In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mech...In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mechanism and flywheel was researched, a design method of transmission parameter optimization was proposed, and the comprehensive matching control strategy was established for the new transmission system. Fuzzy controllers for throttle opening and CVT speed ratio were designed, and power performance and fuel economy of both vehicles respectively equipped with conventional CVT system and new transmission system wrere compared and analyzed by simulation. The results show that power performance and fuel economy of the vehicle equipped with new transmission system are better than that equipped with conventional CVT, thus the rationality of the parameter design method and control algorithm are verified.展开更多
A new class of hybrid particle swarm optimization （PSO） algorithm is developed for solving the premature convergence caused by some particles in standard PSO fall into stagnation. In this algorithm, the linearly dec...A new class of hybrid particle swarm optimization （PSO） algorithm is developed for solving the premature convergence caused by some particles in standard PSO fall into stagnation. In this algorithm, the linearly decreasing inertia weight technique （LDIW） and the mutative scale chaos optimization algorithm （MSCOA） are combined with standard PSO, which are used to balance the global and local exploration abilities and enhance the local searching abilities, respectively. In order to evaluate the performance of the new method, three benchmark functions are used. The simulation results confirm the proposed algorithm can greatly enhance the searching ability and effectively improve the premature convergence.展开更多
This paper proposes a novel virtual inertia controller for converters in power systems,whichcan solve the system’s nonlinearity for frequency support.First,the system dynamics are formulatedas a nonlinear state-space...This paper proposes a novel virtual inertia controller for converters in power systems,whichcan solve the system’s nonlinearity for frequency support.First,the system dynamics are formulatedas a nonlinear state-space,in which the reciprocal of inertia is modeled as controlinput.Correspondingly,a cost function is defined by considering frequency deviation andrate of change of the frequency,which can preserve a tradeoff between critical frequencylimits and respective control energy.Following,the optimal frequency regulation problemis solved by using an online adaptive dynamic programming method,where the actor andcritic neural networks are constructed to approximate the optimal control input and optimalcost function,respectively.After that,the small-signal analysis is provided to identify the stabilityof the converter under the proposed controller.Finally,simulation results verify thatthe frequency response of the system is significantly improved,while retaining more DC sideenergy.展开更多
基金Project(2011BA3019)supported by the Chongqing Natural Science Foundation,China
文摘In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mechanism and flywheel was researched, a design method of transmission parameter optimization was proposed, and the comprehensive matching control strategy was established for the new transmission system. Fuzzy controllers for throttle opening and CVT speed ratio were designed, and power performance and fuel economy of both vehicles respectively equipped with conventional CVT system and new transmission system wrere compared and analyzed by simulation. The results show that power performance and fuel economy of the vehicle equipped with new transmission system are better than that equipped with conventional CVT, thus the rationality of the parameter design method and control algorithm are verified.
文摘A new class of hybrid particle swarm optimization （PSO） algorithm is developed for solving the premature convergence caused by some particles in standard PSO fall into stagnation. In this algorithm, the linearly decreasing inertia weight technique （LDIW） and the mutative scale chaos optimization algorithm （MSCOA） are combined with standard PSO, which are used to balance the global and local exploration abilities and enhance the local searching abilities, respectively. In order to evaluate the performance of the new method, three benchmark functions are used. The simulation results confirm the proposed algorithm can greatly enhance the searching ability and effectively improve the premature convergence.
基金the National Key Research and Development Program of China[2018YFA0702200]National transformative subject:Intelligent evolution mechanism and design of distributed information energy system,National Natural Science Foundation of China[62073065,51907098]China Postdoctoral Science Foundation[2020T130337].
文摘This paper proposes a novel virtual inertia controller for converters in power systems,whichcan solve the system’s nonlinearity for frequency support.First,the system dynamics are formulatedas a nonlinear state-space,in which the reciprocal of inertia is modeled as controlinput.Correspondingly,a cost function is defined by considering frequency deviation andrate of change of the frequency,which can preserve a tradeoff between critical frequencylimits and respective control energy.Following,the optimal frequency regulation problemis solved by using an online adaptive dynamic programming method,where the actor andcritic neural networks are constructed to approximate the optimal control input and optimalcost function,respectively.After that,the small-signal analysis is provided to identify the stabilityof the converter under the proposed controller.Finally,simulation results verify thatthe frequency response of the system is significantly improved,while retaining more DC sideenergy.
