PROPORTIONAL HYDRAULIC VALVE CONDITION MONITORING METHOD FOR ON-LINE FAULT DETECTION
Desyel Ferronatto1; Yesid Asaff2; Pedro Paulo da Cunha Bastos1; Fábio José Souza1; Henrique Raduenz1; Victor Juliano De Negri2; João Marcos Castro Soares1
1 REIVAX S/A Automação e Controle; 2 Federal University of Santa Catarina
doi:10.20906/CPS/COB-2015-0432
Resumo
This paper presents the development of a method for condition monitoring and on-line fault detection on proportional directional valves used on the speed governor of hydroelectric power plants. The method is based on monitoring both the valve supply current and spool position related to a command signal for the valve spool positioning which takes into account the dynamic behaviour of friction and flow forces, solenoid current and valve closed loop controller. A set of valves and cylinders with different characteristics were used to develop the method aiming to cover different hydraulic system conditions. For the evaluation and validation of the method, experimental results with the valve under healthy conditions and with induced faults were compared. The faults were added in a way to represent the spool locking, sleeve and/or spool wear, fluid contamination and the increase of friction forces between the spool and sleeve. Considering that the proposed method requires reference parameters characterizing the valve operation without fault, standard performance tests were proposed to determine the initial parameters. The obtained results prove the effectiveness and robustness of the method for the detection of faults classified as severe even if the valve controller attempts to compensate any faulty behaviour. The method is capable to detect the evolution of the described faults and, based on specified setpoints, to provide alarms for maintenance.
Palavras-chave: Proportional valve; Condition monitoring; Fault detection