ABSTRACT:
This paper
presents the analysis and comparison of the main active techniques for
islanding detection used in grid-connected single phase inverters. These
techniques can be divided into two classes: techniques introducing positive
feedback in the control of the inverter and techniques based on harmonic
injection by the inverter. The algorithms mentioned in this work are simulated
in PSIMTM in order to make a comparative analysis and to establish their
advantages and disadvantages according to IEEE standards.
KEYWORDS:
1. Single phase inverter
2. Active Islanding Detection Methods
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.1.
Block diagram of the developed inverter
EXPECTED SIMULATION RESULTS:
Fig.
2. (a) Active power injection. PCC voltage, RMS Voltage and islanding
detection. (b) Reactive power injection. PCC voltage, frequency and islanding
detection.
Fig. 3. GEFS. PCC voltage, frequency and
islanding detection.
Fig. 4. Impedance detection. PCC voltage and
islanding detection.
CONCLUSION:
In this paper was presented an analysis
of various active methods resident in the inverter for islanding detection in
single phase inverters. It became evident that for the same test conditions as
established by the IEEE 929 all methods met, however the positive feedback
based methods have a longer trip time that those based on harmonic injection
because positive feedback methods should reach the threshold of UOV or UOF, whereas
methods based on harmonic injection what is sought is to detect variations in
the impedance of the grid, which allows to work with smaller detection
thresholds. On the other hand, despite these methods are based on disturbing
the system and degrading the power quality, their effect is not significant and
they are within the harmonic distortion limits set by standards.
REFERENCES:
[1] M, Pietzsch, “Convertidores CC/CA para la conexión directa a
red de sistemas fotovoltaicos: comparación entre topologías de 2 y 3 niveles,”
Bachelor thesis, Universidad Politécnica de Cataluña, España, Dec. 2004.
[2] V. Task, "Evaluation of islanding detection methods for
photovoltaic utility-interactive power systems," Tech. Rep. IEAPVPS
T5-09:2002, March. 2002.
[3] P. Mahat, C. Zhe and B. Bak-Jensen, “Review of islanding
detection methods for distributed generation,” in Third International
Conference on Electric Utility Deregulation and Restructuring and Power
Technologies, 2008, pp.2743-2748.
[4] Mohan, N., Underland, T.M.& Robbins, W.P. 2003 Power
electronics: converters, applications, and design. 3th ed. International. John
Wiley & Sons.
[5] T. Esram and P.L.
Chapman, “Comparison of Photovoltaic Array Maximum Power Point Tracking
Techniques,” Energy Conversion, IEEE Transactions on , vol.22, no.2,
pp.439-449, June 2007.
