How can the isolation devices of a PCS in an energy storage system improve its immunity to disturbances?

The proper use of isolation devices in a PCS is an effective means of improving system immunity, especially against common-mode interference and ground potential differences. Isolation devices work by cutting off direct conductive paths in electrical connections. Main applications and enhancements include:

1. Signal isolation: Using optocouplers, isolated operational amplifiers, or digital isolators (such as magnetic couplers and capacitive couplers) at points of interaction between strong and weak currents (e.g., sampling, driving, and communication). This blocks power ground noise from coupling to a clean control ground through signal lines, significantly improving the anti-interference capability of the control circuit.

2. Power isolation: Using isolated DC/DC modules to power circuits at different potentials (e.g., the driving side and the sampling side) cuts off the propagation path of common-mode noise through power lines.

3. Communication isolation: Using isolated transceiver modules for long-distance communication such as RS485 and CAN to prevent ground loop interference and surge damage. Isolation provides a high-impedance barrier for interference currents, but it is important to ensure that the isolation device's speed, power consumption, and isolation voltage rating meet the requirements.