Quad Booster (Phase shift transformer) 11/66kV 25MVA power export into national grid

[dubstep]

Hi All,

Our client would like to control power flow on a single line of a three line export facility. This facility will export into the larger national grid.

My question is: Should we utilize a phase shift transformer to manipulate the Vs compared to Vr phase angles with intent to control power flow on this one line, would we not be creating an out of synchronization as the grid is producing voltage at a certain phase angled and we will be synchronizing and then wanting to manipulate this angle to control power flow.

Any information in this regard would assist.

Thanks,

 

[crshears]

Hello dubstep,

I don't recognize your "handle"; if you're new here, welcome to the fora [ often pronounced fray ].

Is this a new build or a modification to an existing facility?

If all export lines are operating in parallel, all the phase shifter will do is alter the real and reactive power flows on that one circuit; absent any open point or points, there will be no concern about out-of-phase conditions developing as a solid galvanic condition can be considered to exist at all times. The stations in which I've worked have always been designed in such a way that the synchronization or separation of generation from the grid as that grid's load profile varies over the course of a day can occur independent to the operation of phase shifters to balance tie line flows.

With the generation facility having three different export lines to the grid, I would give very serious consideration to "siloing" the generation output by using open points in the switchyard to configure the amount of generation tied to any one line; this would in all likelihood be cheaper than using a quadrature booster, which is an extremely expensive piece of kit. One of the benefits of this approach is that the available fault current infeed capability is reduced, which imposes less severe current flow under fault conditions. This would have to be followed up with the Authority Having Jurisdiction confirming that the brief periods of having dual sources in parallel while performing make-before-break switching would be acceptable to that AHJ.

The nature of the generation will of course be of great significance, since for obvious reasons generation rejection schemes would have to be employed, and the generation plant would have to be compatible with this configuration.

Hope this helps.


CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]