In the noise test of capacitor

the temperature of capacitor core has an important influence on the noise measurement results. However

there is little paper researching on the influence of capacitor core temperature on its noise. Using the ’GB/T 32524.1—2016 Acoustics-Determination of sound power level and directivity character of power capacitor unit using sound pressure-Part 1: Precision method for hemi-anechoic room’

and according to the given injection current conditions

the sound pressure level and sound power level are measured when the temperature of capacitor core are different. The results show that

with the increases of capacitor core temperature

the sound power level will obviously first rise and then fall

and when the capacitor core temperature approaches the upper limit of the temperature category

the sound power level is significantly higher than that at other temperatures. The maximum deviation in sound power level at difference temperature is 3.5 dB. But the temperature of capacitor core only changes the magnitude of its sound pressure level and sound power level

and does not change the law of radiated noise.