It would be interesting to see the effects of harmonics in the area I live, slap bang in the middle of student land. Many are Chinese or Japanese, PC’s, games consoles, you name it they’ll have it.
I've come across harmonics issues for quite some years now. My field is variable speed drives which are known generators of harmonics. Some these are in the MW range and upwards so harmonics are significant and predictable. Often these have to calculated, presented, and
guaranteed at the bid stage - before any contract is placed. Rock and a hard place.
It is par for the course for us to have to include before and after compliance studies.
On one pumping station, in a mainly residential area, the before measurements were non-compliant
before we commissioned the variable speed drives. And no worse afterwards.
Initially, that puzzled me. We'd put in some fairly big drives - total installed capacity was about 1 MVA. There was a local dedicated transformer for the sub - (11kV to nominally 400V) so the PCC was at 11kV. The harmonics were measured on the 11kV side.
The explanation isn't altogether complicated. Our drives were a mixture of six and 12-pulse units fed from the three-phase supply.These should result in harmonics no lower than 5th (250Hz).
The the analysis showed a high 3rd (150Hz) content. Single phase non-linear loads.
None very big. Just huge numbers of them and that swamped the contribution from our drives.
And that's what you see on my flat topped wavevorm.
