scholarly journals Determining the Load Inertia Contribution from Different Power Consumer Groups

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1588
Author(s):  
Henning Thiesen ◽  
Clemens Jauch

Power system inertia is a vital part of power system stability. The inertia response within the first seconds after a power imbalance reduces the velocity of which the grid frequency changes. At present, large shares of power system inertia are provided by synchronously rotating masses of conventional power plants. A minor part of power system inertia is supplied by power consumers. The energy system transformation results in an overall decreasing amount of power system inertia. Hence, inertia has to be provided synthetically in future power systems. In depth knowledge about the amount of inertia provided by power consumers is very important for a future application of units supplying synthetic inertia. It strongly promotes the technical efficiency and cost effective application. A blackout in the city of Flensburg allows for a detailed research on the inertia contribution from power consumers. Therefore, power consumer categories are introduced and the inertia contribution is calculated for each category. Overall, the inertia constant for different power consumers is in the range of 0.09 to 4.24 s if inertia constant calculations are based on the power demand. If inertia constant calculations are based on the apparent generator power, the load inertia constant is in the range of 0.01 to 0.19 s.

Author(s):  
Jishu Mary Gomez ◽  
Prabhakar Karthikeyan Shanmugam

Background & Objectives: The global power system is in a state of continuous evolution, incorporating more and more renewable energy systems. The converter-based systems are void of inherent inertia control behavior and are unable to curb minor frequency deviations. The traditional power system, on the other hand, is made up majorly of synchronous generators that have their inertia and governor response for frequency control. For improved inertial and primary frequency response, the existing frequency control methods need to be modified and an additional power reserve is to be maintained mandatorily for this purpose. Energy self-sufficient renewable distributed generator systems can be made possible through optimum active power control techniques. Also, when major global blackouts were analyzed for causes, solutions, and precautions, load shedding techniques were found to be a useful tool to prevent frequency collapse due to power imbalances. The pre-existing load shedding techniques were designed for traditional power systems and were tuned to eliminate low inertia generators as the first step to system stability restoration. To incorporate emerging energy possibilities, the changes in the mixed power system must be addressed and new frequency control capabilities of these systems must be researched. Discussion: In this paper, the power reserve control schemes that enable frequency regulation in the widely incorporated solar photovoltaic and wind turbine generating systems are discussed. Techniques for Under Frequency Load Shedding (UFLS) that can be effectively implemented in renewable energy enabled micro-grid environment for frequency regulation are also briefly discussed. The paper intends to study frequency control schemes and technologies that promote the development of self- sustaining micro-grids. Conclusion: The area of renewable energy research is fast emerging with immense scope for future developments. The comprehensive literature study confirms the possibilities of frequency and inertia response enhancement through optimum energy conservation and control of distributed energy systems.


2018 ◽  
Vol 8 (2) ◽  
pp. 2633-2639 ◽  
Author(s):  
K. Soleimani ◽  
J. Mazloum

Power systems include multiple units linked together to produce constantly moving electric power flux. Stability is very important in power systems, so controller systems should be implemented in power plants to ensure power system stability either in normal conditions or after the events of unwanted inputs and disorder. Frequency and active power control are more important regarding stability. Our effort focused on designing and implementing robust PID and PI controllers based on genetic algorithm by changing the reference of generating units for faster damping of frequency oscillations. Implementation results are examined on two-area power system in the ideally state and in the case of parameter deviation. According to the results, the proposed controllers are resistant to deviation of power system parameters and governor uncertainties.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5527
Author(s):  
Ali M. Eltamaly ◽  
Mohamed A. Ahmed ◽  
Majed A. Alotaibi ◽  
Abdulrahman I. Alolah ◽  
Young-Chon Kim

The grid integration of large scale photovoltaic (PV) power plants represents many challenging tasks for system stability, reliability and power quality due to the intermittent nature of solar radiation and the site accessibility issues where most PV power plants are located over a wide area. In order to enable real-time monitoring and control of large scale PV power plants, reliable two-way communications with low latency are required which provide accurate information for the electrical and environmental parameters as well as enabling the system operator to evaluate the overall performance and identify any abnormal conditions and faults. This work aims to design a communication network architecture for the remote monitoring of large-scale PV power plants based on the IEC 61850 Standard. The proposed architecture consists of three layers: the PV power system layer, the communication network layer, and the application layer. The PV power system layer consists of solar arrays, inverters, feeders, buses, a substation, and a control center. Monitoring parameters are classified into different categories including electrical measurements, status information, and meteorological data. This work considers the future plan of PV power plants in Saudi Arabia. In order to evaluate the performance of the communication network for local and remote monitoring, the OPNET Modeler is used for network modeling and simulation, and critical parameters such as network topology, link capacity, and latency are investigated and discussed. This work contributes to the design of reliable monitoring and communication of large-scale PV power plants.


2021 ◽  
Vol 24 (4) ◽  
pp. 109-115
Author(s):  
Vyacheslav Valerievich Guryev ◽  
Vladimir Vyacheslavovich Kuvshinov ◽  
Boris Anatolevich Yakimovich

The Crimean Peninsula is the flagship of the development of renewable energy, as it is not only an actively developing region, but also a resort center. The energy complex of the Crimean Peninsula in recent years has increased due to the construction of new power plants (Balaklava TPP and Tavricheskaya TPP) with a total capacity of 940 MW, as well as the construction of new 220 and 330 kV transmission lines, which ensured that the peninsula’s power supply deficit was covered. A review of the regional development and use of renewable energy sources is carried out. Based on the data obtained, an analysis is made of the problems and prospects for the development of renewable energy in the region. The development of renewable energy for the Crimean Peninsula plays an important role in order to achieve environmental safety and develop the economic potential of the region. The paper substantiates the priority use of renewable energy in the region, as well as the solution of emerging problems with an increase in the share of renewable energy in the total generation. The appearance of excess electricity in the power system and the possibility of balancing the generated power of renewable energy and thermal power plants, while reducing the cost of electricity. Investment attractiveness and active population growth in the region leads to an increase in generating capacity and an increase in the maneuverability of the energy system with a significant impact of RES. The efficiency of renewable energy in the energy system, the world experience in managing renewable energy generation, the actual impact of renewable energy on the energy system in conditions of electricity shortage, and forecast work schedules of the SES wind farm provided by the electric power industry entities in the assigned way are taken into account when forming the dispatch schedule and are accepted at the request of the subject. The available experience of existing SES in the power system of the Republic of Crimea and the city of Sevastopol requires additional research, including through field testing of generating equipment. Further full-scale tests should be carried out under the conditions of a real electric power mode of the power system, which requires the introduction of modern information technologies that ensure the exchange of technological information and the implementation of appropriate control actions. The work is underway to create a regulatory framework for the control of renewable energy source operation.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6177
Author(s):  
Alija Mujcinagic ◽  
Mirza Kusljugic ◽  
Emir Nukic

As a result of the increased integration of power converter-connected variable speed wind generators (VSWG), which do not provide rotational inertia, concerns about the frequency stability of interconnected power systems permanently arise. If the inertia of a power system is insufficient, wind power plants’ participation in the inertial response should be required. A trendy solution for the frequency stability improvement in low inertia systems is based on utilizing so-called “synthetic” or “virtual” inertia from modern VSWG. This paper presents a control scheme for the virtual inertia response of wind power plants based on the center of inertia (COI) frequency of a control area. The PSS/E user written wind inertial controller based on COI frequency is developed using FORTRAN. The efficiency of the controller is tested and applied to the real interconnected power system of Southeast Europe. The performed simulations show certain conceptual advantages of the proposed controller in comparison to traditional schemes that use the local frequency to trigger the wind inertial response. The frequency response metrics, COI frequency calculation and graphical plots are obtained using Python.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4695
Author(s):  
Charlotte Senkpiel ◽  
Wolfgang Hauser

This paper analyses the effects of regional renewable electricity self-sufficiency targets on the power system in Germany. For this purpose, an interdisciplinary approach from social sciences and energy system modelling was chosen, which allows considering qualitative factors such as public acceptance or political stability. Following the concept of context scenarios, consistent raw scenarios are generated by a cross-impact balance analysis (CIB), and the scenarios are quantified by the unit commitment and expansion cost minimisation model ENTIGRIS considering power plants, storages, and the electricity grid. This approach enables an understanding of the system framework conditions and their relationships and allows the combination of qualitative and quantitative scenario descriptors. The most important factors for setting regional self-sufficiency targets were identified through interviews. The main system effects identified are: The regional distribution of generation capacities is strongly influenced by a more demand-oriented installation of generation capacities. This leads to less grid reinforcement, but higher rates of curtailment. In all scenarios, higher utilization of the PV roof potential instead of ground mounted could be observed. The total system costs are increasing only slightly with regional self-supply targets. In general, it was found that the influence of regional self-sufficiency targets is less pronounced in scenarios that already achieve high national RES shares than in scenarios that achieve lower shares, since technology, storage and grid expansion measures are necessary anyway to achieve high RES shares. Overall, the effects here are rather small and the regional objective is not associated with major disadvantages for the system. In a future characterised by stagnation, the system can benefit from regional targeting, as higher renewable shares and lower costs can result. The main conclusion therefore is that regional target setting seem to be beneficial for the overall power system, in terms of system cost, national RE share, acceptance and CO2-emissions.


Author(s):  
S. Othman ◽  
H. M. Mahmoud ◽  
S. A. Kotb

The capacity of the electrical power system in Egypt will increase rapidly in the coming twenty years. In year 2018, nuclear power generation will be connecting to the Egyptian electrical grid. Consequently, the interaction of nuclear power plants and other systems becomes a very important issue, and a detailed nuclear power model for the medium-term and long-term power system stability should be developed. However, there is no nuclear unit model that can describe the detailed characteristics of the nuclear unit in the available commercial power system simulation software. In this paper, a detailed pressurized water reactor (PWR) nuclear unit model for medium-term and long-term power system transient stability is proposed. The model is implemented by a user defined program in PSS/E through PSS/E Matlab Simulink Interface. This model can be used to analyze the interaction of nuclear power plants and other power systems. The simulation results show that the proposed model is valid.


2017 ◽  
Vol 2017 (1) ◽  
pp. 1618-1620 ◽  
Author(s):  
Stephan Brandt ◽  
Frederik Kalverkamp ◽  
Rhea Heßler ◽  
Sebastian Weber

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2207
Author(s):  
Jesus Castro Martinez ◽  
Santiago Arnaltes ◽  
Jaime Alonso-Martinez ◽  
Jose Luis Rodriguez Amenedo

Power system inertia is being reduced because of the increasing penetration of renewable energies, most of which use power electronic interfaces with the grid. This paper analyses the contribution of inertia emulation and droop control to the power system stability. Although inertia emulation may appear the best option to mitigate frequency disturbances, a thorough analysis of the shortcomings that face real-time implementations shows the opposite. Measurement noise and response delay for inertia emulation hinder controller performance, while the inherently fast droop response of electronic converters provides better frequency support. System stability, expressed in terms of rate of change of frequency (ROCOF) and frequency nadir, is therefore improved with droop control, compared to inertia emulation.


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