scholarly journals A Photo-Voltaic Invert-er Cluster Resonance Suppression Method Based on Capacitor Voltage Feed-Forward

2021 ◽  
Vol 2136 (1) ◽  
pp. 012012
Author(s):  
Shengqing Li ◽  
Xin Yao ◽  
Ziran Peng ◽  
Zhichao Shen
Keyword(s):  
Control Structure ◽  
System Control ◽  
Current Feedback ◽  
Lcl Filter ◽  
Feed Forward ◽  
Weak Grid ◽  
Capacitor Voltage ◽  
Simulation And Experiment ◽  
Suppression Method ◽  
Photo Voltaic

Abstract Photo-voltaic inverts usually use LCL filter for filtering, and LCL filter will bring resonance problems to the system. This paper focuses on invert-er side current feedback control (invert-er side current feedback, ICF). This paper proposes a method for suppressing resonance of photo-voltaic invert-er clusters based on capacitor voltage feed-forward. First, establish the ICF mathematical model based on HPF and CVF under the weak grid, qualitatively analyze the resonance mechanism of the cluster invert-er, then analyze the system control structure and stability according to the proposed method, and finally verify the effectiveness of the proposed method through simulation and experiment sexuality and correctness.

scholarly journals Research on Adaptive Suppression of LCL Converter Resonance Grid-Connected System

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Junwei Li ◽  
Yafang Tang ◽  
Junke Li
Keyword(s):  
Particle Swarm Optimization ◽  
Particle Swarm ◽  
Stability Margin ◽  
System Stability ◽  
Current Feedback ◽  
Swarm Optimization ◽  
Lcl Filter ◽  
Rbf Network ◽  
Grid Impedance ◽  
Suppression Method

LCL-type converters are widely used in grid-connected systems due to their small size and good filtering performance. However, the resonance suppression problem brought by the LCL filter cannot be ignored. The capacitive current feedback is a commonly used resonance suppression method. In applications, the grid impedance can cause LCL filter resonance. Thus, this paper presents an adaptive resonance suppression method based on the RBF network optimized by particle swarm optimization. This method optimizes the initial parameters of the RBF network through particle swarm optimization, identifies the parameters of the PI controller by RBF neural network’s own identification capability, and updates the active damping coefficient based on constraints such as stability margin, thereby realizing the LCL-type inverter to maintain the system stability when the grid impedance changes. The effectiveness of the method is verified by experiments.

PMSG Based WECS with PR Control Strategy for Grid Control

2014 ◽  
Vol 573 ◽  
pp. 267-272
Author(s):  
V. Prasath ◽  
S. Vijayalakshmi ◽  
R. Jain Anush
Keyword(s):  
Control Strategy ◽  
Harmonic Distortion ◽  
High Gain ◽  
System Control ◽  
Control Loop ◽  
Current Feedback ◽  
Lcl Filter ◽  
Order Function ◽  
Average Value ◽  
Pr Controller

In this paper, a current feedback control scheme is proposed using Proportional Resonant (PR) for a grid-connected converter with an LCL Filter; PR controller with harmonic compensators has high gain at the desired frequencies for decrease harmonic distortion in the alternative voltage or current. Harmonic compensators of PR controller are limited to several low-order harmonics due to the system instability when the compensated frequency is out of system control loop’s bandwidth. The average value of current flow through inductors of LCL filter is feedback to the PR current regulator. Zero D-axis Control (ZDC) is to control the generator side converter to reduce the DC-link ripples, multi-loop harmonic current controllers are applied to regulate the higher-order harmonics by PR regulators. Consequently control strategy with LCL filter is to reduce third-order function to first-order function. By this way large control loop gain can be chosen to obtain control loop for the required harmonic components of the PR controller. The simulation and experimental results have been illustrated to validate the effectiveness of the proposed method in MATLAB Simulink.

scholarly journals Oscillation Suppression Method by Two Notch Filters for Parallel Inverters under Weak Grid Conditions

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3441 ◽  
Author(s):  
Ling Yang ◽  
Yandong Chen ◽  
Hongliang Wang ◽  
An Luo ◽  
Kunshan Huai
Keyword(s):  
Control Method ◽  
Harmonic Oscillation ◽  
Output Impedance ◽  
Notch Filters ◽  
Current Feedback ◽  
Weak Grid ◽  
Oscillation Suppression ◽  
In Series ◽  
Suppression Method ◽  
Grid Side

With plenty of parallel inverters connected to a weak grid at the point of common coupling (PCC), the impedance coupling interactions between the inverters and the grid are enhanced, which may cause high-frequency harmonic oscillation and further aggravate the system instability. In this paper, a basic technique for inverter output impedance is proposed to suppress the oscillation, showing that the inverter output impedance should be designed relatively high at the harmonic oscillation frequency, while relatively low at other frequencies. On the basis of the proposed technique, two virtual impedances are added to be in parallel and in series with the original inverter output impedance, respectively. Thus, an oscillation suppression method by two notch filters is proposed to realize the virtual impedances and increase the whole system damping. The implementation forms of the virtual impedances are presented by the proposed PCC voltage feedforward and grid-side inductor current feedback with two notch filters. Finally, simulation and experimental results are provided to verify the validity of the proposed control method.

scholarly journals Robust Grid-Current-Feedback Resonance Suppression Method for LCL-Type Grid-Connected Inverter Connected to Weak Grid

2018 ◽  
Vol 6 (4) ◽  
pp. 2126-2137 ◽  
Author(s):  
Xiaoping Zhou ◽  
Leming Zhou ◽  
Yandong Chen ◽  
Zhikang Shuai ◽  
Josep M. Guerrero ◽  
...  
Keyword(s):  
Current Feedback ◽  
Grid Current ◽  
Weak Grid ◽  
Suppression Method ◽  
Grid Connected Inverter

scholarly journals An Integrated Design Approach for LCL-Type Inverter to Improve Its Adaptation in Weak Grid

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2637
Author(s):  
Zheng ◽  
Liu ◽  
Liu ◽  
Li ◽  
Dai ◽  
...  
Keyword(s):  
Design Method ◽  
Robustness Analysis ◽  
Integrated Design ◽  
System Stability ◽  
Lcl Filter ◽  
Weak Grid ◽  
Grid Impedance ◽  
Integrated Design Approach ◽  
Simulation And Experiment ◽  
Grid Connected Inverter

To improve the robustness of grid-connected inverter against grid impedance in a weak grid an integrated design method of LCL-filter parameters and controller parameters is proposed. In the method the inherent relation of LCL-filter parameters and controller parameters is taken into consideration to realize their optimized match. A parameter normalization scheme is also developed to facilitate the system stability and robustness analysis. Based on the method all normalization parameters can be designed succinctly according to the required stability and robustness. Additionally, the LCL parameter and controller parameter can be achieved immediately by restoring normalization parameters. The proposed design method can guarantee the inverter stability and robustness simultaneously without needing any compensation network, additional hardware, or the complicated iterative computations which cannot be avoided for the conventional inverter design method. Simulation and experiment results have validated the superiority of the proposed inverter design method.

Design a Robust RST Controller for Stabilization of a Tri-Copter UAV

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Zain Anwar Ali ◽  
Dao Bo Wang ◽  
Muhammad Aamir
Keyword(s):  
Control Algorithm ◽  
Control Structure ◽  
Flight Test ◽  
System Control ◽  
Test Results ◽  
Output Control ◽  
Aerial Robot ◽  
Mimo Model

<span>Research on the tri-rotor aerial robot is due to extra efficiency<span> over other UAV’s regarding stability, power and size<span> requirements. We require a controller to achieve 6-Degree<span> Of Freedom (DOF), for such purpose, we propose the RST<span> controller to operate our tri-copter model. A MIMO model<span> of a tri-copter aerial robot is challenged in the area of control<span> engineering. Ninestates of output control dynamics are treated<span> individually. We designed dynamic controllers to stabilize the<span> parameters of an UAV. The resulting system control algorithm<span> is capable of stabilizing our UAV to perform numerous<span> operations autonomously. The estimation and simulation<span> implemented inMATLAB, Simulink to verify the results. All<span> real flight test results are presented to prove the success of<span> the planned control structure.<br /><br class="Apple-interchange-newline" /></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

scholarly journals A novel current controller design for grid-integrated PV inverter system

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Ayaz Ahmad ◽  
L. Rajaji ◽  
A. Iqbal
Keyword(s):  
Controller Design ◽  
Vital Role ◽  
Current Feedback ◽  
Lcl Filter ◽  
Design Algorithm ◽  
Grid Voltage ◽  
Pv Inverter ◽  
Current Controller ◽  
Experimental Implementation ◽  
Grid Connected Inverter

AbstractDistributed generators are playing a vital role in supporting the grid in ever-increasing energy demands. Grid code regulation must be followed when integrating the photovoltaic inverter system to the grid. The paper investigates and analyzes a controller model for grid-connected PV inverters to inject sinusoidal current to the grid with minimum distortion. To achieve better tracking and disturbance rejection, a DSP-based current controller is designed with LCL filter. The controller gets the current feedback from the grid, compares it with reference current, and calculates duty cycle to generate PWM pulses to trigger H-bridge converters. The grid voltage is loaded to the initial value in proposed PR controller to ensure the initial inverter voltage to match the grid voltage. The paper presents a novel current controller algorithm for grid-connected inverter system, and simulation is done. A detailed analysis has been carried out to validate the proposed design algorithm. Experimental implementation of the current controller in the DC/AC converter circuits with an LCL filter is done for 5.4 kW to validate and match the simulation model.

Energy Efficiency and Tracking Performance Evaluation for Dual-Mode Model Predictive Control of HVAC Systems

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Zicheng Cai ◽  
Asad A. Ul Haq ◽  
Michael E. Cholette ◽  
Dragan Djurdjanovic
Keyword(s):  
Energy Consumption ◽  
Predictive Control ◽  
Pid Control ◽  
Control Structure ◽  
Tracking Performance ◽  
System Control ◽  
Hvac System ◽  
Dual Mode ◽  
Different Types ◽  
Predictive Controller

This paper presents evaluation of the energy consumption and tracking performance associated with the use of a recently introduced dual-mode model predictive controller (DMMPC) for control of a heating, ventilation, and air conditioning (HVAC) system. The study was conducted using detailed simulations of an HVAC system, which included a multizone air loop, a water loop, and a chiller. Energy consumption and tracking performance are computed from the simulations and evaluated in the presence of different types and magnitudes of noise and disturbances. Performance of the DMMPC is compared with a baseline proportional-integral-derivative (PID) control structure commonly used for HVAC system control, and this comparison showed clear and consistent superiority of the DMMPC.

Influence analysis of the effects of an inductive-resistive weak grid over L and LCL filter current hysteresis controllers

2007 ◽  
Author(s):  
Santiago Cobreces ◽  
Emilio Bueno ◽  
Francisco J. Rodriguez ◽  
Francisco Huerta ◽  
Pedro Rodriguez
Keyword(s):  
Lcl Filter ◽  
Influence Analysis ◽  
Weak Grid
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