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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 685 records · Page 38
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Methodology to Calibrate Fragility Curves Using Limited Real-World Data

With increasing human dependence on electricity and increasing energy demand, electrical infrastructure has emerged to be one of the most critical services. This is one of the main reasons for making the power grid more resilient to extreme events during which uninterrupted power supply is crucial in keeping the consequences of the extreme event limited. The first step towards making the overall power grid more resilient is to evaluate the probabilities of failure for all assets at risk from the excitation caused by extreme events. Thus, this paper presents the methodology to calibrate fragility curves. The strength of the proposed approach is its ability to calibrate the fragility curves utilizing limited data, which is the most common constraint in carrying out such analyses. This paper describes the calibration of transmission tower fragility curves for Puerto Rico utilizing only damage reports for hurricane Maria. That, combined with Puerto Rico's wind modeling & geographic information system, this study also calibrates fragility curves for transmission towers made with four different construction materials.

Bereta dos Reis, Fernando↗
DOE OSTI2018

Synchrophasor Data Correction under GPS Spoofing Attack: A State Estimation-Based Approach

GPS spoofing attack (GSA) has been shown to be one of the most imminent threats to almost all cyber-physical systems incorporated with the civilian GPS signal. Specifically, for our current agenda of the modernization of the power grid, this may greatly jeopardize the benefits provided by the pervasively installed phasor measurement units (PMU). In this paper, we consider the case where synchrophasor data from PMUs are compromised due to the presence of a single GSA, and show that it can be corrected by signal processing techniques. In particular, we introduce a statistical model for synchrophasorbased power system state estimation (SE), and then derive the spoofing-matched algorithms for synchrophasor data correction against GPS spoofing attack. Different testing scenarios in IEEE 14-, 30-, 57-, 118-bus systems are simulated to show the proposed algorithms’ performance on GSA detection and state estimation. Numerical results demonstrate that our proposed algorithms can consistently locate and correct the spoofed synchrophasor data with good accuracy as long as the system observability is satisfied. The accuracy of state estimation is significantly improved compared with the traditional weighted least square method and approaches the performance under the Genie-aided method.

Phasor measurement units, Global Positioning Syste↗
DOE OSTI2022

Achieving American Leadership in the Electric Grid Supply Chain Factsheet

The U.S. electric grid consists of more than 22,000 generators; 55,000 substations; 642,000 miles of high-voltage lines; and 6.3 million miles of distribution lines that serve 153 million customers. To date, much of the smart grid transformation has focused on applying advanced digital information and communication technologies to the power grid to improve the system’s efficiency, flexibility, and security. To achieve the full value of grid modernization, we also need advances in grid hardware. Many critical components supporting the power grid have limited to no domestic manufacturing capacity and face complex challenges in supporting a rapid expansion of the grid to meet multiple objectives, including decarbonization goals.

Source record↗
DOE OSTI2012

Eastern Seaboard Electric Grid Fragility Maps Supporting Persistent Availability

Persistently available power transmission can be disrupted by weather causing power outages with economic and social consequences. This research investigated the effects on the national power grid from a specific weather event, Hurricane Irene, that caused approximately 5.7 million customer power outages along the Eastern Seaboard in August of 2011. The objective was to describe the geographic differences in the grid s vulnerability to these events. Individual factors, such as wind speed or precipitation, were correlated with the number of outages to determine the greatest mechanism of power failure in hopes of strengthening the future power grid. The resulting fragility maps not only depicted 18 counties that were less robust than the design-standard robustness model and three counties that were more robust, but also drew new damage contours with correlated wind speeds and county features.

Persistent Availability↗
DOE OSTI2018

Electric Grid Resilience and Reliability for Grid Architecture

Grid modernization activities cite resilience (sometimes called resiliency) as a key electric power grid characteristic to be improved or maximized, and so it is crucial for the development of resilient grid architectures that the concept of grid resilience be clear and quantifiable. However, attempts to define and quantify a concept of resilience for electric power grids have mostly relied upon ad hoc definitions that do not have much underlying rigor and are often closely tied to reliability, sometimes only differing in terms of scale and frequency of events. While grid reliability would seem to have strong definition given the IEEE 1366 standard, grid resilience is a term that is less clear.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2018

Influence of Insulation Level on Electric Power Quality and Transformation Efficiency of Grid-Connected Photovoltaic Power Plants

The paper considers the influence of the insolation level on the electric power quality indicators and efficiency of a grid-tie inverter operating as part of a grid-connected photovoltaic power plant. Over the course of a year, data were recorded for Moscow on incoming solar radiation and the grid-tie inverter input and output capacity provided by a 1 kW grid-connected photovoltaic power plant. The insolation threshold values for a Solar River 1100 TL inverter are experimentally established, corresponding to both the beginning and end of stable inverter operation, as well as the required phase angle value for the electric energy supplied to the grid.

14 SOLAR ENERGY↗
DOE OSTI2025

Performance Evaluation of Vertical Federated Machine Learning Against Adversarial Threats on Wide-Area Control System: Preprint

Federated machine learning (FL) is gaining significant popularity to develop cybersecurity solutions in power grids because of its advanced capability to support decentralized data handing at local devices, its privacy preservation, and its low-bandwidth requirement. However, the evolving adversarial machine learning (AML) threats raise significant concerns for the cybersecurity of FL architectures. The FL-based split neural network (SplitNN) achieves high performance through the decentralized training of local neural network models while preserving data privacy across multiple entities. In this paper, we propose a methodology for evaluating the performance of a vertical FLbased anomaly detector against different types of AML attacks, including denial-of-service attacks, adversarial data injection attacks, and replay attacks on the trained local models deployed in the grid network. For a case study, we consider the modified IEEE 13-bus system, and we develop SplitNN-based binary and multiclass classification models to detect, locate, and identify different types of data integrity attacks on the volt-watt control with two pooling layers: maximum pooling and AvgPool. Our experimental results, computed through performance metrics, reveal that the severity of these AML attacks varies with the integrated pooling mechanism, the type of classification model, and the nature of the cyberattack. Further, the AML attacks negatively impacted the prediction time per sample for the pretrained SplitNN during the online testing.

adversarial threats↗
DOE OSTI2018

Two-Layer Predictive Controller for V2G and G2V Services Using on Wireless Power Transfer Technology

This paper presents a comprehensive solution that allows electric vehicles (EV) to autonomously charge and discharge their batteries wirelessly during long term parking and/or the transient stops. A two-layer power-flow controller for bidirectional wireless power transfer system (BWPTS) in EVs applications is proposed. The proposed controller can manage the bidirectional power-flow between EV and surrounding infrastructures such as power grid, home microgrid, building micro-grid, road or another vehicle. It consists of two levels of control; the first is responsible for communicating with the surrounding infrastructures and gathering information from driver, charging station, power grid and battery management system and then, based on these information, it estimates the EV's psychological price as a function of its battery's state-of-charge (SOC) and compares it with the energy price to decide whether to charge, discharge or abstain, and how much the charging or discharging rate. The second layer receives the reference signal from the first one and generates the control parameters for two synchronized resonant converters (one is on the vehicle side and the other is on the grid side) to provide the requited power-flow. The proposed controller is adaptively estimating the system parameters to consider the misalignment conditions effects on the system performance. The parameter estimation is achieved using only one voltage sensor. The second layer control is designed based on a new analytical modeling for the power flow in the system. For verification purposes, a prototype for BWPTS was built and driven by the proposed controller, which was implemented using a field-programmable gate array (FPGA) integrated circuit. The proposed controller provides very fast and stable response during both the transient and steady state operation in comparison with the conventional PI controller.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2020

Fault-tolerant grid frequency measurement algorithm during transients

Many critical electric grid operations rely on accurate grid frequency measurements. Unfortunately, the measurement accuracy can be easily undermined by power system transient faults. During a power system transient fault, the power grid voltages and currents are usually highly distorted by high-frequency components. What is worse, the power grid signals could have discontinuity during some system transient faults such as phase angle jump, and the discontinuity could result in large measurement errors to state-of-the-art grid measurement algorithms. In this study, a fault-tolerant grid frequency measurement algorithm during transients is proposed. The new algorithm consists of two stages. The first stage is a transient detector, and it can detect the occurrence of system transient faults instantaneously. The second stage is the intelligent frequency estimator, and it will adapt its measurements according to the transient detector. The performance of the algorithm is evaluated under different steady-state and transient conditions. Both dependability and security of the fault-tolerant algorithm are assessed by using PSCAD simulation data and IEEE Standard test data.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2016

Design of energy storage system to improve inertial response for large scale PV generation

With high-penetration levels of renewable generating sources being integrated into the existing electric power grid, conventional generators are being replaced and grid inertial response is deteriorating. This technical challenge is more severe with photovoltaic (PV) generation than with wind generation because PV generation systems cannot provide inertial response unless special countermeasures are adopted. To enhance the inertial response, this paper proposes to use battery energy storage systems (BESS) as the remediation approach to accommodate the degrading inertial response when high penetrations of PV generation are integrated into the existing power grid. A sample power system was adopted and simulated using PSS/E software. Here, impacts of different penetration levels of PV generation on the system inertial response were investigated and then BESS was incorporated to improve the frequency dynamics.

25 ENERGY STORAGE↗
DOE OSTI2022

Noise-Resilient Quantum Machine Learning for Stability Assessment of Power Systems

Transient stability assessment (TSA) is a cornerstone for resilient operations of todays interconnected power grids. This paper is a confluence of quantum computing, data science and machine learning to potentially address the power system TSA issue. Here, we devise a quantum TSA (QTSA) method to enable scalable and efficient data-driven transient stability prediction for bulk power systems, which is the first attempt to tackle the TSA issue with quantum computing. Our contributions are three-fold: 1) A high expressibility, low-depth (HELD) quantum circuit is designed for accurate and noise-resilient TSA; 2) A quantum natural gradient descent algorithm is developed for efficient HELD circuit training; 3) A systematical analysis on QTSAs performance under various quantum factors is per-formed. QTSA underpins a foundation of quantum-enabled and data-driven power grid stability analytics. It renders the intractable TSA straightforward and effortless in the Hilbert space, and therefore provides stability information for power system operations. Extensive experiments on quantum simulators and real quantum computers verify the accuracy, noise-resilience, scalability and universality of QTSA.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2015

Electric Vehicles and the Electric Grid

In response to the need for the decarbonization of the transport sector and to reduce the reliance on fossil fuels, it is expected that large fleets of plug-in electric vehicles (PEVs) will constitute an important share of the electricity demand in the not so distant future. These devices can, and would behave as any regular demand if they are allowed to charge as soon as they are connected to the electric grid. If such charging process is allowed, then several adverse impacts on the power grids such as increased system-wide peak demand, and early reinforcements of the distribution, transmission and/or generation systems would be required. However, as opposed to conventional demands, these new devices are equipped with a battery that enables them deferring their needs for electric energy in time. If the pliant nature of this demand is exploited in such a way that the charging of these devices takes place when it is more convenient for the power system, then not only would the adverse impacts to the system would be avoided, but also, a new stream of services could be offered to the electric power grid in the form of demand response, power injections in V2G and regulating reserves. This article discusses the consequences of integrating significant volumes of PEVs into power systems, in both, uncontrolled and controlled manners.

Ortega Vazquez, Miguel A.↗
DOE OSTI2016

An Integrated Software Package to Enable Predictive Simulation Capabilities

The power grid is increasing in complexity due to the deployment of smart grid technologies. Such technologies vastly increase the size and complexity of power grid systems for simulation and modeling. This increasing complexity necessitates not only the use of high-performance-computing (HPC) techniques, but a smooth, well-integrated interplay between HPC applications. This paper presents a new integrated software package that integrates HPC applications and a web-based visualization tool based on a middleware framework. This framework can support the data communication between different applications. Case studies with a large power system demonstrate the predictive capability brought by the integrated software package, as well as the better situational awareness provided by the web-based visualization tool in a live mode. Test results validate the effectiveness and usability of the integrated software package.

Chen, Yousu↗
DOE OSTI2023

Multi-level optimization with the koopman operator for data-driven, domain-aware, and dynamic system security

Cyber-Physical Systems (CPSs) like the power grid are critically important but also increasingly vulnerable; ensuring reliable system operation in the face of disruptions is becoming more and more challenging. Multi-Level Optimization (MLO) is a powerful way to model adversarial interactions, which naturally makes it applicable to studying CPS security. However, MLO typically does not address underlying system dynamics, and incorporating nonlinear dynamics is generally infeasible. In this paper, we show how to combine MLO with the Koopman Operator (KO) to remedy this. The KO maps nonlinear dynamics to a lifted space in which those dynamics are linear, thus making it ideal for use with MLO. Moreover, the structure of the KO also provides convenient ways to incorporate domain knowledge into the data-driven process of learning the KO representation of a given system. Here we then demonstrate the use of MLO-KO on a small example problem taken from the power grid domain, discuss the scalability and computational cost of MLO-KO, and identify future research directions for this work.

42 ENGINEERING↗
NASA NTRS2014

Propulsion Electric Grid Simulator (PEGS) for Future Turboelectric Distributed Propulsion Aircraft

NASA Glenn Research Center, in collaboration with the aerospace industry and academia, has begun the development of technology for a future hybrid-wing body electric airplane with a turboelectric distributed propulsion (TeDP) system. It is essential to design a subscale system to emulate the TeDP power grid, which would enable rapid analysis and demonstration of the proof-of-concept of the TeDP electrical system. This paper describes how small electrical machines with their controllers can emulate all the components in a TeDP power train. The whole system model in Matlab/Simulink was first developed and tested in simulation, and the simulation results showed that system dynamic characteristics could be implemented by using the closed-loop control of the electric motor drive systems. Then we designed a subscale experimental system to emulate the entire power system from the turbine engine to the propulsive fans. Firstly, we built a system to emulate a gas turbine engine driving a generator, consisting of two permanent magnet (PM) motors with brushless motor drives, coupled by a shaft. We programmed the first motor and its drive to mimic the speed-torque characteristic of the gas turbine engine, while the second motor and drive act as a generator and produce a torque load on the first motor. Secondly, we built another system of two PM motors and drives to emulate a motor driving a propulsive fan. We programmed the first motor and drive to emulate a wound-rotor synchronous motor. The propulsive fan was emulated by implementing fan maps and flight conditions into the fourth motor and drive, which produce a torque load on the driving motor. The stator of each PM motor is designed to travel axially to change the coupling between rotor and stator. This feature allows the PM motor to more closely emulate a wound-rotor synchronous machine. These techniques can convert the plain motor system into a unique TeDP power grid emulator that enables real-time simulation performance using hardware-in-the-loop (HIL).

electric power grid emulator↗
NASA NTRS2007

[Space Weather Impact on the Electricity Market]

Forbes & St. Cyr (2004, hereafter "FISC") have provided evidence that the electricity market can be impacted by space weather. Our analysis indicated that the estimated market impact for PJM was 3.7 % or approximately $500 million dollars over the 19 month sample period. Kappenman has taken exception to this estimate and contends that we have exaggerated the magnitude of the problem that space weather poses to PJM. There are four specific issues: (1) he claims that we have ignored relevant literature; (2) he asserts that Dst is not an appropriate proxy for GICs in PJM; (3) he charges that our findings are inconsistent with the impact of the 17 September 2000 storm; and (4) he alleges that our discussion of October 2003 storms is misleading. In our article, we have explained our methodology, multivariate regression analysis, with a particular focus on how it compares to correlation analysis. We have also explained the limitations of our analysis. We noted that "...While the Dstlprice relationship was found to be robust, the precise estimate should be treated with a relatively high degree of caution given that econometric modeling is not an exact science as well as the fact that the measure of space weather may be a poor proxy for GICs" (paragraph 96). We have also noted that additional research using local magnetometer data are needed (paragraph 97). We did not claim that that our findings for PJM are representative of the impact of space weather on other power grids. On the contrary, we noted that ... "Only analysis of other power grids will tell. " (paragraph 97). Kappenman inaccurately asserts that we have indicated that our findings . . . "imply much higher total costs are likely across the US and elsewhere in the world." He also inaccurately asserts that we have claimed that " . . . Dst is the most suited proxy for GIC in the PJM grid.. ." Moreover, he inaccurately refers to our analysis as a correlation study that uses Dst as quasi-binary indicator.

SaintCyr, O. Chris↗
DOE OSTI2025

Fast and robust strategies for large-scale mixed-integer SCOPF

This project develops scalable, computationally efficient algorithms to solve realistic large-scale power system optimization problems, including systems with more than 8,000 buses, as part of a larger series of competitions run by ARPA-E. These problems are critical because the secure and reliable operation of the power grid is becoming increasingly challenging, especially under conditions of increased uncertainty and variability. The economic feasibility of our methods is high, given that they are purely software-based solutions designed to operate power grids more efficiently. The technical effectiveness balances heuristics and approximations to provide a trade-off between speed and accuracy.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Survey and Benchmark of Benefits of High Voltage SiC Applications in Medium Voltage Power Distribution Grids

The main objective of this survey and benchmark study is to identify and document potential high-impact applications in today's and future medium voltage (MV) distribution grids that will significantly benefit from high voltage (HV) (i.e. > 3.3 kV) SiC-based power electronics equipment. In particular, it is desirable to identify applications that can utilize the high switching speed and high control bandwidth enabled by SiC-based equipment. Specifically, the benefits of using SiC are quantified through the benchmark analysis and design using simulation for the selected high-impact applications. In addition, to provide grid support services, it is necessary to consider grid requirements in the grid-connected converter's design. Therefore, the impact of grid requirements on the HV SiC-based grid-connected converter is evaluated.

24 POWER TRANSMISSION AND DISTRIBUTION↗