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A method to determine the coordinated operation of power electronics equipment in extra-high voltage networks is described. The method can be used for evaluating network expansion scenarios that use power electronics equipment. At first, the load flow is simplified by using node-branch and branch-branch sensitivities. With these sensitivities a linear problem is defined and used to determine solutions...
This paper identifies and quantifies the unique characteristics of current-limiting fuse operation as seen in the current and voltage waveforms recorded at a monitoring station located upstream from the fault. Characteristics that can be used to identify current-limiting fuse operations by visual inspection are described. More characteristics are extracted using signal processing methods. These characteristics...
Security constrained optimal VAR despatch using 3500 bus Great Britain transmission planning models is investigated in this paper. The investigation demonstrates the value of applying practical reactive branch flow constraints to generator transformers in order to limit the pre-fault reactive utilization. This research also demonstrates that a multi-staged optimization approach can be used to remove...
This paper presents a performance analysis of wind-powered self-excited induction generator (SEIG) and a vector-controlled PWM converter. Three-phase voltage-source converters are the building blocks of a large number of power electronic systems. The origin of difficulties in the control of the above converters is in their nonlinear nature. The PWM current control technique is used to derive the switching...
The deployment of plug-in hybrid vehicles (PHEVs) and micro-combined heat and power (μ-CHPs) technologies creates the opportunity for these units to be optimally operated under various control schemes to enhance electric grid operation. In addition, if vehicle-to-grid (V2G) and thermal storage features are considered, these embedded technologies could have even a greater impact on network performance...
Electric power generation is the second-largest category of greenhouse gas emissions in California, next to transportation. California's administration, legislature, and energy regulators have adopted aggressive targets for renewable energy due to heavy reliance on natural gas as a fuel for electric generation, which will result in profound changes in markets and system operations. The growth of renewable...
Partial discharges (PDs) of power transformers can be measured via ultra high frequency (UHF) technique. Under the integrated condition monitoring and diagnostics framework of HOMIS (Optimal Maintenance Information System for Hydro power stations), an UHF PD monitoring system was developed for power transformers. The system is composed of internal UHF sensor installed in the oil tank, an amplifier...
Calorimetric method has for a long time been applied for energy conversion efficiency measurement in electrical machines. The number of temperature sensors necessary for its successful application in the field constitutes in one of the major drawbacks of the method. The present paper shows how the usage of infrared (IR) thermal imaging techniques can reduce costs and the necessary time for the calorimetric...
In this paper the effect of demand response (DR) resource utilization in the system operation is analyzed by using an optimization based simultaneous market clearing framework. Two distinct utilization patterns that DR can be involved are reserve supplying by Reserve Supplying Demand Response (RSDR) and providing actual curtailment for demand reduction or peak clipping by Peak Clipping Demand Response...
A system based on Artificial Neural Network (ANN) for load predication in power distribution system with chillers is presented in this paper. The proposed system could predict the chillers' load each hour in a day by using the weather conditions as input. Results from this system provide possibility to improve the power factor of the chillers system and to optimize the power distribution in loads...
In order to verify possible corrosion effects due to DC stray currents caused by surface tramway lines, the average difference of potential between the metallic structures of subway tunnels and the ground has been evaluated. A Finite Element Method (FEM) analysis has been performed considering the geometrical structures, the properties of materials used for the tunnel construction, and the real vehicle...
The role and application of energy storage and dynamic reactive power support is discussed in this paper. A well-engineered energy storage plant can help alleviate some of the problems encountered with the integration of intermittent renewable resources and at the same time make renewable power plants more cost effective in existing traditional power system. The intent of this paper is to demonstrate...
Advances in technology and major programs to enhance the electric power system throughout the world have led to the concept of the “Smart Grid”. This concept has been formally defined in various places and is driving many of the current changes in educational curricula at all levels. This paper provides a brief summary of the known definitions and the resulting educational needs for the technical...
In this paper, variable weight theory and set pair analysis (SPA) theory are applied to comprehensive evaluation of power quality. Among existing comprehensive evaluation methods of power quality, the problems about index uncertainty and imbalance case are less considered. The application of variable weight SPA, for ensuring identical discrepancy contrary (IDC) of unsure system, effectively reduces...
Despite the increasing development of Hopf bifurcations detection methods in the last decades, some difficulties still remain to be resolved, as the processing time of these methodologies do not satisfy the speed requirements of power system security analysis in real time. This paper presents a new development for the power system stability margin estimation due to Hopf bifurcation. This development...
The trend in most utilities today is to increase the capacity of their transmission lines wherever practical. It has become increasingly difficult to build new lines because of increased costs to obtain rights of way, public intervention, and state licensing requirements. These obstacles have significantly increased the cost and lead times required to place new lines into service. The lost revenue...
In this paper, an Artificial Neural Network (ANN) based method is developed for quickly estimating the long-term voltage stability margin. The investigation presented in the paper showed that node voltage magnitudes and the phase angles are the best predictors of voltage stability margin. Further, the paper shows that the proposed ANN based method can successfully estimate the voltage stability margin...
In this paper, a comparison of six representative topologies for the implementation of Solid State Transformers (SST) is performed. The objective is to help identify the most suitable topology capable of supporting additional functionalities as compared to a regular transformer, e.g. on-demand reactive power support to grid, voltage regulation, and current limiting. The comparison is based on switch...
Given the UK Government targets on renewables, significant amount of wind generation is expected to be connected in Scotland. Delivering these targets effectively will require not only an appropriate investment in electricity infrastructure, but also fundamental changes in the philosophy of network operation and development to enhance the utilization of the existing networks. This in turn will requires...
Very short-term load forecasting predicts the load over one hour into the future in five-minute steps and performs the moving forecast every five minutes. To quantify forecasting accuracy, the confidence interval is estimated in real-time. An effective prediction with a small associated confidence interval is important for area generation control and resource dispatch, and can help the operator further...
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