Tap changer modeling ULTC
Tap Changer modeling in PSS/E (linear one and non-phase shifting) In reality tap changer can be located on high side or low side of the transformer. Tap Changer voltage increment per tap step can be of positive or negative value based on nameplate.
How PSS/E output changes when tap changer positive and negative voltage step increment is implemented? How to model in Two Winding Transformer input to model case when tap changer is on LV side winding and HV winding?
Scenario A and B Tap Changer (linear and non-phase shifting). Tap Changer location on HV side.
Scenario A Tap Changer location HV side: Yes Base Voltage of subnet on HV winding = 400 kV U rated = 420 kV Tap Max = 21, Tap Min = 1, Tap Neutral = 11, Tap Step [%] = -1, Tap Step = -0.01,
tap ratio X = 0.945 using p.u. tap ratio Y = 1.155 using p.u.
Scenario B Tap Changer location HV side: Yes, Base Voltage of subnet on HV winding = 400kV, U rated = 420 kV, U rated in p.u. = 1.05, Tap Max = 21, Tap Min = 1, Tap Neutral =11, Tap Step [%] = 1, Tap Step = 0.01, tap ratio X = 1.155? tap ratio Y = 0.945?
What will be RMAI and RMI, COD1 (what will be a sign?) in Scenario A? What will be RMAI and RMI, COD1 (what will be a sign?) in Scenario B?
What will be meaning of code COD1 sign?
Does PSS/E support modeling tap changers on LV side of transformer? If so how to do it properly and what will be change in .raw outcome?
For the last question, a two winding transformer can only have one ULTC only the winding 1. Fortunately there is a code to choose where the winding 1 is (ibus or jbus).
OK for some reason Tap Changer can be located only on PSS/E Winding number 1. What is the driving flag from point of GUI? Does it mean if I flip this flag my "i" bus will be swapped with "j" in .raw output and the opposite?
I see that kind of flag under "Winding 1 From end". It would mean by default it is set.