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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 667 records · Page 37

Intrinsic use control for system and use controlled component security

An Initialization Unit (IU) initiates an initial secure connection with an Intrinsic Use Control (IUC) Chip based on very large random numbers (VLRNs). The IUC Chip in turn initiates a secondary secure connection between it and one or more Use Controlled Components (UCCs). Polling by the IU allows confirmation of an ongoing secure connection, and also allows the IUC Chip to confirm the secondary secure connection to the UCCs. Removal or improper polling response from one of the UCCs results in a response from the IUC Chip that may include notification of tampering, or temporary or permanent discontinued operation of the offending UCC. Permanent discontinued operation may include destruction of the offending UCC, and cascaded discontinued operation of all other UCCs secured by the IUC Chip. A UCC may in turn be another nested layer of IUC Chips, controlling a corresponding layer of UCCs, ad infinitum.

Hart, Mark Miles↗

A gimbal platform stabilization for topographic applications

The aim of this work is the stabilization of a Gimbal platform for optical sensors acquisitions in topographic applications using mobile vehicles. The stabilization of the line of sight (LOS) consists in tracking the command velocity in presence of nonlinear noise due to the external environment. The hardware architecture is characterized by an Ardupilot platform that allows the control of both the mobile device and the Gimbal. Here we developed a new approach to stabilize the Gimbal platform, which is based on neural network. For the control system, we considered a plant that represents the transfer function of the servo system control model for an inertial stabilized Gimbal platform. The transductor used in the feed-back line control is characterized by the Rate Gyro transfer function installed onboard of Ardupilot. For the simulation and investigation of the system performance, we used the Simulink tool of Matlab. Results show that the hardware/software approach is efficient, reliable and cheap for direct photogrammetry, as well as for general purpose applications using mobile vehicles.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Tailoring the response of Autonomous Reactivity Control (ARC) systems

The Autonomous Reactivity Control (ARC) system was developed to ensure inherent safety of Generation IV reactors while having a minimal impact on reactor performance and economic viability. In this study we present the transient response of fast reactor cores to postulated accident scenarios with and without ARC systems installed. Using a combination of analytical methods and numerical simulation, the principles of ARC system design that assure stability and avoids oscillatory behavior have been identified. A comprehensive transient analysis study for ARC-equipped cores, including a series of Unprotected Loss of Flow (ULOF) and Unprotected Loss of Heat Sink (ULOHS) simulations, were performed for Argonne National Laboratory (ANL) Advanced Burner Reactor (ABR) designs. With carefully designed ARC-systems installed in the fuel assemblies, the cores exhibit a smooth non-oscillatory transition to stabilization at acceptable temperatures following all postulated transients. To avoid oscillations in power and temperature, the reactivity introduced per degree of temperature change in the ARC system needs to be kept below a certain threshold the value of which is system dependent, the temperature span of actuation needs to be as large as possible.

ARC↗

Cyber-Physical Test Platform for Microgrids: Combining Hardware, Hardware-in-the-Loop, and Network-Simulator-in-the-Loop

This paper presents a cyber-physical testbed, developed to investigate the complex interactions between emerging microgrid technologies such as grid-interactive power sources, control systems, and a wide variety of communication platforms and bandwidths. The cyber-physical testbed consists of three major components for testing and validation: real time models of a distribution feeder model with microgrid assets that are integrated into the National Renewable Energy Laboratory's (NREL) power hardware-in-the-loop (PHIL) platform; real-time capable network-simulator-in-the-loop (NSIL) models; and physical hardware including inverters and a simple system controller. Several load profiles and microgrid configurations were tested to examine the effect on system performance with increasing channel delays and router processing delays in the network simulator. Testing demonstrated that the controller's ability to maintain a target grid import power band was severely diminished with increasing network delays and laid the foundation for future testing of more complex cyber-physical systems.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Simultaneous optimal system and controller design for multibody systems with joint friction using direct sensitivities

Abstract Real-world multibody systems are often subject to phenomena like friction, joint clearances, and external events. These phenomena can significantly impact the optimal design of the system and its controller. This work addresses the gradient-based optimization methodology for multibody dynamic systems with joint friction using a direct sensitivity approach. The Brown–McPhee model has been used to characterize the joint friction in the system. This model is suitable for the study due to its accuracy for dynamic simulation and its compatibility with sensitivity analysis. This novel methodology supports codesign of the multibody system and its controller, which is especially relevant for applications like robotics and servo-mechanical systems, where the actuation and design are highly dependent on each other. Numerical results are obtained using a software package written in Julia with state-of-the-art libraries for automatic differentiation and differential equations. Three case studies are provided to demonstrate the attractive properties of simultaneous optimal design and control approach for certain applications.

Verulkar, Adwait↗

Hierarchical Control of Utility-Scale Solar PV Plants for Mitigation of Generation Variability and Ancillary Service Provision

This paper presents a hierarchical control system to mitigate the variability of solar photovoltaic (PV) power plant and provide ancillary services to the electric grid without the need for additional non-solar resources. With coordinated management of each inverter in the system, the control system commands the power plant to proactively curtail a small fraction of its instantaneous maximum power potential, which gives the plant enough headroom to ramp up production from the overall power plant, for a service such as regulation reserve. This control system is practical for continuously changing cloud cover conditions in partially cloudy days. A case study from a site in Hawaii with one-second resolution solar irradiance data is used to verify the efficacy of the proposed control system. The proposed control algorithm is subsequently compared with the alternative control technology from the literature, the grouping control algorithm; the results show that the proposed hierarchical control system is over 10 times more effective in reducing generator mileage to support power fluctuations from solar PV power plants.

14 SOLAR ENERGY↗

Implementation of an ICS Ransomware Testbed: Scenarios, Variants, and Evaluation Methods

Ransomware attacks on Industrial Control Systems (ICS) have emerged as a formidable threat to the United States’ critical infrastructure, eliciting grave concerns regarding national security. In March 2023, the FBI Internet Crime Complaint Center (IC3) unveiled its 2022 Internet Crime Report, highlighting a concerning 870 complaints related to ransomware impacting U.S. critical infrastructure. Of the country's 16 critical infrastructure sectors, 14 encountered at least one ransomware attack. Notably, while the Healthcare and Public Health sector suffered the most, reporting 210 attacks, sectors pivotal to ICS networks and governmental organizations were also targeted: the Defense Industrial Base reported 1 attack, Water and Wastewater Systems 3, Chemical 19, Energy 15, Government Facilities 115, and Critical Manufacturing 157. For instance, a ransomware attack on a major chemical company could jeopardize not only its production but also pose environmental risks should systems controlling hazardous materials be compromised. In 2022, three ransomware variants predominantly targeted U.S. critical infrastructure: HIVE, with 87 attacks; ALPHV/BlackCat, with 114; and LOCKBIT, with 149. Several cyber-attacks, such as the MOVEit data breach in May 2023 and the Colonial Pipeline ransomware attack in May 2021, have been so impactful that they commanded national attention. The DarkSide hacking group's assault on the Colonial Pipeline, initiated on May 6th, 2021, stands as one of the most substantial and publicly acknowledged cyber-attacks against U.S. critical infrastructure. The group exploited an exposed Virtual Private Network (VPN) password, paving the way for initial intrusion and subsequent data theft. A mere day later, DarkSide unleashed a ransomware attack that compromised vital accounting and billing systems, prompting an immediate shutdown of the pipeline to mitigate further ransomware proliferation across its network. This crisis spurred a robust response from the U.S. president and regulators, culminating in a national emergency declaration related to the pipeline shutdown on May 9th, 2021. This incident mirrors the 2017 NotPetya ransomware attack that significantly impacted the shipping giant Maersk, highlighting an urgent need for fortified cybersecurity across various industries. Future incidents, akin to the Colonial Pipeline attack, could potentially be mitigated—or entirely averted—should government agencies and private entities scrutinize system vulnerabilities, exploring various ransomware types and entry points. Proactive measures, such as conducting experiments on VPN accounts or auditing passwords to pinpoint duplicate usage across diverse systems and software, might illuminate feasible entry points and vulnerability zones within an organization's systems.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

A Cryptographic Method for Defense Against MiTM Cyber Attack in the Electricity Grid Supply Chain

Critical infrastructures such as the electricity grid can be severely impacted by cyber-attacks on its supply chain. Hence, having a robust cybersecurity infrastructure and management system for the electricity grid is a high priority. This paper proposes a cyber-security protocol for defense against man-in-the-middle (MiTM) attacks to the supply chain, which uses encryption and cryptographic multi-party authentication. A cyber-physical simulator is utilized to simulate the power system, control system, and security layers. The correctness of the attack modeling and the cryptographic security protocol against this MiTM attack is demonstrated in four different attack scenarios.

Paul, Shuva↗

Concept of operations for channel characterization and simulation of coaxial transmission channels at the National Ignition Facility (NIF)

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) executes experiments for inertial con nement fusion (ICF), world-class high energy density physics (HEDP), and critical national security missions. While the laser systems, target positioners, alignment systems, control systems, etc. enable the execution of such experiments, NIF’s utility would be greatly reduced without its suite of diagnostics. It would be e ectively “blind” to the incredible physics unleashed in its target chamber. Since NIF diagnostics are such an important part of its mission, the quality and reliability of the diagnostics, and of the data recorded from them, is crucial.

42 ENGINEERING↗

A Hierarchical VLSM-Based Demand Response Strategy for Coordinative Voltage Control between Transmission and Distribution Systems

This paper presents a two-stage hierarchical voltage-load sensitivity matrix (VLSM)-based demand response (DR) algorithm for regulating the voltage at distribution feeders while fulfilling the transmission system DR requests. This allows distributed energy resources be aggregated to provide transmission-level services without causing operational issues in the distribution grids. At the beginning of each operation interval, a transmission system controller will issue DR commands to distribution system controllers. In the first stage, the distribution system controller uses a VLSM-based dispatch algorithm to dispatch the available DR resources on the distribution feeder with an objective to minimize the total voltage deviations at the lowest cost. Then, power flow studies are conducted assuming that the DR commands have been executed. If voltage violations are detected, a second-stage VLSM-based DR dispatch will be performed to remove those violations. After that, the upper and lower DR limits calculated for the next operation interval are sent back to the transmission system controller so the transmission optimization algorithm can use them as operational constraints to make subsequent decisions. The DR resources include smart photovoltaic (PV) inverters that can curtail real power and provide reactive power support, controllable loads and capacitor banks. In conclusion, the IEEE 123-bus test system with 5-minute PV and load data is used to evaluate the performance of the algorithm. In conclusion, simulation results show that the proposed algorithm can fulfill the transmission-level DR requests while maintaining the voltage in the distribution system within limits.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Finite Energy and Bounded Actuator Attacks on Cyber-Physical Systems

As control system networks are being connected to enterprise level networks for remote monitoring, operation, and system-wide performance optimization, these same connections are providing vulnerabilities that can be exploited by malicious actors for attack, financial gain, and theft of intellectual property. Much effort in cyber-physical system (CPS) protection has focused on protecting the borders of the system through traditional information security techniques. Less effort has been applied to the protection of cyber-physical systems from intelligent attacks launched after an attacker has defeated the information security protections to gain access to the control system. In this paper, attacks on actuator signals are analyzed from a system theoretic context. The threat surface is classified into finite energy and bounded attacks. These two broad classes encompass a large range of potential attacks. The effect of theses attacks on a linear quadratic (LQ) control are analyzed, and the optimal actuator attacks for both finite and infinite horizon LQ control are derived, therefore the worst case attack signals are obtained. The closed-loop system under the optimal attack signals is given and a numerical example illustrating the effect of an optimal bounded attack is provided.

Djouadi, Seddik M↗

Network Randomization and Dynamic Defense for Critical Infrastructure Systems

Critical Infrastructure control systems continue to foster predictable communication paths, static configurations, and unpatched systems that allow easy access to our nation's most critical assets. This makes them attractive targets for cyber intrusion. We seek to address these attack vectors by automatically randomizing network settings, randomizing applications on the end devices themselves, and dynamically defending these systems against active attacks. Applying these protective measures will convert control systems into moving targets that proactively defend themselves against attack. Sandia National Laboratories has led this effort by gathering operational and technical requirements from Tennessee Valley Authority (TVA) and performing research and development to create a proof-of-concept solution. Our proof-of-concept has been tested in a laboratory environment with over 300 nodes. The vision of this project is to enhance control system security by converting existing control systems into moving targets and building these security measures into future systems while meeting the unique constraints that control systems face.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Development and evaluation of a prototype tracking system using the treatment couch

Purpose: Tumor motion increases safety margins around the clinical target volume and leads to an increased dose to the surrounding healthy tissue. The authors have developed and evaluated a one-dimensional treatment couch tracking system to counter steer respiratory tumor motion. Three different motion detection sensors with different lag times were evaluated. Methods: The couch tracking system consists of a motion detection sensor, which can be the topometrical system Topos (Cyber Technologies, Germany), the respiratory gating system RPM (Varian Medical Systems) or a laser triangulation system (Micro Epsilon), and the Protura treatment couch (Civco Medical Systems). The control of the treatment couch was implemented in the block diagram environment Simulink (MathWorks). To achieve real time performance, the Simulink models were executed on a real time engine, provided by Real-Time Windows Target (MathWorks). A proportional-integral control system was implemented. The lag time of the couch tracking system using the three different motion detection sensors was measured. The geometrical accuracy of the system was evaluated by measuring the mean absolute deviation from the reference (static position) during motion tracking. This deviation was compared to the mean absolute deviation without tracking and a reduction factor was defined. A hexapod system was moving according to seven respiration patterns previously acquired with the RPM system as well as according to a sin{sup 6} function with two different frequencies (0.33 and 0.17 Hz) and the treatment table compensated the motion. Results: A prototype system for treatment couch tracking of respiratory motion was developed. The laser based tracking system with a small lag time of 57 ms reduced the residual motion by a factor of 11.9 ± 5.5 (mean value ± standard deviation). An increase in delay time from 57 to 130 ms (RPM based system) resulted in a reduction by a factor of 4.7 ± 2.6. The Topos based tracking system with the largest lag time of 300 ms achieved a mean reduction by a factor of 3.4 ± 2.3. The increase in the penumbra of a profile (1 × 1 cm{sup 2}) for a motion of 6 mm was 1.4 mm. With tracking applied there was no increase in the penumbra. Conclusions: Couch tracking with the Protura treatment couch is achievable. To reliably track all possible respiration patterns without prediction filters a short lag time below 100 ms is needed. More scientific work is necessary to extend our prototype to tracking of internal motion.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Command and Control of Utilities Systems

The utilities systems that encompass the Y-12 National Security Complex are an integral part of the entire campus, and are essential to maintaining critical mission focus for the site. Although the utilities systems each differ in function, the central production and distribution model creates a common thread on which each system is run. Several incidents in FY 2018 and FY 2019 documented a lack of overall systems control and highlighted the need to create a better command system that could maintain system availability and decrease possible impacts to the surrounding environment. An initial system was started in September of 2019 to better control mechanical utility distribution systems. The measurement of the system can be modeled against a standard command and control related incident. The corresponding work hours from a typical control-related incident were used as key component to this system model. System effectiveness is modeled against utility’s incidents that demonstrate a loss of command and control. The increased simulations of the model also document control can only be effectively contained within the stated time (3-5 years) by yielding more engineers to complete alignments, or drastically reducing the amount of time for alignments. The total control points of the model document a clear correlation between alignments, control points, and the amount of man-hours per incident. Current data shows that actual incident man-hours (1.88 manhours/ incident since initial system implementation) are near expected incident man-hours (1.81 manhours/ incident) with command and control for October 2021, which documents a 33.3% reduction in man-hours/incident since initial system implementation. A conclusion can be drawn that focus on increasing the amount of controlled points in the system can reduce incidents and the decrease the amount of non-value added work to employee’s day-to-day lives, while also achieving a culture that enhances and sustains utilities reliability.

99 GENERAL AND MISCELLANEOUS↗

Cascaded systems and methods for controlling energy use during a demand limiting period

A cascaded control system is configured to control power consumption of a building during a demand limiting period. The cascaded control system includes an energy use setpoint generator and a feedback controller. The energy use setpoint generator is configured to use energy pricing data and measurements of a variable condition within the building to generate an energy use setpoint during the demand limiting period. The feedback controller is configured to use a difference between the energy use setpoint and a measured energy use to generate a control signal for building equipment that operate to affect the variable condition within the building during the demand limiting period.

Wenzel, Michael J.↗

Cascaded systems and methods for controlling energy use during a demand limiting period

A cascaded control system is configured to control power consumption of a building during a demand limiting period. The cascaded control system includes an energy use setpoint generator and a feedback controller. The energy use setpoint generator is configured to use energy pricing data and measurements of a variable condition within the building to generate an energy use setpoint during the demand limiting period. The feedback controller is configured to use a difference between the energy use setpoint and a measured energy use to generate a control signal for building equipment that operate to affect the variable condition within the building during the demand limiting period.

Wenzel, Michael J.↗

Systems and methods for controlling electrical grid resources

The present invention relates to PMU-based control systems for dampening inter-area oscillations in large-scale interconnected power systems or grids to protect against a catastrophic blackout. The control systems receive phasor measurements from two or more locations on an AC transmission line and generates a power control command to a power resource on the grid.

24 POWER TRANSMISSION AND DISTRIBUTION↗