We all know that our industry has common usage that is known to be in error--current direction versus electron direction to be the most obvious. I am not arguing conventions or names. I am arguing the technical specifics because this is a technical discussion.
Then just focus on what you agree is a phase shift. These are the results of a physical change, not a time delay.
I am still unclear about why you refer to these as "physical phase shifts". I have never heard it expressed that way, so I am unsure why this is considered "physical". From my perspective, nothing "physical" has changed, so I am unclear why this word appears in the description.
It is not like an audio phase shift:
It really is a simple thing. Don't allow the focus on time shifting to cause you to lose sight of how we create phase shifts by physical shifts. It might be hard to focus on a physical shift if you have recently been absorbed in a project dealing with phase shifts in audio signals because the majority of the time there it does mean a time delay.
In the electric world, the majority of the phase shifts we see are physical in nature. The signals have their peaks occurring at different times, but that does not mean the signals are time-shifted versions of each other, especially if we look back at the signal beginning. The shift is the result of a physical difference, not sending a signal through a delay box. We do have propagation delays that can show up when tying long transmission lines together. That delay is a true time shift. But we are talking about the shifts in equipment like we have in the transformers.
The phase shift in a three-phase generator is not caused by a time shift. The fact that the windings are physically shifted relative to each other gives us the phase shift. An artifact caused by something impacting the source to the generator (a tree stuck in the river/lake dam intake, for example) will show up on all three voltages at the same time. The artifacts will be at different locations relative to the peaks because the peaks have a physical phase shift.
In these type cases it is a physical shift, not a time shift, causing the phase shift. It is the same type phase shift I showed in my generator example by physically rotating the generator shaft. It is the same type shift I showed in my open-wye example by taking voltages from different terminals and different directions in a transformer. It is the same type shift I showed in my open-wye graphic with the anomalies.
Phase shifting transformers:
I mentioned phase shifting transformers used in metering as another example of a physical shift causing a phase shift. To give a rough illustration of the physics, look at a high-leg delta. Take a voltage from the high-leg to the center-tap neutral point. Now instead of having a single center-tap point, replace that with a wiper that will allow you to access any point on the center-tap winding.
As we slide the end point of the voltage up and down the winding, we shift the phase of that voltage relative to the others. That is basically how a phase-shifting transformer works in three-phase metering. It is a physical shifting of the voltage that causes the phase shift, not a time shift. Source anomalies will not be time displaced unless you use relative time references (different zero crossings, etc.). In other metering equipment, we actually do use a time delay from impedance circuits to give us the phase shift we need.
Time shift:
In one case, we can have a time shift (delay circuits, propagation delays, etc) that changes the time relationship between one wave and a reference wave. This will also affect the physical relationship between this shifted wave and a reference wave. A source side anomaly will appear at different points in time but at the same place on the waves. If we change the reference time for each wave to be the positive slope zero crossing of each wave, the anomalies will appear at the same relative points in time.
This is not the type of phase shift we are usually concerned with in transformers and generators.
Physical shift:
In another case, we can have a physical shift (taking voltages from different terminals and different directions, etc.) that changes the physical relationship between one wave and a reference wave. This will also affect the timing relationship between this shifted wave and a reference wave. A source side anomaly will appear at the same point in time but at different places on the waves. If we change the reference time for the positive slope zero crossing of each wave to be the positive slope zero crossing of the reference wave, the anomalies will appear at different relative points in time.
This is the type of phase shift we usually are concerned with in transformers and generators.
It is a two-sided coin:
The relative nature of the time reference for the waves makes the time shift and the physical shift two sides of the same coin. Not the same side, but the same coin. It is a two-sided coin because we can look at the same time as a reference for all waves, or we can look at the same physical wave characteristic as a reference for each wave.
Again, there is a relative relationship between the physical shift and the time shift. We can look back at the beginning of signal creation to see which side of the coin we are looking at. Whatever the side, it is still a phase-shift coin. We normally don't care what side of the coin we are looking at because we deal with steady-state conditions.
It might not agree with the terminology you prefer, but it is the way "phase shift" is used as related to shifts in transformers. In addition to "phase shift", you will also see the terms "phase displacement" and "phase difference" and other similar terms used both together and separately.
Do you understand what I mean now?
