| As the power supply of the high-respond electro-hydraulic control system, the constant-pressure supply (CPS) must be possessed of stable performances to improve control precision of the system. Therefore, the analysis for the various factors of the CPS and its dynamic characteristics is significant to enhance the qualities of the CPS. Basis on the discussion in the composing of the CPS system, the main works in the paper are as follow.1. A CPS system in its essential was established with the pressure compensated variable displacement pump (PVP), the long pipeline and the accumulator.2. A mathematic model of the PVP was constructed in detail with a throttle valve as load. With the results of the simulation about the dynamic characteristics of the PVP, the relationship between the characteristics of the pump and the piston torque were discussed and effects on the characteristics of the pump were also discussed with other parameters.3. The models of the long pipeline and the accumulator were separately established and then the simulations were performed by the help of the combination model of a PVP and a throttle valve model. The simulation results show that the pipeline effect exists and that the accumulator has both functions of absorbing pressure pulse and supplying some amount of oil while the oil from the pump is insufficient.4. Using the hydraulic automatic gauge control (HAGC) system in a rolling mill as the load, the simulation model of the CPS with a load was established. The simulation results have revealed that the model of the CPS with a load established in the paper can meet the demands for the flowrate and response to the high-respond electro-hydraulic control system such as in a HAGC system. In addition, with the simulation model, the relationship between the variation of rolling force and the pressure ripple of the CPS was discussed. At the same time, the paper has analyzed the effects of the pressure ripple of the CPS on the precision of HAGC system in a rolling mill. |
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