User Manual of String Inverter
6
2.1.2 Operation Mode
HV string inverter includes three operation modes: standby mode, operation mode
and shutdown mode. The three mode switching conditions are shown in Figure 2-5.
Standby
Mode
Operation
Mode
Shutdown
Mode
Operation mode to standby mode:
Insufficient sunshine or DC switch
is turned off
Standby mode to operation mode:
Abundant sunshine without
system faults
Fault or shutdown command is detected
Standby mode to
shutdown mode: fault or
shutdown command is
detected
Shutdown mode to standby
mode: fault is deleted or
startup command is detected
Figure 2-5
string inverter operation mode
Operation Mode
Description
Standby
1) Standby mode mainly refers to the external environment doesn't meet the operation
condition, such as insufficient sunshine or DC switch is turned off. Under this mode, the
inverter continuously performs self-checking and enters operation mode once the
operation conditions are satisfied.
2) Under standby mode, the inverter will enter shutdown mode after detecting the
shutdown command or faults.
Operation
1) Under the operation mode, the inverter converts DC current of photovoltaic arrays into
AC current and feeds it to the grid. The inverter performs MPPT arithmetic and outputs
the maximum power of photovoltaic arrays.
2) The inverter will enter shutdown mode after detecting the faults or shutdown
command.
3)
The inverter will enter standby mode after detecting the input power of photovoltaic
arrays is lower than the on-grid power generation condition.
Shutdown
1) If the inverter detects a fault occurrence or shutdown command during standby or
operation mode, it enters shutdown mode.
2)
In the shutdown mode, if the inverter detects that the fault has been cleared or the
power-on command, it enters standby mode.
2.2 System Configuration and Application
2.2.1 Application Description
Figure 2-6 shows the application diagram of the string inverter network, Figure 2-7 shows the
design scheme of the distributed PV power plant.
Photovoltaic
panel
String
inverter
Measur i ng
uni t
Grid
Figure 2-6 Application diagram of the string inverter network
Bluesun
Bluesun
5
