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Recently, the self-blast principle of extinguishing the arc by the blast pressure which is generated by the arc itself has been widely applied to the high voltage circuit breaker. In the self-blast principle, the pressure relief valve fitted on the piston is opened to release excessive pressure in the compression volume during high current interruption. The design of the pressure relief valve operation...
This paper describes the full- and reduced-order models of an actuated hydraulic cylinder suitable for system dynamics analysis and motion control design. The full-order model incorporates the valve spool dynamics with combined dead-zone and saturation nonlinearities — inherent for the orifice flow. It includes the continuity equations of hydraulic circuits coupled with the dynamics of mechanical...
Energy saving of compressed air system was studied in this work. The whole process model including compressor's performance, pressure loss of pipeline and pressure change of storage tank was founded. And then compared with performance equations of FSD compressors, energy cost and related Volumetric efficiency change along the variable frequency was achieved. With these models founded, simulations...
A free-piston engine (FPE) requires stabilizing feedback control to manage piston motion and ensure safe operation. A high-fidelity model, which simulates the FPE behavior by combining dynamic, thermodynamic, and hydraulic submodels, is exploited as an engine surrogate for control development. A control-oriented model implicitly describes the FPE piston turnaround position using energy balance principles...
Based on the working principle of the electrohydraulic proportional control system of the working device of the demolition robot, the co-simulation model of the system is established by means of ADAMS and MATLAB. The study of the dynamic characteristics of the system was done, with applying traditional PID control strategy and sliding mode variable structure control respectively, considering the change...
For the rolling system, it should be a multi-variable, strong disturbance and coupled nonlinear system. As the precondition of ensuring the precision of strip thickness, it is necessary to ensure that the system is robust. The controller should be able to suppress the disturbance of the system and remain the system stable under the uncertain parameters. Taking into account the complexity of the system,...
Based on the analysis of the turbine generator system, steam turbine and its speed governor system, synchronous generator and its excitation controller and load model of turbine generator system are modeled mathematically. Then, the model of turbine generator system is simulated in Matlab/Simulink, the model of turbine generator system can conclude characteristics curves that are similar with actual...
In this paper we present an electro-hydraulic load simulation method for the helicopter booster. Based on electro-hydraulic servo control technology, we construct the load simulation system. And then, the mathematical model of load simulation system for the booster is built. The position servo system controller is combined of hysteresis compensation with PI controller and the force servo system controller...
This article analyzes the performance and the energy of a dissimilar redundant hybrid electro-hydraulic actuation system component by EHA and EMA by using Bond Graph method and designs a controller to improve the system performance and efficiency. Firstly, use 20-sim to create EHA and EMA bond graph model, analyze the characteristics of each system; Secondly, construct EHA and EMA collaboration system...
In this paper the nonlinear dynamics of a hydraulic system consisting of centrifugal pump, pressure accumulator and connected load are modeled and a Feedback Linearization controller is designed. Furthermore an Extended Kalman Filter is implemented to include the hydraulic dynamics into the estimation and simultaneously overcome the necessity of flow and pressure measurements. Therefore, the combined...
A friction electro-hydraulic load simulator (FEHLS) has little disturbances of actuator by friction loading. To prove the loading performance of the FEHLS, this paper compares the motion disturbance characteristics between traditional electro-hydraulic load simulator (TEHLS) and FEHLS. Their mathematical models and principle block diagrams are constructed according to their structures. Their motion...
In view of the strongly nonlinear characteristic of electro-hydraulic servo system (EHSS), this paper aims to conduct nonlinear ordinary differential equation (ODE) parameter identification of white-box model based on the knowledge of part of the system information so as to get the accurate nonlinear model that can meet the actual needs. By establishing the state space model of the hydraulic system...
This paper presents control of a typical Electro-Hydraulic Servo System (EHSS) using measurable outputs. Detailed modeling of EHSS is described which takes into account the nonlinearities of solenoid coil, hydraulic pressures and spool motion. Two different controllers are proposed using two different surfaces. The two surfaces considered are finite time converging and asymptotically converging respectively...
One of the urgent tasks in building computer simulators is the choice of a mathematical modeling scheme. The given work considers analytical-simulation approach to modeling human-machine system based on E-networks. In the article principles of building the models of the hardware and software part of the industrial control system and the human operator are proposed.
Starting from the flow characteristics of cylinder controlled by servo valve of hydraulic looper in hot strip mill, a new mathematic model for hydraulic cylinder controlled by servo valve is established by analyzing and deducing the flow characteristics of two cavities of hydraulic cylinder. The model gives up the traditional fuzzy conception of “load-pressure flux”, it is adaptable to many structural...
Cartridge flow valves, widely applied in heavy machine and equipment, have the advantages of low leakage, large flow capacity, and simple structure. However, in the existence technologies, in order to reduce the influence of load variety on valve flow, a pressure differential compensator or a cartridge type flow sensor should be added to proportional throttle valve. This method reduces valve flow...
This paper introduces application and hydraulic system's working principle of the Multi-DOF hydraulic arm, adopts the power bond graph to establish the mathematical model of the hydraulic system, and uses the Matlab software to draw the Bode diagram of the open-loop system. The stability and other time domain performance of the hydraulic system are analyzed by using the engineering control theory,...
This paper presents structure optimization of a spool valve to reduce pressure ripple in a novel linear collaborative rectification pump (CRP). The CRP is with two units, which consists of a cylinder to compress fluid and a spool valve for rectification. The novel pump has the problem of kinematic flow pulsation and pressure ripple the same as conventional piston pump. For the objective of pressure...
The extra torque of electrohydraulic load simulator loading system affects its performance seriously. To eliminate the extra torque, the pressure servo valve control load simulator is proposed. This article establishes the electro-hydraulic load simulator mathematical model based on flow servo valve and pressure servo valve, analyzes the mechanism of overcoming extra torque load and simulation, provides...
The thrust system of TBM propels the cutter head boiling forward and the strong impulse loads on propelling cylinder cause serious vibration problems. Based on the typical thrust system which the thrust cylinders are controlled by pressure reducing valves, the paper obtained the dynamic velocity stiffness, static velocity stiffness, minimum velocity stiffness of the thrust cylinder. According to the...
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