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 7-10 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 SUN2000 is used and the SUN2000 application scenario.
Isolation settings
Specifies the working mode of the SUN2000 according to the grounding status at the DC side and the connection status to the 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 SUN2000 to automatically start after the power grid recovers.
Grid connected recovery time from grid faults (s)
Specifies the waiting time for SUN2000 restart after the power grid recovers.
Grid reconnection voltage upper limit (V)
The standards of certain countries and regions require that the SUN2000 must not export power to the power grid again when the grid voltage exceeds the value of Grid reconnection voltage upper limit after the SUN2000 shuts down due to a fault.
Grid reconnection voltage lower limit (V)
The standards of certain countries and regions require that the SUN2000 must not export power to the power grid again when the grid voltage is below the value of Grid reconnection voltage lower limit after the SUN2000 shuts down due to a fault.
Grid reconnection frequency upper limit (Hz)
The standards of certain countries and regions require that the SUN2000 must not export power to the power grid again when the grid frequency exceeds the value of Grid reconnection frequency upper limit after the SUN2000 shuts down due to a fault.
Grid reconnection frequency lower limit (Hz)
The standards of certain countries and regions require that the SUN2000 must not export power to the power grid again when the grid frequency is below the value of Grid reconnection frequency lower limit after the SUN2000 shuts down due to a fault.
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 7-11 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 threshod (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 threshod 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 threshod (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 thresho 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.
Setting Feature Parameters
Procedure
- Choose , and set feature parameterFigure 7-12 Feature parametersTable 7-7 Feature parameters
Parameter
Description
LVRT
When the power grid voltage is abnormally low for a short time, the SUN2000 cannot disconnect from the power grid immediately and has to work for some time. This is called LVRT.
LVRT triggering threshold (V)
Specifies the threshold for triggering LVRT.
LVRT compensation power factor of reactive power in positive sequence
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 compensation power factor of reactive power in positive sequence to 2, the positive-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage decreases by 10% during LVRT.
LVRT compensation power factor of reactive power in negative sequence
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 compensation power factor of reactive power in negative sequence to 2, the negative-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage decreases by 10% during LVRT.
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.
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.
LVRT mode
Sets LVRT mode. The options are Zero-current mode, Constant current mode, Reactive power priority mode, and Active power priority mode.
LVRT characteristic curve
Specifies the low voltage ride-through capability of the inverter.
HVRT
When the power grid voltage is abnormally high for a short time, the SUN2000 cannot disconnect from the power grid immediately and has to work for some time. This is called high voltage ride-through (HVRT).
HVRT triggering threshold (V)
Specifies the threshold for triggering HVRT. The threshold settings should meet the local grid standard.
HVRT compensation power factor of reactive power in positive sequence
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 compensation power factor of reactive power in positive sequence to 2, the positive-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage increases by 10% during HVRT.
HVRT compensation power factor of reactive power in negative sequence
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 compensation power factor of reactive power in negative sequence to 2, the negative-sequence reactive current generated by the solar inverter is 20% of the rated current when the AC voltage increases by 10% during HVRT.
Grid voltage protection shield during VRT
Specifies whether to shield the undervoltage protection function during LVRT or HVRT.
VRT exit hysteresis threshold
Specifies the LVRT/HVRT recovery threshold.
- This parameter is displayed when LVRT is set to Enable.
- For example, if this parameter is set to 2, the reactive power generated by the inverter is 20% of the rated power when the AC voltage drops by 10% during LVRT.
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.
Voltage rise suppression
The standards of certain countries and regions require that when the output voltage exceeds a certain value, the inverter must suppress voltage rise by outputting reactive power and reducing active power.
Communication interruption duration (min)
Specifies the duration for determining communication interruption. Used for automatic shutdown for protection in case of communication interruption.
Soft start time (s)
Specifies whether to enable the active islanding protection function.
Soft start time after grid failure (s)
Specifies the time for the power to gradually increase when the solar 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 7-13 Power adjustment parametersTable 7-8 Power adjustment parameters
Parameter
Description
Remote power schedule
If this parameter is set to Enable, the solar inverter responds to the remote power scheduling command. If it is set to Disable, the solar inverter does not respond to the command.
Schedule instruction valid duration (s)
Adjusts the time for maintaining the scheduling command.
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 solar inverter shuts down after receiving the 0% power limit command. If this parameter is set to Disable, the solar inverter does not shut down after receiving the 0% power limit command.
Active power change gradient (%/s)
Adjusts the change speed of the active power of the solar inverter.
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 f the solar inverter by fixed value.
This parameter is displayed if Remote power schedule is set to Enable.
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.
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.
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.
PF (U) voltage detection filter time (s)
Specifies the time for filtering the grid voltage in the PF-U curve.
Apparent power baseline (kVA)
Adjust 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.
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).
Cosφ-P/Pn characteristic curve
The inverter adjusts the output power factor cosφ in real time based on P/Pn(%).
