A New Compensation Control Strategy for Grid-connected Wind Turbine and Fuel Cell Inverters in a Microgrid

2017 ◽  
Vol 8 (1) ◽  
pp. 272 ◽  
Author(s):  
A. Naderipour ◽  
A. A. Mohd Zin ◽  
M. H. Habibuddin ◽  
M. Moradi ◽  
M. Miveh ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Wind Turbine ◽  
Distributed Generation ◽  
Control Method ◽  
Harmonic Distortion ◽  
Synchronous Reference Frame ◽  
Wide Range ◽  
Point Of Common Coupling ◽  
Frame Method ◽  
Common Coupling

The use of a new control method for grid-connected inverters for reducing the output current harmonic distortion in a wide range of grid-connected distributed generation (DG) applications, including wind turbine (WT) and fuel cell (FC) inverters is proposed in this paper. The control method designed to eliminate main harmonics in a microgrid (MG) and between MG and point of common coupling (PCC) and responsible for the correction of the system unbalance. Another advantage of the proposed control method is that it can be easily adopted into the DG control system without the installation of extra hardware. The proposed control method is comprised of the synchronous reference frame method (SRF). Results from the proposed control method are provided to show the feasibility of the proposed approach.

scholarly journals A Proposed Harmonic Monitoring System for Large Power Users Considering Harmonic Limits

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4507
Author(s):  
Rosalia Sinvula ◽  
Khaled Mohamed Abo-Al-Ez ◽  
Mohamed Tariq Kahn
Keyword(s):  
Monitoring System ◽  
Renewable Energy Sources ◽  
Electronic Devices ◽  
Harmonic Distortion ◽  
Large Power ◽  
High Penetration ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
Power Utilities ◽  
The Individual

Most power utilities within Southern Africa are faced with the challenges of harmonic distortion due to the high penetration of renewable energy sources (RES) and the use of electronic devices. There is an excessive total harmonic distortion (THD) measured at the point of common coupling (PCC). In this paper, a proposed harmonic monitoring system for large power users (LPUs) is developed. This proposed system considers harmonic limits of the individual and THD of the customers allowed injecting into the network, which should be part of the contractual electricity supply agreement (ESA). Hence, it will enable the monitoring of harmonic distortion to be smooth by determining whether the customer has passed or failed compliance for individual harmonic order and the THD of the voltage. The measurements of harmonic distortion are done using the Unipower power quality (PQ) analyzers that are connected at different points within the industrial network. Measurements of harmonic distortion of an industrial site are compared to the simulation results performed by DIgSILENT software to validate the proposed harmonic monitoring system. Based on the validation results, it is recommended that the ESA between the power utilities and the customers should consist of the harmonic limits.

Experimental verification of DSTATCOM for various non-linear load

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pushpanjali Shadangi ◽  
Sushree Diptimayee Swain ◽  
Pravat Kumar Ray ◽  
Gayadhar Panda
Keyword(s):  
Fuzzy Logic Controller ◽  
Harmonic Distortion ◽  
Pattern Generation ◽  
Total Harmonic Distortion ◽  
Synchronous Reference Frame ◽  
Linear Load ◽  
Hysteresis Controller ◽  
Frame Method ◽  
Non Linear Load ◽  
Static Compensator

Abstract This paper elaborates a hybrid synchronous reference frame method has been proposed for the distribution static compensator (DSTATCOM) to enhance the compensation performance. This controller is designed in such a way that it generate the reference with respect to the change in load to reject the harmonics. Furthermore, a hysteresis controller is employed for switching pattern generation. Fuzzy logic controller is also implemented in MATLAB/simulink environment here to analyze the total harmonic distortion. Experimental analysis of the DSTATCOM demonstrates the potency and reliability of proposed controller over existing control strategy in the from of total harmonic distortion.

scholarly journals Admittance Reshaping Control Methods to Mitigate the Interactions between Inverters and Grid

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2457 ◽  
Author(s):  
Ling Yang ◽  
Yandong Chen ◽  
An Luo ◽  
Kunshan Huai
Keyword(s):  
Design Method ◽  
Harmonic Distortion ◽  
Response Speed ◽  
Control Methods ◽  
Dynamics Model ◽  
Specific Design ◽  
Three Phase ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
System Phase

With the increasing impedance coupling between inverters and grid caused by the phase-locked loop (PLL), traditional three-phase inverters suffer from the harmonic distortion or instability problems under weak grid conditions. Therefore, the admittance reshaping control methods are proposed to mitigate the interactions between inverters and grid. Firstly, a dynamics model of traditional inverter output admittance including main circuit and PLL is developed in the direct-quadrature (dq) frame. And the qq channel impedance of the inverter presents as a negative incremental resistance with the PLL effect. Secondly, two admittance reshaping control methods are proposed to improve the system damping. The first reshaping technique uses the feedforward point of common coupling (PCC) voltage to modify the inverter output admittance. The second reshaping technique adopts the active damping controller to reconstruct the PLL equivalent admittance. The proposed control methods not only increase the system phase margin, but also ensure the system dynamic response speed. And the total harmonic distortion of steady-state grid-connected current is reduced to less than 2%. Furthermore, a specific design method of control parameters is depicted. Finally, experimental results are provided to prove the validity of the proposed control methods.

scholarly journals Experimental Study of the Summation of Flicker Caused by Wind Turbines

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2404 ◽  
Author(s):  
Koldo Redondo ◽  
José Julio Gutiérrez ◽  
Izaskun Azcarate ◽  
Purificación Saiz ◽  
Luis Alberto Leturiondo ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Wind Power Plant ◽  
International Electrotechnical Commission ◽  
Type I ◽  
Electrical Characteristics ◽  
Voltage Fluctuations ◽  
Type Iii ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
Better Than

Integration of wind energy into the grid faces a great challenge regarding power quality. The International Electrotechnical Commission (IEC) 61400-21 standard defines the electrical characteristics that need to be assessed in a Wind Turbine (WT), as well as the procedure to measure the disturbances produced by the WT. One of the parameters to be assessed are voltage fluctuations or flicker. To estimate the flicker emission of a Wind Power Plant (WPP), the standard establishes that a quadratic exponent should be used in the summation of the flicker emission of each WT. This exponent was selected based on studies carried out in WPPs with type I and II WTs. Advances in wind turbine technology have reduced their flicker emission, mainly thanks to the implementation of power electronics for the partial or total management of the power injected into the grid. This work is based on measurements from a WPP with 16 type III WTs. The flicker emission of a single WT and of the WPP were calculated. Low flicker emission values at the Point of Common Coupling (PCC) of the WPP were obtained. The flicker estimation at the PCC, based on the measurement from a single WT, was analyzed using different exponents. The results show that a cubic summation performs better than the quadratic one in the estimation of the flicker emission of a WPP with type III WTs.

DOE FE Distributed Generation Program

2004 ◽  
Vol 1 (1) ◽  
pp. 18-20 ◽  
Author(s):  
Mark C. Williams ◽  
Bruce R. Utz ◽  
Kevin M. Moore
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Distributed Generation ◽  
High Efficiency ◽  
High Reliability ◽  
National Laboratory ◽  
Pacific Northwest National Laboratory ◽  
Hydrogen Economy ◽  
Wide Range ◽  
The U.S

The U.S. Department of Energy’s (DOE) Office of Fossil Energy’s (FE) National Energy Technology Laboratory (NETL), in partnership with private industries, is leading the development and demonstration of high efficiency solid oxide fuel cells (SOFCs) and fuel cell turbine hybrid power generation systems for near term distributed generation (DG) markets with an emphasis on premium power and high reliability. NETL is partnering with Pacific Northwest National Laboratory (PNNL) in developing new directions in research under the Solid-State Energy Conversion Alliance (SECA) initiative for the development and commercialization of modular, low cost, and fuel flexible SOFC systems. The SECA initiative, through advanced materials, processing and system integration research and development, will bring the fuel cell cost to $400 per kilowatt (kW) for stationary and auxiliary power unit (APU) markets. The President of the U.S. has launched us into a new hydrogen economy. The logic of a hydrogen economy is compelling. The movement to a hydrogen economy will accomplish several strategic goals. The U.S. can use its own domestic resources—solar, wind, hydro, and coal. The U.S. uses 20 percent of the world’s oil but has only 3 percent of resources. Also, the U.S. can reduce green house gas emissions. Clear Skies and Climate Change initiatives aim to reduce carbon dioxide (CO2), nitrogen oxides (NOx), and sulfur dioxide (SO2) emissions. SOFCs have no emissions, so they figure significantly in these DOE strategies. In addition, DG—SOFCs, reforming, energy storage—has significant benefit for enhanced security and reliability. The use of fuel cells in cars is expected to bring about the hydrogen economy. However, commercialization of fuel cells is expected to proceed first through portable and stationary applications. This logic says to develop SOFCs for a wide range of stationary and APU applications, initially for conventional fuels, then switch to hydrogen. Like all fuel cells, the SOFC will operate even better on hydrogen than conventional fuels. The SOFC hybrid is a key part of the FutureGen plants. FutureGen is a major new Presidential initiative to produce hydrogen from coal. The highly efficient SOFC hybrid plant will produce electric power and other parts of the plant could produce hydrogen and sequester CO2. The hydrogen produced can be used in fuel cell cars and for SOFC DG applications.

scholarly journals Study and modelling of droop-controlled islanded mesh microgrids

2021 ◽  
Vol 280 ◽  
pp. 05015
Author(s):  
Youssef Hennane ◽  
Abdelmajid Berdai ◽  
Serge Pierfederici ◽  
Farid Meibody-Tabar ◽  
Vitaliy Kuznetsov
Keyword(s):  
Distributed Generation ◽  
Reactive Power ◽  
Control Method ◽  
Logical Consequence ◽  
Single Point ◽  
State Space Model ◽  
Power Sharing ◽  
Active And Reactive Power ◽  
High Penetration ◽  
Point Of Common Coupling

The active and reactive power sharing of distributed generation sources (DGs) connected to isolated microgrids with a single point of common coupling (mono-PCC) to which the loads are also connected has already been the subject of several studies. A high penetration rate of DGs based on renewable energies has as a logical consequence the development and implementation of mesh and more complex multi- PCC microgrids. In this paper, a developed droop control method for synchronization and power sharing between different DGs connected to a mesh islanded multi-PCC microgrid with many distributed generation sources (DGs) and different type of loads (including active load (CPL)) randomly connected to different PCCs is applied. Then, a state model of the entire mesh microgrid is developed integrating the generators with their controllers, power lines, droop algorithms and dynamic loads. This model is then used to study the asymptotic stability and robustness properties of the system. The simulation results confirm the effectiveness of the applied strategies for the synchronization of the different DGs to the microgrid while ensuring an efficient active and reactive power sharing. also, they confirm the validity of the developed state space model of the system.

scholarly journals Generation of Optimal Switching Angle for Nine Level Cascaded H Bridge MLI Using Most Valuable Player Algorithm

2021 ◽  
Vol 12 (6) ◽  
pp. 1919-1927
Author(s):  
Vijaya Anand N, Hema Latha J, G Devadasu, Kumar C
Keyword(s):  
Reactive Power ◽  
Harmonic Distortion ◽  
Voltage Level ◽  
Computing Technique ◽  
Power Exchange ◽  
Point Of Common Coupling ◽  
Terminal Voltage ◽  
Common Coupling ◽  
Micro Grids

Distributed generation (DG) sources often interfaced with grid by a Cascaded H-bridge multilevel inverter with a remote D.C source. The interface inverter has to adapt voltage on the either side of the grid and DG source while it has a control of active and reactive power exchange. The inverter terminal voltage is maintained based on frequency switching technique. However, in applications like micro grids are based on quality of output voltage at the point of common coupling. The present paper discusses an optimal frequency switching methodology that generates optimal fringing angle based on an evolutionary computing technique while maintaining the voltage level at PCC with a reduced harmonic distortion.  Efficacy of the proposed method is illustrated by simulating a 9-level cascaded H bridge in MATLAB environment.

Reduced Rating 30-pulse AC-DC Converter for Power Quality Improvement

2017 ◽  
Vol 6 (3) ◽  
pp. 199 ◽  
Author(s):  
Rohollah Abdollahi
Keyword(s):  
Power Quality ◽  
Harmonic Distortion ◽  
Design Procedure ◽  
Quality Criteria ◽  
Motor Drives ◽  
Unity Power Factor ◽  
Wide Range ◽  
Bridge Rectifier ◽  
Power Quality Improvement ◽  
Point Of Common Coupling

This paper presents the design and analysis of a novel polygon connected autotransformer based 30-phase ac-dc converter which supplies Direct Torque Controlled Induction Motor Drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling. The proposed converter output voltage is accomplished via three paralleled 10- pulse ac-dc converters each of them consisting of 5-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The proposed converter requires only three inter-phase transformers in the dc link that leads to the reduced kilovolt ampere rating, size, weight, and cost of the proposed rectifier. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse and proposed converters from view point of power quality indices. Results show that input current Total Harmonic Distortion (THD) is less than 3% for the proposed topology at variable loads.

Sign in / Sign up

Export Citation Format

Share Document