Battery Storage Aided Grid
Connection PV Power Plants
Typical Structure of a Grid Connected Large PV Power Plant
~
=
PCC
10 kV
Grid
~
L
=
BT
AC Transmission
Line
110 kV
~
=
~
=
Plot 1: 80 x PV.250
Plot 2: 80 x PV.250
Plot 3: 80 x PV.250
Plot 4: 40 x PV.500
 80 MW
Battery Storage Aided Grid Connection of PV Power Plants
AC Transmission
Cables
BT: Step-Up Transformer
2
Attributes of Grid Connected Large PV Power Plants
Generation profile differs from load profile
 Load shifting required
•
Specific generation maximum at noon
 Peak shaving required
•
Requires Electrical Energy Storage (EES)
Requires EES
Rolling clouds lead to sudden voltage drop and rise
 Peak shaving and injection of reactive power required
•
Requires EES
DSO / TSO desires / requires conventional power plant properties
 LV fault ride through capability 
 Fault current capability
Can be improved by EES
 Participation in primary control (provision of positive and negative
Requires EES
active power)
 Provision of positive or negative reactive power 
Battery Storage Aided Grid Connection of PV Power Plants
•
Can be improved by EES
Strong Demand for a Short Term
Electrical Energy Storage System
3
Option: Battery Storage Aided Grid Connection
~
=
PCC
10 kV
Grid
~
=
L
BT
AC Transmission
Line
110 kV
~
=
~
=
=
~
Battery Energy Storage
System BESS
Battery Storage Aided Grid Connection of PV Power Plants
AC Transmission
Cables
BT: Step-Up Transformer
4
Option: Battery Storage Aided Grid Connection
Modbus et al.
IEC 61850
DSO
Grid
SC.500
~
10 … 30 kV
=
SC.Ctrl
SC.Log
~
=
BMS
Grid
SC.500
Battery Container
TKS-SC 1000
~
=
PV.Ctrl
PCC
Connection to 110 kV or
other voltage possible
(add. Transformer req.)
PV.500
PV Power Plant
Battery Storage Aided Grid Connection of PV Power Plants
Power-Plant.Ctrl
PV.Log
~
=
PV.500
TKS-C 1000
5
Battery Energy Storage System BESS – Detailed Prototype Layout
Battery Storage Aided Grid Connection of PV Power Plants
6
BESS – Prototype Layout of Storage Converter
TKS-SC.1000
Inverter Cabinet
Battery Storage Aided Grid Connection of PV Power Plants
Inverter Cabinet + AC / DC Cabinet
7
BESS – Prototype Layout of Battery Container
Battery Container (Example)
Picture Credit: Hoppecke
Positioning and Connection of Batteries
Battery Storage Aided Grid Connection of PV Power Plants
Battery Container (Example)
Picture Credit: Hoppecke
Picture Credit: Hoppecke
8
Battery Technology
•
Electrodes: Tubular lead plates
•
Electrolyte: Diluted sulphuric acid
•
Mature technology, operated at room temperature
•
High degree of standardization
•
Many suppliers on the market, globally available
•
Nominal cell voltage: 2 V
•
Energy density 25 Wh/kg (gravimetric) or 75 Wh/l (volumetric)
•
Efficiency 80 – 90 %
•
Lifetime 6 – 12 years resp. 2000 – 7000 cycles
•
Invest: 100 – 25 EUR/kWh, Renting / Leasing possible => 0 EUR/kWh
Picture Credit: Hoppecke
Battery Storage Aided Grid Connection of PV Power Plants
Lead – Acid (Pb) Batteries
9
Battery Technology
Battery Storage Aided Grid Connection of PV Power Plants
10
Control and Communication Systems
Modbus et al.
IEC 61850
DSO
Grid
SC.500
~
10 … 30 kV
=
SC.Ctrl
SC.Log
~
=
BMS
Grid
SC.500
Battery Container
TKS-SC 1000
~
=
PV.Ctrl
PCC
Connection to 110 kV or
other voltage possible
(add. Transformer req.)
PV.500
PV Power Plant
Battery Storage Aided Grid Connection of PV Power Plants
Power-Plant.Ctrl
PV.Log
~
=
PV.500
TKS-C 1000
11
Control and Communication Systems
SC. Control
SC. Log
Power Utility Bus
Ethernet
BMS
Battery Storage Aided Grid Connection of PV Power Plants
BESS Control /
Power Plant Control
12