| 发电机在运行中,发生单相接地是最常见的故障,其故障点出现电弧接地时会进一步扩大定子绕组绝缘损害甚至铁芯灼伤烧结,如不及时发现并快速切除故障,将发展成为相间或匝间短路。基于上述原因,采用发电机中性点高阻接地与电阻柜相结合,以限制接地电流,防止各种过电压的危害。中性点通过电阻器接地和电阻柜可以把故障电流限制到适当值,提高继电保护的灵敏度作用于跳闸,同时又使故障点仅可能发生局部轻微灼伤,把暂态过电压限制到正常线电压对中性点电压的2.6倍,限制电弧的重燃,防止弧光间隙过电压损坏主设备,同时可有效防止铁磁谐振过电压,从而保证电阻柜中的发电机可以安全并正常运行。
Single-phase grounding in the operation of the generator in, is the most common fault, the fault point in arc grounding will further expand the stator winding insulation damage core burn sintering, even if not found in time and rapid removal of the fault, and will become or interturn short circuit. Based on the above reasons, the combination of high resistance grounding and resistance cabinet in generator is used to limit the grounding current and prevent all kinds of overvoltage. Neutral point grounding through the resistor and resistance ark can limit the fault current to the appropriate value, improve the sensitivity of relay protection on the trip, and also make the point of failure may occur only local minor burns, the transient overvoltage limit to 2.6 times that of the normal line voltage on the neutral point voltage and restrict arc renewed, prevent damage of gap arc over-voltage master device, which can effectively prevent ferroresonance overvoltage at the same time, to ensure the resistance generator can be safe and normal operation of the cabinet.
当前,很多行业对于过电压保护器都有特别的要求,而过电压保护器为一种新型的保护设备,通常主要用于对发电机、变压器、真空开关、电动机等电气设备的绝缘保护,免受过电压对设备仪器造成的损害。电阻柜一方面使继电保护有足够的灵敏度和选择性,同时又使故障点仅可能发生局部轻微损伤,把暂态过电压限制到正常线对中性点电压的26倍以下,防止电弧重燃,避免电弧接地过电压损坏主设备,扩大事故。另一方面由于电阻的阻力对防止铁磁谐振过电压有显着作用。
At present, many industries have special requirements for over-voltage protector, and over-voltage protector for a new type of protection device, usually is mainly used for the generator, transformer, vacuum switch, motor, electrical equipment, such as insulation protection, from the overvoltage of equipment instrument damage. Resistance ark on the one hand, the sensitivity and selectivity of relay protection has enough, at the same time, make the point of failure only mild local damage can occur, limit the transient over-voltage 26 times the normal to the line to neutral voltage, prevent arc reigniting, avoid arc grounding overvoltage damage of main equipment, enlarge the accident. On the other hand, the resistance of the resistance to the ferromagnetic resonance is shown to be effective. |