Primary system:

132 double busbar switching station at MVM ÉMÁSZ (Hungarian DSO) territory:

• 3 pcs. 132 kV transmission line bays;
• 2 pcs. transformer bays: solar power plants connections;
• 1 bus-coupler bay.

Solar power plants:

• 1-1 pcs. 132/22 kV 25MVA power transformer;
• 3-3 pcs. medium voltage feeder bays;
• 8-8 external 22/0.8 kV transformer stations for PV inverter connections;
• PV inverters and PV panels.

The substation automation system (SAS) of the MVM ÉMÁSZ switching station is completely independent from the subsystems. The transmission lines are protected by redundant main protections (main-one and main-two) with line differential and distance protection functions. Distributed low-impedance busbar protection system is applied to protect the 6 bays in double-busbar arrangement. The substation automation and control were put into operation with Protecta EuroProt+ bay unit units and Prolan Power substation gateway with local HMI and engineering workstation in accordance with IEC 61850 communication standard.

The primary and secondary system designs of the two PV plants are completely identical. The 132/22 kV 25 MVA power transformers are protected by doubled differential protection relays and the medium voltage bays are equipped with main and local-backup feeder protection devices. In compliance with the Hungarian regulations, which prohibits island operation, a dedicated protection relay was applied islanding detection for each solar power plant. The substation automation system (SAS) of the MVM ÉMÁSZ switching station is completely independent from the subsystems.

The SAS of the two PV plant stations are independent from each other and from the 132 kV MVM ÉMÁSZ substation. In this case, too, the technical control system was created with a Prolan Power head unit and a local display, field machines manufactured by Protecta. In this case, again, the SAS was put into operation with Protecta EuroProt+ bay control units and Prolan Power substation gateway with local HMI.

There are 8 external transformer stations per solar park to connect to the 22 kV voltage level. Protecta bay control unit was integrated into each external transformer station to provide switchgear data to Prolan Power gateway, which is also independent of the other systems.

Furthermore, the so-called smart loggers are also part of the system; their role is to process and transmit data to the substation gateways provided by the PV inverters as well as controlling the inverters. These have been involved in the communication system integration.