scholarly journals Reference and Limit Governors for Limit Protection of Turbofan Engines

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2803 ◽  
Author(s):  
Wenhao Xu ◽  
Muxuan Pan ◽  
Jiakun Qin ◽  
Jinquan Huang
Keyword(s):  
Invariant Sets ◽  
Multiple Constraints ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Admissible Sets ◽  
Engine Model ◽  
Engine Control System ◽  
Engine Thrust ◽  
Simulation Results ◽  
Limit Protection

This paper proposes a novel architecture of limit protection including the references governors and limit governors and applies this architecture to limit protection in turbofan engines. References governors are designed as add-on schemes to a pre-stability engine control system that modifies reference commands to avoid constraints violation. Limit governors are proposed as an assistant part for references governors adjusting constraints to prevent references from stopping updates. The use of output admissible sets for a class of variable constraints is exploited to form invariant sets. Simulation results based on a turbofan engine model show that references governors with limit governors can effectively enforce the multiple constraints and provide enhanced engine thrust when steady violation occurs.

scholarly journals Impact of Modeling Simplifications on Lightning Strike Simulation for Aeroengine

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yi-fan Qian ◽  
Zhi-feng Ye ◽  
Hai-bo Zhang
Keyword(s):  
Simulation Analysis ◽  
Simulation Software ◽  
Simplified Model ◽  
Lightning Strike ◽  
Electromagnetic Simulation ◽  
Experimental Conditions ◽  
Turbofan Engine ◽  
Engine Model ◽  
Simulation Results ◽  
The Difference

With the development of electromagnetic simulation software and affordable hardware, it is allowed for us to complete simulations for EMC purposes. However, simulation demands will be immense when simulations for models with complex structures, especially aircraft components, have to be solved. Hence, it is meaningful to investigate how to minimize the computational demands. One of the solutions to reduce the simulation expense is the simplification for the simulated model. But the simplified model should be guaranteed to provide credible simulation results which do not deviate from the original model apparently. Generally, the difference between the simulation results and experimental data is estimated, or if the experimental conditions are not achieved, the comparison between the simplified model and the original one has to be analyzed, at least. This paper explores the electromagnetic simulation of a turbofan engine encountering lightning strike. With the simplifications of different components on the turbofan engine, the influences on induced currents of engine controller cables are simulated and analyzed based on the transmission-line matrix method. A combining method of components removal and geometric structure simplification is proposed to simplify the whole engine model. Simplified components include compressor, combustion chamber, turbine, and nozzle. The effects of different simplification methods are quantified, and the rationality of the simplified model is verified by simulation analysis.

Unified Diagnostic Filtering for Turbofan Engine Control Systems Based on Matrix Pencil Observers

2012 ◽  
Author(s):  
Daoliang Tan ◽  
Yue Liu ◽  
Ai He ◽  
Yun Liu ◽  
Xiangxing Kong ◽  
...  
Keyword(s):  
Matrix Pencil ◽  
Fault Detection And Isolation ◽  
Dynamic State ◽  
Engine Control ◽  
Triangular Form ◽  
Turbofan Engine ◽  
Engine Model ◽  
Engine Control System ◽  
Exogenous Disturbances ◽  
The Face

Motivated by decoupling the adverse effect of exogenous disturbances on dynamic state filtering, unknown input observers (UIO’s) have received considerable attention in the fault diagnosis domain over the past decades. The model used in the UIO theory, however, does not include any disturbance item in system outputs. This can impair the robustness of diagnostic performance in the face of output disturbances. In this context, a unified filter, intended for both fault detection and isolation (FDI), is presented through the application of matrix pencil decomposition. First of all, a general fault model for the disturbed engine is formulated, with output disturbances considered. Then, this engine model is transformed by means of decomposing a matrix pencil derived from model matrices in a block triangular form. Based on this decomposition, a reduced-order subsystem can be obtained which is not affected by external disturbances. Finally, a single conventional filter with regional pole assignment constraints is designed to detect and isolate faults of an engine control system. Simulation results on one turbofan engine show the advantages of this given method over the UIO and Kalman filter.

A Min-Max selector controller for turbofan engines with improvement of limit management and low computational burden

2018 ◽  
Vol 41 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Amin Imani ◽  
Morteza Montazeri-Gh
Keyword(s):  
Controller Design ◽  
Optimization Problems ◽  
Sliding Mode ◽  
Transient State ◽  
Careful Analysis ◽  
Limit Values ◽  
Computational Burden ◽  
Turbofan Engines ◽  
Engine Model ◽  
Limit Protection

Recent studies show that there is no guarantee for conventional Min-Max structure containing linear compensators to keep engine limitations in transient state, while limit violation can make dangerous events. Careful analysis indicates that despite the design of limitation loops overshoot-free to reduce the possibility of limit violation, exceeding the limits can occur for some variables affected by engine acceleration or deceleration, when other loop controllers are active. In this study, the limit values of these variables are taken into account in controller design of other loops using state feedback techniques and convex optimization problems, and their dynamic compensators are removed from the Min-Max structure. Thus, in addition to improvement of Min-Max limit protection, computational burden also decreases owing to loop reduction. The condition for limit protection in steady state and thrust tracking assurance is also specified. Simulations carried out with linear and nonlinear turbofan engine model show efficient performance of the proposed methodology in comparison with traditional Min-Max and Min-Max/sliding mode control (SMC) approaches.

Active fault tolerant control of turbofan engines with actuator faults under disturbances

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan-Hua Ma ◽  
Xian Du ◽  
Lin-Feng Gou ◽  
Si-Xin Wen
Keyword(s):  
Active Fault ◽  
Fault Tolerant ◽  
Fault Tolerant Control ◽  
Feedback Controller ◽  
Actuator Faults ◽  
Error Feedback ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Interval Observer ◽  
State Error

AbstractIn this paper, an active fault-tolerant control (FTC) scheme for turbofan engines subject to simultaneous multiplicative and additive actuator faults under disturbances is proposed. First, a state error feedback controller is designed based on interval observer as the nominal controller in order to achieve the model reference rotary speed tracking control for the fault-free turbofan engine under disturbances. Subsequently, a virtual actuator based reconfiguration block is developed aiming at preserving the consistent performance in spite of the occurrence of the simultaneous multiplicative and additive actuator faults. Moreover, to improve the performance of the FTC system, the interval observer is slightly modified without reconstruction of the state error feedback controller. And a theoretical sufficiency criterion is provided to ensure the stability of the proposed active FTC system. Simulation results on a turbofan engine indicate that the proposed active FCT scheme is effective despite of the existence of actuator faults and disturbances.

Study on Engine Kinematics and Dynamics Simulation Based on COSMOSMotion

2012 ◽  
Vol 503-504 ◽  
pp. 731-734
Author(s):  
Xiao Xu Liu ◽  
Min Chen ◽  
Ai Hua Tang
Keyword(s):  
Virtual Prototype ◽  
Dynamics Simulation ◽  
Kinematics And Dynamics ◽  
Engine Model ◽  
Kinematics Simulation ◽  
Simulation Based ◽  
Calculation Results ◽  
Simulation Results ◽  
Dynamics Simulations

The engine model with 4 cylinders is built by SolidWorks, the kinematics and dynamics simulations of the engine virtual prototype are done by COSMOSMotion, the results of kinematics simulation are checked, there are very small errors between the simulation results and the calculation results according to formulas. The mainly results of dynamics simulation are given. The simulation result consists with the parameters of the engine.

Generic New Modeling Technique for Turbofan Engine Thrust

2013 ◽  
Vol 29 (6) ◽  
pp. 1492-1495 ◽  
Author(s):  
Luis Fajardo Rodriguez ◽  
Ruxandra Mihaela Botez
Keyword(s):  
Modeling Technique ◽  
Turbofan Engine ◽  
Engine Thrust

scholarly journals Multi-Fidelity Simulation of a Turbofan Engine With Results Zoomed Into Mini-Maps for a Zero-D Cycle Simulation

2004 ◽  
Author(s):  
Mark G. Turner ◽  
John A. Reed ◽  
Robert Ryder ◽  
Joseph P. Veres
Keyword(s):  
Boundary Conditions ◽  
Fluid Dynamic ◽  
Thermodynamic Cycle ◽  
High Fidelity ◽  
Operating Characteristics ◽  
Cycle Model ◽  
Turbofan Engine ◽  
Engine Model ◽  
Cycle Simulation ◽  
Component Models

A Zero-D cycle simulation of the GE90-94B high bypass turbofan engine has been achieved utilizing mini-maps generated from a high-fidelity simulation. The simulation utilizes the Numerical Propulsion System Simulation (NPSS) thermodynamic cycle modeling system coupled to a high-fidelity full-engine model represented by a set of coupled 3D computational fluid dynamic (CFD) component models. Boundary conditions from the balanced, steady-state cycle model are used to define component boundary conditions in the full-engine model. Operating characteristics of the 3D component models are integrated into the cycle model via partial performance maps generated from the CFD flow solutions using one-dimensional meanline turbomachinery programs. This paper high-lights the generation of the highpressure compressor, booster, and fan partial performance maps, as well as turbine maps for the high pressure and low pressure turbine. These are actually “mini-maps” in the sense that they are developed only for a narrow operating range of the component. Results are compared between actual cycle data at a take-off condition and the comparable condition utilizing these mini-maps. The mini-maps are also presented with comparison to actual component data where possible.

scholarly journals Transient stability analysis of power grids with admissible and maximal robust positively invariant sets

2020 ◽  
Vol 68 (12) ◽  
pp. 1011-1021
Author(s):  
Tim Aschenbruck ◽  
Willem Esterhuizen ◽  
Stefan Streif
Keyword(s):  
Power Systems ◽  
Transient Stability ◽  
Energy Transition ◽  
Power Grids ◽  
Invariant Sets ◽  
Admissible Sets ◽  
Major Fault ◽  
Bounded Disturbances ◽  
One Machine ◽  
Positively Invariant Sets

AbstractThe energy transition is causing many stability-related challenges for power systems. Transient stability refers to the ability of a power grid’s bus angles to retain synchronism after the occurrence of a major fault. In this paper a set-based approach is presented to assess the transient stability of power systems. The approach is based on the theory of barriers, to obtain an exact description of the boundaries of admissible sets and maximal robust positively invariant sets, respectively. We decompose a power system into generator and load components, replace couplings with bounded disturbances and obtain the sets for each component separately. From this we deduce transient stability properties for the entire system. We demonstrate the results of our approach through an example of one machine connected to one load and a multi-machine system.

scholarly journals Algoritma Elephant Herding Optimization: Permasalahan Multiple Constraints Knapsack 0-1

2018 ◽  
Vol 18 (1) ◽  
pp. 13
Author(s):  
Yulia Dewi Regita ◽  
Kiswara Agung Santoso ◽  
Ahmad Kamsyakawuni
Keyword(s):  
Knapsack Problem ◽  
Simplex Method ◽  
Optimization Problems ◽  
Optimal Solution ◽  
Secondary Data ◽  
Multiple Constraints ◽  
Microsoft Excel ◽  
Storage Media ◽  
Simulation Results ◽  
Selection Of

Optimization problems are often found in everyday life, such as when determining goods to be a limited storage media. This causes the need for the selection of goods in order to obtain profits with the requirements met. This problem in mathematics is usually called a knapsack. Knapsack problem itself has several variations, in this study knapsack type used is multiple constraints knapsack 0-1 which is solved using the Elephant Herding Optimization (EHO) algorithm. The aim of this study is to obtain an optimal solution and study the effectiveness of the algorithm comparing it to the Simplex method in Microsoft Excel. This study uses two data, consisting of primary and secondary data. Based on the results of parameter testing, the proven parameters are nClan, nCi,α,β and MaxGen have a significant effect. The final simulation results have also shown a comparison of the EHO algorithm with the Simplex method having a very small percentage deviation. This shows that the EHO algorithm is effective for completing optimization multiple constraints knapsack 0-1. Keywords: EHO Algorithm, Multiple Constraints Knapsack 0-1 Problem.

Optimization-based transient control of turbofan engines: a sequential quadratic programming approach

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jiqiang Wang ◽  
Huan Hu ◽  
Weicun Zhang ◽  
Zhongzhi Hu
Keyword(s):  
Quadratic Programming ◽  
Sequential Quadratic Programming ◽  
Programming Approach ◽  
Evolutionary Computations ◽  
Turbofan Engines ◽  
Flight Envelope ◽  
Transient Control ◽  
Limit Protection ◽  
Computational Resources ◽  
Design Guidance

Abstract Engine transient control has been challenging due to its stringent requirements from both performance and safety. Many methodologies have been proposed such as conventional schedule-based methods, linear parameter varying, multiobjective optimization and evolutionary computations etc. These approaches have been well-established and led to a series of significant results. However, they are either not providing limit protection or requiring exhaustive computational resources, particularly when generating results into full flight envelope applications. Consequently a compromise between limit protection and computational complexity is necessitated. This note considers a sequential quadratic programming (SQP)-based method for full flight envelope investigations. The proposed method can provide important design guidance and the corresponding claims are validated through detailed analysis and simulations.

Sign in / Sign up

Export Citation Format

Share Document