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What are the issues or shortcomings of distance protection protecting transmission line which is connected to solar farm via IBR ?

Does anyone know what caused wide spread power outage in Ecuador yesterday?

Recently numerical Trf Diff relay of an out of service transformer picked up when it’s HV dead tank circuit breaker was being tested for contact resistance by injecting 200A of DC current.I am bit curious to find out CT behaviour or response to pure DC current. Please share your views

Is there a way to find/derive the accuracy class of protection class CT with following specs ? Ratio- 1000/1A, 0.1 Px 500 R 3.0 ohm Is it fair to say that such a CT will equivalent to metering CT of class 1 accuracy?

Does anyone know what caused the power outage in Argentina and Uruguay?

we have an application wherein under voltage load shedding scheme needs to select 3 phase voltage from one of possile three line VTs.Can some one suggest a voltage selection relay capable of accepting three sets of three phase voltages?

Does anyone have experience with ABB make fault current limiter called "Is" ?

What criterion should be followed for designing Under frequency load shedding scheme i.e. should it be based on security i.e.by having contact of main and check relays in series to issue trip or should it be based towards reliability or dependability i.e. by having contact of main and check...

Is there a forum to discuss protection issues related to IEC 61850 standard?

Is it possible to trip switch fuse unit via external trip signal? In other word does HV (22kv)switch fuse unit have trip coil?

Which is a good and easy software package for drawing electrical schematic drawings pertaining electrical power system ?

I would like to know difference,advantages and disadvantages of having transformer tap changer based on variable flux and constant flux method?

Test setup for measuring zero sequence impedance of a line is to short all three phases and then measure the loop impedance between shorted conductors and earth return.Question I have is that ,do we we need to multiply measured ohmic value by three to get actual zero sequence impedance?

Modern protective relays can use either numerically calculated Io or actual neutral current fed via residual connecting of three phase CTs.I not sure if there is any difference between the two? Is one better than other?

I am in process of evaluating and eventually buying relay setting software.Could users of relay setting and or setting database software like Aspen,CAPE,IOS or DigSilent etc care to share their expereince regarding pros and cons of different software

Generally speaking the zone 1 of distance relays is intentionally set to under reach the line length to the tune of 70 to 90 %. Also we know that the under reaching zone 1 is likely to over reach in case the parallel line is out of service and earthed. I invite reders your comments on ways to...

Is over load protection more effective and meaning full than over voltage protection for protecting the capacitor cans from over voltages as any over voltage will necessariliy manifest into over load. Your comments will be highy appreciated.

What are the pros and cons of using CVT instead of inductive VT's for distance relaying?

We are in the process of purchasing SQL based database to capture relay types,settings,history,name plate details,associated softwares and firmware.Your valuable advice regarding features of various relay databases availale in the market will be highly appreciated.

Should we considering zero seq. impedance of YN/yno power transformer(HV star point unearthed but LV directly earthed)in calculting ground fault current contribution ? or will positive sequence impedance will suffice.