Sliding mode current control of a NOCULL converter based on hysteresis modulation method in a wide range of operating conditions

2019 ◽  
Vol 85 ◽  
pp. 214-225 ◽  
Author(s):  
Alireza Goudarzian ◽  
Adel Khosravi ◽  
Navid Reza Abjadi
Keyword(s):  
Sliding Mode ◽  
Current Control ◽  
Operating Conditions ◽  
Modulation Method ◽  
Wide Range

scholarly journals PIDR Sliding Mode Current Control with Online Inductance Estimator for VSC-MVDC System Converter Stations under Unbalanced Grid Voltage Conditions

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2599 ◽  
Author(s):  
Weipeng Yang ◽  
Hang Zhang ◽  
Jungang Li ◽  
Aimin Zhang ◽  
Yunhong Zhou ◽  
...  
Keyword(s):  
Reactive Power ◽  
Sliding Mode ◽  
Current Control ◽  
Operating Conditions ◽  
Gradient Algorithm ◽  
Positive Sequence ◽  
Voltage Source ◽  
Grid Voltage ◽  
Wide Range ◽  
Unbalanced Grid

This study aims to present a novel proportional-integral-derivative-resonant law-based sliding mode current control strategy with online inductance estimator (PIDR-SMCC-OIE) for voltage source converter medium voltage direct current (VSC-MVDC) system converter stations under unbalanced grid voltage conditions. A generalized current reference calculation method, by which the ratio of the amplitude of the active power ripple to that of the reactive power ripple can be continuously controlled without current distortion is presented. A dynamic model of the current control errors in the positive sequence synchronous reference frame is developed, and a PIDR law-based sliding mode current controller is designed, where derivatives of the current references are obtained by simple algebraic operations. An OIE adopting the dynamic filtering method and gradient algorithm is proposed to further improve system robustness. In this OIE, the converter pole voltages are obtained by computation utilizing the gate signals of the switching devices and the DC bus voltage, so that no additional voltage sensors are needed. To verify effectiveness of the PIDR-SMCC-OIE strategy, simulation studies on a two-terminal VSC-MVDC system are conducted in PSCAD/EMTDC. The results show it can provide satisfactory performance over a wide range of operating conditions.

scholarly journals A Fast-Response Sliding-Mode Controller for Boost-Type Converters With a Wide Range of Operating Conditions

2007 ◽  
Vol 54 (6) ◽  
pp. 3276-3286 ◽  
Author(s):  
Siew-Chong Tan ◽  
Y. M. Lai ◽  
Chi K. Tse ◽  
Luis Martinez-Salamero ◽  
Chi-Kin Wu
Keyword(s):  
Sliding Mode ◽  
Fast Response ◽  
Operating Conditions ◽  
Sliding Mode Controller ◽  
Wide Range

Air-fuel ratio and speed control for low emission vehicles based on sliding mode techniques

2002 ◽  
Vol 216 (2) ◽  
pp. 117-124 ◽  
Author(s):  
P F Puleston ◽  
G Monsees ◽  
S K Spurgeon
Keyword(s):  
Sliding Mode ◽  
Speed Control ◽  
Operating Conditions ◽  
Robust Controller ◽  
Automotive Engines ◽  
Fuel Ratio ◽  
Low Emission ◽  
Wide Range ◽  
Unknown Disturbances ◽  
Set Up

This paper deals with the combined air-fuel ratio (AFR) and speed control of automotive engines. The robust controller is developed using dynamic sliding mode (SM) control design methods. The proposed controller set-up is tested under realistic operating conditions by means of computer simulation using a comprehensive non-linear model of a four-stroke engine, specifically provided by the automotive industry for these purposes. This accurate industrial model comprises extensive dynamics description and numerous look-up tables representing parameter characteristics obtained from experimental data. The SM controller set-up proves to be robust to model uncertainties and unknown disturbances, regulating effectively the engine speed for a wide range of set-points while maintaining the AFR at the stoichiometric value.

scholarly journals Power quality improvement of smart microgrids using EMS-based fuzzy controlled UPQC

2019 ◽  
pp. 1181-1197 ◽  
Author(s):  
AHMED A. HOSSAM-ELDIN ◽  
AHMED A. MANSOUR ◽  
MOHAMMED EL-GAMAL ◽  
KARIM H. YOUSSEF
Keyword(s):  
Power Generation ◽  
Power Quality ◽  
Distribution Systems ◽  
Current Control ◽  
Operating Conditions ◽  
Superior Performance ◽  
Voltage Sag ◽  
Nonlinear Load ◽  
Wide Range ◽  
Voltage Swell

The prevalent power quality problems in smart microgrids and power distribution systems are voltage sag, voltage swell, and harmonic distortion. The achievement of pure sinusoidal waveform with proper magnitude and phase is currently a great research and development concern. The aim of this paper is to evaluate and mitigate the smart microgrid harmonics, voltage sag, and voltage swell throughout a 24-h cycle, taking into consideration the variation in solar power generation due to changes in irradiation received by photovoltaic cells, the variation in wind power generation due to changes in wind speed, and the variation of linear and nonlinear load profiles during the day’s cycle. The mitigation of the power quality issues manifested in current harmonics, voltage sag, and voltage swell is achieved through the implementation of a new fully fuzzy controlled unified power quality conditioner (UPQC). It is controlled by an energy management system (EMS). This paper introduces a new control system for the UPQC using full fuzzy logic control. Moreover, fuzzy control is used in current control instead of proportional integral controllers so that it has acceptable performance over a wide range of operating points. The novel approach of an EMS-connected UPQC activates the UPQC at the required time only into the grid. This approach has many benefits by increasing the UPQC lifetime. The effect of the proposed system on the aforementioned issues has been validated through simulation by MATLAB/Simulink. The results are compared with those obtained by conventional methods. The results verify the superior performance of the proposed UPQC to mitigate the problems of current total harmonic distortions, voltage sag, and voltage swell under different operating conditions during the monitoring period.

A Mathematical Model and Performance Evaluation for a Single-Stage Grid-Connected Photovoltaic (PV) System

2008 ◽  
Vol 9 (6) ◽  
Author(s):  
Prajna Paramita Dash ◽  
Amirnaser Yazdani
Keyword(s):  
Mathematical Model ◽  
Control Strategy ◽  
Voltage Control ◽  
Current Control ◽  
Operating Conditions ◽  
Single Stage ◽  
Control Loop ◽  
Pv System ◽  
Wide Range ◽  
The Impact

This paper proposes a control strategy for important transients of a single-stage, three-phase, PV system that is connected to a distribution network. The proposed control strategy adopts an inner current-control loop and an outer DC-link voltage control loop. The current-control mechanism renders the PV system protected against external faults, enables control of the DC-link voltage and, therefore, controls/maximizes the PV system power output. The paper also proposes a feed-forward compensation strategy for the DC-link voltage control loop to mitigate the impact of the nonlinear characteristic of the PV array on the closed-loop stability, and to permit design and optimization of the DC-link voltage controller for a wide range of operating conditions. A mathematical model and a control design methodology are presented for the PV system, and it is shown that under the proposed control, the PV system fulfills the operational requirements of a grid-connected PV system. The effectiveness of the proposed control strategy and the most important transients of the PV system are evaluated through simulation studies conducted on a detailed switched model of the PV system in the PSCAD/EMTDC software environment.

Nonlinear Air-to-Fuel Ratio and Engine Speed Control for Spark Ignition Engines

2000 ◽  
Author(s):  
J. R. Wagner ◽  
D. M. Dawson ◽  
Z. Liu
Keyword(s):  
Control Strategy ◽  
Engine Speed ◽  
Sliding Mode ◽  
Operating Conditions ◽  
Spark Ignition Engines ◽  
Fuel Ratio ◽  
Model Based ◽  
Speed Regulation ◽  
Wide Range ◽  
Automobile Engines

Abstract The wide-range of operating conditions, inherent induction process nonlinearities, and gradual component degradations due to aging, have prompted research into model-based engine control algorithms. Consequentially, a variety of nonlinear and intelligent algorithms have been proposed and experimentally studied. Recent attention has focused on the simultaneous regulation of the air-to-fuel ratio and engine speed using a sliding mode control strategy. In this paper, a nonlinear model-based backstepping control strategy will be proposed for simultaneous air-to-fuel ratio control and speed tracking in passenger/light-duty automobile engines. For comparison purposes, a multi-surface sliding mode controller and an integrated speed-density air-to-fuel controller with attached engine speed regulation will be implemented. Representative numerical results will be presented and discussed.

scholarly journals Sensorless Fractional Order Control of PMSM Based on Synergetic and Sliding Mode Controllers

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1494 ◽  
Author(s):  
Marcel Nicola ◽  
Claudiu-Ionel Nicola
Keyword(s):  
Control System ◽  
Fractional Order ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Speed Control ◽  
Current Control ◽  
Torque Control ◽  
Rotor Speed ◽  
Control Loops ◽  
Wide Range

The field oriented control (FOC) strategy of the permanent magnet synchronous motor (PMSM) includes all the advantages deriving from the simplicity of using PI-type controllers, but inherently the control performances are limited due to the nonlinear model of the PMSM, the need for wide-range and high-dynamics speed and load torque control, but also due to the parametric uncertainties which occur especially as a result of the variation of the combined rotor-load moment of inertia, and of the load resistance. Based on the fractional calculus for the integration and differentiation operators, this article presents a number of fractional order (FO) controllers for the PMSM rotor speed control loops, and id and iq current control loops in the FOC-type control strategy. The main contribution consists of proposing a PMSM control structure, where the controller of the outer rotor speed control loop is of FO-sliding mode control (FO-SMC) type, and the controllers for the inner control loops of id and iq currents are of FO-synergetic type. Superior performances are obtained by using the control system proposed, even in the case of parametric variations. The performances of the proposed control system are validated both by numerical simulations and experimentally, through the real-time implementation in embedded systems.

scholarly journals Constant-Current Gate Driver for GaN HEMTs Applied to Resonant Power Conversion

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2377
Author(s):  
Héctor Sarnago ◽  
Óscar Lucía ◽  
Iulian O. Popa ◽  
José M. Burdío
Keyword(s):  
High Performance ◽  
Cost Effective ◽  
Current Control ◽  
Operating Conditions ◽  
Constant Current ◽  
Efficient Operation ◽  
Zero Voltage Switching ◽  
Resonant Inverter ◽  
Wide Range ◽  
Gate Driver

New semiconductor technology is enabling the design of more reliable and high-performance power converters. In particular, wide bandgap (WBG) silicon carbide (SiC) and gallium nitride (GaN) technologies provide faster switching times, higher operating temperature, and higher blocking voltage. Recently, high-voltage GaN devices have opened the design window to new applications with high performance and cost-effective implementation. However, one of the main drawbacks is that these devices require accurate base current control to ensure safe and efficient operation. As a consequence, the base drive circuit becomes more complex and the final efficiency is decreased. This paper presents an improved gate driver circuit for GaN devices based on the use of a constant current regulator (CCR). The proposed circuit achieves constant current regardless of the operating conditions, solving variations with temperature, aging and operating conditions that may degrade the converter performance. Besides, the proposed circuit is reliable and cost-effective, being applicable to a wide range of commercial, industrial and automotive applications. In this paper, its application to a zero-voltage switching resonant inverter for domestic induction heating was performed to prove the feasibility of this concept.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

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