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3/31/20171
ELECTRICAL AND ELECTRONICS
DEPARTMENT
AMRITA SCHOOL OF ENGINEERING,
ETTIMADAIPRESENTED BY:
MINU YACOB-RET16010
Anti-islanding Detection for Grid
Connected Solar Photovoltaic system
GUIDED BY,
Dr A
VIJAYAKUMARI
ISLANDING
The continued operation of a Distributed generator (DG)
even when the electric utility is absent,
- Unintentional islanding
- Intentional islanding
Effect of Islanding
- hazard for utility line-workers.
- DG being a limited capacity source – entire utility
load come on it - The DG protection will be triggered
- Reclosing into an island may result in damaging
the DG equipment, because of out of-phase
closure.3/31/20172
ANTI-ISLANDING GRID
STANDARDS
IEEE 1547-2003: 4.4.1-For an unintentional island in
which the DR energizes a portion of the Area EPS through
the PCC, the DR interconnection system shall detect the
island and cease to energize the Area EPS within two
seconds of the formation of an island. [1]
The IEEE Std. 1547 and UL 1741 provide thresholds on
the amount of acceptable voltage and frequency deviation.
Thresholds on voltage deviations are in the range of 88% to
110% of the nominal voltage value [2].
3/31/20173
ANTI-ISLANDING TECHNIQUES
3/31/20174 source-[4]
FIG:1
3/31/20175
COMPARISON OF ANTI-ISLANDING
TECHNIQUES• DETECTION TIME
• PARAMETERS TO BE MONITORED
• NON DETECTION ZONE
The NDZ is the range of local loads for which the
islanding prevention method can be made to fail to detect
islanding.
When the utility disconnects, if Pload =PDG, change in the
amplitude or frequency of voltage will be insufficient to
activate any of the standard over/under voltage or
frequency protection devices.
PASSIVE ANTI ISLANDING DETECTION
• Active power is directly proportional to the
voltage.
• When PDG > Pload there is an increase of the
amplitude of the voltage
• if PDG < Pload there is a decrease of the
amplitude of voltage
Pload =PDG+∆P
Qload = QDG +∆Q
3/31/20176
Source-[5]FIG-2
OVER-UNDER VOLTAGE DETECTION
METHOD
3/31/20177
IMPLEMENTATION OF OVER-UNDER VOLTAGE
DETECTION METHOD
CASE 1- 5kW Load(PDG>Pload)
3/31/20178
Power rating of pv system-59.5 kW
Power rating of the load-5kW
Circuit Breaker opening time-.6s to .8s
CASE 1- ACTIVE POWER FLOW
3/31/20179
VOLTAGE AND CURRENT AT PCC
3/31/201710
Case 2-120kW LOAD(PDG<Pload)
3/31/201711
Power rating of pv system-59.5 kW
Power rating of the load-120kW
Circuit Breaker opening time-.6s to .8s
CASE 2-ACTIVE POWER FLOW
3/31/201712
Case 2– VOLTAGE AND CURRENT
AT PCC
3/31/201713
59.2 kW LOAD – VOLTAGE AND
CURRENT AT PCC
3/31/201714
CONCLUSION
3/31/201715
OV/UV passive islanding detection method failed to
detect islanding when the Pload matches the PDG.
The chances of detection of islanding using OV
method is less compared to UV because the change in
voltage during islanding is less.
REFERENCE [1] IEEE Std 1547-2003, Standard for Interconnecting
Distributed Resources with Electric Power Systems,
IEEE, 2003.
[2] Static inverter and charge controllers for use in
photovoltaic systems , UL 1741, Underwriters
Laboratories, Inc., 2001, Std. UL . stems
[3] Francesco De Mango', Marco Liserre, Antonio
Dell'Aquila and Alberto Pigazo Overview of Anti-
Islanding Algorithms for PV Systems. Part I: Passive
Methods. 2006 IEEE.
[4] K. O. Samaroo, “Methodology of Selection, Setting
and Analysis ofAnti-Islanding Protection for
Distribution Generation System,”University Of
Guyana, Department of Electrical Engineering, 2012.3/31/201716
3/31/201717
[5] M. Hanif, M. Basu ,K.Gaughan ‘A Discussion
of Anti-islanding Protection Schemes
Incorporated in a Inverter Based DG’ 2011 IEEE