Preventing Damage in Hydraulic Pumping Systems by using a Pressure Control Strategy

Abstract

This paper presents an experimental study on the development, implementation, and tests of a control strategy applied to pressure control in hydraulic pumping systems. The strategy aims at avoiding severe damage on the hydraulic system due to Water Hammer effects. To accomplish this, it is proposed a suitable modulating control of the pump electric motor torque in order to keep the pressure values in a safe region, for all set of operating conditions. A rig system has been developed to perform experimental tests. From step response tests in the hydraulic rig system, a transfer function model relating the pipe pressure to the motor speed was identified and subsequently applied for PID controller design. The PID control synthesis was performed by using pole-placement techniques and its performance has been assessed in comparison to a PID controller adjusted by using Ziegler-Nichols rules. The obtained results show that the proposed control strategy was able to assure safe plant operation even in extreme operation conditions, as in case of Water Hammer effect.