A new family of active antiislanding schemes based on DQ implementation for grid-connected inverters

Abstract

Unintentional islanding protection of distributed generation is a key function for standards compliance. For those distributed generations that use an inverter as grid interface, the function can be implemented as part of the inverter control. Existing anti-islanding schemes used in inverters have power quality and non-detection zone issues. This paper proposes a new family of schemes that have negligible power quality degradation and no non-detection zone. Design guidelines based on frequency-domain analysis is also provided. Finally, both simulation and experimental results validate the proposed schemes. 1.0-7803-8399-0/04/$20.00 8 2 W IEEE.

An Active Anti-Islanding Method Based on Phase-PLL Perturbation

“…The power factor is almost not affected by the anti-islanding method. Table 3 shows a comparison of the trip time in the inverter under study with several active anti-islanding methods presented in the literature [25], [50]. …”

“…Among the active techniques, the following can be pointed out: Impedance measurement [11], [16], [17], Harmonic injection/detection of impedance [18], Sliding Mode Frequency Shift (SMS) [19], [20], Active Frequency Drift (AFD) [11], [19], [20], Frequency jump [11], [21], Sandia Frequency Shift (SFS) Sandia Voltaje Shift (SVS) [11], [19], [22], [23], [26], Mains Monitoring Units with Allocated All-pole Switching Devices Connected in Series (MSD) [11], Variation of active power and reactive power [10], [24], [25], [26], and General Electric Frequency Schemes (GEFS) [20], [25].…”

Islanding Detection Method for Multi-Inverter Distributed Generation

“…Table 3 shows the simulation results for the time needed for the islanding confirmation (T IC ) in a system with 3 DG units operating at unity power factor. In this case, we consider different conditions of active power mismatch (12) between the DG and the load. …”

“…Positive feedback with d-q current control based family of islanding detection methods is presented in [12] and [13]. These methods consider the relation between the active (P) and reactive (Q) powers with the voltage magnitude (V) and frequency (f) as shown in (4) and (5), and the effects of current magnitude and angle deviation on the output active and reactive powers.…”

Rewiew of Local and Remote Techniques for Islanding Detection in Distributed Generators

“…However, the method has a high probability of interference with other devices including the grid itself. [10], [25], [26], [27]. This method is based on the ability of the inverter to generate independently both active and reactive power.…”