The Shipboard Operation Envelope(SOE) is the safe boundary of the helicopter/ship dynamic interface. The night deck on a ship is usually behind the hangar, where the airflow is turbulent due to the influence of the up...The Shipboard Operation Envelope(SOE) is the safe boundary of the helicopter/ship dynamic interface. The night deck on a ship is usually behind the hangar, where the airflow is turbulent due to the influence of the upper structure, wind and ship speed. The turbulent airnow is the major adverse factor for the safety of shipboard operations. In this paper, the night deck abbot is analysed as the superposition of two penyndicular 2-D airflows.N-S equations are used to calculate the velocity field and the range of turbulent airflow using finite element method. The result is correspondent well with test. Incorporating the influence of the airflow and giving some restrictions on the movements of the ship and on the control margin of the helicopter, the operation envelopes are calculated. The operation envelopes include three types for hovering over the deck, taking-off from and landing on ship, and landing with a landing-aid system. These results are helpful to the pilot training and night safety.展开更多
Maintaining a continuous power balance is crucial for ensuring operational feasibility in power systems.However,due to forecasting difficulties and computational limitations,economic dispatch often relies on discrete ...Maintaining a continuous power balance is crucial for ensuring operational feasibility in power systems.However,due to forecasting difficulties and computational limitations,economic dispatch often relies on discrete interval horizons,which fail to guarantee feasibility within each interval.This paper introduces the concept of a continuous operating envelope for managing intra-interval fluctuations,delineating the range within which fluctuations remain manageable.We propose a parametric programming model to construct the envelope,represented as a polytope that accounts for both timescale and fluctuation dimensions.To address the computational challenges inherent in the parametric programming model,we develop a fast solution method to provide an approximated polytope.The approximated polytope,initially derived from lower-dimensional projections,represents a subset of the exact polytope that ensures operational feasibility.Additionally,we apply a polytope expansion strategy in the original dimensions to refine the approximated polytope,bringing the approximation closer to the exact polytope.Case studies on an illustrative 5-bus and a utility-scale 661-bus system demonstrate that the method effectively and stably provides a continuous operating envelope,particularly for high-dimensional problems.展开更多
Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past years.However,uncertainties,which may come from load forecast...Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past years.However,uncertainties,which may come from load forecasting errors or inaccurate network parameters,have been rarely discussed in DOE calculation,leading to compromised quality of the hosting capacity allocation strategy.This letter studies how to calculate DOEs that are immune to such uncertainties based on a linearised unbalanced three-phase optimal power flow(UTOPF)model.With uncertain parameters constrained by norm balls,formulations for calculating robust DOEs(RDOEs)are presented along with discussions on their tractability.Two cases,including a 2-bus illustrative network and a representative Australian network,are tested to demonstrate the effectiveness and efficiency of the proposed approach.展开更多
文摘The Shipboard Operation Envelope(SOE) is the safe boundary of the helicopter/ship dynamic interface. The night deck on a ship is usually behind the hangar, where the airflow is turbulent due to the influence of the upper structure, wind and ship speed. The turbulent airnow is the major adverse factor for the safety of shipboard operations. In this paper, the night deck abbot is analysed as the superposition of two penyndicular 2-D airflows.N-S equations are used to calculate the velocity field and the range of turbulent airflow using finite element method. The result is correspondent well with test. Incorporating the influence of the airflow and giving some restrictions on the movements of the ship and on the control margin of the helicopter, the operation envelopes are calculated. The operation envelopes include three types for hovering over the deck, taking-off from and landing on ship, and landing with a landing-aid system. These results are helpful to the pilot training and night safety.
基金supported by National Natural Science Foundation of China(No.12371258)Young Elite Scientists Sponsorship Program(No.2023QNRC001)Project of Chongqing Postdoctoral Science Foundation(No.CSTB2023NSCQ-BHX0177).
文摘Maintaining a continuous power balance is crucial for ensuring operational feasibility in power systems.However,due to forecasting difficulties and computational limitations,economic dispatch often relies on discrete interval horizons,which fail to guarantee feasibility within each interval.This paper introduces the concept of a continuous operating envelope for managing intra-interval fluctuations,delineating the range within which fluctuations remain manageable.We propose a parametric programming model to construct the envelope,represented as a polytope that accounts for both timescale and fluctuation dimensions.To address the computational challenges inherent in the parametric programming model,we develop a fast solution method to provide an approximated polytope.The approximated polytope,initially derived from lower-dimensional projections,represents a subset of the exact polytope that ensures operational feasibility.Additionally,we apply a polytope expansion strategy in the original dimensions to refine the approximated polytope,bringing the approximation closer to the exact polytope.Case studies on an illustrative 5-bus and a utility-scale 661-bus system demonstrate that the method effectively and stably provides a continuous operating envelope,particularly for high-dimensional problems.
基金supported by the CSIRO Strategic Project on Network Optimisation&Decarbonisation(No.OD-107890).
文摘Dynamic operating envelopes(DOEs),as key enablers to facilitate distributed energy resource(DER)integration,have attracted increasing attention in the past years.However,uncertainties,which may come from load forecasting errors or inaccurate network parameters,have been rarely discussed in DOE calculation,leading to compromised quality of the hosting capacity allocation strategy.This letter studies how to calculate DOEs that are immune to such uncertainties based on a linearised unbalanced three-phase optimal power flow(UTOPF)model.With uncertain parameters constrained by norm balls,formulations for calculating robust DOEs(RDOEs)are presented along with discussions on their tractability.Two cases,including a 2-bus illustrative network and a representative Australian network,are tested to demonstrate the effectiveness and efficiency of the proposed approach.
