Convertering to a “PQ” diagram

.PS
include(pstricks.m4)

scale=25.4	#scale in [mm]

cct_init

define(`label',`rect_(sqrt($1.x^2+$1.y^2)+$2,atan2($1.y,$1.x))')

_mm=0.5			#[mm]
_V=(1/220)*_mm	#[mm/V]

_min_x=-40*_mm
_max_x=120*_mm
_min_y=-40*_mm
_max_y=80*_mm

_offset=3*_mm

_V_a=33e3/sqrt(3)*_V

_adj=1.40
_delta=33.1734

O: (0,0)

V_a: Rect_(_V_a,0)
E_af: Rect_(_V_a*_adj,_delta)
V_jXsIa: E_af-V_a
I: (V_jXsIa.y*1.5,-V_jXsIa.x*1.5)

_theta=atan2(-V_jXsIa.x,V_jXsIa.y)
_pi=atan2(0,-1)

line from O to V_a ->
line from O to E_af ->

line from V_a to E_af ->
"$3V_a I_a$" at 1/2 between E_af and V_a rjust
"$\dfrac{3V_a^2}{X_s}$" at 1/2 between O and V_a below
"$\dfrac{3V_aE_{af}}{X_s}$" at 1/2 between O and E_af above rjust
"0" at O below ljust

linethick_(0.5)

arcd(O,0.3*_V_a,0,_delta) <->
"$\delta$" at Rect_(0.3*_V_a+1.5*_offset,_delta/2)
arcr(V_a,0.1*_V_a,0,_pi/2+_theta) <->
"$90^\circ{-}\theta$" at (V_a+(rect_(0.1*_V_a+_offset,_pi/4+_theta/2))) ljust

dimension_(from (V_a+(40*_mm,0)) to (V_a+(40*_mm,E_af.y)), _offset*2,"$\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad \dfrac{3V_aE_{af}}{X_s}\sin(\delta)=3V_aI_a\cos(\theta)$",28pt__,_offset,<->)

dimension_(from (V_a.x,-10*_mm) to (E_af.x,-10*_mm), _offset*2,,,_offset,<->)
"$3V_aI_a\sin(\theta)$" at 1/2 between (V_a.x,-10*_mm) and (E_af.x,-10*_mm) below

linethick_(0.2)

line from E_af to (V_a+(30*_mm,E_af.y))

line from (_min_x,0) to (_max_x,0)
line from (0,_min_y) to (0,_max_y)
line dashed from E_af to (E_af.x,0)

.PE