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

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.

2018 ◽  
Vol 10 (11) ◽  
pp. 4140 ◽  
Author(s):  
Seungchan Oh ◽  
Heewon Shin ◽  
Hwanhee Cho ◽  
Byongjun Lee

Efforts to reduce greenhouse gas emissions constitute a worldwide trend. According to this trend, there are many plans in place for the replacement of conventional electric power plants operating using fossil fuels with renewable energy sources (RESs). Owing to current needs to expand the RES penetration in accordance to a new National power system plan, the importance of RESs is increasing. The RES penetration imposes various impacts on the power system, including transient stability. Furthermore, the fact that they are distributed at multiple locations in the power system is also a factor which makes the transient impact analysis of RESs difficult. In this study, the transient impacts attributed to the penetration of RESs are analyzed and compared with the conventional Korean electric power system. To confirm the impact of the penetration of RESs on transient stability, the effect was analyzed based on a single machine equivalent (SIME) configuration. Simulations were conducted in accordance to the Korean power system by considering the anticipated RES penetration in 2030. The impact of RES on transient stability was provided by a change in CCT by increasing of the RES penetration.


2020 ◽  
Vol 12 (23) ◽  
pp. 9844
Author(s):  
Maximilian Borning ◽  
Larissa Doré ◽  
Michael Wolff ◽  
Julian Walter ◽  
Tristan Becker ◽  
...  

To mitigate global warming, the European Union aims at climate neutrality by 2050. In order to reach this, the transportation sector has to contribute especially, which accounts for about a quarter of the European greenhouse gas emissions. Herein, electricity-based fuels are a promising approach for reducing emissions. However, a large-scale deployment of electricity-based fuels has a significant impact on the power system due to high electricity demand and the requirement to use renewable energy sources in order to be sustainable. At the same time, this fuel production could offer additional flexibility for the power system. This article investigates the opportunities and challenges of electricity-based fuels and flexible electricity-based fuel production for the European power system. In a literature analysis, the pivotal role of electricity-based fuels for climate neutrality is confirmed. To analyze the impact of flexible fuel production, European power market simulations for the year 2035 are conducted. Results indicate that flexibilization leads to an increased integration of electricity based on renewable energy sources as well as reductions in both carbon dioxide emissions and total operational costs of the power system. However, very high flexibility levels also benefit high-emission power plants and may even lead to increased emissions.


2020 ◽  
Vol 3 (59) ◽  
pp. 108-116
Author(s):  
O. Rubanenko

The relevance of the transition from traditional to renewable energy sources is investigated in the paper. The most popular renewable energy sources (RES) for Ukraine and the World are highlighted. The trend of changing electricity generation by photovoltaic stations is analyzed. Peculiarities of the functioning of electric networks with RES are considered. A mathematical model of the problem of optimal control of the parameters of the normal mode of the power system (PS) with a high level of integration of photovoltaic power plants (PPS) is presented. The main components of the criterion of optimality in the control of the power system, which must be taken into account when determining it. The article investigates in more detail such a component of the optimality criterion as power equivalent to the loss due to power failure caused by unstable generation. The instability of RES generation, in particular, FES, can be caused by both unpredictable changes in meteorological factors and changes in the technical condition of FES equipment. The photovoltaic module is the main element of any FES, so the article focuses on determining the technical condition of the FEM. Therefore, the main study presented in the article is the development of a neuro-fuzzy model to determine the technical condition of the FEM, which is represented by the coefficient of the total residual resource. For this purpose, the characteristic fault to the FEM, in particular, the fault to the frame of the FEM is analyzed and presented; the fault to cable insulation; the consequences of increasing resistance and heating of the contacts at the junction of the cell busbar FEM; the decrease to the impermeability of the FEM and others.


2021 ◽  
Vol 10 (4) ◽  
pp. 811-818
Author(s):  
Duong Dinh Le ◽  
Duong Van Ngo ◽  
Nhi Thi Ai Nguyen ◽  
Ky Van Huynh

The increasing penetration of renewable energy sources has introduced great uncertainties and challenges into computation and analysis of electric power systems. To deal with uncertainties, probabilistic approaches need to be used. In this paper, we propose a new framework for probabilistic assessment of power systems taking into account uncertainties from input random variables such as load demands and renewable energy sources. It is based on the cumulant-based Probabilistic Power Flow (PPF) in combination with an improved clustering technique. The improved clustering technique is also developed in this study by making use of Principal Component Analysis (PCA) and Particle Swarm Optimization (PSO) to reduce the range of variation in the input data, thus increasing the accuracy of the traditional cumulant-based PPF (TCPPF) method. In addition, thanks to adopting PCA for dimensionality reduction, the improved clustering technique can be effectively dealt with a large number of input random variables so that the proposed framework for probabilistic assessment can be applied for large power systems. The IEEE-118 bus test system is modified by adding five wind and eight solar photovoltaic power plants to examine the proposed method. Uncertainties from input random variables are represented by appropriate probabilistic models. Extensive testing on the test system indicates good performance of the proposed approach in comparison to the traditional cumulant-based PPF and Monte Carlo simulation. The IEEE-118 bus test system is modified by adding five wind and eight solar photovoltaic power plants to examine the proposed method. Extensive testing on the test system, using Matlab (R2015a) on an Intel Core i5 CPU 2.53 GHz/4.00 GB RAM PC, indicates good performance of the proposed approach (PPPF) in comparison to the TCPPF and Monte Carlo simulation (MCS): In terms of computation time, PPPF needs 4.54 seconds, while TCPPF and MCS require 2.63 and 251 seconds, respectively; ARMS errors are calculated for methods using benchmark MCS and their values clearly demonstrate the higher accuracy of PPPF in estimating probability distributions compared to TCPPF, i.e., the maximum (Max) and mean (Mean) values of ARMS errors of all output random variables are: ARMSPPPFmax = 0.11%, ARMSTCPPFmax = 0.55%, and ARMSPPPFmean = 0.06%, ARMSTCPPFmean  = 0.35%.


2021 ◽  
Vol 20 (4) ◽  
pp. 118-126
Author(s):  
Md. Kamrul Islam ◽  
Mohammad Abdul Mannan ◽  
Md. Rifat Hazari

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.       


Author(s):  
Petro Lezhniuk ◽  
Olha Buslavets ◽  
Olena Rubanenko

This article considers the features of the development of renewable energy sources in electrical networks. The main changes in the functional properties of power systems, which include a significant reduction in electricity consumption, change in the structure of electricity consumption, rapid increase in the installed capacity of solar and wind power plants. Electricity consumption in 2020 is almost halved compared to 1990 (from 227 to 119 billion kWh) and as a consequence the share of semi-peak thermal generation, which gave the power system basic flexibility, has significantly decreased (from 71 % in 1990 to 35 % in 2020) and at the same time the share of nuclear generation, which operates in base mode, has increased (from 25 % to 51 %). In particular, consumption by industry with a stable load schedule, decreased (from 146 billion kWh (64 %) to 49 billion kWh (42 %)). At the same time, the demand for electricity by the households, whose consumption profile of which is characterized by significant daily unevenness and sensitivity to meteorological factors, has significantly increased (from 21 billion kWh (9 %) to 37 billion kWh (31 %)). Therefore, the article analyses the preconditions for the problem of flexible generation and explores possible ways to solve them. The optimal composition of electricity generation for Ukraine in the period 2021–2025 is proposed, which provides for the preservation and even increase by optimizing the repair campaign of the share of electricity production by nuclear power plants, the introduction of additional 2–2.5 GW of highly flexible generation and up to 2 GW storage systems (taking into account the pumped-storage power plant), as well as a gradual evolutionary decline in both installed capacity and electricity production by semi-peak coal-fired power plants and maintaining a policy of decarbonisation to ensure its own energy security. A comprehensive approach to compensating for the instability of renewable energy sources generation has been developed, which consists in minimizing the cost of power redundancy in various available ways. The problem of cost optimization for ways to compensate for the instability of renewable energy sources generation is solved by the method of criterion programming. The impact of each backup method on total costs is determined using sensitivity theory.


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