The Research On Variable Frequency Speed Regulation Of Hydraulic Pressure System Based On TMS320LF2407A DSP

Presently most hydraulic pressure systems are drived by asynchronous motors at a constant speed. By using variable pumps or valves, the systems can regulate speed. These speed regulation systems have many defects such as low efficiency, short life, poor ability in resisting pollution and low efficiency in driving system. Except for hydraulic pressure system, Variable frequency speed regulation has been used in many fields widely. In this paper a new way through changing pump's rotate speed to change its output flux is introduced, which could solve the defects in the traditional hydraulic pressure servo control system.Field Oriented Control (FOC) is one of the advanced theories, which is based on motor unification principle, energy conversion and vector coordinate transformation theory. It has many advantages such as novelty, practicability and advancement. By transforming the model of AC motor to DC motor, the stator current is decomposed into two DC parts which are orientated towards the rotator magnetic field and controlled respectively. Thus the magnetic flux and torque are decoupled, In this way, we can control the asynchronous motor in a synchronous way.Using digital signal processor (DSP), TMS320LF2407A, which is special for motor control, we develop a suit of speed adjustable, reliable and highly effective induction drive based on FOC principle. The realization of the whole hardware and the whole software is described detailedly. At the same time, a new Pulse Width Modulation (PWM) named Space Vector Pulse Width Modulation (SVPWM) method is used to control the asynchronous motor. This land of control system has been used in the speed control system of advanced hydraulic elevator. Proved by practice, thevariable-frequency regulating speed system based on SVPWM has better performances such as steady running condition., anti-jamming and less noises of motor.