0000000000073950
AUTHOR
N. P. Patidar
Optimized design of wide-area PSS for damping of inter-area oscillations
In this paper a genetic algorithm based wide area power system stabilizer (PSS) in a multi machine power system for damping of low frequency inter-area oscillations has been presented. The wide area PSS is composed of two stages, the input of one stage is a local signal and the input of other is a global signal. Geometric measure of controllability and observability is used to select the most effective stabilizing signals and location of controller. Tie line active power flow deviation is found to be the most effective input signal. Time domain based objective function is minimized, in which the deviation in the oscillatory rotor speed of generator is involved so that the stability performa…
Load management for voltage security using probabilistic fuzzy decision tree method
During contingency, load management is most important in planning, monitoring and controlling of power system. In transmission system, there is limit for controlling the reactive power in large size power network. In order to manage heavy loading on transmission, load management is necessary to avoid voltage collapse. This paper presents a methodology for load management considering voltage security assessment using probabilistic fuzzy decision tree (PFDT) technique. By using probabilistic fuzzy decision tree method, the load management is calculated in optimal manner in real time and insecure operating conditions are observed. With the help of this method, a real time load management plan …
Minimizing uncertainties with improved power system stability using wide area fuzzy-2 logic based damping controller
In this paper, a centralized Wide Area Damping Controller (WADC) is synthesized based on Interval Type-2 Fuzzy Logic controller. The disturbance is symbolized as distributed in the network with application of momentarily disturbance to the generator in area 1 for few cycles. The response of tie-line active power flow from area-1 to area-2, rotor speed change, rotor mechanical angle deviation, positive sequence voltage are examined by considering the test system with conventional PSS (CPSS), fuzzy type-1 based controller and fuzzy type-2 based controller. The proposed controller performance is analyzed and compared with fuzzy type-1 based controller and CPSS. The simulation results are used …
Passive congregation based particle swam optimization (pso) with self-organizing hierarchical approach for non-convex economic dispatch
This paper proposes a passive congregation based PSO with self-organizing hierarchical algorithm approach for solving the economic dispatch problem of power system, where some of the units have prohibited operating zones. This Algorithm is known to perform better than conventional gradient based optimization methods for non-convex optimization problems. Conventional PSO algorithm is a population based heuristic search, employing problem of premature convergence. In this work, an innovative approach based on the concept of passive congregation based PSO with self-organizing hierarchical approach is employed to overcome the problem of premature convergence in classical PSO method.
Optimal signal selection of wide area damping controller considering time delay in multi-machine power system
This paper presents a validation of selection process for selecting the most effective stabilizing signal to improve damping of inter area oscillations in a multi-machine power system by different signal selection methods. This paper also deals with wide area damping controller scheme compensating time latency of feedback signal in order to damp low frequency inter area oscillations in large power system. Pade approximation to time delay is used with controller synthesis. Eigenvector based coherent machine identification method has been adapted in this research for coherent area identification in multi-machine power system. The selected control signal is tested on the 4 machine 11 bus syste…
Performance Degradation of Discrete PID Controller for Digital Excitation Control System Due to Variation of Sampling Time
Modern digital AVR are consisting PID controller in forward path ensures fast response in the event of disturbance. Digital keypad is used for setting PID gains to improve performance of the system. Digital PID controller reads the error signal at regular interval unlike analog controller that reads the error signal continuously. Regular interval at which digital processor reads error signal is called sampling time that has substantial effect on the performance of the controller and consequently affects the stability of the power system where synchronous generator using digital excitation system is connected in parallel. This paper addresses the issues of variation of sampling time on the p…
Voltage Security Assessment by Using PFDT and CBR Methods in Emerging Power System
Abstract This paper exhibits varied methods for voltage security assessment in a restructured power system. This paper primarily lays emphasis on two methods that are Probabilistic Fuzzy Decision Tree (PFDT) and Case Based Reasoning (CBR). In PFDT, Decision Tree plays an integral role for classification of system. For further classification of power system security, an algorithm is developed to categorise the buses which trouble the security most. After classification of system, by using minimum amount of load curtailment of voltages on buses which made insecure to secure load. Optimization of load is done by curtailing reactive power from insecure buses. In CBR, old cases from database are…
Cascaded PD-PI controller for active power frequency control of two-area multi-units power system
In interconnected multi-area power system; the real power generation within each area has to be managed through active power frequency control considering scheduled power exchange. In this work, two different controllers, namely cascaded PD-PI and conventional PID controller are considered for analyzing the dynamic response of the two area interconnected power system. Area-1 consists of two reheat type thermal generating power plant units and area-2 comprises of two non-reheat type thermal power plant units. The controller gains of PD-PI and PID controllers are efficiently tuned by ‘Teaching Learning based Optimization Technique’. In area-1, 1% step load disturbance is applied for analyzing…
Frequency Regulation of Hybrid Power System by Optimized Adaptive Fuzzy PID Controller
In this study, an adaptive fuzzy PID (AFPID) regulator has been proposed for frequency control of hybrid power system. For controller parameter optimization, an upgraded Whale Optimization Algorithm (WOA) has been employed. In the proposed Upgraded WOA (UWOA) technique, a cosine function is incorporated in the original WOA for determining control parameter to manage the position of whales throughout optimization procedure. Furthermore, scaling factors are employed in original WOA to adjust the travel of whales in search procedure. Proposed UWOA technique is employed to design an AFPID controller for frequency regulation of a hybrid power system It is demonstrated that UWOA technique out per…
Coherency identification and oscillation damping effects of PSS in interconnected power system: A comparative analysis approach
This paper analyzes four different test systems for defining coherent generators in the multi machine power systems based on the Eigen properties of the linearized model of the inter connected power system. The disruption is measured to be dispersed in the network by smearing small signal disturbance in each case. For finding the coherent areas and their tolerances in the inter-connected power system, no generator buses are allocated to each cluster of coherent generator using similar coherency recognition methods. The technique is assessed with four test schemes, and coherent generators and zones are acquired for diverse functioning points to render a more precise consortium approach, whic…