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Prior research has shown that autocorrelation and variance in voltage measurements tend to increase as power systems approach instability. This paper seeks to identify the conditions under which these statistical indicators provide reliable early warning of instability in power systems. First, the paper derives and validates a semi analytical method for quickly calculating the expected variance and...
The increasing penetration of variable and uncertain generation from renewable resources poses a challenge for balancing the power system supply and demand. Violations of this constraint seriously impact system reliability and thus carry with them a very high cost. In order to address the issues created by variable generation increased system flexibility is required. System operators are considering...
This paper proposes a continuous time Markov chain (CTMC) based sequential analytical approach for composite generation and transmission systems reliability assessment. The basic idea is to construct a CTMC model for the composite system. Based on this model, sequential analyses are performed. Various kinds of reliability indices can be obtained, including expectation, variance, frequency, duration...
Low-carbon electric power systems are often characterized by high shares of renewables, such as wind power. The variable nature and limited predictability of some renewables will require novel system operation methods to properly size and cost-efficiently allocate the required reserves. The current state-of-the-art stochastic unit commitment models internalize this sizing and allocation process by...
The integration of wind power has imposed new requirements for regulation reserves. For ensuring adequate regulation reserves, wind power variability and uncertainty must be estimated, and system frequency must comply with frequency performance standards. This work determines regulation capacity and ramping capability requirements as a function of wind installed capacity to comply with CPS1, the North...
The intermittent and uncertainty nature of variable resources rises the need to investigate the effect of the technical operation aspects of power system operation and transmission lines constrains, on estimating the penetration level of variable resources that enhances the economic and operation aspects of power system. The Incorporation of these resources into systems rises the need to evaluate...
In the future, state-of-the-art wind generators (WGs) are expected to produce one of the largest amounts of renewable energy worldwide. Nowadays, wind DFIGs with integrated storage are regarded as the state-of-the-art WGs. In this paper, we propose a comprehensive methodology that aims to solve the problem of distributed coordination and control of state-of-the-art WGs. The goal is for a WF to generate...
Evaluating the risk of capacity deficit in large interconnected power systems is an important task in planning studies in order to supply the demand in the system at a certain risk level. It makes it possible to identify in which parts of the system reinforcements are needed in terms of generating capacity and/or interconnections. In modern power systems, with tie lines interconnecting countries and...
Power system interruptions have financial impacts for the utility, the customer and the community. A consistent approach to financial impact assessment for both planning and operations starts with fault data. Faults can be categorized and correlated with season and time of day in a time-element matrix. Statistical data can be modeled with Beta probability density functions. The paper shows how the...
This paper describes the successes of using high resolution, time-synchronized phasor measurement data from across North America to perform frequency response analysis. The annual analysis is performed to determine the frequency response obligations for each interconnection and Balancing Authority (BA). This analysis utilizes R&D tools developed under industry guidance and Department of Energy...
Spinning reserve (SR) allocation problem is of vital importance in maintaining power systems security and reliability. Considering forecast uncertainties, unit commitment problem and contingencies on the failure of transmission lines, a general probabilistic model for expected total cost is established and its corresponding solution for optimal SR allocation strategy is proposed. The objective function...
The high investment cost associated with upgrading utility grid to supply remote area's demand for electricity makes the implementation of standalone microgrids inevitable. These microgrids normally consist of a mix of energy sources such as diesel generators, photovoltaic arrays, wind turbines, and fuel cells. In order to improve the microgrid reliability, reduce its operation cost, and address operational...
There are various undergoing efforts by system operators to set up an electricity market at the distribution level to enable a rapid and widespread deployment of distributed energy resources (DERs) and microgrids. This paper follows the previous work of the authors in implementing the distribution market operator (DMO) concept, and focuses on investigating the clearing and settlement processes performed...
The microgrid reliability assessment is gaining notorious attention as distributed generation systems are being increasingly installed. The conventional approach to perform this analysis is by means of the Monte Carlo method which may lead to long-lasting simulations when elaborated models are considered. To reduce the overall simulation time, this paper combines a detailed analytical microgrid modeling...
Determination of the optimum number and placement of sectionalizing switches in Distribution Automation (DA) feeders is a very challenging task. This is an important step in the feasibility process of DA projects and one has to consider the trade-off between reliability and economics to arrive at the answer. This paper presents a novel iterative approach based on the relative reduction in the normalized...
Variance Minimization (VM) technique is one of the most popular methods for importance sampling (IS), but it has never been successfully applied to composite (generation and transmission) system reliability evaluation due to the difficulty of solving. In this paper, Geometric Programming (GP) is firstly introduced to repeatedly solve the VM optimization model in multi-levels to adaptively obtain the...
More than one billion people are living in energydeprived rural areas of the world with little or no access to basic energy and other needs. In this work, a Smart Integrated Renewable Energy System, or in short “SIRES”, is proposed to “energize” the rural areas and not just “electrify” them. It is a viable and effective strategy to provide basic needs such as biogas for cooking, water for domestic...
Ancillary Services are critical to help the Electric Reliability Council of Texas (ERCOT) to manage the reliability and security of the grid in Texas. Non-Spin Reserve Service (NSRS) is part of ERCOT's ancillary service sets provided by generation or load resources which can come online within a specified time period (30 minutes) to deal with unexpected generation outage or large forecast errors....
High-voltage, high-power dc transmission based on Modular Multilevel Voltage-Sourced Converters represents currently the best solution when system resilience, flexibility of control, reliability and availability are of essence. In Europe, such systems are currently being installed or considered as interconnectors between several synchronous zones or embedded into a synchronous zone. New concepts and...
One of the top reliability concerns in power systems classified by NERC is hidden failures in protection schemes. Such failures are defects that go undetected under normal operating conditions but manifest themselves during faults or transients, which may lead to the false operation of relaying schemes. Specifically, hidden failures typically lead to incorrect input to relays and adversely affect...
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