Characteristic Analysis And Test Research Of The Hydro-Viscous Speed Regulating System Based On The PID Control Technique

The variable speed fluid coupling and transducer are mainly adopted for starting (braking) of the medium and big power mechanical equipments at home at present. But the practice proves that the two have some defects or deficiencies to a certain extent. This has already caused the attention for more than 20 years in the academia and relevant business circles. The current machines, such as wind motor and water pump, often adopt valve and baffle as speed regulating, but the energy consumption was considerable. Energy saving is in the fifth kind of energy except coal, petroleum, hydroenergy, nuclear energy in the world at present. In a great deal of energy, electric energy is the most general and covers a bigger proportion. So electric saving is an important link in the energy saving.Comparing with the variable speed fluid coupling and transducer, the H. V. D. speed regulating system has many merits, such as: high transmission efficiency, good over-load protection performance, fast respond of the control, low cost, convenient maintenance, etc. Practice has shown in the past 20 years that adopting the H. V. D. as the starting (braking) and speed regulating equipments make the relevant equipments gain good speed regulating performance, and make the enterprises gain remarkable energy saving economic benefits.The electro-hydraulic proportional control and the output speed feedback control schemes of the H. V. D. driving load system have been given. The operating mode in liquid working region, mixed friction region and border friction region is analyzed in this paper. In order to reduce the unstable region of the H. V. D., after analyzing the four effective measures, the PID control technique has been chosen for the H. V. D. control system. On the basis of synthesizing all factors that may affect the system, the system is simplified, and the corresponding mathematical model is established. With the help of simulation tools and soft programming, the mathematical is simulated and analyzed; the simulation results shows that the common control system and that with the PID regulator all have good respond curves, but the speed regulating performance of the PID control...