To monitor partial discharge ultrasonic signals near the stator winding slot of a generator and improve the insulation system state assessment capability

an implantable and highly sensitive PMN-PT piezoelectric thin-film sensor is developed for deployment at the end-winding slot. The effectiveness of this sensor is also validated. First

the PMN-PT thin film is fabricated using the sol-gel method

and the sensor performance is optimized through electrode structure design and acoustic impedance matching materials. Second

the sensor’s strong anti-interference capability

high sensitivity

and excellent frequency response characteristics are validated through needle-tip-pulse discharge experiment and acoustic emission lead-breakage experiment on the polyethylene plate. Finally

an artificial defect is created on the prototype stator winding bar to verify the effectiveness of PMN-PT piezoelectric thin-film sensor in discharge monitoring. The experimental results show that

for the partial discharge event with an apparent discharge of 3 746 pC

the designed PMN-PT sensor can detect a maximum output voltage of 0.4 V

its sensitivity is about 1.74 times higher than that of the traditional ceramic sensor

and the frequency response range is extended to 400 kHz. This study provides an innovative solution for the online monitoring technology of generators

which not only significantly improves the real-time monitoring capability of insulation status

but also lays the foundation for the safe operation of power equipment

demonstrating important application prospects.