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In recent years generation of electricity using wind power has received considerable attention worldwide. Induction machines are mostly used as generators in wind power based generations. Since induction machines have a stability problem as they draw very large reactive currents during fault condition, reactive power compensation can be provided to improve stability. This paper deals with the Impact...
Metallic particle contamination is one of the areas of insulation design that are considered critical. The management and control of particle contamination are crucial considerations as the industry moves forward to higher voltage GIS and long GITL designs using SF6 in some components. Free conducting particles may lower the corona onset and breakdown voltage of a GIS/GITL system considerably. Under...
This paper focuses on the enhancement Available Transfer Capability using FACTS devices. ATC is calculated on the location of FACTS devises based on the VAR loss sensitivity index method, Real power loss index method. Comparison is made for performance of FACTS devises based on the optimal location methods. Available Transfer capability is Enhanced by Multi type FACTS devises i.e combination of TCSC...
Due to the opening or closing of circuit breakers and disconnect switches in Gas Insulated Substations (GIS), Very Fast Transient Over-voltages (VFTO) are generated, which will bring an instantaneous change in voltage with a very short rise time and it is normally followed by oscillation having high frequencies. This paper describes the variations of VFTO magnitudes transformer bushing of a 765 kV...
This paper presents a wavelet fuzzy based protection scheme for a three terminal transmission system, makes use of current signals at three ends of transmission line which are synchronized with the help of global position system clock. A wavelet based multi resolution analysis is used to find the detailed coefficients of the signals which are utilized to calculate fault index. These fault indices...
Gas insulated substations have found their applications in the modern day power industry due to their low space requirement and higher reliability of operation. Their major components include busducts, circuit breakers, transformers that are placed in enclosures filled with sulphur hexafluoride gas. The major component of GIS is the gasinsulated busduct which has conductors enclosed in anearthed metallicenclosure...
The need for compact substations in the densely populated areas has led to the development of gas insulated substations (GIS) which offer a best alternative to conventional air insulated substation in technical, environmental and operational features. The entire parts of these substations are housed in earthed metallic enclosures filled with sulphur hexafluoride gas (SF6). Further research in the...
SF6 gas has been adopted asan alternative of air for insulation technology in modern day industry due to its high dielectric strength and arc quenching properties. In the recent past, electrical substations are employing gas insulation because of its better properties and also lower space requirement. One of the major reasons for the failure of these gas insulated substations (GIS) is the particle...
This paper presents simplified scalar based pulsewidth modulation (PWM) algorithms for the reduction of common mode voltage. Though, the space vector PWM (SVPWM) algorithm gives superior waveform quality, it results in large common mode voltage variations due to the usage of zero voltage vectors. Moreover, the complexity involved in the classical space vector approach is more due to the calculations...
This paper presents a simple and efficient unified pulsewidth modulation (UPWM) algorithm for direct torque controlled induction motor drives. Though the classical direct torque control (DTC) algorithm gives fast dynamic response, it gives large ripples in steady state. To reduce the steady state ripples and to achieve the constant switching frequency operation, space vector pulse width modulation...
The power producers and customers share a regular transmission network for wheeling power from the point of generation to the point of consumption in a restructured power system organization. Every parties in this open access surroundings may try to produce the energy from the cheaper supply for greater profit margin, which may lead to overloading, infringement of line flow, voltage and stability...
The voltage collapse problem can avoid by providing proper reactive power resources to maintain specified voltage profile in the network. The traditional approaches are not sufficient to mitigate reactive power imbalance in the modern power system. Hence one of the emerging technologies like integration of Flexible AC Transmission System (FACTS) devices has been adopted in this paper. A hybrid algorithm...
This paper mainly focused on improvement of voltage stability of the power transmission system with voltage collapse concern. To achieve this, Flexible AC Transmission System (FACTS) devices are suggested to be installed properly in the network. Among all the FACTS devices, the combined compensator such as Inter line power flow controller (IPFC) is considered for its greater flexibility in power control...
Switching operations of circuit breaker, disconnector and fault conditions in a Gas Insulated Substations (GIS) leads to Very Fast Transient Over voltages (VFTO) and Very Fast Transient Currents (VFTC) are developed. These VFTO's and VFTC's leads to generation of Electromagnetic fields in a gas insulated substations. These Electromagnetic fields due to VFTO's and VFTC's leads to greater damages on...
This paper presents a simple generalized pulse widt h modulation (GPWM) algorithm for a 3-phase, 2-level voltage source inverter fed induction motor drives. The space vector approach requires angle and sector estimation for the calculation of gating times of the inverter and hence increases the complexity of the PWM algorithm. However, the proposed algorithm uses the instantaneous phase voltages only...
The Gas Insulated Substation (GIS) have various advantages like compactness, immunity from environmental conditions, high operational reliability, low maintenance cost. In a number of GIS installations, the main design considerations involved in gas insulated equipment are at cone insulator, gas and metal interface. Hence there is a need for control of electric stress in order to reduce internal discharges,...
In this paper, a simplified space vector pulse width modulation (SVPWM) method has been developed for three-phase three-level voltage source inverter fed to direct torque controlled (DTC) induction motor drive. The space vector diagram of three-level inverter is simplified into two-level inverter. So the selection of switching sequences is done as conventional two-level SVPWM method. Where in conventional...
In this paper, a linear programming algorithm is proposed for determining a measure of market concentration in congested transmission systems. The linear program uses the effects of congestors on system to derate line limits of each transmission line. The linear program uses transmission line constraints with derated line limits, generation constraints to calculate maximum SIC for group of buyers...
A high performance electrical drive requires suitable control method, even when the load and parameters of the motor are varying during the motion. This paper proposes Adaptive Neural Fuzzy Inference Systems (ANFIS) controller for minimum switching loss PWM algorithm based vector controlled induction motor drives. In the conventional space vector PWM (CSVPWM) algorithm, the zero voltage applying time...
This paper deals with the movement of free conducting particles inside a single phase Gas Insulated Bus duct(GIB).A two dimensional mathematical model was proposed for determining the movement pattern of metallic particle in GIB by considering all the forces acting on the particle like gravitational, drag and the electric field forces. A particle resting on the inner side of the outer enclosure is...
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