Transient control and voltage regulation of power systems using approximate solution of HJB equation

Author(s):  
Mahdi Jalili Kharaajoo ◽  
M.J. Yazdanpanah
2013 ◽  
Vol 2 (1) ◽  
pp. 78-100 ◽  
Author(s):  
Hassan Bevrani ◽  
Mehrdad Gholami ◽  
Neda Hajimohammadi

Economical harvesting of electrical energy on a large scale considering the environmental issues is a challenge. As a solution, Microgrids (MGs) promise to facilitate the widely penetration of renewable energy sources (RESs) and energy storage devices into the power systems, reduce system losses and greenhouse gas emissions, and increase the reliability of the electricity supply to the customers. Although the concept of MG is already established, the control strategies and energy management systems for MGs which cover power interchange, system stability, frequency and voltage regulation, active and reactive power control, islanding detection, grid synchronization, following contingencies and emergency conditions are still under development. Like a conventional power system, a Micro-grid (MG) needs emergency control and protection schemes to have secure and stable operation. Since MG can operate in both grid-connected and islanded mode, in addition to the control loops and protection schemes, extra issues must be considered. Transition between two operation modes requires an extra control plan to eliminate and stabilize transients due to mode changing. This paper presents an overview of the key issues and new challenges on emergency control and protection plans in the MG systems. The most important emergency control and protection schemes such as load shedding methods that have been presented over the past years are summarized.


2001 ◽  
Vol 21 (10) ◽  
pp. 60-60 ◽  
Author(s):  
Y. Guo ◽  
D. J. Hill ◽  
Y. Wang

2019 ◽  
Vol 9 (14) ◽  
pp. 2813 ◽  
Author(s):  
Sayed Mir Shah Danish ◽  
Ryuto Shigenobu ◽  
Mitsunaga Kinjo ◽  
Paras Mandal ◽  
Narayanan Krishna ◽  
...  

A number of studies realized operation of power systems are unstable in developing countries due to misconfiguration of distribution systems, limited power transfer capability, inconsistency of renewable resources integration, paucity of control and protection measures, timeworn technologies, and disproportionately topology. This study underlines an Afghanistan case study with 40% power losses that is mainly pertinent from old distribution systems. The long length of distribution systems, low-power transfer capability, insufficient control and protection strategy, peak-demand elimination, and unstable operation (low energy quality and excessive voltage deviations) are perceived pre-eminent challenges of Afghanistan distribution systems. Some attainable solutions that fit challenges are remodeling (network reduction), networks reinforcement, optimum compensation strategy, reconfiguration options, improving, and transfer capability. This paper attempts to propose a viable solution using multiobjective optimization method of auto-tap-changer pole transformer (ATCTr). The proposed methodology in terms of optimal numbers and placement of ATCTr can be known as a novel two-dimensional solution. For this purpose, a real case of Kabul City distribution system is evaluated. Simulation results indicate the effectiveness of the proposed method in reducing system losses and improving system overall performance. This approach tends to regulate the voltage deviation in a proper and statutory range with minimum number and optimum placement of ATCTrs. The proposed method is simulated using MATLAB® environment to compare and evaluate performance of the proposed network under different situations and scenarios.


2013 ◽  
Vol 2 (3) ◽  
pp. 216
Author(s):  
Rekha Chaudhary ◽  
Arun Kumar Singh

The objective of this paper is to design controller for non-linear power system using Direct Feedback Linearization technique to improve the transient stability and to achieve better voltage regulation. In case of fault in the power system, power angle and the terminal voltage are the parameters which are to be monitored. The simulation has been carried out taking different values of initial power angles and results were obtained for power angle and terminal voltage. To overcome the demerits of DFL-LQ optimal controller and DFL voltage regulator, co-ordinated controller is proposed. Simulation results show that transient stability of a power system under a large sudden fault has been improved by using co-ordinated controller.


2020 ◽  
Vol 35 (4) ◽  
pp. 2726-2735 ◽  
Author(s):  
Fengjie Hao ◽  
Gang Zhang ◽  
Jie Chen ◽  
Zhigang Liu ◽  
Dongsheng Xu ◽  
...  

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