长园科技集团股份有限公司

The on-load tap changer (OLTC) is a critical component for voltage regulation in transformers with on-load tap-changing capabilities and has a high failure rate of 20%, accounting for 40% of the total failures in on-load tap-changing transformers. Therefore, monitoring the OLTC is particularly important for reducing the failure rate of transformers. 

The OLTC consists of a selector, a switching switch, and an electric mechanism. Common failure modes include: broken drive shafts, poor contact between selector switch contacts, malfunctioning operating mechanisms causing refusal to operate and slipping, failure of limit switches, refusal to cut off, termination, or delayed action of the switching device, loosening or falling off of internal fasteners, and internal leakage. 

The online monitoring system for the condition of the transformer on-load tap changer mainly comprises current sensors, vibration sensors, torque and speed sensors, tap changer monitoring IED, and the monitoring host.