Abstract: A system and method for obtaining frequency-domain admittance/impedance using a few sets of time-series data. Utilizing an Eigensystem Realization Algorithm (ERA) or a dynamic mode decomposition (DMD), the input/output frequency-domain model reflecting voltage/current relationship is identified, and admittance/impedance identification is demonstrated for a grid-connected inverter-based resource (IBR) system. The proposed approach provides a powerful tool to replace the state-of-the-art harmonic injection methodology.

Abstract: Various examples are provided extended Kalman filtering estimators for generators. In one example, among others an extended Kalman filtering estimator includes a dynamics estimator configured to calculate an estimated variable such as an estimated dynamic state or an estimated parameter of a generator, a geometry estimator configured to estimate generator values, and a Kalman filter component configured to determine a correction to the estimated state variable.

Abstract: Devices and methods for mechanism-based feedback controller employed in a wind powered power system are provided. A controller can include a vector control-based voltage source converter with feedback control circuitry. The feedback control circuitry is configured to modulate either a power order or a dc-link voltage order to control coupling between voltage and power. The controller can be connected to a wind-based turbine generator of a wind farm and regulate power deployed to a power grid.

Abstract: Devices and methods for mechanism-based feedback controller employed in a wind powered power system are provided. A controller can include a vector control-based voltage source converter with feedback control circuitry. The feedback control circuitry is configured to modulate either a power order or a dc-link voltage order to control coupling between voltage and power. The controller can be connected to a wind-based turbine generator of a wind farm and regulate power deployed to a power grid.

Abstract: Various examples are provided for feedback control of power systems. The feedback control can provide simultaneous frequency regulation and economic operation of a power system. In one example, a method includes obtaining a frequency difference associated with a generator of a power system; determining an output power adjustment based at least in part upon the frequency difference and a cost function associated with the generator; and providing a power command to a secondary frequency control of the generator, the power command based upon the output power adjustment. In another example, a generator control system includes a primary frequency controller configured to control frequency droop of a generator of a power system; and a secondary frequency controller configured to adjust output power of the generator based at least in part upon a frequency difference associated with the generator and a cost function associated with the generator.

Abstract: Disclosed are various embodiments that relate to multi-agent decision system based at least in part on a dual's dual problem formulation. The embodiments limited the amount of information exchanged among autonomous entities. The embodiments can incorporate existing AC optimal power flow (OPF) software systems. In one embodiments, a subgradient-based iterative method is used.

Abstract: Various examples are provided for parameter estimation of generators. In one example, among others, a method includes collecting data corresponding to a generator using a phasor management unit (PMU) and estimating dynamic parameters of the generator using extended Kalman filtering (EKF) and the collected PMU data. In another example, a system includes at least one application executable in a processing device that obtains operational data corresponding to a generator and estimates a dynamic parameter of the generator using EKF and the operational data. In another example, an EKF estimator includes a dynamics estimator configured to estimate a state variable of a generator, a geometry estimator configured to estimate phasor values associated with the generator, and a Kalman filter gain configured to determine a correction to the state variable.

Abstract: Various examples are related to synchronous generator modeling with frequency control, which can be achieved using unscented Kalman filtering. In one example, a method includes obtaining operational parameters associated with a generator of a power system; determining parameters of a synchronous generator model with frequency control based at least in part upon the operational parameters associated with the generator; and providing a command to a frequency control of the generator, the command updating one or more parameters of the frequency control. In another example, a system includes a generator controller for a generator of a power system; and a computing device in communication with the generator controller, where the computing device is configured to determine parameters of the synchronous generator model using operational parameters associated with the generator and provide a command updating one or more parameters of a frequency control of the generator controller.

Abstract: Various examples are provided that are related to coupling dynamics for, e.g., power systems with iterative discrete decision making architectures. In one example, a method includes determining an output power adjustment using a frequency difference associated with a generator of a first area of a power system and price signals corresponding to power generation in the first area and in a second area coupled to the first area by a tie-line; and providing a power command based upon the output power adjustment to a control system of the generator. In another example, a power system control system includes first and second agents configured to control power generation of a first area and a second area of a power system, respectively. The second agent can control power generation of the second area using frequency differences of generators in the second area and price signals of the first and second areas.

Abstract: Various examples are provided for feedback control of power systems. The feedback control can provide simultaneous frequency regulation and economic operation of a power system. In one example, a method includes obtaining a frequency difference associated with a generator of a power system; determining an output power adjustment based at least in part upon the frequency difference and a cost function associated with the generator; and providing a power command to a secondary frequency control of the generator, the power command based upon the output power adjustment. In another example, a generator control system includes a primary frequency controller configured to control frequency droop of a generator of a power system; and a secondary frequency controller configured to adjust output power of the generator based at least in part upon a frequency difference associated with the generator and a cost function associated with the generator.

Abstract: A microsecond time-resolved mass spectrometry device and method of using desorption electrospray ionization (10) was described for the kinetic study of fast reactions. The device includes a liquid jet generator (64) that is configured to emit a continuous liquid jet (50) having a length. An ambient ionization source (10) is directed toward a selected variable location along the continuous liquid jet (50) to desorb at least a portion of the continuous liquid jet (50). A mass analyzer (30) analyzes a mass-to-charge ratio of an ionized sample that is within the desorbed portion of the continuous liquid jet (50). The acquired mass spectra reflect the reaction progress in different reaction times and, therefore, may be used to derive the reaction rate.

Abstract: A microsecond time-resolved mass spectrometry device and method of using desorption electrospray ionization (10) was described for the kinetic study of fast reactions. The device includes a liquid jet generator (64) that is configured to emit a continuous liquid jet (50) having a length. An ambient ionization source (10) is directed toward a selected variable location along the continuous liquid jet (50) to desorb at least a portion of the continuous liquid jet (50). A mass analyzer (30) analyzes a mass-to-charge ratio of an ionized sample that is within the desorbed portion of the continuous liquid jet (50). The acquired mass spectra reflect the reaction progress in different reaction times and, therefore, may be used to derive the reaction rate.

Abstract: A microsecond time-resolved mass spectrometry device and method of using desorption electrospray ionization (10) was described for the kinetic study of fast reactions. The device includes a liquid jet generator (64) that is configured to emit a continuous liquid jet (50) having a length. An ambient ionization source (10) is directed toward a selected variable location along the continuous liquid jet (50) to desorb at least a portion of the continuous liquid jet (50). A mass analyzer (30) analyzes a mass-to-charge ratio of an ionized sample that is within the desorbed portion of the continuous liquid jet (50). The acquired mass spectra reflect the reaction progress in different reaction times and, therefore, may be used to derive the reaction rate.

Abstract: An apparatus for direct analysis of the redox products, or intermediates, of an electrochemical reaction by coupling an electrochemical cell to desorption electrospray ionization mass spectrometry.

Abstract: An apparatus and method for direct analysis of continuous-flow liquid samples by desorption electrospray ionization-mass spectrometry (DESI-MS) including a sample stage that is adapted to receive a liquid sample and a nebulizing ionizer that is configured to generate a charged, nebulized solvent and thereby desorb at least a portion of the liquid sample from the sample stage.

Abstract: An apparatus for direct analysis of the redox products, or intermediates, of an electrochemical reaction by coupling an electrochemical cell to desorption electrospray ionization mass spectrometry.

Abstract: An apparatus and method for direct analysis of continuous-flow liquid samples by desorption electrospray ionization-mass spectrometry (DESI-MS) including a sample stage that is adapted to receive a liquid sample and a nebulizing ionizer that is configured to generate a charged, nebulized solvent and thereby desorb at least a portion of the liquid sample from the sample stage.