Working Principle
A PID module is used in a PV array that comprises SUN2000s and is often installed in a smart array controller. In the scenario with a double-column transformer, the DC capacity of the PV array should be less than or equal to 10 MW. In the scenario with a dual-split transformer, the DC capacity of the PV array should be less than or equal to 16 MW.
The PID module connects to a three-phase (A, B, and C) power cable, functional earthing cable, and RS485 communications cable. The PID module communicates with the SmartLogger over an RS485 communications cable. The SmartLogger collects the voltages of all SUN2000s and transfers the voltages to the PID module. Then, the PID module injects voltage between the phase wire and the ground cable of the isolation transformer to adjust the voltage between PV+ or PV– of the PV module and the ground until the voltage becomes less than or equal to zero, thereby surpassing the PID effect.
Scenario with a Double-Column Transformer
Scenario with a Dual-Split Transformer
