What are the Main Parameters of Common Mode Filters? Usage Precautions? How to Use in Solar Inverters?

**Main Parameters:**

1. Common-Mode Rejection Ratio (CMRR): Indicates the ratio of the filter's impedance to common-mode signals versus differential-mode signals.
2. Passband: Refers to the extent to which the filter allows differential-mode signals within a certain frequency range to pass through.
3. Cutoff Frequency: Reflects the degree to which the filter suppresses common-mode signals. A lower value indicates stronger suppression of high-frequency common-mode signals.
4. Phase Balance: During filter operation, it is essential to ensure phase balance between the two signal paths to avoid suppressing differential-mode signals.

**Precautions:**

1. The common-mode filter should be installed as close as possible to the signal source and load end to minimize the transmission of common-mode signals.
2. To reduce electromagnetic interference, the input and output of the common-mode filter should use the same type of connection, such as two BNC connectors or two plug connectors.
3. The wiring method for the common-mode filter should follow the correct sequence and steps to ensure normal operation and long-term reliability.

**Application in Solar Inverters:**

Common-mode filters are often used in solar inverters to reduce electromagnetic interference, ensuring the purity and stability of the output signal. Typically, the filter is installed between the solar panels and the inverter to minimize the transmission of electromagnetic interference. Additionally, an extra common-mode filter can be connected at the inverter output to further enhance filtering performance. During use, ensure that the filter's passband and cutoff frequency match the system requirements, and follow the correct wiring steps and sequence to guarantee proper operation.