We have built a medium scale storage unit (170kW, 450 kWh) for the demonstration of its flexible and robust use in diverse applications. This battery energy storage system BESS will first operate connected to 1x 400 kVA OLTC MV/LV transformer station of Elektro Gorenjska supplying Suha village residential grid. In the second demo case, storage unit will be connected to LV industrial grid in Elektro Gorenjska headquarters in Kranj. Since September 2018 the BESS is operational in the first location, Suha.
The Battery Energy Storage System BESS consists of 1 metal enclosure container that embodies the Power Conversion Unit PCU, the Battery Bank Unit BBU, HVAC and system control – PLC.
The first demonstration is already taking place in rural residential area of Suha village, where storage operates from August 2018 onwards.
The second demonstration will take place in Elektro Gorenjska headquarters, where no special construction activities are foreseen.
The only construction activities at both demo sites will be the simple placement of the container near existent transformer stations and the connection to network grid.
Medium scale unit connected to low voltage substation in residential grid
Demonstration of flexible and robust use of medium scale storage unit connected to low voltage substation in TS Suha residential grid is the main purpose of this EG demo case. TS Suha LVN with 7 PV power plants and energy flow in both directions (LVN acting as a regular consumer and as energy source for MV network due to PV production) offers demonstration of variety of project goals as follows:
Medium scale storage unit connected to low voltage substation in industrial grid.
In industrial demonstration case, battery energy storage unit will be situated near the transformer station supplying EG headquarters. It will have two major connections with the adjacent transformer station:
All measurements required for demonstration will be collected on 1 minute period at EG Power Quality server and for the purpose of the Story project accessible at project local SCADA system.
Responsible partners: Elektro Gorenjska and ABB
“Storage as an important near future smart grid device needs to be thoroughly tested to prove technical acceptance and as well as for exploring the acceptable business model.”
Marjan Jerele, Elektro Gorenjska
A number of power network analysers are already installed within the network for the on line monitoring and control purposes (data is registered per one minute time period). LVN single line diagram also shows the installed network power analyser locations. Recently there are 9 fully monitored and data registered locations:
Transformer station
7 PV locations
2 households
EG headquarters with the variety of installed electrical devices will serve as a test bed for connection of medium scale storage unit in the industrial grid. The following apparatus are comprised within the EG premises:
Photovoltaic power plant
Cold storage (Ice bank) within the heating / cooling facility
27 kW combined heat and power unit
2x 630 kVA transformer station
80 kW diesel generator
The following technologies are installed:
2 x 630 kVA transformer station
35 kW photovoltaic power plant
27 kW combined heat and power unit
80 kW diesel generator with network synchronization capabilities and the possibility of adjusting the amount of emitted power
Ice bank within the heating / cooling facility
Demonstration of flexible and robust use of medium scale storage unit connected to low voltage substation in TS Suha residential grid and EG headquarter industrial grid is the main purpose of this EG demonstration cases. TS Suha LVN with 7 PV power plants and energy flow in both directions ( LVN acting as a regular consumer and as energy source for MV network due to PV production ) and as well as industrial demo case offers demonstration of variety of project goals as follows:
Ease of integration in existing infrastructure (including interoperability)
Control and battery management system and its cooperation with the devices in the system (in this case the transformer station and PV units)
A high degree of transformer station self sufficiency
Ensuring maximum efficiency in decentralised energy production
Potential in supporting the regime of the PV production
Impact on efficiency (and thus return of investment) of complete system
High degree of self-sufficiency of battery combination and PV production could deliver
Reliability in the event of blackouts
Peak demand control within the daily load diagram
Reduction of line congestion
Voltage control
For second demonstration case, storage unit will be connected into EG headquarters industrial LV network. Suha village LVN is an example of a 0,4 kV rural cable network ( no overhead lines ) with high penetration of PV generation. The cable network topology and positions of PV and 20/0,4 kV MV/LV transformer station.
