User Manual

18
02 Installation Instructions
User Manual V1.3
2.4.4 Back-up Connection
Declaration for back-up function
The below statement lays out general policies governing the AC-coupled inverters.
1. The back-up function needs the addition of a GoodWe auto-transformer for 120V back-up
loads. Otherwise, the o-grid function may not be used, and back-up loads may be damaged.
2. Some external factors may cause the system to fail on back-up mode. As such, we recommend
the users to be aware of conditions and follow the instructions as below:
• Do not connect loads if they depend on a stable energy supply for a reliable operation.
• Do not connect the loads which may in total exceed the maximum back-up capacity.
• Try to avoid those loads which may create very high start-up current surges such as Inverter
Air-conditioner, high-power pump etc.
• Due to the condition of battery itself, battery current might be limited by some factors
including but not limited to the temperature, weather etc.
Micro-grid system conguration
When A-BP detects the charging power in o-grid mode, it will turn on micro-grid mode. In
order to ensure the stability of a micro-grid, the system conguration must meet the following
rules.
1. A micro-grid system only supports one PV inverter.
2. If the PV panel and PV inverter have been installed, when you select the capacity of A-BP and
battery, please satisfy the following constraint formula.
P
A-BP
> P
PVInverter
[1]
Min{Min.V
BAT
*Min{Max.I
BAT_Chg
,Max.I
A-BP_BatChg
},P
A-BP
} > Min{P
Panel
,P
PVInverter
} [2]
Min.V
BAT
*Min{Max.I
BAT_Chg
,Max.I
A-BP_BatChg
} =Minimum rechargeable power of the battery
P
A-BP
: Rated Power of A-BP
P
PVInverter
: Rated Power of the PV Inverter
P
Panel
: Rated Power of the Panel
Min.V
BAT
: Minimum Output Voltage of the Battery
Max.I
BAT-Chg
: Maximum Charging Current of the Battery
Max.I
A-BP_BatChg
: Maximum Battery Charging Current of A-BP
For example, a set of 7KWPV panel + 7.6KW PV inverter system has been installed, you must choose
8.6KW or9.6KW A-BP. At the same time, the theoretical minimum rechargeable power of the battery only
needs to be greater than 7KW.
3. The battery voltage in the micro-grid system must not be higher than 405V.
4. The PV inverter must respond to the following Frequency-Watt curve.