Closed-loop control

In closed-loop control operations, a setpoint is sent to the product as a digital signal, for example via a ripple control receiver. Here the product reacts to the setpoints and implements them. Subsequently, the product checks whether the specified setpoints matches the actual value, in other words the current value at the point of interconnection. There is a feedback loop with the actual value for further processing. For closed-loop control, it is necessary to measure the feed-in power at the point of interconnection. To this end, an energy meter has to be used, for example the SMA Energy Meter.

Advantages:

• If the grid operator specifies setpoints and directly transmits these to the inverter as digital signals via a ripple control receiver, the product implements these specifications. If the product is used as system manager, it can run subordinate inverters using open-loop control and can transmit the specifications to the subordinate inverters.

• By integrating an energy meter, such as the SMA Energy Meter, the self-consumption can be increased. The energy meter regularly provides feedback to the product regarding the amount of feed-in power at the point of interconnection.

• When electrical loads have been integrated into the system, self-consumption can be increased if the product does not continuously limit its feed-in power, but instead dynamically adapts it at the point of interconnection, depending on the load power consumption. You can thus maximize your PV energy yield. In this case, limited specifications by the grid operator do not cause the product to be restricted to 70%, but instead the 30% excess energy is used by the loads.