HVDC Characteristics Video Lecture - Electrical Engineering (EE)

hello everyone this is Vinay Kumar from
our c100 I would like to give
description about the converter and
hitch a DC system control in general to
DC system requires some control
parameters from this figure it
represents a HVDC single pole often HVDC
system here you can observe supply sent
in and a load side and which are both AC
system networks and the supply ensign
converter can be considered as a
rectifier Gorsedd end converter can be
considered as an inverter circuit from
this figure if you want to consider
current transmission in this particular
HVDC system ID can be represented as ID
is equal to by applying simple Ohm's law
as VD 1 minus VD 2 divided by the line
resistance Rd it can be shows that the
terminal voltage difference divided by
line resistance gives the current
transmission in the HVDC system for
instance if you won't see the power
transmission in this particular network
can be given as power P is equal to e in
VD into ID now if the power transition
is from converter 1 to converter 2 it
should be in the direction from
converter 1 to converter 2 now in some
cases there is Nady requirement of power
transmission from load side into supply
siren or the power reversal is possible
if the direction
of voltage terminal terminal voltage is
changing reverse that instance the power
can be transformed from load side into
submitted in in which case the converter
V d2 is the converter on the load side
is concerned as rectifier and converter
one should be worked as an inverter so
this circuit shows equivalent circuit of
a DC transmission system with respect to
this is the rectifier part and on the
right side is an inverter part and this
shows as a line of the DC transmission
system the thermal voltage is on
rectifier and an inverter N and with
respect to these two terminal voltages
you can calculate the current in the
transmission line ID where as this RC 1
and RC 2 gives the representations for
commutation resistances of the rectifier
and inverter side respectively when
these two transmission networks
rectifier and inverter circuits are
considered we need to analyze how much
current is transmitting and what is the
direction of power we require whether
that is from rectifier to inverter are
from inverter to rectifier circuit when
we considering the design feature self
control of a HVDC system the first
limitation of the maximum current so as
to avoid damage to walls and other
current characterizes that means the
maximum current carrying by the devices
or walls should be under control the
second limitation of the fluctuation of
the current Tito fluctuation of the
alternating voltage there may be chances
of commutation failure as well in the
cases of switching the walls and also
there is a requirement of prevention of
arca back of the rectifier walls
and another important desired feature is
to keep the voltage at the sending end
of the line constant at its rated value
so disposable in order to minimize the
losses of a given firm the other
important the third feature is
controlling the power delivered or in
some cases in the frequency at the
London there are basically four reasons
because of which we need to keep the
power factor at high level one is with
respect to power off converter we should
be keep as high as possible and there
one is to reduce the stresses on the
walls and damping circuits the third
reason is to minimize the required
current rating and the copper losses in
the AC lines with the converter the
fourth reason is to minimize the voltage
drops at the terminals of the converter
at it's loading increases weight
considering these two transmission
networks that is rectifier to inverter
we can get the characteristics of the
HVDC transmission line here you can see
the constant the curve between the
constant voltage VD and ID you not have
to get the constant power transmission
from rectifier to inverter you need to
maintain a constant current current and
which is represented by the line a B in
some cases in practical cases there may
be possibility of reduction of voltage
in the rectifier end or at the inverter
end in the both the cases the
characteristics may be changing with
respect to the lines representing C D
and F G so here when these two cases may
be happens this required to maintain
this characteristics constant by
changing the values of inverter
parameter
which is considered as constant
extinction control and this a beeline
presents the constant current control
technique and it also can be done on the
rectifier side so these two control
characteristics can be up time for the
ideal HVDC transmission system this I
conclude this converter control
characteristics thank you thanks for
watching the video thank