The invention provides a device for lower potential induction decay. The device applied to 
photovoltaic system with multiple parallelly-connected inverters comprises an externally-connected solar panel. The externally-connected solar panel is connected to the PV array of the input end of an optional 
inverter. The 
inverter connected with the externally-connected solar panel is marked as an externally-connected 
inverter. The sum of the output 
voltage of the corresponding PV array of the externally-connected inverter and the output 
voltage of the externally-connected solar panel is larger than the input 
voltage of optional one of other (N-1) inverters, wherein N is the number of the parallelly-connected inverters. The 
anode of the externally-connected solar panel is connected with the 
cathode of the corresponding PV array of the first inverter or the 
cathode of the externally-connected solar panel is connected with the 
anode of the corresponding PV array of the first inverter. The device has the advantages that only an extra small solar panel needs to be added to the single input solar panel, 
software control is not needed, the device is simple and reliable, convenient to maintain and quite low in 
relative cost, inverter change is avoided, and 
batch production of the inverters is facilitated.