• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.335-338
• /
• 2009

In this study, in order to investigate the thermal and electrical properties of ZnO arrester block against 60[Hz] AC voltage, the changes in leakage current were measured. The temperature distribution appearing on the ZnO arrester blocks was observed using a forward looking infrared camera. In particular, the correlation between the thermal and electrical properties of a ZnO arrester block was analyzed experimentally. From this analysis, the thermal phenomena resulting from the heat generation and dissipation of the ZnO arrester block were interpreted. The degradation and thermal runaway phenomena of ZnO arrester block are closely related to the temperature limit of the ZnO arrester block. The installation of an additional metal electrode has resulted in the decrease of the leakage current due to the heat dissipation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.05a
• /
• pp.353-356
• /
• 2007

This paper presents the thermal and electrical characteristics of ZnO arrester blocks under the AC voltages. The leakage currents of ZnO arrester blocks were measured as a function of time. The temperature distributions of ZnO arrester blocks were observed by the forward looking infrared camera The degradation and thermal runaway of ZnO arrester blocks were closely related with the temperature limit of ZnO arrester blocks which decided heat generation and dissipation As a result, the degradation and thermal runaway of ZnO arrester blocks depend on the temperature and leakage current of ZnO arrester blocks.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.10
• /
• pp.82-88
• /
• 2007

This paper presents the thermal and electrical characteristics of ZnO arrester blocks under the AC voltages. The leakage currents of ZnO arrester blocks were measured as a function of the time. The temperature distributions of ZnO arrester blocks were observed by the thermal image infrared camera. The degradation and thermal runaway of ZnO arrester blocks were closely related to the temperature limit of ZnO arrester blocks which being decided heat generation and dissipation. The temperature and leakage current of ZnO arrester blocks were sensitively changed in a resistance of ZnO arrester blocks. As a result, the degradation and thermal runaway of ZnO arrester blocks depend on the temperature and leakage current of ZnO arrester blocks.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.458-459
• /
• 2007

This paper describes the characteristics of lightning impulse current of ZnO block for transmission line arrester with external gap. The ageing parameters of lightning arresters are impulse current, moisture ingress, temperature ageing and so on. Especially it is important to estimate the change of electrical characteristics by impulse current. Total energy applied to the ZnO arrester each time is $4/10{\mu}s$, 30kA and $2/20{\mu}s$, 10kA impulse current. Before and After the test, the residual voltage variation of varistors passed was below 5%. According to the test, it is thought that the ZnO arrester shows good stability with impulse current test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.04b
• /
• pp.61-62
• /
• 2009

This paper describes the characteristics of lightning impulse current of ZnO block for transmission line arrester with external gap. The ageing parameters of lightning arresters ate impulse current, moisture ingress, temperature ageing and so on. Especially it is important to estimate the change of electrical characteristics by impulse current. Total energy applied to the ZnO arrester each time is $4/10{\mu}s$, 30kA and $2/20{\mu}s$, 10kA impulse current. Before and After the test, the residual voltage variation of varistors passed was below 5%. According to the test, it is thought that the ZnO arrester shows good stability with impulse current test.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.05a
• /
• pp.303-306
• /
• 2005

This paper presents the frequency-dependent characteristics of leakage currents flowing through ZnO surge arrester block. The leakage current-voltage (I-V) characteristic curves of the commercial ZnO surge arrester blocks were measured. The resistive leakage current was found to increase with increasing frequency in the low conduction region. The capacitance of ZnO block was independent of the magnitude and frequency of the applied voltage. The power losses of ZnO block increase as the frequency of applied voltage increases, because of the dielectric loss related to the frequency of the test voltage.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.3
• /
• pp.44-50
• /
• 2005

This paper deals with the characteristics and reduction methods of the plasma luminosity caused between the ZnO surge arrester block and metal electrodes. In this study, the impulse current generator that can generate $8/20[{\mu}s]$ impulse currents with a peak short-circuit of 10[kA] is designed and fabricated. Plasma luminosity phenomena for fine and used ZnO blocks were observed as a function of the contact states between the ZnO block and electrodes and the polarity of applied impulse voltages. As a result, discharge luminous events are produced near the contact edges between the ZnO block and metal electrodes. The discharge plasma luminosity between the ZnO surge arrester block and low potential electrode is more intensive than that between the ZnO surge arrester block and high potential electrode. Surface flashover of ZnO blocks are mainly caused by plasma generation near the edge of metal electrode. Also, plasma luminosity for the fine ZnO blocks is less than that for the used ZnO blocks. Plasma luminosity at the contact of the ZnO block and ring-type electrode is more intensive than that at the contact of ZnO block and disk electrode. It is desirable to use the disk electrode with the proper contact area to reduce the plasma luminosity caused at the contact point between the ZnO block and electrodes.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1393-1394
• /
• 2007

This paper presents the thermal characteristics of ZnO arrester blocks under the AC voltage. The leakage currents of ZnO arrester blocks were measured as a function of time. The temperature distribution of ZnO arrester blocks were observed by the forward looking infrared camera. The degradation and thermal runaway of ZnO arrester blocks were related to the temperature of ZnO arrster blocks which depended on heat generation and dissipation. As a result, the degradation and thermal runaway of ZnO arrester blocks are associated with the temperature and leakage current of ZnO arrester blocks.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1869-1871
• /
• 2004

The primary role of ZnO arresters is to protect transmission and distribution equipments against lightning surges. The extremely nonlinear V-I characteristics of the ZnO arrester obviates the need for isolation gaps and consequently it is continuously connected to line voltage. For this reason, ZnO arresters are degraded with increasing with time in actual power systems. In this work, the characteristics of the luminous events between the ZnO block and electrodes were investigated. As a result, the luminous events were effected by the impulse and the near polarity of the luminous event was intense near the grounded electrode. Also the luminous event may cause the degradation of ZnO arrester block.

• Proceedings of the KIEE Conference
• /
• 2004.11a
• /
• pp.26-28
• /
• 2004

The primary role of ZnO arresters is to protect transmission and distribution equipments against lightning surges. The extremely nonlinear V-I characteristics of the ZnO arrester obviates the need for isolation gaps and consequently it is continuously connected to line voltage. For this reason, ZnO arresters are degraded with time in actual power systems. In this work, the characteristics of the luminous events caused between the ZnO block and electrodes according to the electrode area were investigated. As a result, the luminous events were effected by electrode area and the longer electrode areas were increased, the more luminous events were decreased. Also the reduction of luminous events was fumed up to the degraded ZnO arrester block.