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@parchie That is correct. For reference here, I only added short circuit contribution from Inverters only. If we add both MPT and inverter contribution, it will come around 36kA. The inverter count has been changed, we are going with 310 Inverters, and going with 78 Transformers, as the last...

So 4 tesla megapack inverters connects to a one MVT rated for 4400KVA, 34.5kV/480v Z=7%.Total 78 MVTs Base current of Inverter is 1324A, multiply with 1.4 times SCC, then Isc-LV side for each inverter is 1854A. Reflect this short-circuit current to the MV side (34.5 kV) using the voltage...

@JJ Roy Thanks for the info. We are working with Tesla to get this info, any chance you have the approximate values on the Tesla Megapack short circuit contribution?

In the process of calculating SCC at MV bus for a BESS plant. Utility POI fault current is at 40kA. Our only MPT size is 230/34.5, 210/280/350MVA, %Z = 10.5 @210MVA. Based on this the SCC at MV bus is coming around 30kA. From the BESS Inverter side planning to use TESLA MP2XL megapack rated...

Does power system monitoring recorder/PMU data needs to be in the FAC-008 report? If so can you share any evidence regarding the same? Thanks.

We are looking to calculate Max, Nominal and Min "Load Usage" of a Wind plant at Point of Interconnection (POI). As the load usage depends on wind speeds, operating characteristics of turbines, and reactive/capacitive banks consumption in the substation etc. Please share any ideas or tools that...

Can anyone recommend the good IBR based (Type3,4 wind power plant, solar and BESS) generation controls training that discusses about NERC compliance like MOD, PRC studies. Converters etc?

Following are the C2 results. Included the C1 results previously. HV bushing is 138KV LV bushing 34.5 KV The bushings are rated for full load capacity of the plant.

After having a recent maintenance testing we observed the following C1 test results. The capacitance values are satisfactory but the PF values were increased for some bushings, when compared to Name plate values mentioned in the report. We also observed change in oil color in the 34.5Kv bushing...

Please see the attached for one of event file on this feeder breakerhttps://files.engineering.com/getfile.aspx?folder=54bcdacf-a8a0-48d5-8888-b6551f9c97e8&file=PC-1_51-1_SEL_351_Dated_10-11-22_0121pm.CFG

Nuisance tripping issue with one of the feeder protection relays (SEL-351) and the event file shows the 67P1T protection element caused the trip. Due to certain initial energization parameters on a few circuits around the fleet and transformer inrush amps cause nuisance trips upon energization...

As per our study this 138kV, ACSR 795 MCM transmission line at the ambient conditions of(104 °F, 2ft/s, 45° wind angle) result in a conductor temperature of 172.2°F at a Max current of 689A and conductor is rated for a Max temperature of 212° F. But as per ACSR conductor behavior, as...

@Parchie, Thanks for the comments on parallel fusing. For reference, we do have cap switchers on individual banks, that operates only during voltage unbalance conditions, that takes the signal from the relay. We only have PT in the, no CTs were installed before in the cap bank/filter bank circuit.

Parchie (Electrical) At 35kV voltage level, even Eaton doesn't have bigger than 100A fuse links, which won't be helpful anyway in this situation.

@Parchie (Electrical) As mentioned by our current fuse manufacturer, the existing fuses when subjected to continuous currents at or around 85-100% of the element melt rating do get warm. It wouldn’t take much of a current surge at 85% to blow it. Potentially a surge when switching your cap...

@ electricuwe (Electrical) Thank you for the cross check. Line 8 item was a rough estimate and it is for cap bank only. And we didn't perform post installation harmonic study, this estimate is before installation of filter bank.

@Parchie, Thank you for the calculation. I cross checked it, and the values are accurate. What is the significance of relative impedance and fudge factor? We also want to upgrade the protection to a CB from the existing 400A fuse, but that is not an economical option for us at this time. I...

@ parchie, thanks you for the details. According to IEEE 519-2014, voltage distortion limit for each harmonic @35kV will same right, which is 3%? Is this the same value that will go in the formula. PLease comment.

@bacon4life Our capacitor bank fuses were not blowing, the problem is with the main power fuses. It is not only limited to filter bank fuses, it is random with other capacitor bank main fuses. Can we tune any non-filter cap bank to 5th harmonic?

@electricuwe I think the general rule of thumb for the main fuses on the capacitor banks is 1.35*rated current of cap bank. Whereas the fuse sizing on the capacitors is 2* Capacitor fundamental current. We have sized our main Cap bank fuse as 1.35 * nominal current. Our cap bank is 17.5MVAR...