Variable-thickness optimization method for shell structures based on a regional evolutionary control strategy

2022 ◽  
Vol 172 ◽  
pp. 108848
Author(s):  
Xinyu Wang ◽  
Changdong Zhang ◽  
Tingting Liu ◽  
Wenhe Liao ◽  
Cong Wang
Author(s):  
Ali Al-Abadi ◽  
YouJin Kim ◽  
Jin-young Park ◽  
Hyunjin Kang ◽  
Özgür Ertunc ◽  
...  

An optimization method that changes the control strategy of the Horizontal Axis Wind Turbine (HAWT) from passive- to active-pitch has been developed. The method aims to keep the rated power constant by adjusting the blade pitch angle while matching the rotor and the drive torques. The method is applied to an optimized wind turbine model. Further, numerical simulations were performed to validate the developed method and for further investigations of the flow behavior over the blades.


2014 ◽  
Vol 24 (01) ◽  
pp. 1450001 ◽  
Author(s):  
Xiaolan Wu ◽  
Guifang Guo ◽  
Jun Xu ◽  
Binggang Cao

Plug-in hybrid electric vehicles (PHEVs) have been offered as alternatives that could greatly reduce fuel consumption relative to conventional vehicles. A successful PHEV design requires not only optimal component sizes but also proper control strategy. In this paper, a global optimization method, called parallel chaos optimization algorithm (PCOA), is used to optimize simultaneously the PHEV component sizes and control strategy. In order to minimize the cost, energy consumption (EC), and emissions, a multiobjective nonlinear optimization problem is formulated and recast as a single objective optimization problem by weighted aggregation. The driving performance requirements of the PHEV are considered as the constraints. In addition, to evaluate the objective function, the optimization process is performed over three typical driving cycles including Urban Dynamometer Driving Schedule (UDDS), Highway Fuel Economy Test (HWFET), and New European Driving Cycle (NEDC). The simulation results show the effectiveness of the proposed approach for reducing the fuel cost, EC and emissions while ensuring that the vehicle performance has not been sacrificed.


Author(s):  
Sergio Andrés Pizarro Pérez ◽  
John E. Candelo-Becerra ◽  
Fredy E. Hoyos Velasco

The inertia issues in a microgrid can be improved by modifying the inverter control strategies to represent a virtual inertia simulation. This method employs the droop control strategy commonly used to share the power of a load among different power sources in the microgrid. This paper utilizes a modified droop control that represents this virtual inertia and applies an optimization algorithm to determine the optimal parameters and improve transient response. The results show better control when different variations are presented in the loads, leading the microgrid to have a better control of the operation. The optimization method applied in this research allows improvement to the transient response, thus avoiding unnecessary blackouts in the microgrid.


2020 ◽  
Vol 21 (5) ◽  
pp. 502
Author(s):  
Chen Chen ◽  
Ruijun Zhang ◽  
Qing Zhang ◽  
Lixin Liu

Aiming at the phenomenon that the elevator car system generates horizontal vibration due to the unevenness of the guide rail and the guide shoe modeling uncertainty caused by friction, wear and spring aging between the rolling guide shoe and the guide rail, a mixed H2/H∞ optimal guaranteed cost state feedback control strategy is proposed. Firstly, as the high-speed elevator car system always exist the phenomenon of stiffness and damping uncertainty in the guide shoe, the LFT method is adopted to construct the state space equation of the car system with parameter uncertainty. Secondly, considering the performance indexes of horizontal acceleration at the center of the car floor and the guide shoe vibration displacement system, an optimal guaranteed performance state feedback controller is designed based on the linear convex optimization method, which to minimize H2 performance index and achieve the specified H∞ performance level. Thirdly, the free matrix is introduced to reduce the conservatism of the controller. Finally, by comparing the simulation results with other control methods under the same conditions, it is verified that the control strategy can make the car system have better vibration suppression ability, and can significantly improve the ride comfort of the elevator.


Sign in / Sign up

Export Citation Format

Share Document