Frequency Hydraulic System Characteristics And The Speed Limit Cut-off Valve Developed

For hydraulic technique, how to acquire the merits of the motor speed regulation technique is such an important subject that it becomes very important of studying on the characteristics of the hydraulic system with motor speed regulation.In chapter 1 the state-of-the-art of the motor speed regulation technique and its application in the hydraulic system is introduced. In chapter 2 a math model of the hydraulic system with motor speed regulation is built, in which the author builds the model of the converter-electromotor with two different modes, the VVVF control and the Advanced Vector Control. Using Matlab, these models is simulated and, after comparing the results of system step response with different system parameters, some useful conclusions is drawn. Then, through relevant experiments data study and theory analysis analyze some characteristics of the hydraulic system with motor speed regulation.Pipe Rupture valve is able to close itself in the event of failure in the main cylinder line or where the down speed exceeds allowable limits in the hydraulic elevator system. In chapter 1 the principle and the research status of the pipe rupture valve and the requirement of the pipe rupture valve in the European Hydraulic Elevator Manufacture and Secure Installation Standards (EN81-2) are also introduced.In chapter 3 dissertates the selection of the pipe rupture valve and the design process of the complete set of the valve. Especially in the design and the selection of the valve, using the simulation software-fluent, the internal flow field of some kinds of different pipe rupture valve are analyzed. And a reasonable structure of valve is worked out. The design of the valve includes calculating, checking, and drawing. The blueprints are all made by AutoCAD and the installation is emulated by Pro/E.In chapter 4 a math model of the pipe rupture valve for the hydraulic elevator system is built. Using Matlab, the step response characteristics of the valve in the elevator system is simulated, comparing the effect of its performance with different structure parameters of the pipe rupture valve, such as hydraulic resistance, diameter of the valve, and spring rigidity, and comparing the valve's dynamic performance under different operating conditions, such as environment temperatures, number of passengers, and emergencies of the hydraulic system, so the paper offers a general and systematic analysis for the pipe rupture valve of the elevator system. These simulation results can be used to analyze the operating conditions and environment requirements for nominal working.In chapter 5 the experiment rigs are introduced first. Because the experiments would concern many performances of the pipe rupture valve, there are two different sets of experiment rigs. Then the results of the experiment is analyzed and compared with the simulation results. On the one hand, it satisfies the simulation conclusions; on the other hand, it draws some useful conclusions. Finally, ensures whether the valve satisfies the requirements of the EN81-2.Conclusively,math model for the hydraulic system with motor speed regulation is built first, including the hydraulic cylinder system and the hydraulic motor system, and the different control mode for the converter too. Then the system parameters are analyzed by simulation comparison with relevant experiments. After that, a complete solution to design the pipe rupture valve of the hydraulic elevator with fluent and Matlab simulation software; deserting the traditional method,gives a solid modeling for the pipe rupture valve with the 3-D CAD software which offers greater effects for the structure design of the pipe rupture valve; Using special electro hydraulic and hydraulic elevator experiment rig, the pipe rupture valve is completed test. The pipe rupture valve has important significance for the utilization and production of the hydraulic elevator technique.