Application note. 0% - 100% feed-in regulation

Transcription

1 Application note 0% - 00% feed-in regulation

2 Contents The 0 W regulation The 0 W regulation 4 Schematic structure 5 Summary of options 7 System outputs In countries where feed-in of solar power into the public grid is undesirable, the controller of the photovoltaic system must ensure that no solar power is fed into the public grid. Depending on self-consumption, the PV system's power may be connected in such way that the user can cover his energy requirements from the solar energy generated by his own system, thus avoiding the need to purchase energy from the public grid. For this purpose, the consumption/feed-in meter is connected to the data logger so that it can calculate the regulation commands for the inverter. If a consumption meter is not connected to the data logger, the logger continuously sends a regulation command to the inverters with a 0% feed-in maximum. This means that feed-in may not take place. The following graph shows what the possible PV power (red) and the power actually consumed at home (green) could look like. The yellow area represents the energy purchased from the public grid. The distribution of areas illustrates that it certainly makes sense to operate consumers around midday since this is when the yield of the available PV power is at its highest. The red area is therefore also the power that is diverted away by the data logger, and hence lost. As soon as no PV energy is available, consumers are supplied from the public grid (yellow). 0 9 PV power available (red area) Energy requirement of a detached home (green area) Bought-in power (yellow area) 8 7 Power [kw] :00 0:00 04:00 06:00 08:00 0:00 :00 4:00 6:00 8:00 0:00 :00 00:00 Time [hh:mm] Diagram for the 0% regulation KACO new energy GmbH Carl-Zeiss-Str. 747 Neckarsulm Germany Tel Fax sales@kaco-newenergy.de By connecting up additional consumers such as heating, water or energy storage systems, the self-consumption, and therefore the consumption of the PV current, can be increased considerably. In the above graph, the green area would grow and the red one shrink. The Powador-proLOG data logger assumes the task of switching on additional consumers since it has a programmable switching output that allows more consumers to be controlled by means of a relay circuit. Alternatively, more consumers can also be connected via the internal "Priwatt" function of the inverter, depending on the system fitted.

3 With our solution, you can use your self-generated green electricity in your own household. In the following schematic diagrams you can see how the two ways of implementation are set up. In addition to the 0 W feed-in it is also possible to implement scenarios such as the 70% rule (in Germany), which provide a partial supply of solar energy. Summary of your options. Schematic structure: Here you can find out which components are needed to deploy our solution for 0 W feed-in. Please pay particular attention to the characteristics of your system, as these are very important when selecting the right components. The total system output power, number of inverters or cable cross-section are characteristics that must be known before you opt for one of the following options. Logger Option < 0 kwp PV generator Self-consumption Consumption metre Inverter Public grid Inverter. Schematic structure: Powador-piccoLOG Logger inverters Communication via RS485 inverters Communication via S0 Self-consumption Inverter Consumption metre Public grid Femto D4 ATTO D4 70A S0 from optical meter reader The difference lies in the position of the meter. If it is positioned between the inverter and the consumer (), it only measures the self-consumption and is therefore the consumption meter. If the counter is installed between the inverter and public grid meter, it will measure the feed-in to the public grid. This must be taken into consideration when configuring the data logger in order to ensure faultless operation. > 6 mm² < 6 mm² S0 from digital meter Analogue meter 4 5

4 If the system size exceeds 0 kwp it is imperative to use a Powador-proLOG XL to be able to implement the inverter dimensioning. Since this data logger can also be used in larger solar parks, you have the possibility of connecting more sensors to the data logger to record the weather conditions. A Modbus TCP / IP interface is also available, to enable the sensors or meters to communicate. System outputs < 0 kwp Designation Item number Description Data logger Powador-piccoLOG 0005 Data logger up to a maximum of / RS485 addresses and an inverter power of 0 kwp Measurement equipment / smart meters Option > 0 kwp ATTO D4 - RS485 measurement equipment - assembly set ph 0009 This packet includes three 70 A current transformers. If the cable diameter including insulation at the measurement point is greater than 9 mm or the current to be measured is above 70 A, the product 005 Plus must be used with the appropriate current transformer. FEMTO D4 - RS485 measurement equipment 005 This product does not include any current transformers. Current transformers must be installed, depending on the installation at the measuring point PV generator Meter reader / counter sensor Counter sensor for optical detection of the counter disk or LED of the analogue counter Current sensors According to local conditions ² FEMTO D4 - current sensors You can find examples HERE If the diameter of the cable including insulation at the measurement point is greater than 9 mm or the current to be measured is greater than 70 A, current sensors must be procured according to local conditions Inverter > 0 kwp Description Item number Description ModBus TCP / IP Powador-proLOG XL inverters Communication via S0 Data logger Powador-proLOG XL Datalogger for up to inverters without power output limitation of the total system. Optionally also available as XL Analogue (700006), XL ISDN (700008) and XL GSM (700007) Meter reader / counter sensor Counter sensor for optical detection of the counter disk or LED of your analogue counter Janitza meter (UMG508) (UMG604 0V) (UMG604 4V) Grid analyser for detecting grid parameters of the system at the transfer point. Communication occurs via Modbus TCP / IP S0 counter TBD TBD MSE Janitza measuring unit Signal from S0 optical sensor Current sensors TBD TBD According to local conditions Digital Modbus TCP / IP meter Signal S0 from digital meter Current sensor >6 mm You can find examples HERE If the diameter of the cable including insulation at the measurement point is greater than 9 mm or the current to be measured is greater than 70 A, current sensors must be procured according to local conditions > 6 mm² Analogue meter 6 7

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