As a simple interested observer, I am aware of the importance of the transmission angle in power transfer situations but what are the practical methods generally employed to adjust the transmission angle on 33KV lines?
Adding series capacitors to the line will also shift your impedance angle and make the line look shorter, while adding inductance will make the line appear longer. This can be a rather costly way but if you have strict power flow requirements it can work. A Phase shifting transformer can also regulate power flow and these would be located at your interconnection points or the source to your system.
At 33 kV, my guess is that the cost of capacitors or phase shifting transformers would be prohibitive, compared to the incremental additional power the line could carry with the additional substation equipment.
Why would we want to control the line angle on a 33 kV line? Maybe if it was a tie between two utilities or the only means of getting power to a critical location.
In most cases the line angle is not controlled and Ohm’s law determines the power flow. Power system operators consider line angle as a fixed quantity, like transformer impedance, except on HV and EHV lines where power flow is critical.