A Novel Multi-Functional Grid-Connected Inverter of Renewable Energy Resources

2013 ◽  
Vol 448-453 ◽  
pp. 2191-2194
Author(s):  
Lei Zhou ◽  
Hong Da Liu ◽  
Ming Jie Chen ◽  
Nai Jun Shen
Keyword(s):  
Renewable Energy ◽  
Distribution Systems ◽  
Reactive Power ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Unit Vector ◽  
Renewable Energy Resources ◽  
Point Of Common Coupling ◽  
Grid Connected Inverter ◽  
And Control

On the basis of analyzing the synthesis application of p-q (instantaneous reactive power) theory and unit vector template, a multi-functional grid-connected inverter (MFGCI) with auxiliary services on power quality enhancement in micro-grid (MG) is presented. The novel control strategy for achieving maximum benefits from these MFGCI when installed in AC MG access to 3-phase 4-wire distribution systems by isolated transformer at the point of common coupling (PCC). This kind of inverter can not only deliver the power generation of renewable energy sources (RESs), but also can perform as active power filter (APF) at their PCC as well as can improve the efficiency of inverter and decrease the hardware investment. Finally, both feasibility and effectiveness of this new topologies and control strategies of MFGCI are verified by PSCAD/EMTDC.

Operation and control of a stand-alone power system with integrated multiple renewable energy sources

2021 ◽  
pp. 0309524X2110241
Author(s):  
Nindra Sekhar ◽  
Natarajan Kumaresan
Keyword(s):  
Renewable Energy ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Solar Pv ◽  
Power Requirement ◽  
Squirrel Cage ◽  
Hysteresis Controller ◽  
Squirrel Cage Induction Generator ◽  
And Control

To overcome the difficulties of extending the main power grid to isolated locations, this paper proposes the local installation of a combination of three renewable energy sources, namely, a wind driven DFIG, a solar PV unit, a biogas driven squirrel-cage induction generator (SCIG), and an energy storage battery system. In this configuration one bi-directional SPWM inverter at the rotor side of the DFIG controls the voltage and frequency, to maintain them constant on its stator side, which feeds the load. The PV-battery also supplies the load, through another inverter and a hysteresis controller. Appropriately adding a capacitor bank and a DSTATCOM has also been considered, to share the reactive power requirement of the system. Performance of various modes of operation of this coordinated scheme has been studied through simulation. All the results and relevant waveforms are presented and discussed to validate the successful working of the proposed system.

scholarly journals Application-Oriented Reactive Power Management in German Distribution Systems Using Decentralized Energy Resources

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4949
Author(s):  
Haonan Wang ◽  
Markus Kraiczy ◽  
Denis Mende ◽  
Sebastian Stöcklein ◽  
Martin Braun
Keyword(s):  
Power Management ◽  
Distribution System ◽  
Distribution Systems ◽  
Reactive Power ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Measurement Data ◽  
Power Exchange ◽  
High Investment ◽  
Decentralized Energy

Due to higher penetration of renewable energy sources, grid reinforcements, and the utilization of local voltage control strategies, a significant change in the reactive power behavior as well as an increased demand for additional reactive power flexibility in the German power system can be predicted. In this paper, an application-oriented reactive power management concept is proposed, which allows distribution system operators (DSO) to enable a certain amount of reactive power flexibility at the grid interfaces while supporting voltage imitations in the grid. To evaluate its feasibility, the proposed concept is applied for real medium voltage grids in the south of Germany and is investigated comprehensively in different case studies. The results prove the feasibility and reliability of the proposed concept, which allows the DSO to control the reactive power exchange at grid interfaces without causing undesired local voltage problems. In addition, it can be simply adjusted and widely applied in real distribution grids without requiring high investment costs for complex information and communication infrastructures. As a significant contribution, this study provides an ideal bridging solution for DSOs who are facing reactive power issues but have no detailed and advanced monitoring system for their grid. Moreover, the comprehensive investigations in this study are performed in close cooperation with a German DSO, based on a detailed grid model and real measurement data.

scholarly journals Indices to Assess the Integration of Renewable Energy Resources on Transmission Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alexandros I. Nikolaidis ◽  
Francisco M. Gonzalez-Longatt ◽  
C. A. Charalambous
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Renewable Energy Sources ◽  
Ghg Emissions ◽  
Electrical Network ◽  
Transmission Network ◽  
Renewable Energy Resources ◽  
Continuous Increase ◽  
And Control ◽  
The Impact

The continuous increase on the penetration levels of Renewable Energy Sources (RESs) in power systems has led to radical changes on the design, operation, and control of the electrical network. This paper investigates the influence of these changes on the operation of a transmission network by developing a set of indices, spanning from power losses to GHG emissions reduction. These indices are attempting to quantify any impacts therefore providing a tool for assessing the RES penetration in transmission networks, mainly for isolated systems. These individual indices are assigned an analogous weight and are mingled to provide a single multiobjective index that performs a final evaluation. These indices are used to evaluate the impact of the integration of RES into the classic WSCC 3-machine, 9-bus transmission network.

scholarly journals Experimental Assessment of a Centralised Controller for High-RES Active Distribution Networks

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3364 ◽  
Author(s):  
Francisco García-López ◽  
Manuel Barragán-Villarejo ◽  
Alejandro Marano-Marcolini ◽  
José Maza-Ortega ◽  
José Martínez-Ramos
Keyword(s):  
Renewable Energy ◽  
Distribution System ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Distribution Networks ◽  
Energy Sources ◽  
Renewable Energy Resources ◽  
Real Time Control ◽  
Control Actions ◽  
Active Distribution Networks

This paper assesses the behaviour of active distribution networks with high penetration of renewable energy sources when the control is performed in a centralised manner. The control assets are the on-load tap changers of transformers at the primary substation, the reactive power injections of the renewable energy sources, and the active and reactive power exchanged between adjacent feeders when they are interconnected through a DC link. A scaled-down distribution network is used as the testbed to emulate the behaviour of an active distribution system with massive penetration of renewable energy resources. The laboratory testbed involves hardware devices, real-time control, and communication infrastructure. Several key performance indices are adopted to assess the effects of the different control actions on the system’s operation. The experimental results demonstrate that the combination of control actions enables the optimal integration of a massive penetration of renewable energy.

scholarly journals Hysteresis Controlled Based Power Quality Improvement in a Renewable Energy Source Connected to Utility grid with BESS Based STATCOM

2021 ◽  
Vol 7 (03) ◽  
pp. 250-255
Keyword(s):  
Renewable Energy ◽  
Digital Signal Processor ◽  
Distribution System ◽  
Distribution Systems ◽  
Fossil Fuels ◽  
Reactive Power ◽  
Neutral Current ◽  
Renewable Energy Sources ◽  
Power Converter ◽  
Energy Sources

This Paper presents a control strategy of the grid interconnected inverter Renewable Energy Sources (RES). This system can achieve the maximum benefits from these grid interconnected inverter when installed in 3-phase 4-wire distribution system. Increasing electrification of daily life causes growing electricity consumption and the rising number of sensitive or critical loads demand for high quality electricity. One of the main problems facing today is that related with the transmission and distribution of electricity. Due to the rapid increase in global energy consumption and the diminishing of fossil fuels, the customer demand for new generation capacities and efficient energy production, delivery and utilization keeps rising. Utilizing distributed generation, renewable energy and energy storage can potentially solve problems as energy shortage. With the increase in load demand, the Renewable Energy Sources (RES) are increasingly connected in the distribution systems which utilizes power electronic Converters/Inverters. The inverter can perform as a multi function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to inject power generated from RES to the grid, and 2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. All of these functions may be accomplished either individually or simultaneously. This new control concept is demonstrated with extensive MATLAB/Simulink simulation studies and validated through digital signal processor-based laboratory experimental results.

scholarly journals Performance Analysis of Three-Phase Solar PV Integrated UPQC Using Space Vector Technique

2020 ◽  
pp. 140-148
Keyword(s):  
Renewable Energy ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Energy Resources ◽  
Power Electronic ◽  
Grid System ◽  
Solar Pv ◽  
Renewable Energy Resources ◽  
Micro Grid ◽  
Micro Grids

: Due to the increase of load demand in future, the generation must also increase. The use of traditional resources such as coal, diesel fuels etc., causes global warming which is leading us to shift to renewable energy resources. Renewable energy resources may in include solar, wind, tidal as the source for production. These are used in small quantities as Distribution Generators (DG) at different locations in a bus system. As the generation of these sources is less when connected to grid, we call them as micro-grids. These micro grids generally use these DGs to distribute power to loads, and involve power electronic elements to control the generation. It induces energy into the system but also create a problem of harmonic distortions and voltage sags. To eliminate these sags and harmonics in the micro grid system caused by the power electronic devices employed by the renewable sources, we induce a UPQC (Unified Power Quality Conditioner) system. The UPQC system eliminates the harmonics in the systems and restores the voltage of the micro-grid system. We introduce a new topology called instantaneous reactive power (IRP) theory in the UPQC control to operate in a more efficient way, by utilizing RES (Renewable Energy Sources) at the DC-link. The RES support the UPQC system by injecting the active power generated by the resources through DC-link.

scholarly journals Optimal Power Flow Techniques under Characterization of Conventional and Renewable Energy Sources: A Comprehensive Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Baseem Khan ◽  
Pawan Singh
Keyword(s):  
Renewable Energy ◽  
Transmission Lines ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Reactive Power Optimization ◽  
Optimal Power ◽  
And Control

The exhaustive knowledge of optimal power flow (OPF) methods is critical for proper system operation and planning, since OPF methods are utilized for finding the optimal state of any system under system constraint conditions, such as loss minimization, reactive power limits, thermal limits of transmission lines, and reactive power optimization. Incorporating renewable energy sources optimized the power flow of system under different constraints. This work presents a comprehensive study of optimal power flows methods with conventional and renewable energy constraints. Additionally, this work presents a progress of optimal power flow solution from its beginning to its present form. Authors classify the optimal power flow methods under different constraints condition of conventional and renewable energy sources. The current and future applications of optimal power flow programs in smart system planning, operations, sensitivity calculation, and control are presented. This study will help the engineers and researchers to optimize power flow with conventional and renewable energy sources.

A Reference Compensation Current Control of Grid-Connected Inverter for Three-Phase Distributed Generators

2013 ◽  
Vol 433-435 ◽  
pp. 1183-1187 ◽  
Author(s):  
Shao Ru Zhang ◽  
Shao Yuan Li
Keyword(s):  
Control Strategy ◽  
Distribution Systems ◽  
Reactive Power ◽  
Neutral Current ◽  
Power Converter ◽  
Active Power ◽  
Current Control ◽  
Renewable Energy Resources ◽  
Current Harmonics ◽  
Grid Connected Inverter

Renewable energy resources (RES) are being increasingly connected in distribution systems by utilizing power electronic converters. However, the extensive use of power electronics has resulted in a rise in power quality (PQ) concerns faced by the utility. A novel control strategy implementing reference compensation current was proposed in this paper. So that these grid-connected inverters can achieve maximum benefits when they installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to transfer active power from RES to the grid, and 2) load reactive power demand support; 3) current harmonics compensation at PCC; and 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. Simulation results show the validity and capability of the novel proposed control strategy.

scholarly journals Review and Comparison of Grid-Tied Inverter Controllers in Microgrids

2020 ◽  
Author(s):  
Tommaso Caldognetto
Keyword(s):  
Power Distribution ◽  
Distribution Systems ◽  
Low Voltage ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Electrical Power ◽  
Voltage Source ◽  
Smart Power ◽  
Operating Modes ◽  
Grid Connected Inverter

<div><div><div><p>Grid-tied inverters are widely used for interfacing renewable energy sources or storage devices to low-voltage electrical power distribution systems. Lately, a number of different control techniques have been proposed to address the emerging requirements of the smart power system scenario, in terms of both functionalities and performance. This paper reviews the techniques proposed for the implementation of current-controlled or voltage-controlled inverters in microgrids. By referring to a voltage source inverter with LCL output filter, the different control architectures are classified as single-, double-, and triple- loop. Then, the functionalities that are needed or recommended in the grid-connected, islanded, and autonomous operating modes of the grid-tied inverter are identified and their implementation in the different control structures is discussed. To validate the analysis and to better illustrate the merits and limitations of the most effective solutions, six control strategies are finally implemented and experimentally compared on a single-phase, grid-connected inverter setup.</p></div></div></div>

scholarly journals VOLTAGE STABILITY INVESTIGATION OF GRID CONNECTED WIND FARM

2009 ◽  
Vol 12 (8) ◽  
pp. 38-46
Author(s):  
Chuong Trong Trinh
Keyword(s):  
Wind Power ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Wind Farm ◽  
Reactive Power ◽  
Stability Limit ◽  
Theoretical Expression ◽  
Renewable Energy Resources ◽  
Point Of Common Coupling ◽  
The Impact

At present, it is very common to find renewable energy resources, especially wind power, connected to distribution systems. The impact of this wind power on voltage distribution levels has been addressed in the literature. The majority of this works deals with the determination of the maximum active and reactive power that is possible to be connected on a system load bus, until the voltage at that bus reaches the voltage collapse point. It is done by the traditional methods of P-V curves reported in many references. Theoretical expression of maximum power limited by voltage stability transfer through a grid is formulated using an exact representation of distribution line with ABCD parameters. The expression is used to plot PV curves at various power factors of a radial system. Limited values of reactive power can be obtained. This paper presents a method to study the relationship between the active power and voltage (PV) at the load bus to identify the voltage stability limit. It is a foundation to build a permitted working operation region in complying with the voltage stability limit at the point of common coupling (PCC) connected wind farm.

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