Reactive Power Setpoint; Behavior In The Absence Of Active And Reactive Power Setpoints; Full And Limited Dynamic Grid Support (Frt) - SMA SUNNY CENTRAL 500CP-JP User Manual

SMA Solar Technology AG
3.8.3

Reactive Power Setpoint

The Sunny Central can provide reactive power. There are eleven different methods for setpoint specification.
These include entering a fixed parameter, processing an external signal from the grid operator or specifying the reactive
power using adjustable characteristic curve parameters (see Section 8.2, page 53).
3.8.4

Behavior in the Absence of Active and Reactive Power Setpoints

In the event of failure of setpoint specifications for active and reactive power control, the inverter is capable of bridging
the gap in one of two ways:
• Use of last default values received
As long as the inverter does not receive any updated default values, it will utilize the last value received (when
setpoint specification takes place via communication) and the last valid mean value (when using analog setpoints).
• Use of proxy values
As long as the Sunny Central does not receive any updated default values, it will utilize the specified proxy values
for active power limitation, reactive power setpoint and displacement power factor. In this case, different proxy
values can be configured for feed-in operation and grid monitoring.
The parameter PwrMonErrMod is used to configure whether the last default values (LastVal) or the configured proxy
values (SubVal) are to be utilized. This setting will be valid for both active and reactive power setpoints.
The proxy values are used when the time since receiving the last valid signal for default values as defined in the parameter
PwrMonErrTm has elapsed.
3.8.5

Full and Limited Dynamic Grid Support (FRT)

With full dynamic grid support, the Sunny Central supports the utility grid during a brief grid voltage drop by feeding in
reactive current. In this case, the behavior of the Sunny Central depends on the percentage ratio of the line voltage V
to nominal voltage V.
With limited dynamic grid support, the Sunny Central interrupts grid feed-in during the grid voltage drop.
Figure 11: Maximum duration of a voltage drop that the Sunny Central can bridge without disconnecting from the utility grid
User Manual
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