• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.13-16
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• 2000

Continuation power flow has been developed to remove the ill-condition problem caused by singularity of power flow Jacobian at and near steady-state voltage instability point in conventional power flow. When solving large-scale power transmission systems, continuation power flow require large computational costs. Therefore, technique to improve the speed of continuation power flow system was required. In this paper Decoupled Power Flow Method (DPFM), Enhanced Decoupled Power Flow Method (EDPFM), Robust Fast Decoupled Power Flow Method (RFDPFM) are applied to continuation power flow algorithm to improve the speed of continuation power flow system.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.894-896
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• 1997

This paper presents the continuation power flow system that is under development. The continuation power flow system provides robust solutions of power flow equations at any operating point. The robust convergency enables one to find solutions even at the point where power flow jacobian becomes singular. Basic concept of an algorithm and its application to static voltage stability analysis are presented.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.3
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• pp.190-196
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• 1999

Continuation power flow has been developed to remove the ill-condition problem caused by singularity of power flow Jacobian at and near at steady-state voltage instability point in conventional power flow. Continuation power flow consists of predictor and corrector. In prddictor, the direction vector at the resent solution is caluculated and the initial guess of next solution is determined at the distance of step length. The selection of step length is a very important part, since computational speed and convergence performance are both greatly affected by the choice of the step length. This paper presents the practical step length selection algorithm using the reactive power generation sensitivith. In numulation, the proposed algorithm is compared with step length selection algorithm using TVI(tangent vector index).

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.46-48
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• 2000

Continuation power flow has been developed to remove the ill-condition problem caused by singularity of power flow Jacobian at and near steady-state voltage instability point in conventional power flow. When solving large-scale power transmission systems, an alternative strategy for improving computational efficiency and reducing computer storage requirements is the decoupled power flow method, which makes use of an approximate version of the Newton-Raphson procedure. This paper presents a technique to improve the speed of continuation power flow system using decoupled power flow method.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.899-901
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• 1998

Continuation power flow is a tool that can trace the path of the solution from the base stable solution. However, the base stable solution cannot be calculated when the initial system load is too large to operate at a stable operating point. This case is called as unsolvable case. This paper presents implementation of the optimal load shedding algorithm on continuation power flow. It performs steady-state analysis of power systems at unsolvable case that can occur in contingency analysis. Numerical simulation on 20-bus test system demonstrates that the continuation power flow applying the optimal load shedding algorithm is robust at solvable and unsolvable cases.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.390-395
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• 2005

The most widely used index for the vulnerable area investigation has been the reactive power margin or sensitivity analysis. But we can only obtain the results of these analyses if the results of load flow are convergent in severe contingencies. Otherwise these methods are not adoptable. This paper presents a good index for overcoming severe contingencies, though the power flow equation is unsolvable using the branch parameter continuation power flow. In simulation, the Korea Electric Power Corporation (KEPCO) Systems are applied.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1290-1292
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• 1999

In this paper. continuation power flow for Power system including UPFC has been performed. The decoupled model, by which power flow can be performed without any modification of conventional power flow program is used as steady-state model. A numerical example has been given to analyze the influence on the voltage stability by UPFC.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.2
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• pp.78-84
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• 2000

This paper introduces a method of determining the maximum real power transfer limit of interface lines, which connect two areas of a power system, using locally parameterized continuation algorithm. This method traces the path of power flow solutions as interface flow is gradually increased under a certain load demand condition and finds the steady state voltage stability limit, the interface flow limit. Voltage stability index is used to indicate how close the maximum limit is reached. Also, this study presents a procedure to determine the security-constrained interface flow limit using the above method. Contingency ranking index is proposed to identify the severity of contingencies. The case study is performed according to the suggested procedure.

• KIEE International Transactions on Power Engineering
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• v.11A no.4
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• pp.27-32
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• 2001

This paper presents a concept of reactive reserve based contingency constrained optimal power flow (RCCOPF). RCCOPF for enhancement of interface flow limit is composed of two modules, which are the modified continuation power flow (MCPF) and reactive optimal power flow (ROPF). In RCCOPF, two modules are repeatedly performed to increase interface flow margins of selected contingent states until satisfying the required enhancement of interface flow limit. In numerical simulation, a simple example with New England 39-bus test system is shown.

• KIEE International Transactions on Power Engineering
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• v.11 no.X00
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• pp.27-32
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• 2001

This paper presents a concept of reactive reserve based contingency constrained optimal power flow (RCCOPF). RCCOPF for enhancement of interface flow limit is composed of two modules, which are the modified continuation power flow (MCPF) and reactive optimal power flow (ROPF). In RCCOPF, two modules are repeatedly performed to increase interface flow margins of selected contingent states until satisfying the required enhancement of interface flow limit. In numerical simulation, a simple example with New England 39-bus test system is shown.