OPERATIONAL MODES OF AN ELECTROHYDRAULIC DRIVE OF A RING GATE FOR A HYDRAULIC TURBINE
The results of an investigation of numerical and experimental operating modes of a multi-actuator electro-hydraulic servo drive designed for manipulating the ring gate of a hydraulic turbine are presented in the work. The modes of normal operation (lifting and lowering) under the action of unbalanced load have been investigated. Theoretical and experimental investigations of normal operation modes were conducted. The experimental part of the study has been implemented by carrying out bench tests involving a three-cylinder electrohydraulic servo actuator controlled by proportional electro hydraulic amplifiers which simulates the gate drive, s three-cylinder load drive simulating the weight load of the gate shield and the load from the stream, two independent pumping stations and a control and measurement system. The theoretical part of investigations was implemented by conducting a numerical experiment on the basis of mathematical models of a three-cylinder electro-hydraulic servo drive made in the MATLAB software package. The mathematical description of drive dynamics is carried out by means of non-linear differential equations. Each drive unit consisting of a power supply, a servo cylinder, a proportional directional valve, feedback circuits and pressure and piston motion sensors is described by three equations: the equation of actuator moving part motion, flow continuity equation through pressure gap of proportional directional valve and pressure chamber of hydraulic cylinder, flow continuity equation through the drain chamber of the hydraulic cylinder and the drain gap of proportional directional valve. Mathematical models of normal operating are solved by the built-in function ODE23S. The experimental and theoretical functional dependences of synchronization error from value of the relative load on the actuator have been obtained. The estimation of the degree of impact of the unbalanced load on the synchronicity of the actuating hydraulic motors work was given.