How to choose between PCSL/π/T type filters in an energy storage system?

The choice between L-type, π-type, and T-type filters in PCS (Port Filtering System) is based on impedance matching, attenuation requirements, and size and cost. L-type filters have a simple structure and are suitable for applications with low source and load impedances and less stringent requirements, providing first-order attenuation. π-type filters (capacitor-inductor-capacitor) have capacitors at both ends, suitable for high source impedance and low load impedance, providing higher differential-mode insertion loss, and are one of the most commonly used input filter structures in PCS. T-type filters (inductor-capacitor-inductor) are suitable for low source impedance and high load impedance, providing better common-mode rejection. The key to selection is analyzing the noise source impedance and load impedance, choosing a topology that allows impedance mismatch at both ends of the filter to achieve the best practical insertion loss. π-type structures are more commonly used for DC-side or AC-side port filtering.