Typical Failure Analysis of Filter Capacitor in Auxiliary Power Supply Unit Inverter
Auxiliary power supply unit(APU),as an important equipment for rail transit vehicles,converts the train's high voltage into medium and low voltage direct current and alternating current,and then supplies power to the train loads,which plays a vital role in guaranteeing the safe and reliable operation of rail transit vehicles.By exploring the specific case of APU three-phase inverter input filter capacitor failure,the article firstly analyzes the root cause of capacitor failure for the existence of abnormal resonant current in the circuit,and finds out that the capacitor failure occurs due to the long-term over-current and over-temperature abnormal working conditions;then it explores and proposes a solution to reduce the resonant current of the circuit,i.e.,to avoid circuit resonance by changing the inductance value of the magnetic ring in the circuit;then the effectiveness of the scheme of avoiding circuit resonance by changing the inductance value of the magnetic ring in the circuit is verified by means of simulation analysis,APU operating characteristic test,capacitor current and temperature rise test,and vehicle dynamic operation test;this finally solves the failure problem of the filter capacitor due to the abnormal resonant current of the circuit.
auxiliary power supply unitcapacitanceresonancefailure
万方数据
维普
