Sumit Banerjee

Determination of the weakest branch in a radial distribution network using local voltage stability indicator at the proximity of the voltage collapse point

This paper presents a unique method to determine the weakest branch or the overstressed branch in a distribution network. This radial feature of the network has been fully exploited to establish the concept of local voltage stability indicator in terms of reactive power. The effectiveness of the proposed method has been successfully tested in 12 bus radial distribution system and the results are found to be in very good agreement.

An analysis of economic load dispatch using different algorithms

The economic load dispatch (ELD) plays an important role in power system operation and control. Different techniques have been used to solve these problems. Recently, the soft computing techniques have widely used in practical applications. This paper shows successful implementation of four evolutionary algorithms, namely particle swarm optimization (PSO), particle swarm optimization with constriction factor approach (PSOCFA), particle swarm optimization with inertia weight factor approach (PSOIWA) and particle swarm optimization with constriction factor and inertia weight factor approach (PSOCFIWA) algorithms to economic load dispatch problem. Power output of each generating unit and optimum fuel cost obtained using all four algorithms have been compared.

An analysis of economic load dispatch with prohibited zone and ramp-rate limit constraints using different algorithms

The economic load dispatch (ELD) plays an important role in power system operation and control. Different techniques have been used to solve these problems. Recently, the soft computing techniques have widely used in practical applications. This paper shows successful implementation of four evolutionary algorithms, namely particle swarm optimization (PSO), particle swarm optimization with constriction factor approach (PSOCFA), particle swarm optimization with inertia weight factor approach (PSOIWA) and particle swarm optimization with constriction factor and inertia weight factor approach (PSOCFIWA) algorithms are used to economic load dispatch problem. Here prohibited zone and ramp-rate limit constraints are considered to solve this problem. Power output of each generating unit and optimum fuel cost obtained using all four algorithms have been compared.

Proposed procedure for estimation of maximum permissible load bus voltage of a power system within reactive loading index range

In recent years many authors largely given attention to the effect of active loading index for low voltage distribution system. But this paper presents a novel approach for determining the reactive loading index of a low voltage distribution system at the proximity of voltage collapse point. The proposed procedure of maximum permissible load bus voltage of a power system within reactive loading index range was tested on the simple IEEE 14 bus, IEEE 30 bus, and IEEE 57 bus systems. The effectiveness of the proposed loading index against the load reactive power for different values of load voltages within reactive loading index range are estimated faithfully and significant results are observed to be in very good agreement.

Voltage Stability Index of Radial Distribution Networks by Considering Distributed Generator for Different Types of Loads

The paper presents an approach on voltage stability analysis of distribution networks for loads of different types. A voltage stability index is proposed for identifying the node, which is most sensitive to voltage collapse. It is shown that the node, at which the value of voltage stability index is maximum, is more sensitive to voltage collapse. For the purpose of voltage stability analysis, constant power, constant current, constant impedance and composite load modeling are considered. Distributed generation can be integrated into distribution systems to meet the increasing load demand. It is seen that with the insertion of distributed generator DG, load capability limit of the feeder has increased for all types of loads. By using this voltage stability index, one can measure the level of voltage stability of radial distribution systems and thereby appropriate action may be taken if the index indicates a poor level of stability. The effectiveness of the proposed method is demonstrated through two examples.

An analysis of economic load dispatch with ramp-rate limit constraints using different algorithms

The economic load dispatch (ELD) plays an important role in power system operation and control. Different techniques have been used to solve these problems. Recently, the soft computing techniques have widely used in practical applications. This paper shows successful implementation of four evolutionary algorithms, namely particle swarm optimization (PSO), particle swarm optimization with constriction factor approach (PSOCFA), particle swarm optimization with inertia weight factor approach (PSOIWA) and particle swarm optimization with constriction factor and inertia weight factor approach (PSOCFIWA) algorithms. Here ramp-rate limit constraints are considered to solve this problem. Here three cases have been considered. Four algorithms have been applied for each case. Optimum fuel cost is taken from each algorithm is compared for each cases (Case study I, II and III).

Short-term hydrothermal scheduling using particle swarm optimization with constriction Factor and Inertia Weight Approach

The paper presents Particle Swarm Optimization with Constriction Factor and Inertia Weight Approach which is applied to determine the optimal hourly schedule of power generation in a hydrothermal power system. The objective of the hydrothermal scheduling problem is to find out the discharge of hydro plants and power generation of thermal plants to minimize the total fuel cost at a schedule horizon while satisfying various constraints. In the present work, the effects of valve point loading in the fuel cost function of the thermal plants are also considered. The developed algorithm is illustrated for a test system consisting of four hydro plants and three thermal plants. It is found that proposed particle swarm optimization with constriction factor and inertia weight factor approach (PSOCFIWA) appears to be the powerful to minimize fuel cost.

Voltage stability margin of distribution networks for composite loads

The paper presents voltage stability margin (VSM) of radial distribution network by considering a unique reactive loading index for composite loads. It is shown that the branch, at which the value of reactive loading index is minimum, is considered to be the weakest branch of the system. Then, the voltage stability margin (VSM) of the feeder is selected heuristically. It is the product of reactive loading indices of all branches of the feeder. The VSM of all feeders can be evaluated. The feeder which has the smallest value of VSM can be considered as the weakest feeder of the system and is at the proximity of voltage collapse. So, for multiple feeders, the voltage stability margin of a system may be considered as the VSM of the feeder which has the smallest value. The effectiveness of the proposed VSM has been successfully tested on a 12.66 kV radial distribution network consisting of 33 nodes and the results are found to be in very good agreement.

Implementation of quassi-oppositional TLBO technique on economic load dispatch problem considering various generator constraints

This paper presents a novel modified teaching learning based optimization method(TLBO) i.e quasi-oppositional TLBO (QOTLBO) algorithms to solve economic load dispatch problem of the thermal plant without considering transmission losses. The offered methodology can manage ELD problems using nonlinearities such as valve point loading, ramp rate limit and prohibited zone. The objective of ELD problem is to evaluate the optimal power generation allocation of units to satisfy the load demand, and also the overall cost of generation should be minimized, and different operational constraints should be fulfilled. General TLBO, a newly appeared evolutionary algorithm depend on two basic ideas of education namely teaching phase and learning phase. The efficiency of the offered algorithms has been checked on test system with equality and inequality constraints. The result is compared with the other existing techniques which prove the efficiency of algorithms.

Impact of distributed generator on voltage stability analysis of distribution networks under critical loading conditions for composite loads

The paper presents voltage stability analysis of radial distribution networks under critical loading conditions without and with distributed generator (DG) for composite loads. A new voltage stability index is proposed for identifying the node, which is most sensitive to voltage collapse. The effectiveness of the proposed method without and with considering DG for loads of composite types has been successfully tested on a 12.66 kV radial distribution network consisting of 33 nodes and the results are found to be in very good agreement.