Ideal Transformer (3-phase)

Three-phase ideal two-winding (HV / LV) transformer: no leakage, no magnetizing branch, no losses. Enforces V_LV,LL = V_HV,LL / n with n the line-to-line voltage ratio, for any Y / YN / Δ connection on each side and an exact HV→LV vector-clock phase shift (even clocks for Yy / Dd, odd clocks for Yd / Dy). A YN star point is either grounded internally or brought out to an HV_n / LV_n port. Per-phase HV and LV line currents can be monitored with a '+ve in' / '+ve out' sign convention. A grounded wye facing a delta is an ideal zero-sequence short, so do not drive that winding from an ideal source with a grounded neutral (give the source some impedance or a floating neutral). Use for level-shifting, phase-shifting, and isolation in three-phase studies where the transformer impedance does not matter.

Category: Transformers

Ports

Port	Kind	Signal	Notes
HV	Three-phase terminal	—
LV	Three-phase terminal	—
HV_n	Electrical terminal	—	Shown when HV connection is YN (wye + neutral) and HV neutral is Neutral exposed (HV_n port)
LV_n	Electrical terminal	—	Shown when LV connection is yn (wye + neutral) and LV neutral is Neutral exposed (LV_n port)

Parameters

Config

Parameter	Type	Default	Units	Description	ID
n (HV:LV, line-to-line)	Number	1	—	Line-to-line voltage ratio V_HV,LL : V_LV,LL = n : 1 (e.g. 230 kV : 115 kV is n = 2). The per-winding turns ratio follows from the connections: n for Yy and Dd, n/√3 for Yd, n·√3 for Dy.	turns_ratio
HV connection	Choice: Y (floating N) / YN (wye + neutral) / Δ delta	YN (wye + neutral)	—	HV winding connection. `Y` = wye with a floating (isolated) neutral. `YN` = wye with an accessible neutral; the `HV neutral` selector below decides whether it is grounded internally or brought out to the HV_n port. `D` = delta (winding a spans phases a→b).	hv_connection
HV neutral	Choice: Neutral exposed (HV_n port) / Grounded internally	Grounded internally	—	How the HV star point is handled (YN only). `Exposed`: brought out to the HV_n port — ground it externally or connect an impedance. `Grounded`: solidly tied to ground inside the transformer (no HV_n port).	hv_neutral
LV connection	Choice: y (floating n) / yn (wye + neutral) / d (delta)	yn (wye + neutral)	—	LV winding connection. `y` = wye with a floating (isolated) neutral. `yn` = wye with an accessible neutral; the `LV neutral` selector below decides whether it is grounded internally or brought out to the LV_n port. `d` = delta (winding a spans phases a→b).	lv_connection
LV neutral	Choice: Neutral exposed (LV_n port) / Grounded internally	Grounded internally	—	How the LV star point is handled (yn only). `Exposed`: brought out to the LV_n port. `Grounded`: solidly tied to ground inside the transformer (no LV_n port).	lv_neutral
HV→LV vector clock	Choice: 0 (in phase) / 2 (−60°) / 4 (−120°) / 6 (180°) / 8 (+120°) / 10 (+60°)	0 (in phase)	—	Phase shift of LV relative to HV in 30° clock units (LV lags HV by 30° × clock). Yy and Dd connections admit only even clocks.	hv_lv_clock_even
HV→LV vector clock	Choice: 1 (−30°) / 3 (−90°) / 5 (−150°) / 7 (+150°) / 9 (+90°) / 11 (+30°)	1 (−30°)	—	Phase shift of LV relative to HV in 30° clock units (LV lags HV by 30° × clock). Yd and Dy connections admit only odd clocks, e.g. YNd1, Dyn11.	hv_lv_clock_odd
Current monitoring - HV side	Choice: Off / On	Off	—	Emit the per-phase HV line currents (at the HV terminals) as simulator observables.	measure_hv_current
HV positive direction	Choice: +ve in / +ve out	+ve in	—	Sign convention for the monitored HV line currents. '+ve in' = positive when current flows into the transformer at the HV terminal; '+ve out' = positive when it flows out.	hv_current_dir
Current monitoring - LV side	Choice: Off / On	Off	—	Emit the per-phase LV line currents (at the LV terminals) as simulator observables.	measure_lv_current
LV positive direction	Choice: +ve in / +ve out	+ve out	—	Sign convention for the monitored LV line currents. '+ve in' = positive when current flows into the transformer at the LV terminal; '+ve out' = positive when it flows out (the default, so power delivered to an LV load reads positive).	lv_current_dir

Current Monitoring

Parameter	Type	Default	Units	Description	ID
HV name A	Text	I_HVa	—	Signal name for the Phase A HV line current. Blank skips this phase; change the default when you have several monitored transformers — duplicate ids collide.	i_hv_name_a
HV name B	Text	I_HVb	—	Signal name for the Phase B HV line current. Blank skips this phase.	i_hv_name_b
HV name C	Text	I_HVc	—	Signal name for the Phase C HV line current. Blank skips this phase.	i_hv_name_c
LV name A	Text	I_LVa	—	Signal name for the Phase A LV line current. Blank skips this phase.	i_lv_name_a
LV name B	Text	I_LVb	—	Signal name for the Phase B LV line current. Blank skips this phase.	i_lv_name_b
LV name C	Text	I_LVc	—	Signal name for the Phase C LV line current. Blank skips this phase.	i_lv_name_c

Observables

Default name	Kind	Recorded when	Description	ID
set by HV name A	Signal	Current monitoring - HV side is on	Phase A HV line current (A). Positive into the HV_a terminal for '+ve in' (default), out of it for '+ve out'.	i_HV_a
set by HV name B	Signal	Current monitoring - HV side is on	Phase B HV line current (A).	i_HV_b
set by HV name C	Signal	Current monitoring - HV side is on	Phase C HV line current (A).	i_HV_c
set by LV name A	Signal	Current monitoring - LV side is on	Phase A LV line current (A). Positive out of the LV_a terminal for '+ve out' (default), into it for '+ve in'.	i_LV_a
set by LV name B	Signal	Current monitoring - LV side is on	Phase B LV line current (A).	i_LV_b
set by LV name C	Signal	Current monitoring - LV side is on	Phase C LV line current (A).	i_LV_c