In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a tra...In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a transfer function with interval parameters. The considered model describes for example an oriented PV （photovoltaic） system. As a controller a P （proportional） controller was applied. It is very simple and their application in the situation we deal with assures the suitable control performance. The controller is going to be implemented at digital platform. To construct the control system a cost function proposed by the authors was applied. It describes both the energy consumption and the sample time of controller. The proposed cost function is a function of plant parameters, describing the dynamics of the plant and controller parameters： proportional gain and sample time. For the cost function a simple geometric interpretation can be given： for fixed plant parameters and varying controller parameters it is a surface in the Ra plane. This fact can be applied to assign of optimal controller. Theoretical results were depicted by a numerical example.展开更多
A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator （RF） is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based o...A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator （RF） is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based on which the modeling simplifications are proposed. Then, the mathematical models for the evaporator, cabinet and duct-fan are presented. The whole system is divided into two subsystems--refrigerant cycling system and air cycling system. In order to simplify the model, two closed-loop systems are broken into the compressor component and the evaporator component, respectively. A general distributed parameter model is employed for evaporator with homogeneous flow to simplify the two-phase evaporating flow region. The z-transfer function model is used to describe the cabinet load. Computational fluid dynamics （CFD） method is employed to obtain the pressure drop and flow rate curve of the duct-fan model.展开更多
文摘In the paper the proposition of a discrete, robust, minimal energetic P servo controller for second order plant is presented. The plant under consideration is described with the use of a state space equation and a transfer function with interval parameters. The considered model describes for example an oriented PV （photovoltaic） system. As a controller a P （proportional） controller was applied. It is very simple and their application in the situation we deal with assures the suitable control performance. The controller is going to be implemented at digital platform. To construct the control system a cost function proposed by the authors was applied. It describes both the energy consumption and the sample time of controller. The proposed cost function is a function of plant parameters, describing the dynamics of the plant and controller parameters： proportional gain and sample time. For the cost function a simple geometric interpretation can be given： for fixed plant parameters and varying controller parameters it is a surface in the Ra plane. This fact can be applied to assign of optimal controller. Theoretical results were depicted by a numerical example.
文摘A dynamic approach for the modeling, simulation and analysis of no-frost Refrigerator （RF） is discussed. In Part I, the complex interactions among the components in the cooling system are analyzed in detail, based on which the modeling simplifications are proposed. Then, the mathematical models for the evaporator, cabinet and duct-fan are presented. The whole system is divided into two subsystems--refrigerant cycling system and air cycling system. In order to simplify the model, two closed-loop systems are broken into the compressor component and the evaporator component, respectively. A general distributed parameter model is employed for evaporator with homogeneous flow to simplify the two-phase evaporating flow region. The z-transfer function model is used to describe the cabinet load. Computational fluid dynamics （CFD） method is employed to obtain the pressure drop and flow rate curve of the duct-fan model.
