Lukmanul Hakim

A Study on the Effect of Generation Shedding to Total Transfer Capability by Means of Transient Stability Constrained Optimal Power Flow

In nowadays deregulated market, total transfer capability (TTC) calculation, which is the basis for evaluating available transfer capability (ATC), has been becoming more significant. During the last decade, transient stability constraints have been included in the optimal power flow approach to maximize TTC. However, no previous work on investigating the effect of generation shedding action to TTC has been reported. Therefore, in this paper, we propose a TTC maximization by means of transient stability constrained optimal power flow considering the generation shedding action. Proper selection of the generator to shed is based on its Lagrange multiplier value of transient stability constraint. Our simulation results show how TTC can be increased to anticipate possible generation shedding.

A Solution of Total Transfer Capability Using Transient Stability Constrained Optimal Power Flow

In nowadays deregulated market, available transfer capability (ATC) is a measure of the network capability for further commercial activity above the already committed uses. This paper deals with the development of an interior point nonlinear programming methodology for evaluating dynamic ATC. By establishing a novel method for integrating transient stability constraints into conventional steady-state ATC problem, we have proposed the dynamic ATC solution methodology using a transient stability constrained OPF (TSCOPF). In actual power system, we have to consider several controller/modeling to evaluate dynamic stability to simulate real system. We have proposed unbalanced three phase model for transmission lines in our TSCOPF. In the proposed method, we can consider any fault sequence on transmission lines and buses. In this paper, we propose an extension of transient stability constrained OPF with consideration of the generator shedding after the fault. The proposed TSCOPF method will be applied to IEEJ EAST10 test system to demonstrate the effectiveness of generator shedding.

Study of environmental condition using wavelet decomposition based on infrared image

In this paper, we report our experiment about wavelet decomposition for study environmental condition based on infrared images. Infrared images acquired by consumer digital camera, after replacing the infrared stoping filter with filter SRS, and the images captured sequentially every two hours (from 06:00-16:00). The result of this research is the increasing air pollution characterized using wavelet decomposition by increasing index value from 0-3 and amount of white spots about 60% (from 5%-65%). Finally wavelet decomposition was made to estimate the environmental condition, especially air pollution, based on infrared image.

A solution of maximum transfer capability using TSCOPF with load shedding action

In a deregulated electric power industry where electric power export and import among interconnected areas are frequent, transmission network plays an even more significant role in allowing inter-area transfers. In order to maintain secure power transfers, security limit such as transient stability constraint has been imposed to power transfer, hence allowing secure power transfer for a possible contingency at the cost of curtailing existing transaction. This paper explores the possibility of allowing higher power transfer in a transient stability-limited environment by utilizing load shedding action. The problem is approached as maximization of power transfer and solved by our Transient Stability-Constrained Optimal Power Flow (TSCOPF).

A three-phase power flow analysis for electrical power distribution system with low voltage profile

This paper proposes a three-phase power flow software tool based on voltage rectangular coordinates and the full Newton-Raphson method. The proposed method is then implemented using Python scripting language and its mathematical library. Comparison with the well-known software OpenDSS developed by EPRI shows promising results. The proposed formulation, in fact, is able to solve ill-conditioned power flow cases. In particular, when tested on a system with very low voltage profile, the proposed method is able to converge without the need to convert the load to voltage-dependent type load as it happens in OpenDSS.

Intensity average value of image segmentation for infrared image of environmental condition

In this paper, we make a report our research about intensity average value of image segmentation for infrared image of air pollution. Infrared image of environmental condition (captured sequentially every two hours, from 06:00-16:00) processed using wavelet transform. After that processed, used image segmentation to get intensity average value distribution from 0 till 255 to obtain trending graphic of pollution. Infrared image divided into 4, 8, and 16 segments. The result of this research is the increasing air pollution characterized at 12:00 and 16:00, by increasing intensity average value from 13%-27%. Finally intensity average value of image segmentation was made to estimate the environmental condition, especially air pollution, based on infrared image.

Development of a power flow software for distribution system analysis based on rectangular voltage using python software package

This paper presents our work on developing a power flow software tool based on rectangular voltage coordinates using the Python scripting language. Rectangular coordinates show higher computational efficiency and better convergence properties than polar formulation. The proposed software tool benefits from Newton-Raphson method to solve the power flow problem. A graphical user interface is also developed and constitutes an initial step towards future development. Results of the proposed power flow software tool are compared to other open source software packages. The proposed work shows good convergence characteristic and proves to perform similarly to other available software tools.

A solution of preventive control by means of Transient Stability Constrained OPF

In the recently deregulated electricity market, a more secure of power system operation is essential. One of the methods to avoid the risk of compromising power system instability is preventive control which often comes in the form of generation rescheduling. This paper attempts to solve transient stability preventive control problem by generation redispatch utilizing the Primal-Dual Interior Point Method (PDIPM) Non Linear Programming (NLP) Transient Stability Constrained Optimal Power Flow (TSCOPF). A linear cost model is derived to accommodate generation redispatch. Our simulation shows that the proposed method is able to solve the transient stability preventive control problem by rescheduling necessary active power generation.