Research Of Power Amplifier Of Active Magnetic Bearings Based On The Accommodating Digit PID

Active magnetic bearing (AMB) is a new type supporting part. It was a typical mechatronics product and involved electromagnetic, mechanics, rotordynamics, control theory and computer science. Because of its contact-free manner between the rotor and the stator, the rotor can rotate at very high speed and almost no wear. In addition, the AMB has many advantages such as longer lifetime, no need of lubrication, low power loss, low noise, etc. So the AMB fits some execrably environments, such as high speed, vacuum super clean, etc.Therefore, power amplifier is a crucial part in the AMB control system. It is used to magnify or convert the control signal into a power signal with enough energy to drive the electromagnetic iron actuators. So the performance of power amplifier plays an important role in the technique capability of control system. Traditional analog amplifier to adjust parameters inconvenient, difficult to achieve optimal control, and vulnerable to outside interference, and other shortcomings, with comparative figures for power amplifier, a high degree of hardware integration, control performance, and anti-jamming capabilities, the advantages of faster response. So this is the point of innovation in analog power amplifier research study on the basis of digital power amplifier and improve the performance of magnetic bearings.Firstly, this paper summarized the general situation and the current development of the electromagnetic bearing control technique and the key problems that face. Secondly, on the basis of the principle of the magnetic bearing, deduced nonlinear relationship between the magnetic force and control current, rotor's displacement in single-degree-of-freedom. Thirdly, the hardware system based on TMS320C6713 was presented including AD circuit, DA circuit and etc. Experiment was carried out on each part. Fourthly, and details on the magnetic bearings power amplifier involved in the design of the structure of power circuit, the current rate of change, the efficiency of power amplifiers, power devices, switching frequency, soft-switch technology, and other performance indicators, and then introduced a single degree of freedom and more freedom of the measurement system and made a displacement measurement of magnetic bearings key technologies and solutions, Furthermore, study and analysis on the theory of EMC was also included. At last, in Matlab established a number of magnetic bearings power amplifier model, a simulation of Simulink, followed by the location of curves, step-response curve, the current ripple curve and follow the current curve.Finally, according to the results of system simulation shows that the number of power amplifier control performance to meet the requirements of analog amplifier, and because of the advantages of digital power amplifier itself, the digital power amplifier can replace traditional analog power amplifier.