The invention provides an online monitoring device, monitoring method and
system for lubricating oil of a gearbox of a wind
turbine generator. The device comprises a lubricating oil monitoring bypass, an online monitoring device, a
data transmission and control module, a
cloud server and a
client. The lubricating oil monitoring bypass is connected to a main oil way of a gearbox outlet in parallel, lubricating oil is led out from the main oil way, when the lubricating oil flows through the online monitoring device, real-
time data of various parameters of oil liquid are comprehensively collected and sent to the
data transmission and control module, then the data are uploaded to the
cloud server through
wireless communication setting on the module, after the
client obtains the
monitoring data, the
monitoring data are comprehensively processed and analyzed through a
system software program according to compensation parameters obtained through an early-stage experiment, effective monitoring of the quality of the lubricating oil is achieved, a certain basis is provided for follow-up control measures and fault diagnosis, and basic maintenance, regulation and control operation is achieved through the
data transmission and control module. According to the device, the method and the
system, the requirement of off-line detection is met, and the defect of off-line detection is overcome.