特高压CVT的选型对运行可靠性的影响

随着电压等级的提高,电容分压器节数增多,受运行条件的影响也加大,选型对保证1000kVCVT的正常工作至关重要。选型不当,可加剧CVT受运行条件的影响,甚至不能正常运行。为避免此情况,需选用的CVT电容分压器阻抗比对运行条件不敏感,特别是分压器低压臂阻抗受运行条件的影响要小。基于这点,分析1000kV分体式CVT和一体式CVT在运行中受运行条件的影响大小是十分必要的,否则,将给1000kVCVT的正常运行带来十分不利的影响。

Type Selection and Operation of 1000 kV Capacitor Voltage Transformer

Capacitor voltage transformer (CVT) decreases the voltage with capacitance bleeder, and complete the work that convert high voltage to low voltage with electromagnetic unit. The low voltage is just what the measurement, protection and monitoring needs. With the increase of the voltage grade, the pitch number of capacitance bleeder increase accordingly, so that the impact of operation conditions on the capacitance bleeder is also strengthened. So in order to guarantee work normally, the type selection of CVT is essential. Otherwise, the improper selection of type will aggravate the influence of operation conditions to CVT, even cause CVT can't operate normally. In order to avoid this, it's the most important thing that reducing the change of impedance rate of capacitance bleeder because of the change of operation conditions as much as possible, especially, the change of impedance of low voltage arm of bleeder because of the change of operation conditions should be avoided. Based on this, operation conditions have great different impact on 1000kV detachable CVT and integrated CVT. When selects the type of CVT, if don't realize this, it will bring very unfavorable influence to the normal operation of 1000kVCVT. So, once the type selecting of the equipment is improper which will cause that it's difficult to guaranteeing the running quality of 1000kV CVT. In order to avoid the emergence of this situation, operation state of CVT with different structure is been analysed in this paper, which is for 1000kV equipment selecting type to consult.