Previously, Importance of protection against inrush current in stationary device is determined. In this post, different mitigation methods are addressed. Pre-Magnetizing Transformer: Function: To magnetize the transformer core at starting with regulated voltage source before connecting with main supply and prevent from saturation of core. Fig. Medium voltage side pre-magnetizing transformer Fig. Low voltage side pre-magnetizing transformer Application: Marine transformer Limitation : No. of components are more, require external small size auxiliary transformer, cost is more. Pre-Insertion Resistor/Rheostat with controlled switching: Function: To mitigate the inrush current by providing external resistance at starting and switching control is used to bypass that rheostat after initial few cycles . Application : MV transformer energization
Hi, WeEngineers, thank you for your excellent explain for "Difference between re-ignition and re-strike in switching devices". I am a little bit confused, may I know the "cycle" in Fig. means it included full positive half wave and negative half wave ? However 1/4 cycle in the Fig. looks like just only in negative half wave. If the Fig. is correct, , the 1/4 cycle will be 20/2/4 = 2.5 ms in 50 Hz power system. To my understanding, 1/4 cycle will be 50/4 = 5 ms. As above, may I know what is your suggestion? Thank you very much and have a nice day.
ReplyDelete