CAJ | 학술논문

由于发电厂厂用电系统或者外部电网的暂态过程，导致输入辅机变频器的电压降低，可能出现辅机工况紊乱，甚至变频器切除，低电压穿越已经成为辅机正常运行必须考虑的问题。安装附加装置可以在尽可能少地改变原电路基础上应对低电压问题，其中增加升压模块、直流侧安装储能装置、交流侧安装在线式UPS是比较典型的方案。通过在PSCAD/EMTDC软件中建模仿真证明，直流侧储能装置以及交流侧UPS系统的安装，在低电压穿越时对辅机变频器基本无影响，但这2种方案费用较高；而增加升压模块可能导致变频器直流侧过电压，需要采取抑制措施，但其费用较低，可根据现场条件以及技术经济性综合考虑采用何种方案。
유우발전엄엄용전계통혹자외부전망적잠태과정，도치수입보궤변빈기적전압강저，가능출현보궤공황문란，심지변빈기절제，저전압천월이경성위보궤정상운행필수고필적문제。안장부가장치가이재진가능소지개변원전로기출상응대저전압문제，기중증가승압모괴、직류측안장저능장치、교류측안장재선식UPS시비교전형적방안。통과재PSCAD/EMTDC연건중건모방진증명，직류측저능장치이급교류측UPS계통적안장，재저전압천월시대보궤변빈기기본무영향，단저2충방안비용교고；이증가승압모괴가능도치변빈기직류측과전압，수요채취억제조시，단기비용교저，가근거현장조건이급기술경제성종합고필채용하충방안。
Frequency converter voltage of auxiliaries may drop due to transient state process of power plant auxiliary power system or external power networks, which results in operation condition turbulence of auxil-iaries or even frequency converter removal. Therefore, low voltage ride through (LVRT) must be taken into consideration for the normal operation of auxiliaries. By installing attachment the original circuit can be less changed. A typical scheme is to increase voltage boosting modules, install energy storage device at DC side and online UPS at AC side. It is proved by modeling and simulation in PSCAD/EMTDC software that the en-ergy storage device at DC side and UPS at AC side have little impact on frequency converter of auxiliaries during low voltage ride through, but the two schemes are costly; however, increase of voltage boosting mod-ules may result in overvoltage at DC side of frequency converter and some suppression measures must be tak-en, but this scheme is less costly. The schemes can be chosen in comprehensive consideration of field condi-tions as well as technical and economical efficiencies.