scholarly journals A Methodology for Provision of Frequency Stability in Operation Planning of Low Inertia Power Systems

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 737
Author(s):  
Michał Kosmecki ◽  
Robert Rink ◽  
Anna Wakszyńska ◽  
Roberto Ciavarella ◽  
Marialaura Di Somma ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Storage System ◽  
Rate Of Change ◽  
System Level ◽  
Operation Planning ◽  
Planning Period ◽  
Power Sources ◽  
Real Time Digital Simulator

Along with the increasing share of non-synchronous power sources, the inertia of power systems is being reduced, which can give rise to frequency containment problems should an outage of a generator or a power infeed happen. Low system inertia is eventually unavoidable, thus power system operators need to be prepared for this condition. This paper addresses the problem of low inertia in the power system from two different perspectives. At a system level, it proposes an operation planning methodology, which utilises a combination of power flow and dynamic simulation for calculation of existing inertia and, if need be, synthetic inertia (SI) to fulfil the security criterion of adequate rate of change of frequency (RoCoF). On a device level, it introduces a new concept for active power controller, which can be applied virtually to any power source with sufficient response time to create synthetic inertia. The methodology is demonstrated for a 24 h planning period, for which it proves to be effective. The performance of SI controller activated in a battery energy storage system (BESS) is positively validated using a real-time digital simulator (RTDS). Both proposals can effectively contribute to facilitating the operation of low inertia power systems.

scholarly journals Enhancing Oscillation Damping in an Interconnected Power System with Integrated Wind Farms Using Unified Power Flow Controller

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 322 ◽  
Author(s):  
Ping He ◽  
Seyed Arefifar ◽  
Congshan Li ◽  
Fushuan Wen ◽  
Yuqi Ji ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Time Domain ◽  
Power Flow ◽  
Unified Power Flow Controller ◽  
Time Domain Simulation ◽  
Interconnected Power System ◽  
Dynamic Time ◽  
Oscillation Damping ◽  
Power Flow Controller

The well-developed unified power flow controller (UPFC) has demonstrated its capability in providing voltage support and improving power system stability. The objective of this paper is to demonstrate the capability of the UPFC in mitigating oscillations in a wind farm integrated power system by employing eigenvalue analysis and dynamic time-domain simulation approaches. For this purpose, a power oscillation damping controller (PODC) of the UPFC is designed for damping oscillations caused by disturbances in a given interconnected power system, including the change in tie-line power, the changes of wind power outputs, and others. Simulations are carried out for two sample power systems, i.e., a four-machine system and an eight-machine system, for demonstration. Numerous eigenvalue analysis and dynamic time-domain simulation results confirm that the UPFC equipped with the designed PODC can effectively suppress oscillations of power systems under various disturbance scenarios.

scholarly journals Load Frequency Control of Photovoltaic-Gasifier for Interconnected Two-Area Power Systems

2019 ◽  
Vol 9 (1) ◽  
pp. 2101-2105
Keyword(s):  
Power Systems ◽  
Power System ◽  
Pid Control ◽  
Pid Controller ◽  
Power Flow ◽  
Frequency Control ◽  
Load Frequency Control ◽  
Interconnected Power System ◽  
Load Frequency ◽  
Tie Line

Load frequency control (LFC) in interconnected power system of small distribution generation (DG) for reliability in distribution system. The main objective is to performance evaluation load frequency control of hybrid for interconnected two-area power systems. The simulation consist of solar farm 10 MW and gasifier plant 300 kW two-area in tie line. This impact LFC can be address as a problem on how to effectively utilize the total tie-line power flow at small DG. To performance evaluation and improve that defect of LFC, the power flow of two-areas LFC system have been carefully studied, such that, the power flow and power stability is partially LFC of small DG of hybrid for interconnected two-areas power systems. Namely, the controller and structural properties of the multi-areas LFC system are similar to the properties of hybrid for interconnected two-area LFC system. Inspired by the above properties, the controller that is propose to design some proportional-integral-derivative (PID) control laws for the two-areas LFC system successfully works out the aforementioned problem. The power system of renewable of solar farm and gasifier plant in interconnected distribution power system of area in tie – line have simulation parameter by PID controller. Simulation results showed that 3 types of the controller have deviation frequency about 0.025 Hz when tie-line load changed 1 MW and large disturbance respectively. From interconnected power system the steady state time respond is 5.2 seconds for non-controller system, 4.3 seconds for automatic voltage regulator (AVR) and 1.4 seconds for under controlled system at 0.01 per unit (p.u.) with PID controller. Therefore, the PID control has the better efficiency non-controller 28 % and AVR 15 %. The result of simulation in research to be interconnected distribution power system substation of area in tie - line control for little generate storage for grid connected at better efficiency and optimization of renewable for hybrid. It can be conclude that this study can use for applying to the distribution power system to increase efficiency and power system stability of area in tie – line.

Techniques for the Identification of Critical Nodes Leading to Voltage Collapse in a Power System

2018 ◽  
Vol 19 (2) ◽  
Author(s):  
Isaiah Adebayo ◽  
Adisa Jimoh ◽  
Adedayo Yusuff
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Eigenvalue Decomposition ◽  
Step Size ◽  
Suggested Approach ◽  
Voltage Instability ◽  
Critical Nodes ◽  
Voltage Stability Enhancement ◽  
Stability Enhancement

AbstractThis paper proposes two techniques for the identification of critical buses in a power system. The technique of Network Structural Theory Participation Factor (NSTPF) depends on the network structural interconnection of buses as captured by the admittance matrix of the system and is formulated based on the fundamental circuit theory law using eigenvalue decomposition method. Another power flow based technique which depends on the system maximum loadability, the system step size among other factors is also proposed. Traditional power flow based techniques are used as benchmarks to determine the significance of the proposed methods. To ensure voltage stability enhancement, STATCOM FACTS device is installed at the selected weak load buses of the practical Nigerian 24 bus and IEEE 30 bus test systems. The results of the simulation obtained show that, the suggested approach of NSTPF is more suitable in the identification of weak buses that are liable to voltage instability in power systems as it requires less computational burden and also saves time compared to techniques based on power flow solutions.

scholarly journals Optimization of Short-term Modes of Hydrothermal Power System

2020 ◽  
Vol 209 ◽  
pp. 07014
Author(s):  
Tulkin Gayibov ◽  
Bekzod Pulatov
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Plants ◽  
Optimal Planning ◽  
Hydroelectric Power ◽  
Short Term ◽  
Planning Period ◽  
Time Intervals ◽  
Large Power ◽  
Integral Constraints

Optimal planning of short-term modes of power systems is a complex nonlinear programming problem with many simple, functional and integral constraints in the form of equalities and inequalities. Especially, the presence of integral constraints causes significant difficulties in solving of such problem. Since, under such constraints, the modes of power system in separate time intervals of the considered planning period become dependent on the values of the parameters in other intervals. Accordingly, it becomes impossible to obtain the optimal mode plan as the results of separate optimization for individual time intervals of the period under consideration. And the simultaneous solution of the problem for all time intervals of the planning period in the conditions of large power systems is associated with additional difficulties in ensuring the reliability of convergence of the iterative computational process. In this regard, the issues of improving the methods and algorithms for optimization of short-term modes of power systems containing thermal and large hydroelectric power plants with reservoirs, in which water consumption is regulated in the short-term planning period, remains as an important task. In this paper, we propose the effective algorithm for solving the problem under consideration, which makes it possible to quickly and reliably determine the optimal operating modes of the power system for the planned period. The results of research of effectiveness of this algorithm are presented on the example of optimal planning of daily mode of the power system, which contains two thermal and three hydraulic power plants..

scholarly journals Effect of Hybrid Power Station Installation in the Operation of Insular Power Systems

Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 38 ◽  
Author(s):  
Bouzounierakis ◽  
Katsigiannis ◽  
Fiorentzis ◽  
Karapidakis
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Storage System ◽  
Power Station ◽  
Hybrid Power ◽  
Load Demand ◽  
Test Operation ◽  
Hourly Data

Greece has a large number of islands that are isolated from the main interconnected Greek power system; however, a majority of them are to be interconnected in the mainland grid over the next decade. A large number of these islands present a significant amount of wind and solar potential. The nature of load demand and renewable production is stochastic; thus, the operation of such isolated power systems can be improved significantly by the installation of a large-scale energy storage system. The role of storage is to compensate for the long and short-term imbalances between power generation and load demand. Pumped hydro storage (PHS) systems represent one of the most mature technologies for large-scale energy storage. However, their advantages have not been proven in practice for cases of medium and small-sized isolated insular systems. Regarding Greece, which contains a large number of isolated insular systems, a PHS system in the island of Ikaria started its test operation in 2019, whereas in Europe only one PHS system operates in El Hierro (Canary Islands). This paper studies the effect of installing a wind-PHS hybrid power station in the operation of the insular power system of Samos, Greece, according to the latest regulatory framework. The implemented analysis uses real hourly data for a whole year, and examines the effects of such an installation considering investors’ and power system operators’ viewpoints. More specifically, the economic viability of this project under different billing scenarios is compared, and its impact on the insular power system operation for various PHS sizes is examined.

scholarly journals Probabilistic Optimal Power Flow for Day-Ahead Dispatching of Power Systems with High-Proportion Renewable Power Sources

2020 ◽  
Vol 12 (2) ◽  
pp. 518
Author(s):  
Yue Chen ◽  
Zhizhong Guo ◽  
Hongbo Li ◽  
Yi Yang ◽  
Abebe Tilahun Tadie ◽  
...  
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Test System ◽  
Power Sources ◽  
Renewable Power ◽  
Point Estimate Method ◽  
Optimal Power ◽  
Simulation Results ◽  
Point Estimation Method

With the increasing proportion of uncertain power sources in the power grid; such as wind and solar power sources; the probabilistic optimal power flow (POPF) is more suitable for the steady state analysis (SSA) of power systems with high proportions of renewable power sources (PSHPRPSs). Moreover; PSHPRPSs have large uncertain power generation prediction error in day-ahead dispatching; which is accommodated by real-time dispatching and automatic generation control (AGC). In summary; this paper proposes a once-iterative probabilistic optimal power flow (OIPOPF) method for the SSA of day-ahead dispatching in PSHPRPSs. To verify the feasibility of the OIPOPF model and its solution algorithm; the OIPOPF was applied to a modified Institute of Electrical and Electronic Engineers (IEEE) 39-bus test system and modified IEEE 300-bus test system. Based on a comparison between the simulation results of the OIPOPF and AC power flow models; the OIPOPF model was found to ensure the accuracy of the power flow results and simplify the power flow model. The OIPOPF was solved using the point estimate method based on Gram–Charlier expansion; and the numerical characteristics of the line power were obtained. Compared with the simulation results of the Monte Carlo method; the point estimation method based on Gram–Charlier expansion can accurately solve the proposed OIPOPF model

scholarly journals Structural Condition for Controllable Power Flow System Containing Controllable and Fluctuating Power Devices

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1627 ◽  
Author(s):  
Saher Javaid ◽  
Mineo Kaneko ◽  
Yasuo Tan
Keyword(s):  
Power System ◽  
Flow Control ◽  
Power Flow ◽  
Flow System ◽  
Power Balance ◽  
Power Demand ◽  
Power Devices ◽  
Power Sources ◽  
Power Flow Control ◽  
Power Fluctuations

This paper discusses a structural property for a power system to continue a safe operation under power fluctuation caused by fluctuating power sources and loads. Concerns over global climate change and gas emissions have motivated development and integration of renewable energy sources such as wind and solar to fulfill power demand. The energy generated from these sources exhibits fluctuations and uncertainty which is uncontrollable. In addition, the power fluctuations caused by power loads also have the same consequences on power system. To mitigate the effects of uncontrollable power fluctuations, a power flow control is presented which allocates power levels for controllable power sources and loads and connections between power devices. One basic function for the power flow control is to balance the generated power with the power demand. However, due to the structural limitations, i.e., the power level limitations of controllable sources and loads and the limitation of power flow channels, the power balance may not be achieved. This paper proposes two theorems about the structural conditions for a power system to have a feasible solution which achieves the power balance between power sources and power loads. The discussions in this paper will provide a solid theoretical background for designing a power flow system which proves robustness against fluctuations caused by fluctuating power devices.

scholarly journals Optimal Sizing and Spatial Allocation of Storage Units in a High-Resolution Power System Model

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3365 ◽  
Author(s):  
Lukas Wienholt ◽  
Ulf Müller ◽  
Julian Bartels
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Power Transmission ◽  
Renewable Generation ◽  
Large Power ◽  
Transmission Grid ◽  
Storage Units

The paradigm shift of large power systems to renewable and decentralized generation raises the question of future transmission and flexibility requirements. In this work, the German power system is brought to focus through a power transmission grid model in a high spatial resolution considering the high voltage (110 kV) level. The fundamental questions of location, type, and size of future storage units are addressed through a linear optimal power flow using today’s power grid capacities and a generation portfolio allowing a 66% generation share of renewable energy. The results of the optimization indicate that for reaching a renewable energy generation share of 53% with this set-up, a few central storage units with a relatively low overall additional storage capacity of around 1.6 GW are required. By adding a constraint of achieving a renewable generation share of at least 66%, storage capacities increase to almost eight times the original capacity. A comparison with the German grid development plan, which provided the basis for the power generation data, showed that despite the non-consideration of transmission grid extension, moderate additional storage capacities lead to a feasible power system. However, the achievement of a comparable renewable generation share provokes a significant investment in additional storage capacities.

Integration of Power System Real-Time Digital Simulator and Optimal Power Flow

2012 ◽  
Vol 590 ◽  
pp. 195-200
Author(s):  
Meng Jen Chen ◽  
Yu Chi Wu ◽  
Wen Shiush Chen ◽  
Pei Wei Huang ◽  
Tsung Wei Tsai
Keyword(s):  
Steady State ◽  
Power System ◽  
Real Time ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Optimal Power ◽  
Communication Architectures ◽  
Analog Channels ◽  
Real Time Digital Simulator ◽  
Steady State Performance

In this paper, a framework for integrating a real-time digital simulator and EMS-OPF program is proposed and addressed, through two different communication architectures: asynchronous and synchronous. Validation of these communication architectures is carried out by Ethernet UDP/IP (asynchronous) and analog channels of IO card (synchronous). With this framework, both dynamic and steady-state performance of a power system can be studied easily in real-time mode.

scholarly journals Exploiting Coarse-Grained Parallelism Using Cloud Computing in Massive Power Flow Computation

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2268 ◽  
Author(s):  
Dong-Hee Yoon ◽  
Sang-Kyun Kang ◽  
Minseong Kim ◽  
Youngsun Han
Keyword(s):  
Cloud Computing ◽  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Computation Time ◽  
Coarse Grained ◽  
Contingency Analysis ◽  
Flow Computation ◽  
Cloud Computing System ◽  
The Impact

We present a novel architecture of parallel contingency analysis that accelerates massive power flow computation using cloud computing. It leverages cloud computing to investigate huge power systems of various and potential contingencies. Contingency analysis is undertaken to assess the impact of failure of power system components; thus, extensive contingency analysis is required to ensure that power systems operate safely and reliably. Since many calculations are required to analyze possible contingencies under various conditions, the computation time of contingency analysis increases tremendously if either the power system is large or cascading outage analysis is needed. We also introduce a task management optimization to minimize load imbalances between computing resources while reducing communication and synchronization overheads. Our experiment shows that the proposed architecture exhibits a performance improvement of up to 35.32× on 256 cores in the contingency analysis of a real power system, i.e., KEPCO2015 (the Korean power system), by using a cloud computing system. According to our analysis of the task execution behaviors, we confirmed that the performance can be enhanced further by employing additional computing resources.

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