Proposed Title: Grid Tied Battery Energy Storage Systems Smart Controllers
Submission Type: Project
Author: Sherif Abdelrazek
Major:Electrical Engineering
Author Conact Information:
email: [email protected]
Faculty Advisor: Dr. Sukumar Kamalasadan
Advisor Contact Information:
Education Level: PhD Student
tel:704-773-9011
University: The University of North Carolina in Charlotte
email:[email protected]
tel: 704-687-7099
I. INTRODUCTION
The applications in which energy storage systems can be used hold considerable value to energy producers, grid
operators and in turn, energy consumers. Battery Energy Storage Systems’ (BESS) technology (out of different energy
storage technologies) is suitable for applications that improve dynamic stability, transient stability, voltage support
[3], area control/ frequency regulation, transmission capability [4, 5] and power quality. These characteristics are
suitable for performing the intended applications of this project. These applications include electric energy time shift
(ETS), voltage support, and renewable capacity firming [1, 2].
II. METHODOLOGY
The project setup consists of the BESS connected in conjunction with a 1MW PV station. The PV station is
controlled to operate at unity power factor. The battery capacity is 0.25 MW and the inverter capacity 1MVA. Fig. 1
shows the regions of ESS controllability. The studied control scheme relies on using an inverter with a relatively high
capacity compared to that of the battery. This capacity difference is used for reactive power dispatch to allow voltage
support capability.
Maximum ESS
Inverter Apparent
Power Capacity
Q-Axis
2nd Quadrant
P-Sink
Q-Source
Cap
cm
PESS+jQ ESS
ESS
PESdmS+jQ Cap
Q ESS
axC
dm
S PCC
Cap
x
ma
P PV
p
Ca
ES
+jQ
A1
A2
A3
A4
S
dm
S
ES
+P
1st Quadrant
P-Source
Q-Source
cm
PESS
dm
PESS
3rd Quadrant
P-Sink
Q-Sink
ESS
QInd
ESS
Ind |
dm
|Q ESS
PESS-j
PEScmS-j|Q Ind
|
QPV=0
P-Axis
max
PPV
PP max S dm
ax
V+
PE dm PCC I
SS j|Q In
d
ES
S |
4th Quadrant
P-Source
Q-Sink
Fig. 1 ESS active and reactive power supplying capabilities.
Voltage Support
VPCC ,δ PCC
VSS , δSS
Reactive Power
Calculation
PV Station
(1MW-1.25MVA)
Reference
Reactive Power
(QESSr)
Substation
Test Feeder
SMS
(1MVA)
Max Charge Rate
Time of Day
(ToD)
Feeder
Load
Peak Load
Detector
Memory
Max Discharge Rate
Idle
Energy
Calculations &
Logic
Energy Time Shift
SoC
Real-Time PV Active Power O/P
PPV
PPV
Memory
Data
Conditioning
+
PC
Hard
Limiter
POPR-
Reference Active
Power (PESSr)
Zero
Selector
SoC
Rate
Limiter
-
Logic
+
Intermittency Detection
TPVst & TPVend
Calculation
Historical PV Output Data
PV Station Capacity Firming
Logic
Time of Day
(ToD)
Fig. 2 Block diagram schematic for PV station capacity firming, energy time shift and voltage support applications.
Area A1 in Fig. 1 shows the ESS power capability. This is also the power output region for zero active power output
from the PV station installed at the point of common coupling (PCC). As the PV station output increases, the
controllable region is shifted to the right till it becomes A2 at maximum (PV) output. A4 shows the control regions
used during PV station capacity firming (PVCF) application.
III. SIMULATION RESULTS
A. PV Capacity Firming
Fig. 3 shows results for PVCF
(a)
(b)
(c)
Fig. 3 PVCF simulation results without SoC constraint. (a) PV power output compared to OPR. (b) BESS output power with battery SoC plotted
on the second y-axis. (c) PCC active power output after PVCF compared to PV power output.
B. Combined PVCF & ETS for a Single Day
As shown in Fig. 4. After performing PVCF with maximization of SoC taken into account, the remaining energy in
the battery (95% SoC) was sufficient to allow effective peak load shifting.
Fig. 4 PV station, PCC & substation active power outputs, feeder load and battery SoC during PVCF & ETS applications with SoC constraint
C. Voltage Support
Fig. 6 shows the results of voltage support
(a)
(b)
Fig. 5 Feeder loads and generation. (a)Active power output of substation & ESS, plotted with feeder active power load. (b)Reactive power output
of substation & ESS, plotted with feeder reactive power load
Fig. 6 Voltage profile at PCC with and without ESS voltage support application.
IV. CONCLUSION
The devised algorithms were found efficient in performing their respective purposes.
V. REFERENCES
[1]
[2]
[3]
[4]
[5]
Ribeiro, P. F., Johnson, B. K., Crow, M. L., Arsoy, A., & Liu, Y. (2001). Energy storage systems for advanced power applications. In
Proceedings of the IEEE (Vol. 89, pp. 1744–1756). doi:10.1109/5.975900
Teleke, S., Baran, M. E., Huang, a Q., Bhattacharya, S., & Anderson, L. (2009). Control Strategies for Battery Energy Storage for Wind Farm
Dispatching. IEEE Transactions on Energy Conversion, 24, 725–732. doi:10.1109/tec.2009.2016000
W. R. Lachs and D. Sutanto, “Battery storage plant within large load centers,” IEEE Trans. Power Syst., vol. 7, pp. 762–769, May 1992.
M. A. Casacca, M. R. Capobianco, and Z. M. Salameh, “Lead-acid battery storage configurations for improved available capacity,” IEEE
Trans. Energy Conversion, vol. 11, pp. 139–145, Mar. 1996.
N.W. Miller, et.al., “Design and commissioning of a 5 MVA, 2.5 MWh battery energy storage,” in Proc. 1996 IEEE Power Engineering
Society Transmission and Distribution Conf., 1996, pp. 339–345.