<s>
Capability	B-Algorithm
curve	I-Algorithm
of	O
an	O
electrical	O
generator	O
describes	O
the	O
limits	O
of	O
the	O
active	O
(	O
MW	O
)	O
and	O
reactive	O
power	O
(	O
MVAr	O
)	O
that	O
the	O
generator	O
can	O
provide	O
.	O
</s>
<s>
at	O
the	O
upper	O
part	O
of	O
the	O
curve	O
(	O
generator	O
produces	O
a	O
lot	O
of	O
reactive	O
power	O
)	O
operation	O
requires	O
higher	O
voltage	O
on	O
the	O
output	O
of	O
the	O
generator	O
and	O
thus	O
higher	O
excitation	B-Algorithm
field	I-Algorithm
.	O
</s>
<s>
The	O
rotating	O
excitation	B-Algorithm
winding	O
has	O
its	O
own	O
field	O
heating	O
limit	O
;	O
</s>
<s>
The	O
corners	O
between	O
the	O
sections	O
of	O
the	O
curve	O
define	O
the	O
limits	O
of	O
the	O
power	B-Application
factor	I-Application
(	O
PF	O
)	O
that	O
the	O
generator	O
can	O
sustain	O
at	O
its	O
nameplate	O
capacity	O
(	O
the	O
illustration	O
has	O
the	O
PF	O
ticks	O
placed	O
at	O
0.85	O
lagging	O
and	O
0.95	O
leading	O
angles	O
)	O
.	O
</s>
<s>
Due	O
to	O
flexibility	O
allowed	O
by	O
the	O
presence	O
of	O
the	O
power	O
converter	O
,	O
the	O
doubly-fed	O
and	O
full-converter	O
wind	O
generators	O
on	O
the	O
market	O
have	O
different	O
shapes	O
of	O
the	O
capability	B-Algorithm
curve	I-Algorithm
:	O
"	O
triangular	O
"	O
,	O
"	O
rectangular	O
"	O
,	O
"	O
D-shape	O
"	O
(	O
the	O
latter	O
one	O
resembles	O
the	O
D-curve	O
of	O
a	O
synchronous	O
generator	O
)	O
.	O
</s>
<s>
They	O
simply	O
absorb	O
the	O
reactive	O
power	O
(	O
like	O
any	O
typical	O
induction	O
machine	O
)	O
,	O
so	O
a	O
switched	O
capacitor	O
bank	O
is	O
usually	O
used	O
to	O
correct	O
the	O
power	B-Application
factor	I-Application
to	O
unity	O
.	O
</s>
<s>
Since	O
the	O
current	O
state	O
of	O
these	O
networks	O
does	O
not	O
include	O
the	O
voltage	O
regulation	O
,	O
the	O
inverters	O
in	O
these	O
units	O
were	O
operating	O
at	O
the	O
unity	O
power	B-Application
factor	I-Application
.	O
</s>
<s>
Since	O
the	O
power	O
limit	O
of	O
an	O
invertor	O
is	O
based	O
on	O
the	O
maximum	O
total	O
current	O
,	O
the	O
natural	O
shape	O
of	O
the	O
capability	B-Algorithm
curve	I-Algorithm
is	O
similar	O
to	O
a	O
semicircle	O
,	O
and	O
at	O
full	O
capacity	O
the	O
real	O
power	O
always	O
needs	O
to	O
be	O
lowered	O
if	O
the	O
reactive	O
power	O
is	O
to	O
be	O
produced	O
or	O
absorbed	O
.	O
</s>
