17 research outputs found
Causative Cyberattacks on Online Learning-based Automated Demand Response Systems
Power utilities are adopting Automated Demand Response (ADR) to replace the
costly fuel-fired generators and to preempt congestion during peak electricity
demand. Similarly, third-party Demand Response (DR) aggregators are leveraging
controllable small-scale electrical loads to provide on-demand grid support
services to the utilities. Some aggregators and utilities have started
employing Artificial Intelligence (AI) to learn the energy usage patterns of
electricity consumers and use this knowledge to design optimal DR incentives.
Such AI frameworks use open communication channels between the
utility/aggregator and the DR customers, which are vulnerable to
\textit{causative} data integrity cyberattacks. This paper explores
vulnerabilities of AI-based DR learning and designs a data-driven attack
strategy informed by DR data collected from the New York University (NYU)
campus buildings. The case study demonstrates the feasibility and effects of
maliciously tampering with (i) real-time DR incentives, (ii) DR event data sent
to DR customers, and (iii) responses of DR customers to the DR incentives
MaDEVIoT: Cyberattacks on EV Charging Can Disrupt Power Grid Operation
This paper examines the feasibility of demand-side cyberattacks on power
grids launched via internet-connected high-power EV Charging Stations (EVCSs).
By distorting power grid frequency and voltage, these attacks can trigger
system-wide outages. Our case study focuses on Manhattan, New York, and reveals
that such attacks will become feasible by 2030 with increased EV adoption. With
a single EVCS company dominating Manhattan, compromising a single EVCS server
raises serious power grid security concerns. These attacks can overload power
lines and trip over-frequency (OF) protection relays, resulting in a power grid
blackout. This study serves as a crucial resource for planning authorities and
power grid operators involved in the EV charging infrastructure roll-out,
highlighting potential cyberthreats to power grids stemming from high-power
EVCSs.Comment: This paper is accepted for publication in the proceeding of IEEE ISGT
NA 2024 in Washington DC, US
Dynamic Model of Back-to-Back Converter for System-Level Phasor Simulation
The power system is expected to evolve rapidly with the increasing deployment
of power electronic interface and conditioning systems, microgrids, and hybrid
AC/DC grids. Among power electronic systems, back-to-back (BTB) converters can
be a powerful interface to integrate microgrids and networked microgrids. To
study the integration of such devices into large power systems, a balance
between power electronics model fidelity and system-level computational
efficiency is critical. In system-level simulations of bulk power systems
dominated by synchronous generators, detailed electromagnetic models of
back-to-back converters may be unnecessary and also computationally
inefficient. This paper focuses on developing a simple phasor model for
back-to-back converters that can be easily integrated into powerflow solvers to
facilitate large-scale power system simulations. The model is implemented using
C language and integrated into GridLAB-D, an open source software for
distribution systems studies, as a potential new capability. The GridLAB-D
phasor domain model is validated against the electromagnetic transient (EMT)
simulation of the detailed switching model. Simulation results show that the
phasor model successfully captures the dominant dynamics of the converter with
significantly shorter simulation elapsed time
Weather Sensitive High Spatio-Temporal Resolution Transportation Electric Load Profiles For Multiple Decarbonization Pathways
Electrification of transport compounded with climate change will transform
hourly load profiles and their response to weather. Power system operators and
EV charging stakeholders require such high-resolution load profiles for their
planning studies. However, such profiles accounting whole transportation sector
is lacking. Thus, we present a novel approach to generating hourly electric
load profiles that considers charging strategies and evolving sensitivity to
temperature. The approach consists of downscaling annual state-scale sectoral
load projections from the multi-sectoral Global Change Analysis Model (GCAM)
into hourly electric load profiles leveraging high resolution climate and
population datasets. Profiles are developed and evaluated at the Balancing
Authority scale, with a 5-year increment until 2050 over the Western U.S.
Interconnect for multiple decarbonization pathways and climate scenarios. The
datasets are readily available for production cost model analysis. Our open
source approach is transferable to other regions
Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study
Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
GODEEEP Light Duty Vehicle (LDV) Hourly Time Series Loads by County
<p>Each file contains projected light duty vehicle (LDV) load by county for a particular U.S. state, GCAM-USA scenario, and climate pathway as specified in the file name. For the full discussion of the methodology, please see <a href="https://godeeep.pnnl.gov/pubs/EV_Load_Shapes_GODEEEP_Arxiv.pdf">https://godeeep.pnnl.gov/pubs/EV_Load_Shapes_GODEEEP_Arxiv.pdf</a>. For the balancing authority level timeseries, please see <a href="https://doi.org/10.5281/zenodo.7888568">10.5281/zenodo.7888568</a>. The code used to produce this data is available at <a href="https://github.com/GODEEEP/transportation_electrification">https://github.com/GODEEEP/transportation_electrification</a>. Note that fleet sizes at the state scale are derived from the GCAM-USA scenario output. Downscaling to the county scale uses the electric vehicle penetration rates found in the appendix of <a href="https://www.pnnl.gov/sites/default/files/media/file/EV-AT-SCALE_1_IMPACTS_final.pdf">M. Kintner-Meyer, S. Davis, S. Sridhar, D. Bhatnagar, S. Mahserejian and M. Ghosal, "Electric vehicles at scale-phase I analysis: High EV adoption impacts on the western US power grid", Tech. Rep., 2020</a>. To harmonize the state scale LDV energy use from the GCAM-USA scenarios with the LDV load calculated with EV-Pro Lite, a scale factor was applied to the county level loads, so note that if the reported scale factor is much different than 1.0 there is potentially some disagreement between the load and the fleet size. This scale factor has already been applied to the loads reported in these files (but has NOT been applied to the fleet sizes).</p><h4><strong>GCAM-USA scenarios</strong></h4><p>See <a href="https://doi.org/10.5281/zenodo.7838871">10.5281/zenodo.7838871</a> and <a href="https://doi.org/10.5281/zenodo.8377778">10.5281/zenodo.8377778</a> for more details</p><ul><li>BAU_Climate - a business-as-usual scenario without IRA incentives</li><li>business_as_usual_ira_ccs_climate - a business-as-usual scenario with IRA incentives for CCS technology</li><li>NetZeroNoCCS_Climate - a scenario targeting net-zero by 2050 without IRA incentives, disallowing CCS technology</li><li>net_zero_ira_ccs_climate - scenario targeting net-zero by 2050 with IRA incentives for CCS technology</li></ul><h4><strong>Climate pathways</strong></h4><p>See <a href="https://doi.org/10.1038/s41597-023-02485-5">10.1038/s41597-023-02485-5</a> for more details</p><ul><li>rcp45cooler - historical weather patterns projected into the future with a warming signal applied commensurate with a cooler ensemble of RCP4.5 CMIP6 models</li><li>rcp85hotter - historical weather patterns projected into the future with a warming signal applied commensurate with a hotter ensemble of RCP4.5 CMIP6 models</li></ul><h4><strong>Fields in the data files:</strong></h4><ul><li>time - hourly timestamp in UTC representing the preceding hour of data</li><li>county - the county name</li><li>State - the state abbreviation for this county</li><li>FIPS - FIPS code for the county</li><li>balancing_authority - the balancing authority responsible for the load reported in this row; note that some counties span multiple balancing authorities and their load is divided between those balancing authorities proportional to the population residing within that balancing authority</li><li>load_MWh - load on the grid caused by the charging of LDVs during this hour within this county and balancing authority in megawatt hours</li><li>temperature_celsius - mean temperature within this county and balancing authority in degrees Celsius</li><li>fleet_size - number of electrified LDV cars within this county and balancing authority</li><li>daily_miles - average number of miles traveled per day per LDV within this county and balancing authority in miles/day</li><li>scale_factor - the values in the load_MWh field have been scaled by this multiplier in order to harmonize the state scale LDV loads with the GCAM-USA scenarios</li></ul><h4><strong>Changelog</strong></h4><ul><li>v1.0.1 - added fleet_size, daily_miles, and scale_factor to the output, and updated the README accordingly</li></ul><h4><strong>Acknowledgements</strong></h4><p>This research was supported by the Grid Operations, Decarbonization, Environmental and Energy Equity Platform (GODEEEP) Investment, under the Laboratory Directed Research and Development (LDRD) Program at Pacific Northwest National Laboratory (PNNL).</p><p>PNNL is a multi-program national laboratory operated for the U.S. Department of Energy (DOE) by Battelle Memorial Institute under Contract No. DE-AC05-76RL01830.</p>
GODEEEP Light Duty Vehicle (LDV) Hourly Time Series Loads by County
<p>Each file contains projected light duty vehicle (LDV) load by county for a particular U.S. state, GCAM-USA scenario, and climate pathway as specified in the file name. For the full discussion of the methodology, please see <a href="https://godeeep.pnnl.gov/pubs/EV_Load_Shapes_GODEEEP_Arxiv.pdf">https://godeeep.pnnl.gov/pubs/EV_Load_Shapes_GODEEEP_Arxiv.pdf</a>. For the balancing authority level timeseries, please see <a href="https://doi.org/10.5281/zenodo.7888568">10.5281/zenodo.7888568</a>.</p><p>GCAM-USA scenarios (see <a href="https://doi.org/10.5281/zenodo.7838871">10.5281/zenodo.7838871</a> and <a href="https://doi.org/10.5281/zenodo.8377778">10.5281/zenodo.8377778</a> for more details):</p><ul><li>`BAU_Climate` - a business-as-usual scenario without IRA incentives</li><li>`business_as_usual_ira_ccs_climate` - a business-as-usual scenario with IRA incentives for CCS technology</li><li>`NetZeroNoCCS_Climate` - a scenario targeting net-zero by 2050 without IRA incentives, disallowing CCS technology</li><li>`net_zero_ira_ccs_climate` - scenario targeting net-zero by 2050 with IRA incentives for CCS technology</li></ul><p>Climate pathways (see <a href="https://doi.org/10.1038/s41597-023-02485-5">10.1038/s41597-023-02485-5</a> for more details):</p><ul><li>`rcp45cooler` - historical weather patterns projected into the future with a warming signal applied commensurate with a cooler ensemble of RCP4.5 CMIP6 models</li><li>`rcp85hotter` - historical weather patterns projected into the future with a warming signal applied commensurate with a hotter ensemble of RCP4.5 CMIP6 models</li></ul><p>Fields in the data files:</p><ul><li>`time` - hourly timestamp in UTC representing the preceding hour of data</li><li>`load_MWh` - load on the grid caused by the charging of LDVs during this hour within this county and balancing authority in megawatt hours</li><li>`temperature_celsius` - mean temperature within this county and balancing authority in degrees Celsius</li><li>`FIPS` - FIPS code for the county</li><li>`balancing_authority` - the balancing authority responsible for the load reported in this row; note that some counties span multiple balancing authorities and their load is divided between those balancing authorities proportional to the population residing within that balancing authority</li><li>`State` - the state abbreviation for this county</li></ul><p> </p><p>This research was supported by the Grid Operations, Decarbonization, Environmental and Energy Equity Platform (GODEEEP) Investment, under the Laboratory Directed Research and Development (LDRD) Program at Pacific Northwest National Laboratory (PNNL). </p><p>PNNL is a multi-program national laboratory operated for the U.S. Department of Energy (DOE) by Battelle Memorial Institute under Contract No. DE-AC05-76RL01830.</p>