DIAGNOSTIC METHOD AND DIAGNOSTIC SYSTEM FOR HYDRAULIC MACHINE, HYDRAULIC MACHINE, AND RENEWABLE ENERGY TYPE POWER GENERATOR

摘要

A method of diagnosing a hydraulic machine which includes a rotor shaft, a cylinder, a piston forming a working chamber together with the cylinder, and a high-pressure valve and a low-pressure valve (30) provided for the working chamber, and which is configured to perform conversion between rotational motion of the rotor shaft and reciprocal motion of the piston, includes: a pressure-measuring step of detecting a pressure of the working chamber (24); and a damage-detecting step of detecting a damage of the low-pressure valve (30) on the basis of a pressure detection result obtained in the pressure-measuring step. The low-pressure valve (30) is a poppet valve disposed between a low-pressure line of the hydraulic machine and the working chamber (24), for controlling a communicating state between the low-pressure line and the working chamber (24). The damage-detecting step includes detecting the damage of the low-pressure valve (30) on the basis of a change rate of a pressure of the working chamber (24) in each cycle of the reciprocal motion of the piston.