Alpha ESS PWG2-100K, User Manual, Page: 8 / 49

might result in device damage.
1.3
System application
As shown in Fig.1-2, energy storing power generation system is composed of battery or PV, storage inverter and AC
distribution unit. Batteries or PV are input to the storage inverter after series-parallel connection of unit. Storage
inverter outputs it to AC distribution unit. It operates in different modes according to the need.
Storage inverter plays a core role in the whole system and is characterized with high conversion efficiency, wide
range input voltage, rapid on/off-grid switching and convenient maintenance. It has a complete protection function
(such as islanding protection, DC overvoltage protection, AC overvoltage-under-voltage protection, over
frequency-under frequency protection, inverted sequence protection and output overload protection) and can
meet on/off-grid operation requirements. The input side of storage inverter is single route input, its output side is
set with an isolation transformer, and it can conduct low-voltage on-grid.
Battery
bank
PCS Grid
DC
distribution
box
AC
distribution
box
PV
Load
Fig.1-2 Energy storing system diagram
The battery bank can be accumulator or lithium battery, but the mixed use of different kinds of batteries is forbidden. The DC
voltage must be higher than the required lowest value, otherwise the PCS will not operate normally.
Danger

There is deadly high voltage between the anode and cathode of battery bank, and make sure the disconnection between
the battery bank and PCS when servicing the equipment.