Map-Operation of distance relays located near Voltage source convertors

[dfdt]

Does any member has experience or know of the possibility of distance relay's inability to perform as designed due to suppression of negative sequence current or limited positive sequence current contribution from voltage source converters commonly applied at HVDC stations? I have heard that distance relays may either under or overreach for a fault on an AC network especially if it is located near close proximity of a VSC source

 

[DTR2011]

I know of an HVDC station that caused all kinds of problems with power line carrier systems, including the PLC based AMR system on the distribution lines.

 

[davidbeach]

I don't know about HVDC stations, but I've run into a number of reports large IBR (Inverter Based Resources - PV and type 4 wind) confusing distance elements and the associated directional elements because of a lack of zero and negative sequence components in the inverter output during fault.

It seems that if you're trying to clear faults under those conditions, particularly if you have IBRs at both ends, you may need to rely on differential or even traveling wave to ensure proper operation.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[cuky2000]

Distance relaying measures voltage and current to determine electrical distance from the fault location. A difference of synchronous generating plants, a Voltage Source Converter (VSC), HVDC, or any power electronic base system reduces the system short circuit significantly.

A distance relay connected to a low SC system may not have enough current for its accurate operation. The penetration of large VSC will force us to readapt and adjust the traditional protection philosophy particularly those using distance relays in transmission lines nearby VSC.

Below is an excerpt indicating some of the concerns associated with distance relays operating near a VSC hopping that help illustrating the potential concern and motivate us for implementing possible solutions.