What Are The Advantages And Disadvantages of The Hydraulic System in The Hydraulic Station?

What are the advantages and disadvantages of the hydraulic system in the hydraulic station?

The hydraulic actuator moves very quickly. The traffic speed transfer function is basically an oscillation of an inherent frequency, but as the flow rate increases and the parameters are matched, you can increase the inherent frequency to a level higher than the natural frequency of the electro-hydraulic servo valve.

With an inherent frequency of 100 Hz, the frequency response of the hydraulic actuator is fast, making it easy to start, stop, and perform high-speed reversing. Compared to mechanical and electrical system actuators, the inherent frequency is generally much higher.

(2) The volume and weight of the hydraulic actuator are much smaller than those of the electric-mechanical actuator of the same size. This is because hydraulic actuators (such as valves, cylinders or motors) are used.

The increase in volume and weight leads to a slower increase in power compared to the growth of electromechanical actuators. This is because the former increases power through the increased fluid flow rate and pressure. Both the size and weight of the power increase simultaneously. However, high-strength and lightweight metal materials can achieve a reduction in size and weight.

(3) The hydraulic actuator operates smoothly and has strong anti-interference capabilities. Particularly, it exhibits excellent low-speed performance and a smooth transition between mechanical and electrical systems. It is also susceptible to electromagnetic waves and other external disturbances.

(4) Within the speed range of the hydraulic actuator, there is a high power gain.

The disadvantages of the hydraulic servo system:

(1) Hydraulic signals are easier to correct because they are slow. While speed is achieved through the transmission of information at the speed of light, it is based on signals and is easier to integrate and correct. However, in the past, due to the absence of power levels in electro-hydraulic servo systems that used electrical signals, and in some aspects, this system has the advantages of the two liquid servos.

(2) The structure of the hydraulic servo system is complex, with high precision and high cost.

(3) The liquid volume elastic modulus changes with temperature and the content in the air when mixed with oil. When the temperature changes, it has a significant impact on the system performance. In contrast, the temperature has little effect on the volume elastic modulus of the gas, and it has little impact on the pneumatic performance of the control system. The viscosity of the liquid has a significant influence on temperature, resulting in increased low friction loss; it also increases in high-temperature leakage and is prone to cavitation.

(4) In case of an oil leakage in the hydraulic system of the hydraulic station, it not only pollutes the environment but also may cause fires. Hydraulic oil is prone to contamination and can lead to blockages in the actuators.