| 1. |
- Tajdinian, Mohsen, et al.
(författare)
-
An enhanced approach for probabilistic evaluation of transient stability
- 2020
-
Ingår i: International Journal of Electrical Power & Energy Systems. - : ELSEVIER SCI LTD. - 0142-0615 .- 1879-3517. ; 120
-
Tidskriftsartikel (refereegranskat)abstract
- Due to the high penetration of renewable energy resources leading to the enhancement of uncertainty, the probabilistic assessment of the transient stability has become more important than deterministic assessment. In a previous method published by the authors, an algorithm to find the probability density function of the transient stability margin of the power system was published. This present paper presents a modified algorithm to find the probability density function of critical clearing time for each generator for the whole power grid for a certain contingency and during the fault-on period. First, the critical corrected kinetic energy is calculated based on a modified sensitivity-based algorithm at each step of the simulation during the fault-on period. Since the total kinetic energy of the generators does not contribute in the critical kinetic energy of the whole system, a new criterion - based on the rate of change of kinetic energy - is utilized to classify severely disturbed generators from less disturbed generators. Utilizing critical corrected kinetic energy of the whole power grid, an index based on the critical clearing time, so-called network critical clearing time, is calculated. Eventually, the proposed algorithm is applied on the optimal placement of a superconducting magnetic energy storage unit. It is shown that utilizing the proposed objective function for locating superconducting magnetic energy storage units effectively results in the improvement of the transient stability margin of the power system.
|
|
| 2. |
- Azizi, Ali, et al.
(författare)
-
Decentralized Multi-Objective Energy Management With Dynamic Power Electronic Converters and Demand Response Constraints
- 2023
-
Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 11, s. 146297-146312
-
Tidskriftsartikel (refereegranskat)abstract
- Energy management plays a pivotal role in enhancing the economic efficiency of power systems. However, it is noteworthy that a substantial number of microgrids (MGs) exhibit inherent unbalances that impose a range of critical issues, including voltage instability, elevated losses, power quality violations, safety concerns, and inefficiencies in energy management. Fast-acting power electronic converters present a relevant and efficacious solution for balancing such complex networks. This paper investigates the application of such converters within the realm of 3-phase unbalanced networks, wherein the proposed algorithm not only ameliorates network imbalances but also yields substantial reductions in operational costs, power losses, voltage deviations, and emissions. Demand response (DR) program has been applied to the model to enhance the system efficiency. The uncertainty about electric demand and renewable energy sources is considered in the simulation model for precise results. By implementing DR programs and penetrating distributed generators (DGs), the proposed model has been shown to reduce network losses and operation costs by 23% and 80%, respectively. Also, the total up-to-down voltage deviation of the voltage profile has been significantly reduced by 400%.
|
|
| 3. |
- Keivanimehr, Mehran, et al.
(författare)
-
Load Shedding Frequency Management of Microgrids Using Hierarchical Fuzzy Control
- 2021
-
Ingår i: 2021 World Automation Congress (WAC). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 216-221
-
Konferensbidrag (refereegranskat)abstract
- Frequency control is one important issue in autonomous operating mode of Microgrids (MGs). In stand-alone microgrids, when generation power is not enough, it is inevitable to shed some parts of the load. This paper presents a decentralized fuzzy controller for optimal load shedding in MGs. The proposed controller which is separately installed for each load center uses a hierarchical fuzzy controller approach to make the optimal decision. Three inputs of the hierarchical fuzzy controller are the power of non-critical load, the load energy not supplied and its interruption frequency. From a specific time of the past, these inputs are calculated for all load centers, and updated periodically. The non-critical part of the loads which can be shed to survive network. Each decentralized controller of the loads has a bilateral communication with the microgrid central controller to transact some information, periodically. Simulation results on a typical microgrid with several load buses showing the effectiveness of the proposed method.
|
|
