Electric Power Transmission And Distribution Equipment

The U.S. electrical grid must be upgraded, and there is a strong debate about the characteristics of the next-generation electrical network. However, slow growth of electricity usage, among other factors, means that the demand for transmission and distribution (T&D) equipment is growing slowly also. Within the T&D equipment sector, switchgear and transformers are still the dominant segments, but sales of meters are growing rapidly in response to increased demands for security, safety, and connectivity. Six firms hold about 40 percent of the T&D equipment market share, selling to electric utilities, nonutility industrial firms, commercial firms, and residential customers. Foreign trade is also important in this industry, with the United States running a substantial trade deficit

Flexible Operation of Electric Power Transmission Grids

In order to reduce carbon emissions and increase sustainability many countries in the world are switching to renewable sources of energy for electricity production. European Commission has set targets for its Member States to reduce such emissions and proposed share of renewables of around 30% in gross final energy consumption by 2030. Moreover, the electricity market is decentralized in Europe. As a result of decentralization and increased renewable penetration into the system, Transmission System Operators (TSOs) are faced with new challenges to operate their system securely. Some of the means of congestion management by the TSOs have become costly after decentralization. Moreover, variability associated with renewables can create congestion in a distant grid location which belongs to another TSO. Hence, TSOs are forced to find alternatives to operate their systems securely and in a cost effective manner. Inter-TSO coordination is one such non-costly alternative which requires increasing attention when more renewables are integrated into the system. The coordination (preventively and/or curatively) will help to operate the existing transmission grids more flexibly when more renewables integration demands transmission expansion, which is severely limited in Europe

Transmission System and Rural Electrification Scheme in Nigeria: Issues, Challenges, Constraints and Way forward

This paper x-rayed the transmission system and rural electrification scheme in Nigeria. The electric power transmission network and rural electrification scheme were critically reviewed in terms of issues, challenges, constraints, roles and current state of the power systems to identify their areas of strength and shortcomings in the Nigeria power sector. The paper further proposes the way forward to enhance the performance of the Nigeria’s electric power transmission system and rural electrification scheme

Minimization of Losses on Electric Power Transmission Lines

Availability of electric power has been the most powerful vehicle for facilitating economic, industrial and social developments of any nation. Electric power is transmitted by means of transmission lines which deliver bulk power from generating stations to load centres and consumers. For electric power to get to the final consumers in proper form and quality, losses along the lines must be reduced to the barest minimum. In this paper, a mathematical model of losses along electric power transmission lines was developed using a combination of ohmic and corona losses. The resulting model, which is a nonlinear multivariable unconstrained optimization problem, was minimized using the classical optimization technique. From the results, we were able to see that power losses on transmission lines will be minimized if we transmit electric power at a very low current and at an operating voltage that is very close to the critical disruptive voltage. Also the spacing between the conductors should be large in comparison to their diameters. These results, gotten by the use of an analytical method, conform to the existing results for power transmission. Keywords: Power Losses, Minimization, Transmission, Classical Optimization, Mathematical Model

Control of MTDC Transmission Systems under Local Information

High-voltage direct current (HVDC) is a commonly used technology for long-distance electric power transmission, mainly due to its low resistive losses. In this paper a distributed controller for multi-terminal high-voltage direct current (MTDC) transmission systems is considered. Sufficient conditions for when the proposed controller renders the closed-loop system asymptotically stable are provided. Provided that the closed loop system is asymptotically stable, it is shown that in steady-state a weighted average of the deviations from the nominal voltages is zero. Furthermore, a quadratic cost of the current injections is minimized asymptotically

Blackouts, risk, and fat-tailed distributions

We analyze a 19-year time series of North American electric power transmission system blackouts. Contrary to previously reported results we find a fatter than exponential decay in the distribution of inter- occurrence times and evidence of seasonal dependence in the number of events. Our findings question the use of self-organized criticality, and in particular the sandpile model, as a paradigm of blackout dynamics in power transmission systems. Hopefully, though, they will provide guidelines to more accurate models for evaluation of blackout risk.blackout, risk, fat-tailed distribution, power grid

Electric power transmission and distribution systems : costs and their allocation

National Science Foundation Grant no. SIA73-07871 A0

Power Flow Control of Power Systems Using UPFC Based on Adaptive Neuro Fuzzy

Optimization of system capacity electric power transmission systems requires a reliable power flow controller. The power flow controllers must be able to control the level of electrical voltage and active and reactive power flow without reducing the level of stability and security of the transmission system. Latest technology in the control of power flow is a Unified Power Flow Controller (UPFC). The entire transmission line parameters are impedance, voltage, and phase angle can be controlled simultaneously by the UPFC. The method used in the conventional algorithms based UPFC is still firmly with logic. These algorithms have difficulties to electric power transmission systems multimachine very dynamic, i.e. systems that are experiencing rapid changes in the electrical load from time to time. Therefore, in this study was developed based on neuro-fuzzy method is applied to the adaptive UPFC for adaptively controlling the power flow in electric power transmission systems multimachine very dynamic. In this study, three phase fault is applied to the multimachine system. The results are taken to be consideration of PI and neuro-fuzzy controllers. The PI and neuro-fuzzy controllers show nearly same results but there is a low overshoot occurred during the fault in the neuro-fuzzy controllers results. According to results that UPFC improves the system performance under the transient and the normal conditions. However, it can control the power flow in the transmission line, effectively

Dickey-Lincoln School Lakes Project: Transmission System Planning Study

The purpose of this report is to investigate various transmission system alternatives and recommend a plan of service to integrate power from the Dickey-Lincoln School Lakes (D-L) Project into the New England electric power transmission system