水轮发电机ZnO-SiC混合阀片灭磁电阻研究

De-Excitation Resistance of ZnO-SiC Hybrid Valve Plate of Hydrogenerator

随着水轮发电机装机容量的不断增加,为电磁感应提供磁场的励磁电流也不断增加,在系统发生故障时,发电机组的迅速、安全、可靠灭磁,已成为一个亟待解决的课题。本研究采用电磁暂态分析软件ATP-EMTP建立了水轮发电机灭磁仿真模型,随后仿真分析了氧化锌灭磁电阻的灭磁性能,研究发现,氧化锌电阻片虽然可以快速灭磁,但是参数不同的电阻片能量吸收严重不均匀,这极有可能导致系统热崩溃等问题。针对上述问题,笔者提出了氧化锌电阻片与碳化硅电阻片结合的混合灭磁电阻。实验证明,混合灭磁电阻兼顾了灭磁的快速与安全两方面,这对发电机灭磁电阻的设计、制造和故障分析具有重要参考价值。

As the installed capacity of hydro-generators continues to increase,the excitation current that provides the magnetic field for electromagnetic induction is also increasing.When the system fails,the rapid,safe,and reliable de-excitation of the generator set has become an urgent issue to be solved.The author uses the electromagnetic transient analysis software ATP-EMTP to establish a hydro-generator demagnetization simulation model,and then simulates and analyzes the demagnetization performance of the zinc oxide demagnetization resistor.The experiment found that although the zinc oxide resistor can quickly demagnetize,the energy absorption of different resistors is seriously uneven,which is very likely to cause problems such as thermal collapse of the system.In response to the above problems,the author proposes a hybrid demagnetization resistor combining zinc oxide resistors and silicon carbide resistors.Experiments have proved that the hybrid de-excitation resistor takes into account both the fast and safe aspects of de-excitation,which has important reference value for the design,manufacture and failure analysis of generator de-excitation resistors.