In the proposed paper, it is described how a Solar PV Farm along with a battery storage system can be used to regulate grid voltage in a PV-Wind integrated distributed generation System.
At night time Solar PV system is normally dormant (i.e. it does not generate power) but the stored power in batteries can be utilised efficiently to regulate the common coupling voltage by means of a FACTS based Static Synchronous Compensator (STATCOM) thereby improving the power quality.
Various Utilities are facing major issues with Grid Integration of various types of Renewable Energy Distributed Systems while ensuring power quality ,Regulation and Stability. During day time the inverter of PV system provides the power to Grid but during night time PV farm is inactive and stored energy in the batteries can be used as power source to PV inverter for implementing a STATCOM.
with advancements in RES and increasing DG systems to provide for load demand the quality of power has to be maintained to optimum value and this paper focuses purely on improving regulation of voltage without using external regulation devices but the installed RES system.
In order to implement and validate the concept of the prescribed paper SIMULINK Tool has been used.
Table of Contents
I. INTRODUCTION
II. DG SYSTEM OVERVIEW
III. SOLAR PV FARM AS A BATTERY CHARGER
IV. DOUBLE FED INDUCTION GENERATOR
V. STATCOM
VI. CONTROL SCHEME FOR PV INVERTER
VII. SIMULATION RESULTS
VIII. CONCLUSION
IX. REFERENCES
Research Objectives and Key Topics
The primary objective of this research is to investigate a method for regulating grid voltage in an integrated wind and solar PV distributed generation system, specifically by utilizing the PV solar farm's inverter as a STATCOM during nighttime when it is otherwise inactive.
- Voltage regulation in integrated wind-PV systems
- Utilization of existing PV inverters as STATCOM devices
- Mitigation of grid instability during nighttime
- Modeling of doubly fed induction generators (DFIG)
- Simulation and validation using MATLAB/SIMULINK
Excerpt from the Book
IV. DOUBLE FED INDUCTION GENERATOR
The Double Fed Induction Generator (DFIG) is a generating principle widely used in wind turbines. It is based on an induction generator with a multiphase wound rotor and a multiphase slip ring assembly with brushes for access tothe rotor windings. It is possible to avoid the multiphase slip ring assembly but there are problems with efficiency, cost and size. A better alternative is a brushless wound-rotor doubly-fed electric machine.The principle of the DFIG is that the rotor windings are connected to the grid via slip rings and the back-to-back voltage source converter that controls both the rotor and the grid currents. Thus rotor frequency can freely differ from the grid frequency (50 or 60 Hz). By using the converter to control the rotor currents, it is possible to adjust the active and reactive power fed to the grid from the stator independently of the generator's turning speed. The control principle used is either the two-axis current vector control or direct torque control (DTC). DTC has turned out to have better stability than current vector control, especially when high reactive currents are required from the generator.
Summary of Chapters
I. INTRODUCTION: Discusses the challenges of integrating large-scale renewable energy systems into transmission grids and proposes using the existing PV infrastructure as a voltage regulation device.
II. DG SYSTEM OVERVIEW: Provides the technical configuration of the integrated wind energy and PV system, including the modeling of the wind farm and solar farm components.
III. SOLAR PV FARM AS A BATTERY CHARGER: Explains the operational modes of a solar farm during nighttime, focusing on how a bidirectional inverter and storage battery can be utilized.
IV. DOUBLE FED INDUCTION GENERATOR: Details the mechanism and control principles of the DFIG, which is the primary generation technology used in the wind turbines studied.
V. STATCOM: Describes the function of a Static Synchronous Compensator as an advanced device for reactive power compensation and voltage profile improvement.
VI. CONTROL SCHEME FOR PV INVERTER: Outlines the PI-based voltage-regulation loops and phase-locked loop (PLL) synchronization used to control the inverter.
VII. SIMULATION RESULTS: Presents the findings from the SIMULINK-based study, comparing normal conditions against fault scenarios at the 25kV bus.
VIII. CONCLUSION: Summarizes the effectiveness of the proposed strategy in maintaining grid stability without needing additional dedicated hardware.
Keywords
Renewable Energy, Distributed Generation, Solar PV Farm, Wind Energy, STATCOM, Voltage Regulation, Battery Storage, Doubly Fed Induction Generator, Power Quality, MATLAB, SIMULINK, Inverter Control, Grid Integration, Reactive Power, Transmission Grids.
Frequently Asked Questions
What is the core focus of this research paper?
The paper focuses on improving grid voltage regulation in an integrated wind and solar PV system by utilizing the PV inverter as a STATCOM during the night.
What are the central thematic areas?
The study centers on renewable energy integration, power electronics, distributed generation stability, and active/reactive power control strategies.
What is the primary objective or research question?
The primary goal is to validate if an existing solar farm inverter can be repurposed as a STATCOM to regulate PCC voltage during nighttime without installing additional expensive regulation devices.
Which scientific methodology is employed?
The authors use mathematical modeling of renewable systems and conduct computer-based simulation experiments using the MATLAB/SIMULINK software tool.
What content is covered in the main body?
The main body covers the integration of wind and PV systems, the role of DFIGs, the design of the STATCOM, control schemes for inverters, and the simulation results under various grid conditions.
Which keywords best characterize this work?
Key terms include Distributed Generation, STATCOM, Voltage Regulation, PV-Wind Integration, and Power Electronics.
How does the system behave during a grid fault?
According to the simulation results, the PV array STATCOM is activated at 1 second during a fault, successfully compensating and restoring the system to normal conditions after 1.2 seconds.
What is the benefit of the DFIG technology mentioned in the study?
The DFIG allows for variable speed operation, which enables maximum energy extraction from wind for varying wind speeds, while optimizing turbine efficiency.
Why is the PV solar farm typically considered inactive at night?
Solar PV systems generate power only when sunlight is available; during the night, they do not produce real power and their inverters would typically remain unutilized.
- Quote paper
- Shrey Naik (Author), Varun Pratapsinha Jadhav (Author), 2014, Regulation Of Grid Voltage using an integrated Wind-PV system as STATCOM in Distributed Generation systems., Munich, GRIN Verlag, https://www.hausarbeiten.de/document/283560
