It is important for the operators to know the current output data from the photovoltaic plants and to be able to manage the output from these plants as needed to keep the grid stable.
Solar-Log™ models are flexible systems to meet the different regulatory and operating requirements from individual countries and grid operators.
For photovoltaic plants up to 30 kWp, plant operators in Germany can choice which type of power limits to use:
Solar-Log™ offers two variants for the fixed reduction of 70% at the feed-in point.
The reduction offers the following options for implementation.
With Solar-Log™ PM+ devices, a feed-in cap for the inverters with allowances for self-consumption can be configured.
With this innovative solution, the loss that results from the X % reduction can be minimized and implemented as follows.
The German Renewable Energy Act (EEG) requires "simplified feed-in management" for plants up to 100 kWp and can be impletement in the following ways.
Simple feed-in management can also implement the “remote controlled with the calculation of self-consumption” function. To carry out this function, the Solar-Log™ only needs a special power meter to measure the current self-consumption in the house.
The power grid management for photovoltaic plants (production plants) in the medium voltage network
Plants larger than 100 kWp in the medium voltage network often have advanced requirements.
This technology allows bi-directional communication between the the telecontrol system and grid operator. The signals are transmitted between the telecontrol system and Solar-Log 2000 PM+ via I/O Box(es) with the PM package. The Solar-Log™ I/O Box can receive and send a wide range of signals from various grid operators. Depending on which value has to be transmitted to the grid operator, a measurement of transformer voltage with the Solar-Log™ Utility Meter is required.
Controlling active power and regulating reactive power represents a special technical challenge. Grid operators rely on various solutions here.
Both options can be implemented in combination with the Solar-Log™ Utility Meter. Other functions such as the fixed value cos phi shift factor or performance related cos phi functions can be implemented without additional measurements.
Complex grid operator requirements can be implemented by using telecontrol systems that are directly connected to the Solar-Log™ via the TCP-based Modbus protocol. With this set up, the command signals and response signals between the remote control technology and the Solar-Log 1900 PM+ and 2000 PM+ are relayed back and forth via the protocol without potential-free and analog interfaces. This direct connection with remote control technology can implement communication according to IEC 60870-C, 61850-5-101 and -104.
