Power factor 1

[jncza]

We have a hydro generation station comprising of 3 generators generating 3Mw each.We ensure that the kvars(leading or lagging) generated is always less than half of the kva generated to ensure a powerfactor close to unity.We supply our own process plant with an average load of 7,5Mw.The powerfactor at the plant varies between 0,83 to 0,87.When we synchronise to the national grid the meters at the grid substation read a poor powerfactor of 0,40.The powerfactor at the plant still reads 0.87 .Why the big difference?.

 

[rbulsara]

Utility meter is reading pf of what it is supplying not that of your total plant...

Is this a extended paralleling to share load or just a momentary/short duration paralleling to transfer loads?

What % of load is provided by the grid when in parallel.

It may just be exchange of small load and much of it may be reactive power.

 

[busbar]

 
More information is needed to resolve the problem. Given the three-way connection of site generation, plant load and utility feed, power factors alone can be misleading. For an adequate grasp of system loading, kilowatt and kilovar quantites for each ‘branch’ should be measured.

It may be that the utility feed is serving a large kilovar demand with proportionally little kilowatt demand.