Problem description :
On a farm, three 60KTL-M0 inverters are installed, two of them made a lot of noise, using a mobile phone application, recordings were made on site, the noise is around 80dB for the three inverters.
Onsite test :
In order to measure the sound, the steps below has been respected :
1- Install on your phone an App designed to measure noise
2- Place your phone at a distance of 1meter from the inverter, having the maintenance door closed, and measure the noise level using the App, then get screenshots:
Noise Source :
The electromagnetic noise of solar inverters mainly comes from inductors. When a solar inverter is grid-tied, the output current passes through the inductors, and strong electromagnetic fields are formed at the inductors. Affected by the electromagnetic force, the air gap inside the coil is squeezed and vibrates, and then makes sound. Because the solar inverter generates an industrial frequency alternating current, the current that passes through the inductors has the industrial frequency and the superposition of high frequency modulation. Some frequencies are just within the range of human hearing (20 Hz to 20 kHz).
The noise generated by the inductors depends on the working mode of the solar inverter.
Possible Solution :
In case of sound from the inverters, the firmware of the devices should be checked and updated first.
Impact of noise on the equipment :
The equipment with loud voices is running properly and the power generated by the equipment is the same as that generated by the equipment with low voices. The noise of the inverter mainly comes from the inductor, which is made of copper and iron. The noise does not affect the service life and reliability of the inductor and does not affect the reliability of the product. In addition, Huawei's incoming materials and delivery devices have undergone strict production aging and testing quality inspection to ensure the quality of delivery.
