FIELD OF INVENTION
The present invention relates to an electro-hydraulic converter for
turbine control in electro-hydraulic governing system of steam turbines.
The converter converts the signals from the electric controller into
hydraulic signal. This converter is based on Proportional valve
Technology particularly for turbine control system of 210, 250, 500, 600
MW Steam Turbines.
BACKGROUND OF THE INVENTION
Currently, the system is based on moving coil technology in which
electric signal acts on moving coil causing precise & small displacement
which gets amplified through pilot valve & amplifier piston. This results
in desired mechanical displacement.
For simplifying the assembly & overcoming the supply constraints of
moving coil, an electro-hydraulic converter is required to replace the
available system.
OBJECTS OF THE INVENTION
The primary object of the present invention is to propose an electro-
hydraulic converter for turbine control in electro-hydraulic governing
system of steam turbines.
Another object of the present invention is to propose an electro-hydraulic
converter for turbine control in electro-hydraulic governing system of
steam turbines in which similar mechanical motion is obtained for
transmission to the Follow-up Piston assembly for getting it converted
into hydraulic signal.
Further object of the present invention is to propose an electro-hydraulic
converter for turbine control in electro-hydraulic governing system of
steam turbines using existing mounting arrangement.
Still another object of the present invention is to propose an electro-
hydraulic converter for turbine control in electro-hydraulic governing
system of steam turbines which overcomes disadvantages associated
with the known art.
Yet another object of the present invention is to propose an electro-
hydraulic converter for turbine control in electro-hydraulic governing
system of steam turbines which is efficient.
STATEMENT OF INVENTION
According to this invention, there is provided an electro-hydraulic
converter for turbine control in electro-hydraulic governing system of
steam turbines comprising of proportional valve, manifold plate, piston,
casing and position transmitter wherein the control signals from electro-
hydraulic controller operates on proportional valve and control fluid is
admitted to the valve through manifold plate resulting in corresponding
mechanical displacement of piston.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent
from the ensuing description when read in conjunction with the
accompanying drawings and wherein:
Fig. 1 shows : sectional view of electro-hydraulic converter.
Fig. 2 shows: top view of electro-hydraulic converter.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO
THE ACCOMPANYING DRAWINGS;
The present invention discloses an electro-hydraulic converter for turbine
control in electro-hydraulic governing system of steam turbines as shown
in figure 1 and 2.
The electro-hydraulic converter comprising of a base plate (11)
supporting a piston (7) with a holder (5). The piston is provided in
connection with position transmitter (2) through a guide rod (6). Further,
there is provision of bush (8 & 10) on both sides of said piston as shown
in figure 1. A casing (4) with cover (3) accommodates middle part of the
piston with bush and a sealing ring (9) above the bush.
However, the principal components of the converter are proportional
valve (1), Manifold plate (12), EHC Piston (7), Casing (4) and position
transmitter (2). The control signals from the electro-hydraulic controller
operates on Proportional valve (1) through, a matching amplifier module.
The control fluid from connection 'a' is admitted to Proportional valve (1)
through the Manifold plate (12). This control fluid is routed to the space
above or below the piston (7) according to control signal acting on
proportional valve (1) and the opposite side of the piston is opened to the
fluid drain. The motion of the piston (7) produces a simultaneous
feedback action on the proportional valve (1) via the position transmitter
(2). The control command gets modified and in the equilibrium position,
there is no flow through the proportional valve (1).
It is to be noted that the present invention is susceptible to
modifications, adaptations and changes by those skilled in the art. Such
variant embodiments employing the concepts and features of this
invention are intended to be within the scope of the present invention,
which is further set forth under the following claims:-
WE CLAIM;
1. An electro-hydraulic converter for turbine control in electro-
hydraulic governing system of steam turbines comprising of
proportional valve, manifold plate, piston, casing and position
transmitter wherein the control signals from electro-hydraulic
controller operates on proportional valve and control fluid is
admitted to the valve through manifold plate resulting in
corresponding mechanical displacement of piston.
2. An electro-hydraulic converter as claimed in claim 1, wherein the
control signals operates through a matching amplifier module.
3. An electro-hydraulic converter as claimed in claim 1 or 2, wherein
the control fluid is routed to the space above or below the piston
according to the control signal acting on said valve and the
opposite side of the piston is opened to the fluid drain.
4. An electro-hydraulic converter as claimed in any of the preceding
claims, wherein said piston's motion produces a simultaneous feed
back action on the valve via the position transmitter.
5. An electro-hydraulic converter as claimed in any of the preceding
claims, comprising of a base plate supporting said piston, which is
provided in connection with the position transmitter through a
guide rod.
6. An electro-hydraulic converter for turbine control in electro-
hydraulic governing system of steam turbines substantially as
herein described with reference to the accompanying drawings.

This invention relates to an electro-hydraulic converter for turbine
control in electro-hydraulic governing system of steam turbines
comprising of proportional valve, manifold plate, piston, casing and
position transmitter wherein the control signals from electro-hydraulic
controller operates on proportional valve and control fluid is admitted to
the valve through manifold plate resulting in corresponding mechanical
displacement of piston.