Stability Index Based Voltage Collapse Prediction and Contingency Analysis

C. Subramani,Subhransu Sekhar Dash,M. Jagdeeshkumar,M. Arun Bhaskar 대한전기학회 2009 Journal of Electrical Engineering & Technology Vol.4 No.4

Voltage instability is a phenomenon that could occur in power systems due to stressed conditions. The result would be an occurrence of voltage collapse leading to total blackout of the system. Therefore, voltage collapse prediction is an important part of power system planning and operation, and can help ensure that voltage collapse due to voltage instability is avoided. Line outages in power systems may also cause voltage collapse, thereby implying the contingency in the system. Contingency problems caused by line outages have been identified as one of the main causes of voltage instability in power systems. This paper presents a new technique for contingency ranking based on voltage stability conditions in power systems. A new line stability index was formulated and used to identify the critical line outages and sensitive lines in the system. Line outage contingency ranking was performed on several loading conditions in order to identify the effect of an increase in loading to critical line outages. Correlation studies on the results obtained from contingency ranking and voltage stability analysis were also conducted, and it was found that line outages in weak lines would cause voltage instability conditions in a system. Subsequently, using the results from the contingency ranking, weak areas in the system can be identified. The proposed contingency ranking technique was tested on the IEEE reliability test system.

Stability Index Based Voltage Collapse Prediction and Contingency Analysis

Subramani, C.,Dash, Subhransu Sekhar,Jagdeeshkumar, M.,Bhaskar, M. Arun The Korean Institute of Electrical Engineers 2009 Journal of Electrical Engineering & Technology Vol.4 No.4

Voltage instability is a phenomenon that could occur in power systems due to stressed conditions. The result would be an occurrence of voltage collapse leading to total blackout of the system. Therefore, voltage collapse prediction is an important part of power system planning and operation, and can help ensure that voltage collapse due to voltage instability is avoided. Line outages in power systems may also cause voltage collapse, thereby implying the contingency in the system. Contingency problems caused by line outages have been identified as one of the main causes of voltage instability in power systems. This paper presents a new technique for contingency ranking based on voltage stability conditions in power systems. A new line stability index was formulated and used to identify the critical line outages and sensitive lines in the system. Line outage contingency ranking was performed on several loading conditions in order to identify the effect of an increase in loading to critical line outages. Correlation studies on the results obtained from contingency ranking and voltage stability analysis were also conducted, and it was found that line outages in weak lines would cause voltage instability conditions in a system. Subsequently, using the results from the contingency ranking, weak areas in the system can be identified. The proposed contingency ranking technique was tested on the IEEE reliability test system.

Zero-one Integer Programming Approach to Determine the Minimum Break Point Set in Multi-loop and Parallel Networks

Moirangthem, Joymala,Dash, Subhransu Sekhar,Ramaswami, Ramas The Korean Institute of Electrical Engineers 2012 Journal of Electrical Engineering & Technology Vol.7 No.2

The current study presents a zero-one integer programming approach to determine the minimum break point set for the coordination of directional relays. First, the network is reduced if there are any parallel lines or three-end nodes. Second, all the directed loops are enumerated to reduce the iteration. Finally, the problem is formulated as a set-covering problem, and the break point set is determined using the zero-one integer programming technique. Arbitrary starting relay locations and the arbitrary consideration of relay sequence to set and coordinate relays result in navigating the loops many times and futile attempts to achieve system-wide relay coordination. These algorithms are compared with the existing methods, and the results are presented. The problem is formulated as a setcovering problem solved by the zero-one integer programming approach using LINGO 12, an optimization modeling software.

An Efficient Control Strategy Based Multi Converter UPQC using with Fuzzy Logic Controller for Power Quality Problems

Paduchuri. Chandra Babu,Subhransu Sekhar Dash,C. Subramani,S. Harish Kiran 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

A custom power device provides an integrated solution to the present problems that are faced by the utilities and power distribution. In this paper, a new controller is designed which is connected to a multiconverter unified power quality conditioner (MC-UPQC) for improving the power quality issues adopted modified synchronous reference frame (MSRF) theory with Fuzzy logic control (FLC) technique. This newly designed controller is connected to a source in order to compensate voltage and current in two feeders. The expanded concept of UPQC is multi converter-UPQC; this system has a two-series voltage source inverter and one shunt voltage source inverter connected back to back. This configuration will helps mitigate any type of voltage / current fluctuations and power factor correction in power distribution network to improve power quality issues. In the proposed system the power can be conveyed from one feeder to another in order to mitigate the voltage sag, swell, interruption and transient response of the system. The control strategies of multi converter-UPQC are designed based on the modified synchronous reference frame theory with fuzzy logic controller. The fast dynamics response of dc link capacitor is achieved with the help of Fuzzy logic controller. Different types of fault conditions are taken and simulated for the analysis and the results are compared with the conventional method. The relevant simulation and compensation performance analysis of the proposed multi converter-UPQC with fuzzy logic controller is performed.

Factors affecting long-term availability of medicinal plants in India

Singh Preet Amol,Dash Subhransu,Choudhury Abinash,Bajwa Neha 한국작물학회 2024 Journal of crop science and biotechnology Vol.27 No.2

The majority of conventional medications and food supplements are created following the processing of medicinal plants. As majority of the medicinal plants are collected from the forests, the rise in the demand for herbal goods is placing significant strain on the forests while encouraging unsustainable wild harvesting of therapeutic plants. The current study's objective is to gain insight into current debates on the value chain of medicinal or therapeutic plants, role of various Indian acts, i.e., Forest Act, Forests Right Act, export, and other variables affecting the sustainable supply of herbs. A targeted literature search on online databases, scientific studies, and authentic texts was performed to understand the value chain, consumption, export, Indian laws, endangered species, and capacity building institutions, limitations, and future of medicinal plants. The World Flora Online database was used to verify the scientific names of the plants. Value chains for medicinal plants are wide and complex. There is need to weaken the role of middlemen and giving forest gatherers and farmers more negotiating leverage especially through artificial intelligence. The Ministry of AYUSH and National Medicinal Plants Board both play significant roles in India's medicinal plant sector. The different acts and rules pertaining to medicinal plants conservation, usage, transit, and trade should work in harmony and there is need for exclusive medicinal plants policy across India. Maintaining a balance between the protection of medical plant species and a sustainable supply of herbs to support the sector based on medicinal plants while empowering forest gatherers is urgently needed

Online Control of DC Motors Using Fuzzy Logic Controller for Remote Operated Robots

Prema, K.,Kumar, N. Senthil,Dash, Subhransu Sekhar The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

In this paper, a fuzzy logic controller is designed for a DC motor which can be used for navigation control of mobile robots. These mobile robots can be used for agricultural, defense and assorted social applications. The robots used in these fields can reduce manpower, save human life and can be operated using remote control from a distant place. The developed fuzzy logic controller is used to control navigation speed and steering angle according to the desired reference position. Differential drive is used to control the steering angle and the speed of the robot. Two DC motors are connected with the rear wheels of the robot. They are controlled by a fuzzy logic controller to offer accurate steering angle and the driving speed of the robot. Its location is monitored using GPS (Global Positioning System) on a real time basis. IR sensors in the robot detect obstacles around the robot. The designed fuzzy logic controller has been implemented in a robot, which depicts that the robot could avoid obstacle as well as perform its operation efficiently with remote online control.

Online Control of DC Motors Using Fuzzy Logic Controller for Remote Operated Robots

K. Prema,N. Senthil Kumar,Subhransu Sekhar Dash 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

In this paper, a fuzzy logic controller is designed for a DC motor which can be used for navigation control of mobile robots. These mobile robots can be used for agricultural, defense and assorted social applications. The robots used in these fields can reduce manpower, save human life and can be operated using remote control from a distant place. The developed fuzzy logic controller is used to control navigation speed and steering angle according to the desired reference position. Differential drive is used to control the steering angle and the speed of the robot. Two DC motors are connected with the rear wheels of the robot. They are controlled by a fuzzy logic controller to offer accurate steering angle and the driving speed of the robot. Its location is monitored using GPS (Global Positioning System) on a real time basis. IR sensors in the robot detect obstacles around the robot. The designed fuzzy logic controller has been implemented in a robot, which depicts that the robot could avoid obstacle as well as perform its operation efficiently with remote online control.