scholarly journals FRT and Transient Stability Augmentation of Grid-Connected PV Station Using Virtual Synchronous Generator

2021 ◽  
Vol 20 (4) ◽  
pp. 118-126
Author(s):  
Md. Kamrul Islam ◽  
Mohammad Abdul Mannan ◽  
Md. Rifat Hazari
Keyword(s):  
Control System ◽  
Power System ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Synchronous Generator ◽  
Frequency Stability ◽  
Pv System ◽  
Damping Characteristics ◽  
Grid Codes ◽  
Virtual Synchronous Generator

Due to the extensive integration of renewable energy sources (RESs), i.e., photovoltaic (PV) system, the future power system is developing into an inverter-based system from a dominated alternator-based power system. This massive penetration of inverter-based PV system reduced the system inertia and damping characteristics of the power grid, impacting the fault ride-through (FRT) capability and causes frequency instability. Modern grid codes require that PV systems should work in the same way as conventional power plants and assist the system during transient state. However, most of the conventional inverter control mechanisms failed to fulfill the requirements of grid codes, especially when the penetration ratio of the PV system is close to the conventional unit. Therefore, this paper proposes a virtual synchronous generator (VSG) control mechanism of PV system inverter to augment FRT competency and frequency stability. The proposed VSG control system mimics the behavior of conventional power plants. To observe and evaluate the proposed controller behavior, simulation analyses were executed in the PSCAD/EMTDC software for both proposed and conventional controllers. The simulation results clearly indicate that the proposed VSG control system has sufficient damping characteristics to ensure FRT capability and frequency stability.       

scholarly journals Inertia Theory Frequency Dynamic Analysis and Control of Power System with High Proportion of Renewable Source

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Badar ul Islam ◽  
Zuhairi Baharudin ◽  
Parameshwari Kattel
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Frequency Stability ◽  
Test System ◽  
Energy Sources ◽  
Power Imbalance ◽  
Pv System ◽  
System Inertia

Power plant emissions are a major cause of pollution in the environment. This necessitates the progressive replacement of conventional power plants with renewable energy sources. Changes in the quotas for conventional generating and renewable energy sources present new issues for modern power networks for example photovoltaic and wind turbines are replacing conventional power plants, which do not add to system inertia and due to the earth’s diurnal cycle and weather conditions. Solar radiations are not consistent all through the day, and photovoltaic (PV) generation is sometimes insufficient to meet the power requirement of the shifting local load. The amount of inertia in the power system, as well as the action of adjustable frequency reserves and the amount of power imbalance, all have an impact on frequency stability. As a result, estimating power system inertia and assessing frequency response are required so that necessary actions can be taken to assure frequency stability. In this way, the system frequency, power, and voltage stability are the major issues when high proportion of renewables are added. In this paper, we explained estimating power system inertia-related frequency problems. The approach account for the frequency and voltage fluctuations that occur after a disturbance and estimate the system’s total inertia constant as well as its overall power imbalance. The anticipated technique based on computational intelligence is used to analyze frequency responses from simulations of a test system under various circumstances on SIMULINK and focuses on the standalone PV system is critical for controlling it. As a result, the modelling of a PV system, battery, and generator using analogous circuits is discussed. As a matter of fact, maximum power should be harvested from a PV array to increase its efficiency that is depicted from the result outcomes of this research.

scholarly journals Renewable Energy System on Frequency Stability Control Strategy Using Virtual Synchronous Generator

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1697 ◽  
Author(s):  
Lingling Li ◽  
Hengyi Li ◽  
Ming-Lang Tseng ◽  
Huan Feng ◽  
Anthony S. F. Chiu
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Large Scale ◽  
Synchronous Generator ◽  
Frequency Stability ◽  
Stability Control ◽  
System Stability ◽  
Generator System ◽  
System Frequency ◽  
Virtual Synchronous Generator

This study constructs a novel virtual synchronous generator system based on a transfer function, and optimizes the parameters of the model by using the improved whale algorithm to improve the frequency control ability of virtual synchronous generator. Virtual synchronous generator technology helps to solve the problem that the integration of large-scale renewable energy generation into the power system leads to the deterioration of system frequency stability. It can maintain the symmetry of grid-connected scale and system stability. The virtual synchronous generator technology makes the inverter to have the inertia and damping characteristics of a synchronous generator. The inverter has the inertia characteristics and damps to reduce the frequency instability of high penetration renewable energy power system. The improved whale algorithm is efficient to find the best combination of control parameters and the effectiveness of the algorithm is verified by microgrid and power system. The results show that the proposed frequency coordination control scheme suppresses the frequency deviation of power system and keep the system frequency in a reasonable range.

Research on Grid-Connected Photovoltaic Power System Based on Virtual Synchronous Generator

2014 ◽  
Vol 703 ◽  
pp. 343-347
Author(s):  
Ya Yun Guan ◽  
Yu Xin Sun ◽  
Kai Shi ◽  
Huang Qiu Zhu ◽  
Xian Xing Liu
Keyword(s):  
Power System ◽  
Synchronous Generator ◽  
Solar Photovoltaic ◽  
Pv System ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
The Mathematical Model ◽  
Virtual Synchronous Generator

In order to realize the solar photovoltaic (PV) system connecting with grid friendly, a PV system with voltage-controlled inverter based on virtual synchronous generator (SG) is presented. This kind of system has features of SG, which supply the virtual moment of inertia to grid. The mathematical model of PV and virtual SG is built, and the control strategy of the maximum power point tracking (MPPT) is also studied in the paper. Simulation model of the grid-connected PV power system is built on Matlab/Simulink. Finally, correctness and feasibility of this system are verified by simulation results.

scholarly journals A New Virtual Synchronous Generator Design Based on the SMES System for Frequency Stability of Low-Inertia Power Grids

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5641
Author(s):  
Gaber Magdy ◽  
Abualkasim Bakeer ◽  
Morsy Nour ◽  
Eduard Petlenkov
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Power Grid ◽  
Renewable Energy Sources ◽  
Synchronous Generator ◽  
Frequency Stability ◽  
Power Grids ◽  
Renewable Power ◽  
Utility Grid ◽  
Virtual Synchronous Generator

In light of the challenges of integrating more renewable energy sources (RESs) into the utility grid, the virtual synchronous generator (VSG) will become an indispensable configuration of modern power systems. RESs are gradually replacing the conventional synchronous generators that are responsible for supplying the utility grid with the inertia damping properties, thus renewable power grids are more vulnerable to disruption than traditional power grids. Therefore, the VSG is presented to mimic the behavior of a real synchronous generator in the power grid through the virtual rotor concept (i.e., which emulates the properties of inertia and damping) and virtual primary and secondary controls (i.e., which emulate the conventional frequency control loops). However, inadequate imitation of the inertia power owing to the low and short-term power of the energy storage systems (ESSs) may cause system instability and fail dramatically. To overcome this issue, this paper proposes a VSG based on superconducting magnetic energy storage (SMES) technology to emulate the needed inertia power in a short time and thus stabilizing the system frequency at different disturbances. The proposed VSG based on SMES is applied to improve the frequency stability of a real hybrid power grid, Egyptian Power System (EPS), with high renewables penetration levels, nonlinearities, and uncertainties. The performance superiority of the proposed VSG-based SMES is validated by comparing it with the traditional VSG approach based on battery ESSs. The simulation results demonstrated that the proposed VSG based on the SMES system could significantly promote ultra-low-inertia renewable power systems for several contingencies.

scholarly journals Comparison of Virtual Synchronous Generator Strategies for Control of Distributed Energy Sources and Power System Stability Improvement

2021 ◽  
Author(s):  
Guilherme Penha da Silva Júnior ◽  
Thiago Figueiredo do Nascimento ◽  
Luciano Sales Barros
Keyword(s):  
Power Systems ◽  
Power System ◽  
Renewable Energy Sources ◽  
Synchronous Generator ◽  
System Stability ◽  
Control Mode ◽  
Voltage Source ◽  
Energy Sources ◽  
And Performance ◽  
Virtual Synchronous Generator

The high integration of distributed generation (DG) system based on renewable energy sources (RES) in the power system requires changes regarding the control mode of these sources with some urgency. Such changes seek to maintain the stability of the power systems. Thus, there is a demand for using control techniques on DGs/RESs that can mitigate the disturbances caused by low inertia and the lack of control over the dispatched powers. As a solution, one can use virtual synchronous generator (VSG) techniques making the voltage  source inverter (VSI) control behave similarly to the traditional synchronous generator (SG). This paper presents a literature review and performance tests for the main VSG topologies used in DGs/RESs: ISE, VSYNC, VISMA and Synchronverter. The implementation of VSG in the DGs/RESs has made possible increase inertia in the grid and, additionally regulate the active and reactive powers separately and bidirectionally. So, it has been possible to meet power system requirements; being able to operation both grid-connected or island-mode, which is ideal for microgrids. The results obtained confirm the literature reports. It was observed that the Synchronverter topology presented advantages over the other VSG topologies.

Virtual Synchronous Generator Control of Power System including Large-scale Wind Farm by Cooperative Operation between Battery and LFC Hydro Power Plant

2020 ◽  
Vol 140 (6) ◽  
pp. 531-538
Author(s):  
Kotaro Nagaushi ◽  
Atsushi Umemura ◽  
Rion Takahashi ◽  
Junji Tamura ◽  
Atsushi Sakahara ◽  
...  
Keyword(s):  
Power Plant ◽  
Power System ◽  
Large Scale ◽  
Wind Farm ◽  
Synchronous Generator ◽  
Hydro Power ◽  
Virtual Synchronous Generator

scholarly journals Dynamics Analysis Using Koopman Mode Decomposition of a Microgrid Including Virtual Synchronous Generator-Based Inverters

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4581
Author(s):  
Yuko Hirase ◽  
Yuki Ohara ◽  
Naoya Matsuura ◽  
Takeaki Yamazaki
Keyword(s):  
Power System ◽  
System Dynamics ◽  
Dimensional Space ◽  
Supply And Demand ◽  
Transient State ◽  
Synchronous Generator ◽  
Response Analysis ◽  
Power System Dynamics ◽  
Mode Decomposition ◽  
Virtual Synchronous Generator

In the field of microgrids (MGs), steady-state power imbalances and frequency/voltage fluctuations in the transient state have been gaining prominence owing to the advancing distributed energy resources (DERs) connected to MGs via grid-connected inverters. Because a stable, safe power supply and demand must be maintained, accurate analyses of power system dynamics are crucial. However, the natural frequency components present in the dynamics make analyses complex. The nonlinearity and confidentiality of grid-connected inverters also hinder controllability. The MG considered in this study consisted of a synchronous generator (the main power source) and multiple grid-connected inverters with storage batteries and virtual synchronous generator (VSG) control. Although smart inverter controls such as VSG contribute to system stabilization, they induce system nonlinearity. Therefore, Koopman mode decomposition (KMD) was utilized in this study for consideration as a future method of data-driven analysis of the measured frequencies and voltages, and a frequency response analysis of the power system dynamics was performed. The Koopman operator is a linear operator on an infinite dimensional space, whereas the original dynamics is a nonlinear map on a finite state space. In other words, the proposed method can precisely analyze all the dynamics of the power system, which involve the complex nonlinearities caused by VSGs.

scholarly journals MOSAIK and FMI-Based Co-Simulation Applied to Transient Stability Analysis of Grid-Forming Converter Modulated Wind Power Plants

2021 ◽  
Vol 11 (5) ◽  
pp. 2410
Author(s):  
Nakisa Farrokhseresht ◽  
Arjen A. van der Meer ◽  
José Rueda Torres ◽  
Mart A. M. M. van der Meijden
Keyword(s):  
Power System ◽  
Time Domain ◽  
Power Plants ◽  
Transient Stability ◽  
Renewable Energy Sources ◽  
Critical Factor ◽  
Primary Control ◽  
Simulation Approach ◽  
Wide Range ◽  
Grid Side

The grid integration of renewable energy sources interfaced through power electronic converters is undergoing a significant acceleration to meet environmental and political targets. The rapid deployment of converters brings new challenges in ensuring robustness, transient stability, among others. In order to enhance transient stability, transmission system operators established network grid code requirements for converter-based generators to support the primary control task during faults. A critical factor in terms of implementing grid codes is the control strategy of the grid-side converters. Grid-forming converters are a promising solution which could perform properly in a weak-grid condition as well as in an islanded operation. In order to ensure grid code compliance, a wide range of transient stability studies is required. Time-domain simulations are common practice for that purpose. However, performing traditional monolithic time domain simulations (single solver, single domain) on a converter-dominated power system is a very complex and computationally intensive task. In this paper, a co-simulation approach using the mosaik framework is applied on a power system with grid-forming converters. A validation workflow is proposed to verify the co-simulation framework. The results of comprehensive simulation studies show a proof of concept for the applicability of this co-simulation approach to evaluate the transient stability of a dominant grid-forming converter-based power system.

scholarly journals A Review of Virtual Inertia Techniques for Renewable Energy-Based Generators

2020 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Emilio Gómez-Lázaro ◽  
Eduard Muljadi ◽  
Ángel Molina-Garcia
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Power Plants ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
Extensive Discussion ◽  
Renewable Sources ◽  
Virtual Inertia ◽  
Alternative Sources

Over recent decades, the penetration of renewable energy sources (RES), especially photovoltaic and wind power plants, has been promoted in most countries. However, as these both alternative sources have power electronics at the grid interface (inverters), they are electrically decoupled from the grid. Subsequently, stability and reliability of power systems are compromised. Inertia in power systems has been traditionally determined by considering all the rotating masses directly connected to the grid. Thus, as the penetration of renewable units increases, the inertia of the power system decreases due to the reduction of directly connected rotating machines. As a consequence, power systems require a new set of strategies to include these renewable sources. In fact, ‘hidden inertia,’ ‘synthetic inertia’ and ‘virtual inertia’ are terms currently used to represent an artificial inertia created by inverter control strategies of such renewable sources. This chapter reviews the inertia concept and proposes a method to estimate the rotational inertia in different parts of the world. In addition, an extensive discussion on wind and photovoltaic power plants and their contribution to inertia and power system stability is presented.

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