Optimal location of static var compensator device for damping oscillations

Problem statement: Static Var Compensators (SVC) devices are used to improve voltage and reactive power conditions in AC systems. An additional task of SVC is to increase transmission capacity as result of power oscillation damping. The effectiveness of this controller depends on its optimal location and proper signal selection in the power system network. A residue factor had been proposed to find the optimal location of the SVC controllers to damp out the inter-area mode of oscillations. Approach: The proposed residue factor was based on the relative participation of the parameters of SVC controller to the critical mode. A simple approach of computing the residue factor had been proposed, which combined the linearized differential algebraic equation model of the power system and the SVC output equations. Input-output controllability analyses were used to assess the most appropriate input signals (stabilizing signal) for SVC device. Results: The placements of SVC controller had been obtained for the base case as well as for the critical contingency cases. Conclusion: The effectiveness of the proposed method was demonstrated on 25 bus of south Malaysian power system

New combined model of high impedance arcing fault in overhead transmission system

High impedance fault is a popular complex phenomenon that exhibits high nonlinear behavior. For most distinctive characteristics of high impedance fault, are asymmetry and nonlinearity, so, in order to obtain an accurate model of high impedance fault, it is necessary to develop a model that gives the most distinctive characteristics of high impedance fault. In this paper we propose a novel model of high impedance arcing fault in electrical power transmission system. Proposed model is based on the digital arc model incorporated with specially developed custom model which has been designed in PSCAD/EMTDC program. The results is clearly reveal that the proposed model gives the important characteristics of high impedance fault (HIF) which is essential for development of reliable detection algorithms

A hybrid power transfer allocation approach for deregulated power systems

Power transfer allocation is one of the major issues in deregulated power industry. This paper presents a hybrid technique for power transfer allocation. It is based on combining the existing power flow tracing methods that determines the power share from generators to line flows and loads. The advantages of the proposed method are demonstrated by the tests conducted on the IEEE 30-bus system and also on a practical bus equivalent power system of south Malaysia. The proposed method provides better reliability and minimizes the limitations of conventional power flow tracing methods

Wind and solar radiation potential assessment in Kano, Nigeria using Weibull and Samani models

clean, source free, environmentally friendly and renewable source of energy such as wind and solar energy can be used for providing sustainable power supply to remedy an epileptic and unreliable power supply systems. For decades, electric power supply situation in Kano, Nigeria has been a major source of serious concern. The epileptic power supply has hindered the socio-economic growth industrialization and, subsequently, increase air pollution due to individual stand-alone diesel generators. Various government incentives and policies have little or no effect to improve the availability and reliability of the electric power. The aviation industries especially the Navigation and communication equipment required, apart from availability, a reliable power sources because of their sensitivity to reliable and safe Aircraft navigation. The need for an alternate renewable energy system (RES) of power supply away from the National grid and diesel generator is inevitable at Kano. This paper proposes an assessment of wind and solar energy potentialities at Kano in Nigeria using Weibull distribution methods and the Samani model to determine the wind features and estimate global solar radiation potentials respectively for power supply generation. A six years (2009-2014) monthly mean wind speed data measured at 10 m height was collected and extrapolated to 50 m height level for statistical analysis, while 22 years monthly solar radiation, temperature amplitude and relative humidity of the location were obtained from NASA web to calibrate, validate and evaluate the Samani model, ten years (2003-2012) maximum and minimum temperature were then used to predict the global solar radiation on horizontal surface of the location. The minimum Weibull average wind speed was found to be 8.60 m/s and the maximum average wind speed was 11.24 m/s while the minimum power density was 440.03 W/m2 and the highest was 947.26 W/m2 at the 10 m height level. The lowest average global solar radiation on the horizontal surface was 17.96 MJ/m2/d and highest average global solar radiation on the horizontal surface was 26.38 MJ/m2/d. The site has been found to have great potentials for wind and solar utility power generation capacity

Application of ANFIS for Distance Relay Protection in Transmission Line

The techniques hybrid intelligent was introduced in transmission protection that usage in electric power systems. There was applied ANFIS for distance relay protection particularly for transmission line. If a fault occurs during the transmission line identification caused by unwanted fault thus the power delivery to the consumer becomes not going well. Therefore, it would need to provide an alternative solution to fix this problem. The objective of this paper uses impedance transmission line to determine how long the channel spacing will be protected by distance relay. It has been distance relays when fault occurs in transmission line with the application Sugeno ANFIS. The simulation shows it excellent testing results can be contributed to an alternate algorithm that it has good performance to protecting system in transmission line. This application used by using software Matlab

Improving Voltage Profile of Islanded Microgrid using PI Controller

In islanding operating mode of microgrid, the voltage and frequency of system must be maintained by the microgrid, or else the system will crumble due to the characteristics of different distributed generators (DG) utilized in microgrid. The voltage and frequency lost provision when main grid is disconnected. This paper presents PI controller based voltage controller to regulate voltage to its normal condition. The controller is proposed to be utilized individually with each distributed generator (DG) in microgrid. The controller compares inverter output voltage with voltage at point of common coupling (PCC) and its output is feed to PWM pulse generator to generate appropriate pulses for inverter to regulate voltage to its nominal value. The simulation results of proposed system are shown using MATLAB/Simulink platform

Optimal location of FACTS devices for damping oscillations

Damping of electromechanical oscillations between interconnected synchronous generators is necessary for a secure system operation. While local oscillations involving one or more generators swinging against the rest of the system are mainly influenced by a restricted number of local system parameter- the behavior of low frequency inter-area oscillations is generally determined by global parameters of larger parts of the power system. Power System Stabilizers (PSSs) applied on selected generators can effectively damp local oscillation modes; their limited influence on inter-area modes, however, lead to the fact that they may not be considered as the only solution to damp interarea oscillations. Flexible AC Transmission Systems are being increasingly used to better utilize the capacity of existing transmission systems. Flexible AC Transmission System (FACTS) is a technology based solution to help the utility industry deal with changes in the power delivery business. A major thrust of FACTS technology is the development of power electric based systems that provide dynamic control of the power transfer parameters transmission voltage, line impedance and phase angle [1]. The static var compensator (SVC), which is a shunt device, provides dynamically variable shunt impedance to regulate the series compensator (TCSC), which is a Series FACTS controller, is used to change the effective reactance of the line dynamically, thereby controlling the real power flow in the lines. The unified power flow controller (UPFC) is used to control the real and reactive powers simultaneously in a line by injecting a series voltage across the line. It also injects a shunt reactive current at one of the line-end buses to maintain the bus voltage at a specified value [2, 3]. FACTS devices are provided with supplementary controllers for damping out small signal oscillations [4-8], and the effectiveness of damping the oscillations depends on the location of FACTS controllers. Several methods [2–4] have been proposed for the placement of FACTS controllers. Previous studies [9–10] considered only static criterion like improving power transfer, available transfer capability (ATC), loss minimizations and did not consider any dynamic criteria for the placement of the FACTS controllers. A sensitivity based approach has been developed in some researches for determining the optimal placement of FACTS devices in electricity market having pool and contractual dispatches [11-13]. [11] Shows that few locations of FACTS devices can be decided based on sensitivity factors and then optimal dispatch problem must solved for finding suitable placement of UPFC in a congested system. [15] Implements Genetic Algorithm to finding the best location for TCSC to maximizing total transfer capacity. Tuning of FACTS parameters has been proposed for improving damping of weakly damped inter-area modes. [16-17] proposed a method for selecting suitable feedback signal to FACTS controllers for improving the damping. Sadikovic and Korba [18] used residue, called location index for effective damping, to find suitable location for damping inter-area mode of oscillations, also in the work of [14] and [19], the method used only UPFC placement based on only single operating condition. No consideration of other FACTS devices

Investigating the impact of distributed generators power factor to simultaneous optimization analysis

In this paper, the Particle Swarm Optimization (PSO) technique is used to determine the optimal coordination for Distributed Generator (DG). The DG output and location is determined simultaneously. Furthermore, this study covers both single and multiple DGs analyses. Five different Power Factor (PF) values are also assigned to the DG units, which are 0.8, 0.85, 0.9, 0.95 and 1.0. Thus, the impacts of DG power factor to the optimal placement and output are investigated. From the result, the optimal DG placement is similar, regardless of the PF condition. For the single DG unit, the optimal location is bus 6 and for three DGs analysis, the optimal locations are at buses 14, 24, 30. However, the PF significantly influences the optimal DG output, power loss reduction and voltage profile improvement. Three DGs with PF 0.8 is the best option to reduce the power loss in the distribution network to the lowest valu

Thyristor control series capacitor ANFIS controller for damping oscillations

This study applies Adaptive Neuro Fuzzy Inference System (ANFIS)-based TCSC controller for damping oscillations. ANFIS which tunes the fuzzy inference system with a back propagation algorithm based on collection of input-output data makes fuzzy system to learn ANFIS controller is designed to damp out the low frequency local and inter-area oscillations of the Multimachine power system. Direct inverse control techniques are used in the design-of TCSC ANFIS controller which is derived directly from neural networks counterpart’s methodologies of the power system and the controller network to provide optimal damping. By applying this controller to the TCSC devices the damping of inter-area modes of oscillations in a multi-machine power system is handled properly. The effectiveness of the proposed TCSC ANFIS controller is demonstrated on two area four machine power system (Kundur system) which has provided a comprehensive evaluation of the learning control performance. Finally, several fault and load disturbance simulation results are presented to stress the effectiveness of the proposed TCSC controller in a multimachine power system and show that the proposed intelligent controls improve the dynamic performance of the TCSC devices and the associated power networ

Determination of best location of UPFC device for damping oscillation

Unified Power Flow Controller (UPFC) is use for controlling the real and reactive power on the transmission line and the bus voltage simultaneously and independently. An additional task of UPFC is to increase transmission capacity as result of power oscillation damping. The effectiveness of this controller depends on its optimal location in the power system network. A residue factor has been proposed to find the optimal location of the UPFC controllers and Eigen value analyses are used to assess the most appropriate input signals (stabilizing signal) for supplementary damping control of UPFC to damp out the inter-area mode of oscillations. The proposed residue factor is based on the relative participation of the parameters of UPFC controller to the critical mode. A simple approach of computing the residue factor has been proposed, which combines the linearized differential algebraic equation model of the power system and the UPFC output equations. The placements of UPFC controllers have been obtained for the base case and for the dynamic critical contingences. The effectiveness of the proposed method of placement is demonstrated on practical network of 25 bus south Malaysian Power system