Operations Related to the Special User
Ensure that the DC side of the SUN2000 is energized before setting grid parameters, protection parameters, feature parameters, and grid adjustment parameters.
Setting Grid Parameters
Procedure
- Choose and set grid parameters.Figure 7-13 Grid parametersTable 7-5 Grid parameters
Parameter
Description
Grid Code
Set this parameter based on the grid code of the country or region where the inverter is used and the inverter application scenario.
Isolation settings
Set the working mode of the inverter based on the grounding status at DC side and the connection to the power grid.
Output mode
Specifies whether the inverter output has a neutral wire based on the application scenario.
Automatically start upon grid recovery
Specifies whether to allow the inverter to automatically start after the power grid recovers.
Grid connected recovery time from grid faults (s)
Specifies the time after which the inverter begins restarting after the power grid recovers.
Grid reconnection voltage upper limit (V)
The standards of certain countries and regions require that after the inverter shuts down for protection due to a fault, if the power grid voltage is higher than Grid reconnection voltage upper limit, the inverter is not allowed to reconnect to the grid.
Grid reconnection voltage lower limit (V)
The standards of certain countries and regions require that after the inverter shuts down for protection due to a fault, if the power grid voltage is lower than Grid reconnection voltage lower limit, the inverter is not allowed to reconnect to the grid.
Grid reconnection frequency upper limit (Hz)
The standards of certain countries and regions require that after the inverter shuts down for protection due to a fault, if the power grid frequency is higher than Grid reconnection frequency upper limit, the inverter is not allowed to reconnect to the grid.
Grid reconnection frequency lower limit (Hz)
The standards of certain countries and regions require that after the inverter shuts down for protection due to a fault, if the power grid frequency is lower than Grid reconnection frequency lower limit, the inverter is not allowed to reconnect to the grid.
Reactive power compensation (cosφ-P) trigger voltage (%)
Specifies the voltage threshold for triggering reactive power compensation based on the cosφ-P curve.
Reactive power compensation (cosφ-P) exit voltage (%)
Specifies the voltage threshold for exiting reactive power compensation based on the cosφ-P curve.
Setting Protection Parameters
Procedure
- Choose and set protection parameters.Figure 7-14 Protection parametersTable 7-6 Protection parameters
Parameter
Description
Voltage unbalance protection threshold (%)
Specifies the solar inverter protection threshold when the power grid voltage is unbalanced.
10-min overvoltage protection threshold (V)
Specifies the 10-minute overvoltage protection threshold.
10-min overvoltage protection duration (ms)
Specifies the 10-minute overvoltage protection duration.
Level-N overvoltage protection threshold (V)
Specifies the level-N grid overvoltage protection threshold.
NOTE:- N can be 1, 2, 3, 4, 5, or 6.
- When HVRT is set to Enable, and the value of Level-1 overvoltage protection threshold is larger than that of HVRT threshold, the solar inverter may repeatedly start and shut down if the power grid voltage is between the two values.
Level-N overvoltage protection duration (ms)
Specifies the level-N grid overvoltage protection duration.
NOTE:N can be 1, 2, 3, 4, 5, or 6.
Level-N undervoltage protection threshold (V)
Specifies the level-N grid undervoltage protection threshold.
NOTE:- N can be 1, 2, 3, 4, 5, or 6.
- When LVRT is set to Enable, and the value of Level-1 undervoltage protection threshold is less than that of LVRT threshold, the solar inverter may repeatedly start and shut down if the power grid voltage is between the two values.
Level-N undervoltage protection duration (ms)
Specifies the level-N grid undervoltage protection duration.
NOTE:N can be 1, 2, 3, 4, 5, or 6.
Level-N overfrequency protection threshold (Hz)
Specifies the level-N grid overfrequency protection threshold.
NOTE:N can be 1, 2, 3, 4, 5, or 6.
Level-N overfrequency protection duration (ms)
Specifies the level-N grid overfrequency protection duration.
NOTE:N can be 1, 2, 3, 4, 5, or 6.
Level-N underfrequency protection threshold (Hz)
Specifies the level-N grid underfrequency protection threshold.
NOTE:N can be 1, 2, 3, 4, 5, or 6.
Level-N underfrequency protection duration (ms)
Specifies the level-N grid underfrequency protection duration.
NOTE:N can be 1, 2, 3, 4, or 5.
Active islanding protection
Specifies whether to enable the active islanding protection function.
Setting Feature Parameters
Procedure
- Choose , and set feature parameterFigure 7-15 Feature parametersTable 7-7 Feature parameters
Parameter
Description
LVRT
LVRT is short for low voltage ride-through. When the grid voltage is abnormally low for a short time, the inverter cannot disconnect from the power grid immediately and has to work for some time.
Threshold for triggering LVRT (V)
Specifies the threshold for triggering LVRT. The threshold settings should meet the local grid standard.
This parameter is displayed when LVRT is set to Enable.
LVRT gradient K1
During LVRT, the solar inverter needs to generate positive-sequence reactive power to support the power grid. This parameter is used to set the positive-sequence reactive power generated by the solar inverter.
For example, if you set LVRT gradient K1 to 2, the increment of positive-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage decreases by 10% during LVRT.
This parameter is displayed when LVRT is set to Enable.
LVRT gradient K2
During LVRT, the solar inverter needs to generate negative-sequence reactive power to support the power grid. This parameter is used to set the negative-sequence reactive power generated by the solar inverter.
For example, if you set LVRT gradient K2 to 2, the increment of negative-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage decreases by 10% during LVRT.
This parameter is displayed when LVRT is set to Enable.
Percentage of LVRT reactive current limiting
During LVRT, the solar inverter needs to limit the reactive current.
For example, if you set Percentage of LVRT reactive current limiting to 50, the reactive current upper limit of the solar inverter is 50% of the rated current during LVRT.
This parameter is displayed when LVRT is set to Enable.
Threshold of LVRT zero-current mode
When Zero current due to power grid fault is enabled, if the power grid voltage is less than the value of Threshold of LVRT zero-current mode during LVRT, the zero current mode is used. Otherwise, the mode configured in LVRT mode is used.
This parameter is displayed when LVRT is set to Enable.
LVRT mode
Sets LVRT mode. The options are Zero-current mode, Constant current mode, Reactive power priority mode, and Active power priority mode.
This parameter is displayed when LVRT is set to Enable.
LVRT characteristic curve
Specifies the low voltage ride-through capability of the inverter.
HVRT
HVRT is short for high voltage ride-through. When the grid voltage is abnormally high for a short time, the inverter cannot disconnect from the power grid immediately and has to work for some time.
Threshold for triggering HVRT (V)
Specifies the threshold for triggering HVRT. The threshold settings should meet the local grid standard.
This parameter is displayed when HVRT is set to Enable.
HVRT gradient K1
During HVRT, the solar inverter needs to generate positive-sequence reactive power to support the power grid. This parameter is used to set the positive-sequence reactive power generated by the solar inverter.
For example, if you set HVRT gradient K1 to 2, the increment of positive-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage increases by 10% during HVRT.
This parameter is displayed when HVRT is set to Enable.
HVRT gradient K2
During HVRT, the solar inverter needs to generate negative-sequence reactive power to support the power grid. This parameter is used to set the negative-sequence reactive power generated by the solar inverter.
For example, if you set HVRT gradient K2 to 2, the increment of negative-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage increases by 10% during HVRT.
This parameter is displayed when HVRT is set to Enable.
Grid voltage protection shield during VRT
Specifies whether to shield the undervoltage protection function during LVRT or HVRT.
This parameter is displayed when LVRT or HVRT is set to Enable.
VRT exit hysteresis threshold
Specifies the LVRT/HVRT recovery threshold.
- This parameter is displayed when LVRT or HVRT is set to Enable.
- LVRT recovery threshold = Threshold for triggering LVRT + VRT exit hysteresis threshold
- HVRT recovery threshold = Threshold for triggering HVRT - VRT exit hysteresis threshold
Zero current due to power grid fault
Certain countries and regions have requirements on the output current during high/low voltage ride-through. In this case, set this parameter to Enable. After this parameter is set to Enable, the output current is less than 10% of the rated current during high/low voltage ride-through.
This parameter is displayed when LVRT or HVRT is set to Enable.
Active islanding protection
Specifies whether to enable the active islanding protection function.
Automatic OFF due to communication interrupted
The standards of certain countries and regions require that the inverter must shut down after the communication is interrupted for a certain time.
If Automatic OFF due to communication interrupted is set to Enable and the inverter communication is interrupted for a specified time (set by Communication interruption duration), the inverter will automatically shut down.
Automatic ON due to communication resumed
If this parameter is set to Enable, the inverter automatically starts after communication recovers. If this parameter is set to Disable, the inverter needs to be started manually after communication recovers.
This parameter is displayed when Automatic OFF due to communication interrupted is set to Enable.
Communication interruption duration (min)
Specifies the duration for determining communication interruption. Used for automatic shutdown for protection in case of communication interruption.
Soft start/boot time (s)
Specifies the duration for the power to gradually increase when the inverter starts.
Soft start time after grid failure (s)
Specifies the time for the power to gradually increase when the inverter restarts after the power grid recovers.
TCP heartbeat interval (s)
Specifies the TCP link timeout period for the solar inverter to connect to the management system.
TCP frame length
Specifies the maximum length of the TCP frame sent by the northbound device to the solar inverter.
Heartbeat period at application layer (min)
Specifies the timeout period for the solar inverter to connect to the management system.
Parallel communication mode
Sets the communication mode between the master and slave servers in SDongle scenarios.
Setting Power Adjustment Parameters
Procedure
- Choose and set power adjustment parameters.Figure 7-16 Power adjustment parametersTable 7-8 Power adjustment parameters
Parameter
Description
Remote power schedule
If this parameter is set to Enable, the inverter responds to the scheduling instruction from the remote port. If this parameter is set to Disable, the inverter does not respond to the scheduling instruction from the remote port.
Schedule instruction valid duration (s)
Specifies the time for maintaining the scheduling instruction.
When this parameter is set to 0, the scheduling instruction takes effect permanently.
Maximum active power (kW)
Specifies the output upper threshold for the maximum active power to adapt to different market requirements.
OFF at 0% power limit
If this parameter is set to Enable, the inverter shuts down after receiving the 0% power limit command. If this parameter is set to Disable, the inverter does not shut down after receiving the 0% power limit command.
Active power change gradient (%/s)
Specifies the change speed of the inverter active power.
Derated by active power % (%)
Adjusts the active power output of the inverter by percentage.
This parameter is displayed if Remote power schedule is set to Enable.
If this parameter is set to 100, the inverter outputs based on the maximum output power.
Derated by fixed active power (kW)
Adjusts the active power output of the inverter by fixed value.
This parameter is displayed if Remote power schedule is set to Enable.
For 1000 V inverters, the maximum value of this parameter for the SUN2000-25KTL-US is 27.5 kW.
Night-time reactive power output
In some specific application scenarios, a power grid company requires that the inverter can perform reactive power compensation at night to ensure that the power factor of the local power grid meets requirements.
This parameter is displayed when Isolation settings is set to Input ungrounded, with TF.
Enable reactive power parameters at night
When this parameter is set to Enable, the inverter outputs reactive power based on the setting of Reactive power compensation at night. Otherwise, the inverter executes the remote scheduling command.
This parameter is displayed when Night-time reactive power output is set to Enable.
Night-time reactive power compensation (kVar)
During the reactive power compensation at night, the reactive power is scheduled by fixed value.
This parameter is displayed when Night-time reactive power output and Enable reactive power parameters at night are set to Enable.
Reactive power change gradient (%/s)
Specifies the change speed of the inverter reactive power.
Reactive power adjustment time (s)
Specifies the adjustment time for the reactive power to reach the target value during reactive power adjustment.
Plant active power gradient (min/100%)
Specifies the rate of active power rise due to sunlight changes.
Average active power filtering time (ms)
Specifies the period of active power rise due to sunlight changes. This parameter is used with Plant active power gradient.
Power factor
Specifies the power factor of the inverter.
This parameter is displayed if Remote power schedule is set to Enable.
Reactive power compensation (Q/S)
Specifies the reactive power output by the inverter.
Overfrequency derating
If this parameter is set to Enable, the active power of the inverter will be derated according to a certain slope when the grid frequency exceeds the frequency that triggers overfrequency derating.
Frequency for triggering overfrequency derating (Hz)
The standards of certain countries and regions require that the output active power of inverters be derated when the power grid frequency exceeds a certain value.
- This parameter is displayed when Overfrequency derating is set to Enable.
- When setting this parameter, ensure that the following condition is met: Frequency for exiting overfrequency derating ≤ Frequency for triggering overfrequency derating < Cutoff frequency of overfrequency derating.
Frequency for exiting overfrequency derating (Hz)
Specifies the frequency threshold for exiting overfrequency derating.
- This parameter is displayed when Overfrequency derating is set to Enable.
- When setting this parameter, ensure that the following condition is met: Frequency for exiting overfrequency derating ≤ Frequency for triggering overfrequency derating < Cutoff frequency of overfrequency derating.
Cutoff frequency of overfrequency derating (Hz)
Specifies the frequency threshold for cutting off overfrequency derating.
- This parameter is displayed when Overfrequency derating is set to Enable.
- When setting this parameter, ensure that the following condition is met: Frequency for exiting overfrequency derating ≤ Frequency for triggering overfrequency derating < Cutoff frequency of overfrequency derating.
Cutoff power of overfrequency derating (%)
Specifies the power threshold for cutting off overfrequency derating.
- This parameter is displayed when Overfrequency derating is set to Enable.
Power recovery gradient of overfrequency derating (%/min)
Specifies the recovery rate of the overfrequency derating power.
- This parameter is displayed when Overfrequency derating is set to Enable.
PF (U) voltage detection filtering time (s)
Specifies the time for filtering the grid voltage in the PF-U curve.
Apparent power baseline (kVA)
Adjusts the apparent output baseline of the inverter.
Active power baseline (kW)
Adjusts the active output baseline of the inverter.
Communication disconnection fail-safe
In the inverter export limitation scenario, if this parameter is set to Enable, the inverter will perform active power derating by percentage when the communication between the inverter and the SmartLogger or Smart Dongle is disconnected for more than the time specified by Communication disconnection detection time.
Communication disconnection detection time (s)
Specifies the fail-safe detection time for the disconnection between the inverter and the SmartLogger or Smart Dongle.
This parameter is displayed when Communication disconnection fail-safe is set to Enable.
Closed-loop controller
Specifies the grid-tied power controller. Before setting the parameter, confirm the controller type. Incorrect setting will result in abnormal power output of the solar inverter. Solar inverter applies only to the scenario where a single solar inverter is used or where a single inverter is used with a Smart Dongle.
Limit value for minimum PF of Q-U characteristic curve
Limits the current PF value to restrict the Q-U curve output reactive power.
Power percentage for triggering Q-U scheduling
Specifies the reference apparent power, in percentage. When the actual apparent power of the inverter is greater than the value of this parameter, the Q-U characteristic curve scheduling function is enabled.
Q-U characteristic curve
The inverter adjusts Q/S (the ratio of the output reactive power to apparent power) in real time based on U/Un(%) (the ratio of the actual power grid voltage to the rated power grid voltage).
Q-P characteristic curve
The inverter adjusts Q/Pn (the ratio of the output reactive power to the rated active power) in real time based on P/Pn(%) (the ratio of the actual active power to the rated active power).
Cosφ-P/Pn characteristic curve
The inverter adjusts the output power factor cosφ in real time based on P/Pn(%).
