scholarly journals Measurement-based exponential recovery load model: development and validation

DYNA ◽  
2015 ◽  
Vol 82 (192) ◽  
pp. 131-140
Author(s):  
Luis Rodríguez-García ◽  
Sandra Pérez-Londoño ◽  
Juan Mora-Flórez
Keyword(s):  
Power Systems ◽  
Model Development ◽  
Estimation Method ◽  
Test System ◽  
System Stability ◽  
Load Modeling ◽  
Load Model ◽  
Model Generalization ◽  
Modeling Strategy ◽  
And Control

<p>Load modeling is an important task in power system stability analysis and control. Taking this into account, the development of dynamic load models using a measurement-based load modeling strategy and an improved particle swarm optimization algorithm is presented in this paper. To accomplish this objective, a measurement-based parameter estimation method is used for identification of an exponential recovery load model. Measurements are obtained performing dynamic simulation of an IEEE 30-bus test system under several disturbances, and additionally, cross validation technique is applied for an analysis of load model generalization capability. An adequate load modeling improves the comprehension of load behavior and the capability of reproduce transient events on power systems.</p>

scholarly journals Heterogeneous Inertia Estimation for Power Systems with High Penetration of Converter-Interfaced Generation

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5047
Author(s):  
Diala Nouti ◽  
Ferdinanda Ponci ◽  
Antonello Monti
Keyword(s):  
Power Systems ◽  
Estimation Algorithm ◽  
System Stability ◽  
Rotational Inertia ◽  
Heterogeneous Distribution ◽  
Proper Actions ◽  
High Penetration ◽  
System Operator ◽  
And Control ◽  
System Inertia

The increasing and fast deployment of distributed generation is posing challenges to the operation and control of power systems due to the resulting reduction in the overall system rotational inertia and damping. Therefore, it becomes quite crucial for the transmission system operator to monitor the varying system inertia and damping in order to take proper actions to maintain the system stability. This paper presents an inertia estimation algorithm for low-inertia systems to estimate the inertia (both mechanical and virtual) and damping of systems with mixed generation resources and/or the resource itself. Moreover, the effect of high penetration of distributed energy resources and the resulting heterogeneous distribution of inertia on the overall system inertia estimation is investigated. A comprehensive set of case studies and scenarios of the IEEE 39-bus system provides results to demonstrate the performance of the proposed estimator.

scholarly journals Conformance Testing and Analysis of Synchrophasor Communication Message Structures and Formats for Wide Area Measurement Systems in Smart Grids

2017 ◽  
Vol 6 (2) ◽  
pp. 106
Author(s):  
Adeyemi Charles Adewole ◽  
Raynitchka Tzoneva
Keyword(s):  
Power Systems ◽  
Power System ◽  
Communication Networks ◽  
Smart Grids ◽  
Data Communication ◽  
System Stability ◽  
Area Measurement ◽  
Wide Area ◽  
Protection And Control ◽  
And Control

The renewed quest for situational awareness in power systems has brought about the use of digital signal processing of power system measurements, and the transmission of such data to control centres via communication networks. At the control centres, power system stability algorithms are executed to provide monitoring, protection, and control in order to prevent blackouts. This can be achieved by upgrading the existing Supervisory Control and Data Acquisition (SCADA) systems through the deployment of newly proposed power system synchrophasor-based applications for Wide Area Monitoring, Protection, and Control (WAMPAC). However, this can only be done when there is a complete understanding of the methods and technologies associated with the communication network, message structure, and formats required. This paper presents an analysis of the IEEE C37.118 synchrophasor message framework, message formats, and data communication of synchrophasor measurements from Phasor Measurement Units (PMUs) for WAMPAC schemes in smart grids. A newly designed lab-scale testbed is implemented and used in the practical experimentation relating to this paper. Synchrophasor measurements from the PMUs are captured using a network protocol analyzer software-Wireshark, and the compliance of the synchrophasor message structures and formats captured was compared to the specifications defined in the IEEE C37.118 synchrophasor standard.

scholarly journals A stabilising control strategy for Cyber-Physical Power Systems

2018 ◽  
Author(s):  
Etinosa Ekomwenrenren ◽  
Hatem Alharbi ◽  
Taisir Elgorashi ◽  
Jaafar Elmirghani ◽  
Petros Aristidou
Keyword(s):  
Power Systems ◽  
Power System ◽  
Control Strategy ◽  
Physical Nature ◽  
System Stability ◽  
Wide Area ◽  
Equivalent Model ◽  
Communication Infrastructure ◽  
Damping Controllers ◽  
And Control

The cyber-physical nature of electric power systems has increased immensely over the last decades, with advanced communication infrastructure paving the way. It is now possible to design wide-area controllers, relying on remote monitor and control of devices, that can tackle power system stability problems more effectively than local controllers. However, their performance and security relies extensively on the communication infrastructure and can make power systems vulnerable to disturbances emerging on the cyber side of the system. In this paper, we investigate the effect of communication delays on the performance and security of wide-area damping controllers (WADC) designed to stabilise oscillatory modes in a Cyber-Physical Power System (CPPS). We propose a rule-based control strategy that combines wide-area and traditional local stabilising controllers to increase the performance and maintain the security of CPPS. The proposed strategy is validated on a reduced CPPS equivalent model of Great-Britain (GB).

scholarly journals Load Flow Analysis in Hybrid AC-DC Transmission Network

2021 ◽  
pp. 617-624
Author(s):  
Ajith M ◽  
Dr. R. Rajeswari
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Short Circuit ◽  
Flow Analysis ◽  
Load Flow ◽  
System Stability ◽  
And Control

Power-flow studies are of great significance in planning and designing the future expansion of power systems as well as in determining the best operation of existing systems. Technologies such as renewables and power electronics are aiding in power conversion and control, thus making the power system massive, complex, and dynamic. HVDC is being preferred due to limitations in HVAC such as reactive power loss, stability, current carrying capacity, operation and control. The HVDC system is being used for bulk power transmission over long distances with minimum losses using overhead transmission lines or submarine cable crossings. Recent years have witnessed an unprecedented growth in the number of the HVDC projects. Due to the vast size and inaccessibility of transmission systems, real time testing can prove to be difficult. Thus analyzing power system stability through computer modeling and simulation proves to be a viable solution in this case. The motivation of this project is to construct and analyze the load flow and short circuit behavior in an IEEE 14 bus power system with DC link using MATLAB software. This involves determining the parameters for converter transformer, rectifier, inverter and DC cable for modelling the DC link. The line chosen for incorporation of DC link is a weak bus. This project gives the results of load flow and along with comparison of reactive power flow, system losses, voltage in an AC and an AC-DC system.

scholarly journals Quasi-Z-Source Inverter-Based Photovoltaic Power System Modeling for Grid Stability Studies

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 508
Author(s):  
Lluís Monjo ◽  
Luis Sainz ◽  
Juan José Mesas ◽  
Joaquín Pedra
Keyword(s):  
Power Systems ◽  
Power System ◽  
System Modeling ◽  
Power Conversion ◽  
System Stability ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Stability Problems ◽  
Sensitivity Studies ◽  
And Control

Quasi-Z-source inverters (qZSIs) are becoming a powerful power conversion technology in photovoltaic (PV) power systems because they allow energy power conversion in a single stage operation. However, they can cause system resonances and reduce system damping, which may lead to instabilities. These stability problems are well known in grid-connected voltage source converter systems but not in quasi-Z-source inverter (qZSI)-based PV power systems. This paper contributes with Matlab/Simulink and PSCAD/EMTDC models of qZSI-based PV power systems to analyze transient interactions and stability problems. These models consider all power circuits and control blocks of qZSI-based PV power systems and can be used in sensitivity studies on the influence of system parameters on stability. PV power system stability is assessed from the proposed models. The causes of instabilities are analyzed from numerical simulations and possible solutions are proposed.

An Investigative Study on Impact of Frequency Dynamics in Load Modeling

2020 ◽  
Vol 01 (01) ◽  
Author(s):  
Musa Mohammed ◽  
◽  
Abubakar Abdulkarim ◽  
Adamu Sa’du Abubakar ◽  
Abdullahi Bala Kunya ◽  
...  
Keyword(s):  
Power System ◽  
Reactive Power ◽  
Low Voltage ◽  
Model Performance ◽  
System Stability ◽  
Normal System ◽  
Area Network ◽  
Load Modeling ◽  
Feed Forward Neural Network ◽  
Load Model

Load modeling plays a significant impact in assessing power system stability margin, control, and protection. Frequency in the power system is desired to be kept constant, but in a real sense, it is not constant as loads continually change with time. In much literature, frequency dynamics are ignored in the formulation of load models for the basic assumption that it does not affect the models. In this paper, the composite load model was formulated with Voltage-Frequency Dependency (V-FD) on real and reactive powers and applied to estimate the load model. 2- Area network 4- machines Kundur test network was used for testing the developed model. The model was trained with measurements from a low voltage distribution network supplying the Electrical Engineering department at Ahmadu Bello University, Zaria. Both training and testing data were captured under normal system operation (dynamics). To evaluate the V-FD model performance, Voltage-Dependent (VD) model was examined on the same measured data. The work makes use of the Feed Forward Neural Network (FFNN) as a nonlinear estimator. Results obtained indicate that including frequency dynamics in modeling active power reduces the accuracy of the model. While in modeling reactive power the model performance improves. Hence, it can be said that including frequency dynamics in load modeling depends on the intended application of the model.

Intelligent Control and Optimal Operation of Complex Electric Power Systems Using Hierarchical Neural Networks

2010 ◽  
pp. 291-320
Author(s):  
Dingguo Chen ◽  
Ronald R. Mohler
Keyword(s):  
Neural Networks ◽  
Power Systems ◽  
Optimal Operation ◽  
System Stability ◽  
Practical Applications ◽  
Control Robustness ◽  
Optimization And Control ◽  
Prediction And Control ◽  
Hierarchical Neural Networks ◽  
And Control

This chapter is aimed at developing a unified neural network based framework that can be utilized in prediction and control of complex dynamic system behaviors. In particular, in power systems, accurate prediction of system load behavior provides vital information to allow for optimal planning and most economic operation of power systems; on the other hand, the real-time system stability must be maintained against various random factors, disturbances and contingencies. The hierarchical neural networks are studied in depth in the context of prediction, optimization and control; and unified design techniques are developed for providing control robustness, optimality and prediction accuracy as well. The unified methodology builds upon hierarchical neural networks, and may be utilized and extended for other practical applications.

Novel Real-Time Stability Assessment Algorithm Based on Synchro-Phasors Measurement and Parallel Algorithms for Multi-Machine Networks.

2012 ◽  
Vol 13 (3) ◽  
Author(s):  
Mohamed Abdelwahhab Ali ◽  
Wagdy Mohamed Mansour ◽  
Wael Refaat Anis ◽  
Fahmy Metwally Bendary
Keyword(s):  
Power Systems ◽  
Parallel Algorithms ◽  
Real Time ◽  
Transient Stability ◽  
Test System ◽  
System Stability ◽  
Stability Assessment ◽  
Varying Coefficients ◽  
Rotor Angle ◽  
Time Varying Coefficients

Abstract The introduction of wide area measurements has brought a need for real time assessment methods of power systems, which are accurate and fast. The time varying coefficients in synchronous machine equations make it difficult to find solutions to obtain machine voltages, currents and flux linkages when expressed in phase quantities under transient conditions. The paper presents an approach to design power system transient stability assessment using direct methods for a multi-machine network based on multiple synchronized phasors, measured from Phasor Measurement Units (PMUs) and generator parameters. The generator rotor angle was derived from phasor measurements of voltage and current, and generator parameters using direct algorithm . The method assumes that a temporary fault is applied to the system therefore the pre-fault and post-fault conditions are similar. The multi-machine system was reduced to groups denoted Single Machine to Equivalent Bus (SMEB) models and another groups denoted Load Equivalent Bus (LEB) using Parallel Algorithms (PAs) [1]. The use of these PAs eliminates the SPMUs at each bus in the system, and it is required number of SPMUs only equals the number of generator buses. So that, the Equal Area Criterion in both rotor angle domain and time domain can be applicable for the SMEBs groups to assess the system stability in real-time through the Synchro-Phasors Measurements Units (SPMUs). A temporary three phase fault was simulated at test system comprises 2-machine, 8-bus network for validating the novel algorithm.

scholarly journals Bi-Level Dispatch and Control Architecture for Power System in China Based on Grid-Friendly Virtual Power Plant

2021 ◽  
Vol 11 (3) ◽  
pp. 1282
Author(s):  
Qingwen Xu ◽  
Yongji Cao ◽  
Hengxu Zhang ◽  
Wen Zhang ◽  
Vladimir Terzija
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Power System ◽  
Renewable Energy Sources ◽  
System Stability ◽  
Control Architecture ◽  
Virtual Power ◽  
Virtual Power Plant ◽  
Virtual Power Plants ◽  
And Control

Non-synchronous renewable energy sources (RESs) have strong volatility and low inertia, which brings about great challenges on the accommodation of RESs and the security and stability of power systems. This paper proposes a bi-level power system dispatch and control architecture based on the grid-friendly virtual power plant (GVPP), so as to accommodate RESs flexibly and securely. The typical dispatch and control system of the power system in China is presented, and the particular challenges stemming from non-synchronous RESs are analyzed. The functional requirements, concept, and fundamental design of the GVPP are provided, which is distinguished from traditional virtual power plants (VPPs) for its active participation in power system stability control. Based on the cloud platform, a bi-level dispatch and control architecture considering two objectives is established. First, in the inner level, the GVPP operates to promote the accommodation of RESs under normal condition. Then, from the perspective of out-level power systems, GVPPs serve as spinning reserves for power support under contingencies. Besides, the key problems to be solved in the development of the GVPP-based architecture are summarized. Although the architecture is proposed for the power system in China, it can be applied to any power systems with similar challenges.

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