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Most of the power system networks have significant dynamic loads. In this paper, induction motor is considered as a dynamic load which causes voltage stability problems in power systems. This paper presents an analysis to investigate the critical parameters of power systems with dynamic loads for stability studies. To investigate the critical parameters, a single machine infinite bus (SMIB) system...
This paper introduces a concept of real-time optimization of hybrid fuel-cell power plants as an alternative distributed generation source that improves the power quality and reliability of the power grid. One of the most important issues of plant operation is the optimal control of the power plant, leading to significant economic and environmental benefits. As a commercialized fuel cell technology,...
Methods have previously been developed that improve the computational efficiency and convergence of Monte Carlo simulation (MCS) when computing the reliability indices of power systems. One of these techniques works by pruning the state space in such a manner that the MCS samples a state space that has a higher density of failure states than the original state space. This paper presents a new approach...
This paper provides a novel view for the performance evaluation of protective relays. The paper starts with a Gaussian model for the protective relay setting to describe the effective zone of protection by considering the measurement errors, and introduces the performance index “protectability” for the protective relays. Protectability is defined including the correct trip probability (CTP) and no...
This paper discusses a method for automated steady state analysis of power electronics systems using the formalism of Component Connection Models (CCMs). The method offers several advantages: power electronic system's equation can be derived automatically for any power processor configuration, different ideal semiconductor switching device models can be formally incorporated and the model is suitable...
This paper analyzes prospects in future energy networks to meet expected demand with a multi-carrier energy system in dependence of storage power. We describe solution approaches to solve a multi-period optimization model that combines different energy storages within a network of clusters of local energy converters and storages, so called “Energy Hubs”. The planning of the Energy System is tested...
Using bulk energy storage systems such as pumped-hydro electric storage (PHES) and compressed-air energy storage (CAES) with wind power plants offers advantages. They are well-proven technologies and more economical compared to batteries. Being synchronous machines, apart from the ability to regulate wind farm real power output, they can also be used to provide reactive power to support wind farms,...
Deregulated electricity markets in the U.S. currently minimize total bid costs to select bids and their generation levels but determine payments based on market clearing prices. The inconsistency between auction and settlement mechanisms can lead to a significantly higher consumer payment. This gives rise to the “payment cost minimization,” an alternative auction mechanism that minimizes consumer...
With growing applications for protection, control, monitoring and measurement systems for power system applications, the necessity for very reliable and accurate frequency and phase angle measurement of the power system voltage is also growing. This paper describes a linear phase locked loop for three phase systems for precise measurement of the frequency and phase angle of the line voltage. However,...
A methodology to solve the network expansion planning problem considering N-1 security criterion is proposed. The main idea to achieve the desired results is to separate the whole problem into two subproblems and solve them iteratively. The aim of upper level problem is to solve the mixed-integer programming model with all identified constraints. For the lower level problem, all N-1 contingencies...
The outage of a line due to a fault can be expensive, hence the fault has to be cleared as fast as possible. Digital protection relays consist of fault locators based on several methods. Due to the availability of highly accurate GPS based time references the investigation of two-terminal methods combined with signal analysis tools makes sense in the first place. The aim of this paper is to develop...
This paper presents a comprehensive optimization method for the diagnosis of large substation steel grounding grid integrity status, and the detection and location of any corrosion spot before digging out the grounding grid. A grounding grid is modeled as a circuit network, and fault diagnosis equations are derived by applying Tellegen's theorem, optimization theory and fault diagnosis theory for...
Component derating and reconfiguration for distribution reliability is proposed in this work. Under the budget constraints postponing predictive maintenance is seen in many utilities. This practice can cause adverse effects on the performance of the utility. This work proposes a technique to improve the system reliability by derating the component with time varying hazard rate. Derating of a component...
In this paper a fast, practical maximum loading point (MLP) calculation method is presented. The calculation process is based on the properties of the normal vector to the feasibility boundary computed close to MLP, which is calculated through a load flow method with step size optimization (LFSSO). Moreover, a practical procedure is added to the overall calculation process to include the operator's...
This paper presents a mathematical model to simulate and analyze electromagnetic transients in transmission lines using a mono-phase representation of these lines comparing results models with and without frequency influence in longitudinal parameters. For this, π circuits and state variables are used for composing a linear system that is solved through iterative numeric routines. This routine is...
The increasing presence of single-phase distributed generators and unbalanced loads in the electric power system may lead to unbalance of the three phase voltages, resulting in increased losses and heating. To decrease this voltage unbalance problem three-phase four-wire inverter-connected distributed generation units may be used. In this paper, the influence of the control strategy of three-phase...
The field of distribution system analysis has made significant advances in the past ten years. It is now standard practice when performing a power flow simulation to use an algorithm that is capable of unbalanced per-phase analysis. Recent work has also focused on examining the need for time-series simulations instead of examining a single time period, i.e., peak loading. One area that still requires...
This paper describes an adaptive filtering to reduce noise in the analog input circuits of microprocessor-based protection relay (digital relay) systems. Considering that digital relays tend to have multiple functions, it is important to raise signal to noise ratios (SNR) in analog input circuits to a level that will satisfy the requirements of these functions. We have realized a noise reduction method...
This paper presents a feedback linearization based controller design methodology for a unified power flow controller (UPFC) to achieve rapid reference signal tracking in the internal level. Feedback linearization control (FBLC) is a nonlinear technique based on differential geometry theory and overcomes the drawback of traditional PI control linearzing at one specific operating condition. FBLC is...
Negotiation of secure bilateral transactions has become an important issue for better operation, planning and management of competitive electricity markets. In this paper, secure bilateral transactions have been determined with minimum deviations in economic generation schedule and real power losses for hybrid electricity markets. The generation pattern and real and reactive power loss has been obtained...
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