Modeling of Variable Frequency Constant-Pressure Water Supply Instrument for Warship Based on System Identification

Warship variable frequency constant-pressure water supply instrument is a new kind of water supply device applying alternating current frequency conversion technology and programmable logic control technology to warship water supply. The instrument can keep the water pressure at a constant value according to the rate of water flow by controlling the frequency of the pump. Its characteristics of nonlinearity, hysteresis and variability bring difficulties to system modeling. By interpolating and fitting of input and output data obtained from experiment making use of data processing tools in MATLAB software, the model of variable frequency constant-pressure water supply instrument for warship was established in the thesis based on least square system identification. Also, the error check and simulation research were conducted. The results indicated that the model can fully reflect working characteristics of variable frequency constant-pressure water supply instrument with high veracity and reliability.