Photovoltaic inverter broadband carrier interference

Why do inverters have high switching frequencies?

Higher switching frequencies reduce the harmonic content, or THD, in the output voltage and supply a sinusoidal waveform to the connected load. However, the process of reducing THD by choosing high switching frequency results in the generation of electromagnetic interference in the inverter.

How to reduce electromagnetic interference in inverters?

Figuring out how to reduce electromagnetic interference in inverters is something that designers must devote considerable attention to. There are various techniques to choose from; EMI filters are one such method, generally used in the input side as well as the output side of inverters to reduce EMI.

Are photovoltaic inverters prone to EMI?

Photovoltaic inverters are inherently low-frequency devices that are not prone to radiating EMI. No interference is expected above 1 MHz because of the inverters’ low-frequency operation.

Does a PV system have a risk of electro-magnetic interference?

While the risk of electro-magnetic and/ or radar interference from PV systems is very low, it does merit evaluation, if only to improve the confidence of site owners and other stakeholders.

How does a power inverter affect the efficiency of a system?

Author to whom correspondence should be addressed. Power inverters produce common mode voltage (CMV) and common mode current (CMC) which cause high-frequency electromagnetic interference (EMI) noise, leakage currents in electrical drives application and grid-connected systems, which consequently drops the efficiency of the system considerably.

Does a low frequency inverter cause interference?

No interference is expected above 1 MHz because of the inverters’ low-frequency operation. In addition, interaction at lower frequencies (100 kHz to1 MHz) is also very low risk because of the poor coupling of these extremely long wavelengths to free space, limiting propagation of the signal.