Author(s):  
C. Crainic ◽  
R. Harvey ◽  
A. Thompson

Previous real time engine models used for control development and test have utilized either linear techniques or simplified aero-thermodynamics. With the increased speed now available from dedicated PC based computer systems it was felt that it should be possible to develop a full aerodynamic and thermodynamic model of the engine that would have the capability to run in a real time bench environment and approach the accuracy of our best unlimited time models. The paper describes such a model that has successfully been produced for a three spool turboprop engine, and shows that it matches, in a real time environment, the transient performance of a model run with unlimited execution time. This model has the additional capability of starting from zero speed and running back down to zero speed on shut down, all in real time environment. The model was based on an existing model of a three spool turboprop engine which already included full transient heat transfer and volume dynamics effects. Modifications to this that were necessary to satisfy the requirement to model the starting regime and to decrease the convergence time resulted in a more efficient model methodology. The component map representation was changed as was the iteration logic, by removing internal iterations and by making the solver matrix more strongly diagonal. For the real time environment the code had to provide a solution within a maximum of 10 ms. The final real-time model only differed from the modified full transient model in the use of the solver logic. The number of overall iterative passes were limited to two, and balances that were shown not to significantly modify the accuracy of the solution were removed. The net result of the work is the elimination of two simplified models.


1997 ◽  
Vol 31 (3) ◽  
pp. 45-51
Author(s):  
Jianmin Hou ◽  
Xuandong Li ◽  
Xiaocong Fan ◽  
Guoliang Zheng
Keyword(s):  

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1723
Author(s):  
Félix Dubuisson ◽  
Miloud Rezkallah ◽  
Hussein Ibrahim ◽  
Ambrish Chandra

In this paper, the predictive-based control with bacterial foraging optimization technique for power management in a standalone microgrid is studied and implemented. The heuristic optimization method based on the social foraging behavior of Escherichia coli bacteria is employed to determine the power references from the non-renewable energy sources and loads of the proposed configuration, which consists of a fixed speed diesel generator and battery storage system (BES). The two-stage configuration is controlled to maintain the DC-link voltage constant, regulate the AC voltage and frequency, and improve the power quality, simultaneously. For these tasks, on the AC side, the obtained power references are used as input signals to the predictive-based control. With the help of the system parameters, the predictive-based control computes all possible states of the system on the next sampling time and compares them with the estimated power references obtained using the bacterial foraging optimization (BFO) technique to get the inverter current reference. For the DC side, the same concept based on the predictive approach is employed to control the DC-DC buck-boost converter by regulating the DC-link voltage using the forward Euler method to generate the discrete-time model to predict in real-time the BES current. The proposed control strategies are evaluated using simulation results obtained with Matlab/Simulink in presence of different types of loads, as well as experimental results obtained with a small-scale microgrid.


2014 ◽  
Vol 67 (3) ◽  
pp. 523-537 ◽  
Author(s):  
Aigong Xu ◽  
Zongqiu Xu ◽  
Xinchao Xu ◽  
Huizhong Zhu ◽  
Xin Sui ◽  
...  

On 27 December 2012 it was announced officially that the Chinese Navigation Satellite System BeiDou (BDS) was able to provide operational services over the Asia-Pacific region. The quality of BDS observations was confirmed as comparable with those of GPS, and relative positioning in static and kinematic modes were also demonstrated to be very promising. As Precise Point Positioning (PPP) technology is widely recognized as a method of precise positioning service, especially in real-time, in this contribution we concentrate on the PPP performance using BDS data only. BDS PPP in static, kinematic and simulated real-time kinematic mode is carried out for a regional network with six stations equipped with GPS- and BDS-capable receivers, using precise satellite orbits and clocks estimated from a global BDS tracking network. To validate the derived positions and trajectories, they are compared to the daily PPP solution using GPS data. The assessment confirms that the performance of BDS PPP is very comparable with GPS in terms of both convergence time and accuracy.


2004 ◽  
Author(s):  
Thomas Winsel ◽  
Mohamed Ayeb ◽  
Heinz J. Theuerkauf ◽  
Stefan Pischinger ◽  
Christof Schernus ◽  
...  
Keyword(s):  

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