Does anyone have a good reference o how to calculate the capacitive charging currents in a 13.8kV network that involves 16 substations that are interconnected through overhead and underground cables?
I'm also looking for another reference to explain how to calculate the Transient Recovery Voltage (TRV) for network protection.
I appreciate if anyone can help.

Reference = "Electrical Transients in Power Systems" by Allan Greenwood. This is an excellent reference for calculating transients. For your network, your level of detail will depend on what you plan to use the calculation for but the general approach is to calculate the system impedances (including shunt capacitive reactance) associated with each individual element in the network using traditional power system analysis techniques. Run a load-flow analysis of the network to determine charging for complex networks consisting of many elements; or perform hand calculations for simple networks with just a few elements.