Studies On The Dynamic Performance Of Direct Drive Servo Valve

Due to strong anti-pollution, low cost, low slow, high resolution, good static and dynamic performance, the direct drive electro hydraulic servo valve(DDV) was widely used in the hydraulic servo field. However, the design or research on the DDV commonly depend on empirical formulas or some unreasonable assumptions, so it is even more important to focus on the DDV and the test system while build an effective model.In this paper, theoretical analysis, simulation and experimental were adopted to investigate the dynamic performance of DDV. Firstly, the working principle of permanent magnet linear force motor(LFM) was analyzed while a new model of LFM was built when the flux leakage of permanent magnet(PM) and reluctance of magnetic element was considered. In order to verify the model that proposed above, a simulation model that based on physical mechanism in software Ansoft Maxwell was studied.Secondly, the mathematic model of the DDV and it’s dynamic performance testing system was derived according to the power-bond graph theory which was introduce in this paper. Then the frequency response performance of the DDV and testing system on different amplitude of the input signal was got by the Matlab software.At last, the MOOG D633 DDV was used to build an experiment platform and the frequency response experiment was conducted. So the mathematic model of DDV and testing system were consideredreasonable according to the comparison of the experiment and simulation results.