scholarly journals A Frequency Adaptive Scheme Based on Newton Structure of PRRC for LCL-Type Inverter Connected with Weak Grid

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4225
Author(s):  
Chengbi Zeng ◽  
Sudan Li ◽  
Hanwen Wang ◽  
Hong Miao
Keyword(s):  
Repetitive Control ◽  
Harmonic Distortion ◽  
Adaptive Scheme ◽  
Computational Burden ◽  
Weak Grid ◽  
Control Scheme ◽  
Sample Frequency ◽  
Fractional Delay ◽  
Pr Controller ◽  
Online Tuning

Repetitive control (RC) is gradually used in inverters tied with weak grid. To achieve the zero steady-state error tracking of inverter current and compensate the harmonic distortion caused by frequency fluctuation, a frequency adaptive (FA) control scheme for LCL-type inverter connected with weak grid is proposed. This scheme adopts a proportional resonance (PR) controller in parallel with RC (PRRC) to overcome the disadvantages caused by RC inherent one-cycle time delay. A fractional delay (FD) filter based on the Newton structure is proposed to approximate the fraction item of fs/f, where fs and f are sample frequency and grid frequency, respectively. The structure of the proposed FD filter is relatively simple; moreover, coefficients of the filter maintain constant so as not to need online tuning even when grid frequency fluctuates, which decreases the computational burden considerably. The feasibility and effectiveness of the proposed FA control scheme, named as Newton-FAPRRC, are all verified by the simulation and experimental results.

A Decentralized Neuro-Adaptive Control Scheme to Suppress Chaotic/Hyperchaotic Dynamics of Smart Valves Network

2018 ◽  
Vol 13 (5) ◽  
Author(s):  
Peiman Naseradinmousavi ◽  
Hashem Ashrafiuon ◽  
Mostafa Bagheri
Keyword(s):  
Initial Conditions ◽  
Adaptive Method ◽  
Critical Parameters ◽  
Computationally Efficient ◽  
Adaptive Scheme ◽  
Computational Burden ◽  
Trade Offs ◽  
Control Scheme ◽  
Practical Feasibility ◽  
Adaptive Control Scheme

In this effort, we utilize a decentralized neuro-adaptive scheme in extinguishing both the chaotic and hyperchaotic dynamics of the so-called “Smart Valves” network. In particular, a network of two dynamically interconnected bidirectional solenoid actuated butterfly valves undergoes the harmful chaotic/hyperchaotic dynamics subject to some initial conditions and critical parameters. Crucial trade-offs, including robustness, computational burden, and practical feasibility of the control scheme, are thoroughly investigated. The advantages and shortcomings of the decentralized neuro-adaptive method are compared with those of the direct decentralized adaptive one to yield a computationally efficient, practically feasible, and robust scheme in the presence of the coupled harmful responses.

The Simulation Research of the Five Level Photovoltaic Grid-Connected Inverter Based on Repetitive and PI Control

2012 ◽  
Vol 608-609 ◽  
pp. 34-37
Author(s):  
Jie Liu ◽  
Song Zhen Yuan
Keyword(s):  
Control Algorithm ◽  
Repetitive Control ◽  
Harmonic Distortion ◽  
Pi Control ◽  
Simulation Research ◽  
Compound Control ◽  
Control Scheme ◽  
Switch Type ◽  
Real Time Tracking ◽  
Grid Connected Inverter

Introducing a kind of bidirectional switch type five level inverter, and put forward the compound control scheme which repetitive control and PI adjustment are combined. And a detailed analysis of the repetitive control algorithm. Through the Matlab/simulink to simulate under different control modes. The results show that, the five-livel inverter which using repetitive PI control, its output grid-connected current waveform stability, harmonic distortion rate is small, and can real-time tracking the network voltage.

Speed Synchronization System of Master-Slave Motor Based on Repetitive Control

2014 ◽  
Vol 644-650 ◽  
pp. 523-526
Author(s):  
Yun Ling ◽  
Huan Chen ◽  
Fei Li
Keyword(s):  
Real Time ◽  
Spectrum Analysis ◽  
Repetitive Control ◽  
Speed Control ◽  
Time Spectrum ◽  
Mechanical Resonance ◽  
Synchronization System ◽  
Speed Controller ◽  
Control Scheme ◽  
Magnet Wire

In the wrapping process of magnet wire, as the haulage speed of master motor varies periodically, it is difficult for slave wrapping motor to track master motor due to the mechanical resonance, which destabilizes the wrapping pitch. In the proposed system, the synchronization speed control scheme of master-slave motor based on repetitive control compensation is employed. In the process of control, real-time spectrum analysis of the haulage speed is given, which can be used to adjust the parameters of wrapping speed controller adaptively with the acquired characteristic information of the mechanical resonant. Simulation shows that wrapping speed can track haulage speed well in the proposed system, and the maximum tracking synchronous deviation can be reduced to 56% of that in the system without repetitive control.

scholarly journals Flyback Photovoltaic Micro-Inverter with a Low Cost and Simple Digital-Analog Control Scheme

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4239
Author(s):  
Salam J. Yaqoob ◽  
Adel Obed ◽  
Rana Zubo ◽  
Yasir I. A. Al-Yasir ◽  
Hussein Fadhel ◽  
...  
Keyword(s):  
Digital Signal Processor ◽  
Low Cost ◽  
Harmonic Distortion ◽  
Single Stage ◽  
System Component ◽  
Maximum Efficiency ◽  
System Efficiency ◽  
Control Scheme ◽  
The Cost ◽  
Micro Inverter

The single-stage flyback Photovoltaic (PV) micro-inverter is considered as a simple and small in size topology but requires expensive digital microcontrollers such as Field-Programmable Gate Array (FPGA) or Digital Signal Processor (DSP) to increase the system efficiency, this would increase the cost of the overall system. To solve this problem, based on a single-stage flyback structure, this paper proposed a low cost and simple analog-digital control scheme. This control scheme is implemented using a low cost ATMega microcontroller built in the Arduino Uno board and some analog operational amplifiers. First, the single-stage flyback topology is analyzed theoretically and then the design consideration is obtained. Second, a 120 W prototype was developed in the laboratory to validate the proposed control. To prove the effectiveness of this control, we compared the cost price, overall system efficiency, and THD values of the proposed results with the results obtained by the literature. So, a low system component, single power stage, cheap control scheme, and decent efficiency are achieved by the proposed system. Finally, the experimental results present that the proposed system has a maximum efficiency of 91%, with good values of the total harmonic distortion (THD) compared to the results of other authors.

scholarly journals Fuzzy Logic Controlled Renewable Energy based DC Smart-Grid-System with Improved-Performance

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3283-3289
Keyword(s):  
Smart Grid ◽  
Closed Loop ◽  
Harmonic Distortion ◽  
Grid System ◽  
Power Sources ◽  
Renewable Power ◽  
Voltage Quality ◽  
Pr Controller ◽  
Improved Performance ◽  
Smart Grid System

The DC smart-grid-system (DCSGS) becomes more and more popular and it is seen as an alternative to the AC. In DCSGS, voltage quality and harmonic distortion issues affects the performance of integrated renewable power sources. To improve the voltage quality, SEPIC converter is used to step up the output of PV cell. In DCSGS, output of PV is stepped-up using SEPIC. The output of wind generator is also rectified and stepped-up using SEPIC. This effort covenants with modeling&-simulation of CL(closed-loop)-DC-SGS (smart grid system) with PR controller and FLC in DCSGS. The performance of DCSGS with PR and FLC are compared and their results are presented. The results indicate that FLC controlled close-loop DCSGS gives superior response

Implementation of Single-Phase Two-Switch Midpoint Unidirectional Multilevel Converter System

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Open Loop ◽  
Current Control ◽  
Control Technique ◽  
Control Scheme

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.

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