How does the rise in ground potential of a power storage system (PCS) affect its immunity?

When a PCS system is subjected to lightning strikes, power grid overvoltage, or the operation of internal high-power switches, the grounding system may experience a transient ground potential rise (GPR). This rise can severely impact equipment immunity:

1. Increased common-mode interference: The risen ground potential can apply a high common-mode voltage between the internal circuitry and the reference ground through the equipment grounding wire, cable shielding, or parasitic capacitance.

2. Insulation breakdown risk: Exceeding the equipment's insulation withstand level can lead to equipment damage.

3. Logic malfunctions: For insufficiently isolated communication or control lines, the ground potential difference can be converted into differential-mode interference, causing signal errors or equipment resets.

Remedial measures include: reducing the grounding system impedance; installing surge protectors (SPDs) on incoming and outgoing cables; and using fiber optic cables or isolators to transmit sensitive signals, cutting off the ground potential difference path.