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Common mode interference and Differential mode interference of PFC Chokes
Mar 15, 2019

Generally, we often divide interference into two categories in EMI Power Filters: common mode interference and differential mode interference. Common mode interference is the undesired potential difference between any current carrying conductor and the reference ground; and differential mode interference is the undesired potential difference between any two current carrying conductors. The source of these two kinds of interference can be considered from the following two aspects.

1. Common mode interference:

During the transmission of overhead conductors, the electromagnetic environment of the surrounding space is radiated. The amplitude and phase of the signals induced by the live, neutral and safe ground are almost equal. Since the safety ground is connected to the earth, it is formed. Common mode interference between the live, neutral, and safe ground.

2. Differential mode interference:

Different devices sharing a single transmission line. When one of the devices performs a switching operation, a signal having a substantially equal amplitude and an opposite phase is formed between the live line and the neutral line. This type of signal is differential mode interference.