Research On Variable Frequency Pump-Control-Motor Speed Governing And Compensation Characteristics

The hydraulic with inverter is a new kind of energy saving transmission technique. High power & high inertia pump-control-motor speed governing system with inverter is the basic transmission system of hydraulic systems with inverter, and it has extensive potential application in many kinds of equipments such as tunnel boring machine, hydraulic heave machine and injection machine. But it has main key problems such as long response time, low speed stiffness, imperfect control performance and efficiency because "of. it includes inverter and electromotor.The main research contents are as follows. The performance simulating in time domain and open loop step experiment of pump-motor speed governing system with inverter are made. The energy consumption analysis and experiment of the two systems, which are pump-control-motor speed governing system with inverter and hydraulic speed governing system with inlet throttle, are given. Software direct compensating motor speed loss of open loop pump-control-motor speed governing system with inverter is studied deeply in theory and experiment. The applications of fuzzy control, single neuron control and genetic algorithm in pump-control-motor speed governing system with inverter are studied, and some useful conclusions are obtained. Concretely, the dissertation's main contributions are as follows.(1) The dissertation theoretically analyses software direct compensating motor speed loss of open loop pump-control-motor speed governing system with inverter. The motor speed loss formula and compensating coefficient formula are given, and this provides the theoretic foundation for using software direct compensating method. The dissertation puts forward the control scheme of software direct compensating motor speed loss of open loop pump-control-motor speed governing system with inverter, and the method of "load sectionalization linear compensation". Because of this, the speed governing accuracy and the speed stiffness of the system are enhanced.(2) The new compounded compensation control structures are presented according to high power & high inertia pump-control-motor speed governing system with inverter. The comparison experiments of different control structures testified compounded compensation control structures are effectiveness. These compounded compensation control structures provides new clew and method for improving control performance of high power & highinertia pump-control-motor speed governing system with inverter.(3) The dissertation puts forward the method optimizing the parameters of PID controller and fuzzy PID controller based on real code genetic algorithm. This provides new clew for making the controller's parameters of pump-control-motor speed governing system with inverter certain.(4) The performance simulating in time domain and open loop step experiment of pump-motor speed governing system with inverter are made, and the rules of parameter change affecting response performance are obtained. The theoretic references are provided to improve the system's performance.(5) The energy consumption analysis and experiment of the two systems, which are pump-control-motor speed governing system with inverter and hydraulic speed governing system with inlet throttle, are made. Some useful conclusions are obtained. New clews are provided to enhance the total efficiency of hydraulic speed governing system with inverter.