In order to design a comfortable-oriented vehicle suspension structure, the network synthesis method was utilized to transfer the problem into solving a timing robust control problem and determine the structure of ''inerter-spring-damper'' suspension. Bilinear Matrix Inequality was utilized to obtain the timing transfer function. Then, the transfer function of suspension system can be physically implemented by passive elements such as spring, damper, and inerter. By analyzing the sensitivity and quantum genetic algorithm, the optimized parameters of inerter-spring-damper suspension were determined. A quarter-car model was established. The performance of the inerter-spring-damper suspension was verified under random input. The simulation results manifested that the dynamic performance of the proposed suspension was enhanced in contrast with traditional suspension. The root mean square of vehicle body acceleration decreases by 18.9%. The inerter-spring-damper suspension can inhibit the vertical vibration within the frequency of 1-3 Hz effectively and enhance the performance of ride comfort significantly.
Speed control and smooth regulation in an electro-hydraulic motion control system under negative load (over-running load) are crucial to mobile machineries, vehicles, and motion simulation equipment. Problems, such as bad natural stability, bad dynamic performance for small adjusting signal, serious coupling, and difficulty to coordinate between speed smoothness and speed regulation, exist in traditional valve-controlled and pump-controlled electro-hydraulic power mechanism. The coordinated motion control scheme, which is based on independent regulation of inlet/outlet oil for electro-hydraulic power mechanism has attracted the attention of many scholars. In the last two decades, many progresses had been made in coordinated control technology, employing in inlet/outlet independent metering and pump/valves independent regulation. Moreover, the technology has been widely used in the electro-hydraulic operating system in hydraulic excavator and the speed smoothness control system in heavy transport vehicles. In this study, recent advancements and upcoming trends in coordinated control and inlet/outlet independent metering for electro-hydraulic power mechanism under sustained negative load are reviewed. Firstly, related research advancements are summarized, including flow rate regulation mechanism based on inlet/outlet coordinated control, coordinated control strategy and nonlinear control method of electro-hydraulic control system. Then, nonlinear modeling of inlet/outlet independent metering and pump/valves independent regulation in electro-hydraulic control system is presented. In addition, the electro-hydraulic speed smoothness control and energy recovery for heavy engineering vehicles under long down-slope is discussed and reviewed. Finally, existing problems and future trends of inlet/outlet coordinated control for an electro-hydraulic power mechanism under sustained negative load are presented.
In view of the issues that the current comprehensive energy supply reliability evaluation mainly focuses on the distributed energy system and rarely involves the mutual coupling of energy supply networks and the coordination of energy stations in the regional energy Internet, an evaluation method of energy supply reliability considering electricity-gas coupling and coordination between energy stations was proposed. First, the framework of regional energy Internet (REI) is established, the energy flow relationship among the main parts in the REI and the influence of electricity-gas coupling on reliability are analysed; second, considering building virtual energy storage and demand response, the rigid and flexible reliability evaluation indexes are proposed from the energy and time levels; third, the operation strategies of normal, failure and repair periods of each energy station are put forward, and the optimal load reduction model of REI aiming at the minimum total rigid energy shortage is established. Moreover, the method and process of energy supply reliability evaluation combining fault mode effect analysis (FMEA) and Monte Carlo simulation are proposed. Finally, through a practical example, the impact of demand response, multiple energy storage resources, electricity-gas coupling and interstation coordination on reliability is analysed.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Abstmcf-Control algorithms of SMES based on a 12-pulse IGBT current source converter were developed for improving customer power quality. The control performances include uninterruptible power supplies (UPS) and load fluctuation leveling.To demonstrate the control algorithms, both simulations and experiments were carried out on a 20kJ/15kW grid model SMES system. The results of the simulations and experiments are presented and compared in this paper.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.