Adaptive virtual-inertia control and chicken swarm optimizer for frequency stability in power-grids penetrated by renewable energy sources

The paper describes special aspects of using the wind power plants (wind turbines) in the power grid. The paper provides the classification and schematic presentation of AC wind turbines, analyzes the role, place and performance of wind power plants in Smart Grid systems with a large share of renewable energy sources. The authors also reviews a detailed analysis of existing AC wind turbines in this paper. Recommendations are given for how to enhance the wind power plants in smart grids in terms of reliability, and introduce the hardware used in the generation, conversion and interface systems into the existing power grid. After the wind power plants had been put online, the relevance of the Smart Grid concept for existing power grids was obvious. The execution of such projects is assumed to be financially costly, requires careful study, and development of flexible algorithms, but in some cases this may be the only approach. The analysis of using wind turbines shows that the structural configuration of wind power plants can be based on the principles known in the power engineering. The approaches may differ, not fundamentally, but in engineering considerations. it is necessary to point out that the method of controlling dual-power machines is quite comprehensive so that their wide use will face operational problems caused by the lack of highly professional specialists in electric drives. Therefore, it seems advisable to use square-cage asynchronous generators in wide applications. The paper shows that as the renewable energy sources are largely used in power grids, there is an issue of maintaining the power generation at a required level considering the variability of incoming wind energy. This results in the malfunctions in the operation of relay protection devices and emergency control automatics (RP and ECA), and the complicated control. Also, the standards of the CIS countries and regulatory documents miss the requirements for the wind turbine protections, taking into account their specialty causing the inefficient standard protective logic, which does not work correctly in a number of abnormal and emergency operating modes, and especially Smart Grid in power grids.

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Provision of Frequency Stability of an Islanded Microgrid Using a Novel Virtual Inertia Control and a Fractional Order Cascade Controller

Energies ◽

10.3390/en14144152 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4152

Author(s):

Soroush Oshnoei ◽

Mohammadreza Aghamohammadi ◽

Siavash Oshnoei ◽

Arman Oshnoei ◽

Behnam Mohammadi-Ivatloo

Keyword(s):

Fractional Order ◽

Degrees Of Freedom ◽

Search Algorithm ◽

Frequency Control ◽

Renewable Energy Sources ◽

Dynamic Performance ◽

Frequency Stability ◽

Virtual Inertia ◽

Inertia Control ◽

System Frequency

Nowadays, the renewable energy sources in microgrids (MGs) have high participation to supply the consumer’s demand. In such MGs, the problems such as the system frequency stability, inertia, and damping reduction are threatened. To overcome this challenge, employing the virtual inertia control (VIC) concept in the MG structure could be considered as a viable solution to improve the system frequency response. Hence, this work proposes a novel modeling for VIC in an islanded MG that provides simultaneous emulation of the primary frequency control, virtual inertia, and damping. To show the efficiency of the proposed technique, a comparison is made between the dynamic performance of the proposed VIC and conventional VIC under different scenarios. The results indicate that the proposed VIC presents superior frequency performance in comparison with conventional VIC. In addition to VIC modeling, a new cascade controller based on three-degrees of freedom and fractional-order controllers (FOCs) is proposed as an MG secondary controller. The effectiveness of the proposed controller is compared to tilt-integral-derivative and FO proportional-integral-derivative controllers. The Squirrel search algorithm is utilized to obtain the optimal coefficients of the controllers. The results demonstrate that the proposed controller improves the MG frequency performance over other controllers. Eventually, the sensitivity analysis is performed to investigate the robustness of the proposed controller in the face of the variations of the parameters.

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IMPROVING THE DYNAMICS OF AN INVERTER-BASED PV GENERATOR DURING LOAD DUMPS

Informatyka Automatyka Pomiary w Gospodarce i Ochronie Środowiska ◽

10.35784/iapgos.24 ◽

2019 ◽

Vol 9 (4) ◽

pp. 83-86

Author(s):

Łukasz Kwaśny

Keyword(s):

Renewable Energy ◽

Dynamic Properties ◽

Renewable Energy Sources ◽

Power Grids ◽

Energy Sources ◽

Power Sources ◽

Full Load ◽

Transient States ◽

Non Linear ◽

Pv Generator

In distribution power grids supplied by dispersed power sources, for example RES (Renewable Energy Sources), in the event of a load dump, unexpected transient states may appear. These states involve a dangerous increase in voltage or current. This situation may lead to the disconnection of these sources. To prevent this phenomenon, a non-linear anti-windup regulator with a conditional integrator has been proposed. This solution allows a significant improvement of the generator’s dynamic properties both at load dump and on return to full load.

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The Present Trends and Challenges in Renewable Energy Sources Connected to a Grid

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k2109.1081219 ◽

2019 ◽

Vol 8 (12) ◽

pp. 3118-3130

Keyword(s):

Renewable Energy ◽

Smart Grids ◽

Renewable Energy Sources ◽

Power Grids ◽

Energy Sources ◽

Self Healing ◽

Monitoring And Control ◽

Decentralized Generation ◽

Policy Interventions ◽

And Control

Smart grids are alterations of the traditional power grids where the monitoring and control of the electricity system are faster and easier than before due to their automated self-healing and sensing processes. However, their primary target is two-way communication, which is only feasible if the decentralized generation of power will exist alongside the national grid. In that light, this report first gives a comprehensive description of smart grids and their history. Afterward, it examines the two major groups of challenges to the penetration of the technology; that is technical and regulatory, policy, and economic challenges. Case studies from the U.S., Canada, Korea, California, and Sweden are used to illustrate the discovered trends and challenges to renewable energy sources connected to grids and demonstrate possible solutions. The research design employed in the study is diagnostic since the problem, its history, and solutions are all reviewed in the report. The study's recommendation is policy interventions to solve both the regulatory and technical challenges to the proliferation of gridded renewables.

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