Low Frequency Oscillations ◽  
Wide Range ◽  
And Performance ◽  
Honey Bee Mating Optimization ◽  
Better Than

Recently, honey bee mating optimization (HBMO) technique and genetic algorithms (GA) have attracted considerable attention among various modern heuristic optimization techniques. This paper presents the application and performance comparison of HBMO and GA optimization techniques, for coordinated design of STATCOM and PSS. The design objective is to enhance damping of the low frequency oscillations. The design problem of the controller is formulated as an optimization problem and both HBMO and GA optimization techniques are employed to search for optimal controller parameters. The performance of both optimization techniques for damping low frequency oscillations are tested and demonstrated through nonlinear time-domain simulation and some performance indices studies to different disturbances over a wide range of loading conditions. The results show that the designed controller by HBMO performs better than GA in finding the solution. Moreover, the system performance analysis under different operating conditions show that the φ based controller is superior to the C based controller.

scholarly journals Design of a robust PID-PSS for an uncertain power system with simplified stability conditions

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Vijaya Lakshmi A.S.V ◽  
Ramalinga Raju Manyala ◽  
Siva Kumar Mangipudi
Keyword(s):  
Power System ◽  
Low Frequency ◽  
Design Procedure ◽  
Operating Conditions ◽  
Stability Conditions ◽  
Power System Stabilizers ◽  
Interval System ◽  
Performance Error ◽  
Single Machine Infinite Bus ◽  
And Performance

Abstract In a deregulated power system uncertainty exists and lack of sufficient damping can lead to Low Frequency Oscillations (LFO). The problem can be addressed using robust Power System Stabilizers (PSS). In this paper, an optimal procedure to design a robust PID-PSS using interval arithmetic for the Single Machine Infinite Bus (SMIB) power system is proposed. The interval modelling captures the wide variations of operating conditions in bounds of system coefficients. In the proposed design procedure, simple and new closed loop stability conditions for an SMIB interval system are developed and are used to design an optimum PID-PSS for improving the performance of an SMIB system. The optimum PID-PSS is attained by tuning the parameters using the FMINCON tool provided in MATLAB. The robustness of the proposed PID-PSS design is validated and compared to other notable methods in the literature when the system is subjected to different uncertainties. The simulation results and performance error values show the effectiveness of the proposed robust PID-PSS controller.

MODERN EQUIPMENT FOR DETERMINING TRACTOR-SPEED PROPERTIES OF THE VEHICLE: CHARACTERISTICS’ ANALYSIS IN LABORATORY CONDITIONS

2019 ◽  
Vol 16 (3) ◽  
pp. 276-289
Author(s):  
N. V. Savenkov ◽  
V. V. Ponyakin ◽  
S. A. Chekulaev ◽  
V. V. Butenko
Keyword(s):  
Environmental Performance ◽  
Operating Conditions ◽  
Special Role ◽  
Development Stages ◽  
Advantages And Disadvantages ◽  
Force Transfer ◽  
Characteristics Analysis ◽  
And Performance ◽  
Loading Devices ◽  
Structural Solutions

Introduction. At present, stands with running drums are widely used for various types of tests. Power stands play a special role. Such stands take the mechanical power from the driving wheels of the car. This simulates the process of movement of the vehicle under operating conditions. Such equipment has various designs, principles of operation and performance. It is also used in tests that are different by purpose, development stages and types: research, control, certification, etc. Therefore, it is necessary in order to determine the traction-speed, fuel-efficient and environmental performance characteristics.Materials and methods. The paper provides the overview of the power stands with running drums, which are widespread on the domestic market. The authors carried out the analysis of the main structural solutions: schemes of force transfer between the wheel and the drum; types of loading devices; transmission layout schemes and features of the control and measuring complex. The authors also considered corresponding advantages and disadvantages, recommended spheres of application, demonstrated parameters and characteristics of the units’ workflow, presented components and equipment.Discussion and conclusions. The authors critically evaluate existing models of stands with running drums. Such information is useful for choosing serial models of stands and for developing technical tasks for designing or upgrading the equipment.

Application of vacuum belt press filters for cane mud filtration and performance comparison with rotary filters

2014 ◽  
pp. 298-301 ◽  
Author(s):  
Arnaud Petit
Keyword(s):  
Electricity Consumption ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Vacuum Filter ◽  
Sugar Mill ◽  
Belt Press ◽  
Vacuum Belt ◽  
And Performance ◽  
Mud Filtration ◽  
The Impact

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.

scholarly journals A 2.1 GHz, 210 μW, —189 dBc/Hz DCO with Ultra Low Power DCC Scheme

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 805
Author(s):  
Shi Zuo ◽  
Jianzhong Zhao ◽  
Yumei Zhou
Keyword(s):  
Low Power ◽  
Current Efficiency ◽  
Phase Noise ◽  
Duty Cycle ◽  
Semiconductor Manufacturing ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Cmos Process ◽  
Ultra Low Power ◽  
Measured Phase

This article presents a low power digital controlled oscillator (DCO) with an ultra low power duty cycle correction (DCC) scheme. The DCO with the complementary cross-coupled topology uses the controllable tail resistor to improve the tail current efficiency. A robust duty cycle correction (DCC) scheme is introduced to replace self-biased inverters to save power further. The proposed DCO is implemented in a Semiconductor Manufacturing International Corporation (SMIC) 40 nm CMOS process. The measured phase noise at room temperature is −115 dBc/Hz at 1 MHz offset with a dissipation of 210 μμW at an oscillating frequency of 2.12 GHz, and the resulin figure-of-merit is s −189 dBc/Hz.

scholarly journals Observer-based robust integral of the sign of the error control of class I of underactuated mechanical systems: Theory and real-time experiments

2021 ◽  
pp. 014233122110313
Author(s):  
Afef Hfaiedh ◽  
Ahmed Chemori ◽  
Afef Abdelkrim
Keyword(s):  
Real Time ◽  
Error Control ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Mechanical Systems ◽  
Class I ◽  
Control Input ◽  
Underactuated Mechanical Systems ◽  
Control Scheme ◽  
And Performance

In this paper, the control problem of a class I of underactuated mechanical systems (UMSs) is addressed. The considered class includes nonlinear UMSs with two degrees of freedom and one control input. Firstly, we propose the design of a robust integral of the sign of the error (RISE) control law, adequate for this special class. Based on a change of coordinates, the dynamics is transformed into a strict-feedback (SF) form. A Lyapunov-based technique is then employed to prove the asymptotic stability of the resulting closed-loop system. Numerical simulation results show the robustness and performance of the original RISE toward parametric uncertainties and disturbance rejection. A comparative study with a conventional sliding mode control reveals a significant robustness improvement with the proposed original RISE controller. However, in real-time experiments, the amplification of the measurement noise is a major problem. It has an impact on the behaviour of the motor and reduces the performance of the system. To deal with this issue, we propose to estimate the velocity using the robust Levant differentiator instead of the numerical derivative. Real-time experiments were performed on the testbed of the inertia wheel inverted pendulum to demonstrate the relevance of the proposed observer-based RISE control scheme. The obtained real-time experimental results and the obtained evaluation indices show clearly a better performance of the proposed observer-based RISE approach compared to the sliding mode and the original RISE controllers.

scholarly journals A New MPPT Algorithm for Photovoltaic Power Generation under Uniform and Partial Shading Conditions

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 483
Author(s):  
Novie Ayub Windarko ◽  
Muhammad Nizar Habibi ◽  
Bambang Sumantri ◽  
Eka Prasetyono ◽  
Moh. Zaenal Efendi ◽  
...  
Keyword(s):  
Power Generation ◽  
Duty Cycle ◽  
Operating Conditions ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Partial Shading ◽  
Photovoltaic Panel ◽  
Maximum Power Point Tracker ◽  
Photovoltaic Power ◽  
Power Point

During its operation, a photovoltaic system may encounter many practical issues such as receiving uniform or non-uniform irradiance caused mainly by partial shading. Under uniform irradiance a photovoltaic panel has a single maximum power point. Conversely under non-uniform irradiance, a photovoltaic panel has several local maximum power points and a single global maximum power point. To maximize energy production, a maximum power point tracker algorithm is commonly implemented to achieve the maximum power operating point of the photovoltaic panel. However, the performance of the algorithm will depend on operating conditions such as variation in irradiance. Presently, most of existing maximum power point tracker algorithms work only in a single condition: either uniform or non-uniform irradiance. This paper proposes a new maximum power point tracker algorithm for photovoltaic power generation that is designed to work under uniform and partial shading irradiance conditions. Additionally, the proposed maximum power point tracker algorithm aims to provide: (1) a simple math algorithm to reduce computational load, (2) fast tracking by evaluating progress for every single executed duty cycle, (3) without random steps to prevent jumping duty cycle, and (4) smooth variable steps to increase accuracy. The performances of the proposed algorithm are evaluated by three conditions of uniform and partial shading irradiance where a targeted maximum power point is located: (1) far from, (2) near, and (3) laid between initial positions of particles. The simulation shows that the proposed algorithm successfully tracks the maximum power point by resulting in similar power values in those three conditions. The proposed algorithm could handle the partial shading condition by avoiding the local maxima power point and finding the global maxima power point. Comparisons of the proposed algorithm and other well-known algorithms such as differential evolution, firefly, particle swarm optimization, and grey wolf optimization are provided to show the superiority of the proposed algorithm. The results show the proposed algorithm has better performance by providing faster tracking, faster settling time, higher accuracy, minimum oscillation and jumping duty cycle, and higher energy harvesting.

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