A Single-Phase High-Impedance Ground Faulty Feeder Detection Method for Small Resistance to Ground Systems Based on Current-Voltage Phase Difference.

At present, the small resistance to ground system (SRGS) is mainly protected by fixed-time zero-sequence overcurrent protection, but its ability to detect transition resistance is only about 100 Ω, which is unable to detect single-phase high resistance grounding fault (SPHIF). This paper analyzes the zero-sequence characteristics of SPHIF for SRGS and proposes a SPHIF feeder detection method that uses the current-voltage phase difference. The proposed method is as follows: first, the zero-sequence current phase of each feeder is calculated. Second, the phase voltage root mean square (RMS) value is used to determine the fault phase and obtain its initial phase as the reference value. The introduction of the initial phase of the fault phase voltage can highlight the fault characteristics and improve the sensitivity and reliability of feeder detection, and then CVPD is the difference between each feeder ZSC phase and the reference value. Finally, the magnitude of CVPD is judged. If the CVPD of a particular feeder meets the condition, the feeder is detected as the faulted feeder. Combining the theoretical and practical constraints, the specific adjustment principle and feeder detection logic are given. A large number of simulations show that the proposed method can be successfully detected under the conditions of 5000 Ω transition resistance, -1 dB noise interference, and 40% data missing. Compared with existing methods, the proposed method uses phase voltages that are easy to measure to construct SPHIF feeder detection criteria, without adding additional measurement and communication devices, and can quickly achieve local isolation of SPHIF with better sensitivity, reliability, and immunity to interference.

Evidências de validade do Zulliger-SC para avaliação do relacionamento interpessoal de crianças / Evidence of validity of Zulliger-SC to the assessment of children's interpersonal relationship / Evidencias de validez de la prueba de Zulliger-sc para la evaluación de relación interpersonal de niños

Objetivou-se examinar evidências de validade de critério para o teste de Zulliger-Sistema Compreensivo (ZSC), tendo como foco os indicadores de relacionamento interpessoal. 119 crianças, de ambos os sexos, do quarto ao sexto ano do ensino fundamental, responderam a um sociograma para a seleção de dois grupos de participantes: o primeiro contendo 26, classificadas como mais populares e 22 classificadas como menos populares. Esses dois grupos responderam ao ZSC. Considerou-se para a análise as seguintes variáveis: M, FM, m; a e p; COP e AG; GHR e PHR; FT, TF e T; Food; PER; PureH, SumH e Índice de Isolamento. Os indicadores, mais frequentes nas crianças mais populares com diferenças estatisticamente significativas, foram Mp (p=0,04), p (p=0,05) e marginalmente significativa PureH (p=0,06). No grupo de crianças menos populares a maior frequência estatisticamente significativa foi H<(H)+Hd+(Hd) (x²=4,16, p=0,04). Conclui-se que quatro variáveis contribuíram para discriminar os grupos, o que evidencia validade de critério.

This study aimed to examine criterion validity evidence for ZSC, focusing on interpersonal relationships indicators. 119 primary school children of both sexes from the fourth to the sixth year responded to the sociogram which allowed to select two groups of participants: the first containing 26 classified as the most popular and 22 classified as less popular. These two groups responded to the ZSC. The analysis considered: M, FM, m; a, p; COP, AG; GHR, PHR; FT, TF, T; Food; PER; PureH, SumH and Index Isolation rates. The indicators that showed statistically significant differences, higher among the most popular children, were Mp (p=0.04), p (p=0.05) and PureH (p=0.06) marginally significant. In the less popular group the highest statistically significant was H<(H)+Hd+(Hd) (x²=4.16, p=0.04). In conclusion, four variables contributed to discriminate groups, which contributes to demonstrate criterion validity.

El objetivo del trabajo fue examinar evidencias de validez de criterio para el test ZSC, cuyo foco fueron los indicadores de relacionamiento interpersonal. 119 niños de ambos sexos, del cuarto al sexto año de educación primaria, respondieron al sociograma lo que permitió la selección de dos grupos de participantes: el primer contiene 26 clasificados como los más populares y el otro 22 clasificados como menos populares. Estos dos grupos respondieron a el ZSC. Se consideraron para el análisis los indicadores: M, FM, m; a e p; COP e AG; GHR e PHR; FT, TF e T; Food; PER: PureH, SumH e Índice de Aislamiento. Aquellos que revelaron diferencia estadística significativa, con mayor frecuencia entre los niños más populares fueron: Mp (p=0,04), p (p=0,05) y PureH (p=0,06) fue marginalmente significativa. En el grupo de niños menos populares la mayor frecuencia fue: H<(H)+Hd+(Hd) (x²=4,16, p=0,04). Se concluye que cuatro variables contribuyeron a discriminar grupos, lo que demuestra su contribución para la evidencia de validez de criterio.