Investigation of the islanding detection of induction generators

Abstract

This paper provides an analysis of the performance of the under/over frequency and under/over voltage relays for islanding detection of squirrel-cage induction generators. This analysis is based on the nondetection zones, which are determined by extensive dynamic simulations using PSCAD/EMTDC. The presented nondetection zones are constructed considering different reactive power compensation and different detection times. Analysis on the nondetection zones is developed, and the influence of the required detection time and of the reactive power compensation on the nondetection zone is highlighted.

Power imbalance application region method for distributed synchronous generator anti-islanding protection design and evaluation

“…In these situations, the NDZs and the shape of the PIAR will be different from the ones presented in this paper, since NDZs are dependent on the DG technology, protection devices and requirements. This can be observed in [16], where NDZs were obtained for induction generators, and in [17,18], which shows NDZs obtained for inverter-based DGs. It is worth mentioning that the accuracy of the PIAR method depends on the system load characterization, because according to [15], voltage dependent loads tend to alter the NDZ shape.…”

“…The non-detection zones of frequency-based relays are areas in the reactive power imbalance versus active power imbalance plan ( Q × P), which define operating conditions that cause the protection devices to fail to detect islanding [15][16][17]. They are strongly dependent on the required islanding detection time, relays types and settings, and type of the distributed generator (synchronous, inverter-based or asynchronous).…”

“…Usually, the implementation of passive techniques is cheaper and simpler than the implementation of communication-based and active schemes. Nevertheless, they tend to have large non-detection zones, if the overall generation meets loads in an islanded system [15,16]. Therefore, one big challenge is how to adjust passive anti-islanding schemes to detect islanding efficiently and to minimize false trip occurrences.…”

“…The new method, called Power Imbalance Application Region (PIAR) is based on the non-detection zone concept [15][16][17], and defines an area in the power mismatch plan (reactive power imbalance versus active power imbalance plan), within which a relay non-detection zone must be located, if both protection requirements should be met. Non-detection zones have been used as an effective technique to evaluate the performance of anti-islanding protection schemes in machine-based [15,16] and inverter-based DG [17,18]. In this work, they are also employed as a method to adjust anti-islanding protection schemes.…”

Metodologias de ajuste das proteções anti-ilhamento de geradores distribuídos considerando múltiplos eventos

“…A análise das proteções de tensão e frequência é estendida para geradores de indução em [50], sendo verificado que o tempo de atuação está associado à compensação de potência reativa do gerador. Além disso, em [51] é verificado o efeito dos compensadores estáticos do gerador de indução na detecção de ilhamento pelas funções de sub/sobrefrequência.…”