scholarly journals Transient Stability Prediction for Real-Time Operation by Monitoring the Relative Angle with Predefined Thresholds

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 838 ◽  
Author(s):  
A. Diaz-Alzate ◽  
John Candelo-Becerra ◽  
Juan Villa Sierra
Keyword(s):  
Power Systems ◽  
Power System ◽  
New England ◽  
Real Time ◽  
Transient Stability ◽  
Online Data ◽  
Relative Angle ◽  
Time Operation ◽  
Real Time Operation ◽  
Measurement Units

Under real-time operation, early detection of oscillations that lead to instability is of noteworthy importance for power system operators. This paper demonstrates how the relative angle (RA) obtained with online data from phasor measurement units (PMUs) and predefined thresholds of the relative angle (PTRA) obtained with offline simulations are valuable for the monitoring and prediction of transient stability. Primary features of the method consist of first calculating the maximum and minimum relative angles by offline simulations of different contingencies. Next, the voltage angles at buses that represent areas of the power system are measured to calculate the center of inertia (COI). Finally, the RA of the generators at each area is determined during the online operation to monitor stability behaviors and identify those that lead to a loss of synchronism. The method was validated in the New England 39-bus and the IEEE 118-bus power systems by performing contingencies, finding critical stability angles, monitoring areas and controlling the predicted unstable events with control actions, such as generation and load tripping, with enough time to return to stability.

scholarly journals Localized Transient Stability (LTS) Method for Real-time Localized Control

2018 ◽  
Vol 7 (1) ◽  
pp. 73
Author(s):  
Abdul Malek Miah
Keyword(s):  
Power Systems ◽  
Power System ◽  
New England ◽  
Real Time ◽  
Transient Stability ◽  
Stable Equilibrium ◽  
Measured Data ◽  
Test Results ◽  
Generator System ◽  
Full Power

<p>Very recently, a new methodology was introduced solely for the purpose of real-time localized control of transient stability. The proposed new method is based on the localized transient stability of a power system. This is completely a new idea in transient stability. In this method, the post-fault power system is represented by a two-generator localized power system at the site of each individual generator. If each of these localized power systems reaches its respective stable equilibrium, then the full power system also reaches its stable equilibrium. Therefore, in terms of real-time localized control of transient stability, if each of the localized power systems is driven to its respective stable equilibrium by local control actions with local computations using the locally measured data, then the full power system is driven to its stable equilibrium. Thus the method can be easily implemented for real-time localized control of transient stability. In this paper, the details of the mathematical formulations are presented. Some interesting test results on the well-known New England 39-bus 10-generator system are also presented in this paper to demonstrate the potential of the proposed method for use in real-time localized control of transient stability.</p><p> </p>

scholarly journals Transient Stability Control Based on Kinetic Energy Changes Measured by Synchronized Angular Velocity

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6893
Author(s):  
A. F. Diaz-Alzate ◽  
John E. Candelo-Becerra ◽  
Albert Deluque-Pinto
Keyword(s):  
Kinetic Energy ◽  
Angular Velocity ◽  
Power Systems ◽  
Real Time ◽  
Transient Stability ◽  
Stability Control ◽  
Area Measurement ◽  
Velocity Signal ◽  
Large Power ◽  
Time Operation

Real-time transient stability studies are based on voltage angle measures obtained with phasor measurement units (PMUs). A more precise calculation to address transient stability is obtained when using the rotor angles. However, these values are commonly estimated, which leads to possible errors. In this work, the kinetic energy changes in electric machines are used as a criterion for evaluating and correcting transient stability, and to determine the precise time of insertion of a special protection system (SPS). Data from the PMU of the wide-area measurement system (WAMS) are used to construct the SPS. Furthermore, it is assumed that a microcontroller can be located in each generation unit to obtain the synchronized angular velocity. Based on these measurements, the kinetic energy of the system and the respective control action are performed at the appropriate time. The results show that the proposed SPS effectively corrects the oscillations fast enough during the transient stability event. In addition, the proposed method has the advantage that it does not depend on commonly proposed methods, such as system models, the identification of coherent machine groups, or the structure of the network. Moreover, the synchronized angular velocity signal is used, which is not commonly measured in power systems. Validation of the method is carried out in the New England power system, and the findings show that the method is helpful for real-time operation on large power systems.

scholarly journals Multi-Objective Stochastic Optimization for Determining Set-Point of Wind Farm System

2021 ◽  
Vol 13 (2) ◽  
pp. 624
Author(s):  
Van-Hai Bui ◽  
Akhtar Hussain ◽  
Thai-Thanh Nguyen ◽  
Hak-Man Kim
Keyword(s):  
Power System ◽  
Stochastic Optimization ◽  
Real Time ◽  
Output Power ◽  
Wind Farm ◽  
Reserve Capacity ◽  
Set Point ◽  
Time Operation ◽  
Real Time Operation ◽  
Optimal Set

Due to the uncertainty in output power of wind farm (WF) systems, a certain reserve capacity is often required in the power system to ensure service reliability and thereby increasing the operation and investment costs for the entire system. In order to reduce this uncertainty and reserve capacity, this study proposes a multi-objective stochastic optimization model to determine the set-points of the WF system. The first objective is to maximize the set-point of the WF system, while the second objective is to maximize the probability of fulfilling that set-point in the real-time operation. An increase in the probability of satisfying the set-point can reduce the uncertainty in the output power of the WF system. However, if the required probability increases, the set-point of the WF system decreases, which reduces the profitability of the WF system. Using the proposed method helps the WF operator in determining the optimal set-point for the WF system by making a trade-off between maximizing the set-point of WF and increasing the probability of fulfilling this set-point in real-time operation. This ensures that the WF system can offer an optimal set-point with a high probability of satisfying this set-point to the power system and thereby avoids a high penalty for mismatch power. In order to show the effectiveness of the proposed method, several case studies are carried out, and the effects of various parameters on the optimal set-point for the WF system are also analyzed. According to the parameters from the transmission system operator (TSO) and wind speed profile, the WF operator can easily determine the optimal set-point using the proposed strategy. A comparison of the profits that the WF system achieved with and without the proposed method is analyzed in detail, and the set-point of the WF system in different seasons is also presented.

An Instructional Power Systems Laboratory

1997 ◽  
Vol 34 (1) ◽  
pp. 5-15
Author(s):  
Jan Heydeman
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Real Time ◽  
Transient Stability ◽  
Dynamic Loads ◽  
Research And Teaching ◽  
University Of Technology ◽  
Power Frequency

A real time analog power system simulator for research and teaching has been developed at Delft University of Technology. The simulator consists of 1 swing bus, 7 generators, 2 tap changing transformers, 9 dynamic loads, 12 lines and 12 busbars. Experiments on control of voltage and power-frequency and on steady-state and transient stability are shown.

scholarly journals Comparison of Two Energy Management System Strategies for Real-Time Operation of Isolated Hybrid Microgrids

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6770
Author(s):  
Luis Santiago Azuara-Grande ◽  
Santiago Arnaltes ◽  
Jaime Alonso-Martinez ◽  
Jose Luis Rodriguez-Amenedo
Keyword(s):  
Power Systems ◽  
Real Time ◽  
Energy Management ◽  
Management System ◽  
Optimization Criterion ◽  
Optimal Operation ◽  
Energy Management System ◽  
Correct Operation ◽  
Time Operation ◽  
Real Time Operation

The propagation of hybrid power systems (solar–diesel–battery) has led to the development of new energy management system (EMS) strategies for the effective management of all power generation technologies related to hybrid microgrids. This paper proposes two novel EMS strategies for isolated hybrid microgrids, highlighting their strengths and weaknesses using simulations. The proposed strategies are different from the EMS strategies reported thus far in the literature because the former enable the real-time operation of the hybrid microgrid, which always guarantees the correct operation of a microgrid. The priority EMS strategy works by assigning a priority order, while the optimal EMS strategy is based on an optimization criterion, which is set as the minimum marginal cost in this case. The results have been obtained using MATLAB/Simulink to verify and compare the effectiveness of the proposed strategies, through a dynamic microgrid model to simulate the conditions of a real-time operation. The differences in the EMS strategies as well as their individual strengths and weaknesses, are presented and discussed. The results show that the proposed EMS strategies can manage the system operation under different scenarios and help power system operator obtain the optimal operation schemes of the microgrid.

Sign in / Sign up

Export Citation Format

Share Document