| 连接于变压器中性点与大地之间的一种限流电气保护设备,在电网正常运行时不工作,当电网线路出线故障时,变压器中性点电压将产生偏移,如果变压器中性点接有接地电阻装置,它可以将配电网中性点强制接地,并限制其故障电流,使继电保护设备有足够的时间进行检测,实现跳闸和备用切换,避免配电网和电气设备遭到破坏.
Connection between transformer neutral point and the earth a current-limiting electrical protection equipment, don't work in the normal operation of power grid, when a fault line qualification, transformer neutral point will produce offset voltage, if transformer neutral point grounding resistance device, it can be distribution network neutral point grounding compulsory, and limiting the fault current, make the relay protection device has enough time for testing, realize the trip and the standby switch, avoid the distribution network and electrical equipment damage.
电阻柜采用不锈钢、镍铬合金(Cr20Ni80)或铁铝铬钛合金制作.阻值稳定:电阻温度系数2.17×10-4Ω℃(电阻温度系数至315℃为0.000225/C,至426℃为0.000249/C,至537℃为0.000283/C,至648℃为0.000313/C),确保了保护的灵敏度.在1000℃高温下能保持良好的抗氧化性能,能适用于污染严重的环境.高温下拥有良好的韧性,不变质,不易断裂,使用寿命长(承诺30年).抗拉强度高,能有效抵制电动力的作用.熔点高达1500℃,短时允许温升为760℃,持续允许温升385℃.合理的散热结构,电阻元件采用栅格结构,具有最佳的冷却气流通道,避免了局部高温点与易灼烧点.
Resistance ark of stainless steel, nickel chromium alloy (Cr20Ni80) or iron chromium aluminum titanium alloy production. Resistance stability, temperature coefficient of resistance Ω 2.17 x 10-4 ℃ (temperature coefficient of resistance to 315 ℃ for 0.000225 / C, and 426 ℃ for 0.000249 / C, and 537 ℃ for 0.000283 / C, and 648 ℃ for 0.000313 / C), to ensure that the sensitivity of protection. Under the high temperature of 1000 ℃ can keep good oxidation resistance, can apply to the serious environmental pollution. The heat with good toughness, not bad, not easy fracture, long service life (commitment to 30 years.) high tensile strength, can effectively resist the effect of electric power. Melting point 1500 ℃, short time allows the temperature to 760 ℃, continue to allow temperature 385 ℃. The reasonable structure of heat dissipation, resistance element USES the grid structure, has the best cooling air flow channel, to avoid the local high temperature point and burning point. |