scholarly journals Impedance-Based Interactions in Grid-Tied Three-Phase Inverters in Renewable Energy Applications

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 464 ◽  
Author(s):  
Teuvo Suntio ◽  
Tuomas Messo ◽  
Matias Berg ◽  
Henrik Alenius ◽  
Tommi Reinikka ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Experimental Measurements ◽  
Stability Assessment ◽  
Transient Performance ◽  
Energy Applications ◽  
Impedance Ratio ◽  
Three Phase ◽  
The Cross ◽  
And Performance ◽  
The Stability

Impedance-ratio-based interaction analyses in terms of stability and performance of DC-DC converters is well established. Similar methods are applied to grid-connected three-phase converters as well, but the multivariable nature of the converters and the grid makes these analyses very complex. This paper surveys the state of the interaction analyses in the grid-connected three-phase converters, which are used in renewable-energy applications. The surveys show clearly that the impedance-ratio-based stability assessment are usually performed neglecting the cross-couplings between the impedance elements for reducing the complexity of the analyses. In addition, the interactions, which affect the transient performance, are not treated usually at all due to the missing of the corresponding analytic formulations. This paper introduces the missing formulations as well as explicitly showing that the cross-couplings of the impedance elements have to be taken into account for the stability assessment to be valid. In addition, this paper shows that the most accurate stability information can be obtained by means of the determinant related to the associated multivariable impedance ratio. The theoretical findings are also validated by extensive experimental measurements.

scholarly journals Coupling Influence on the dq Impedance Stability Analysis for the Three-Phase Grid-Connected Inverter

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3676
Author(s):  
Chuanyue Li ◽  
Taoufik Qoria ◽  
Frederic Colas ◽  
Jun Liang ◽  
Wenlong Ming ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Nyquist Plot ◽  
Current Control ◽  
Impedance Ratio ◽  
Three Phase ◽  
Grid Impedance ◽  
Nyquist Criterion ◽  
Grid Connected Inverter ◽  
The Stability ◽  
The Right

The dq impedance stability analysis for a grid-connected current-control inverter is based on the impedance ratio matrix. However, the coupled matrix brings difficulties in deriving its eigenvalues for the analysis based on the general Nyquist criterion. If the couplings are ignored for simplification, unacceptable errors will be present in the analysis. In this paper, the influence of the couplings on the dq impedance stability analysis is studied. To take the couplings into account simply, the determinant-based impedance stability analysis is used. The mechanism between the determinant of the impedance-ratio matrix and the inverter stability is unveiled. Compared to the eigenvalues-based analysis, only one determinant rather than two eigenvalue s-function is required for the stability analysis. One Nyquist plot or pole map can be applied to the determinant to check the right-half-plane poles. The accuracy of the determinant-based stability analysis is also checked by comparing with the state-space stability analysis method. For the stability analysis, the coupling influence on the current control, the phase-locked loop, and the grid impedance are studied. The errors can be 10% in the stability analysis if the couplings are ignored.

scholarly journals Three phase modular multilevel inverter-based multi-terminal asymmetrical DC inputs for renewable energy applications

2020 ◽  
Vol 23 (4) ◽  
pp. 831-839 ◽  
Author(s):  
Taiea A. Ahmed ◽  
Essam E.M. Mohamed ◽  
Abdel-Raheem Youssef ◽  
A.A. Ibrahim ◽  
Mahmoud S.R. Saeed ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Multilevel Inverter ◽  
Energy Applications ◽  
Three Phase

scholarly journals An enhanced 17-level hybridized multilevel inverter with stair case modulation

2020 ◽  
Vol 11 (4) ◽  
pp. 1872
Author(s):  
Hemalatha Javvaji ◽  
Basavaraja Banakara
Keyword(s):  
Renewable Energy ◽  
Solid State ◽  
Power Consumption ◽  
Output Voltage ◽  
Multilevel Inverter ◽  
Energy Applications ◽  
Multi Level ◽  
Simulation Results ◽  
And Performance ◽  
Cascaded Multilevel Inverter

This paper proposes a Hybridized Symmetric Cascaded Multilevel Inverter for voltage levels ranging from 5 levels to 17 levels. The proposed Multi Level Inverter (MLI) topology is built using a modified H-bridge inverter that results in an increased output voltage levels with a smaller number of solid-state switches. This technique enhances the h-bridge configuration from three level to five level by means of a bi-directional switch at source. Gating pulses of hybridized symmetric MLI are generated through staircase modulation. The operation and performance of the proposed topology is tested for different output voltage levels, simulation results prove that the proposed technique results in less THD at all levels with lesser power consumption and are easily applicable for renewable energy applications.

scholarly journals Speckle Cross-Correlation Method in Measuring Fine Surface Displacements

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. Bahrawi ◽  
N. Farid ◽  
M. Abdel-Hady
Keyword(s):  
Cross Correlation ◽  
Correlation Method ◽  
Industrial Applications ◽  
Correlation Technique ◽  
Surface Displacements ◽  
Speckle Patterns ◽  
The Cross ◽  
And Performance ◽  
The Stability ◽  
Cross Correlation Technique

Industrial applications need regular testing for the lifetime, movement, strength, and performance of manufacturing machines during production process. Since speckle photography is a simple economic technique, it is used in investigating object response under mechanical and thermal effects depending on the movement of the speckle patterns with respect to the deformation strength and direction. In the present work, the cross-correlation technique is used to analyze the speckle patterns by iterative method to define both values and directions of rigid body translation and expansion. In order to check the accuracy of the cross-correlation technique, the results are compared with the displacement values given by analyzing the Young's interference fringes resulted from the Fourier transformation of the speckle patterns. This noncontact technique is found to be accurate and informative depending on the stability and sensitivity of the optical system. This method of measurement is an effective tool in studying the hard cases of objects and machines under various effects.

Nonlinear adaptive control of grid-connected three-phase inverters for renewable energy applications

2015 ◽  
Vol 90 (1) ◽  
pp. 53-67 ◽  
Author(s):  
N. Mahdian-Dehkordi ◽  
M. Namvar ◽  
H. Karimi ◽  
P. Piya ◽  
M. Karimi-Ghartemani
Keyword(s):  
Adaptive Control ◽  
Renewable Energy ◽  
Nonlinear Adaptive Control ◽  
Energy Applications ◽  
Three Phase

scholarly journals Minimization of Cross-Regulation in PV and Battery Connected Multi-Input Multi-Output DC to DC Converter

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6534
Author(s):  
Vibha Kamaraj ◽  
N. Chellammal ◽  
Bharatiraja Chokkalingam ◽  
Josiah Lange Munda
Keyword(s):  
Renewable Energy ◽  
Hybrid System ◽  
Mimo Systems ◽  
Mimo System ◽  
Energy Resource ◽  
Renewable Energy Resources ◽  
Speed Of Response ◽  
The Cross ◽  
Predicted Values ◽  
The Stability

This paper proposes a digital model predictive controller (DMPC) for a multi-input multi-output (MIMO) DC-DC converter interfaced with renewable energy resources in a hybrid system. Such MIMO systems generally suffer from cross-regulation, which seriously impacts the stability and speed of response of the system. To solve the contemporary issues in a MIMO system, a controller is required to attenuate the cross-regulation. Therefore, this paper proposes a controller, which increases speed of response and maintains stable output by regulating the load voltage independently. The inductor current and the capacitor voltage of the proposed converter are considered as the controlling parameters. With the aid of Forward Euler’s procedure, the future values are computed for the instantaneous values of controlling parameters. Cost function defines the control action by the predicted values that describe the system performance and establish optimal condition at which the output of the system is required. This allows proper switching of the system, thereby helping to regulate the output voltages. Thus, for any variation in load, the DMPC ensures steady switching operation and minimization of cross-regulation. To prove the efficacy of proposed DMPC controller, simulations followed by the experimental results are executed on a hybrid system consisting of dual-input dual-output (DIDO) positive Super-Lift Luo converter (PSLLC) interfaced with photovoltaic renewable energy resource. The results thus obtained are compared with the conventional PID (proportional integrative derivative) controller for validation and prove that the DMPC controller is able to control the cross-regulation effectively.

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