FIELD OF THE INVENTION:
The present invention generally relates to a system for efficient operation of a
hydro power generating station. The invention, in particular relates to 3 system
for extracting optimally the mechanical power from a turbine during a part load
operation of the power station. More particularIy, the invention relates to a
system for automatic and optimum load sharing of a plurality of generating
machines in hydro power plants.
BACKGROUND OF THE INVENTION:
Hydropower generation depends on the available water head and discharge
through the machines. The regulation or water discharge for the head acting on
a machine decides its generating capacity. In general, there are number of
generating machines in a powerhouse and the generation rt of individual machine
depends on the discharge flowing through it. Hydro machines are tailor made
and are designed keeping in view the efficiency weightage factor at various loads
which are decided by power utility depending on grid loading. The normal load
variation allowed in hydro machines is normally 40% to 100% depending on the
type of a machine , Since the performance characteristics of a hydro turbine
follows a curved line (ref. Fig. 1) with a peak efficiency at certain part load, the
variation in efficiency within the peermissible range is generally in the order of 5
to 7%.

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Normally the plant operator at a hydro power plant lack the help of a suitable
device to monitor efficiency variation of the turbine at different operating
conditions, hence the loading of individual machine in part load demand is
accomplished arbitrarily. This generally leads to operation of the machines in
non-optimum zones leading to loss of efficiency and more maintenance.
OBJECTS OF THE INVENTION:
It is therefore an object of the present invention to propose a system for
automatic and optimum load-sharing of a plurality of generating machines in
hydro-power plants which eliminates the disadvantages of prior art.
Another object of the present invention is to propose a system for automatic and
optimum load-sharing of a plurality of generating machines in hydro-power
plants which in particular provides data input to the operator during part-load
regime in respect of the distributable optimum load among the plurality of
generating machines.
An yet another object of the present invention is to propose a system for
automatic and optimum load-sharing of a plurality of generating machines in
hydro power plants which enables each of the plurality of generating machines
to operate in best-possible efficiency zone thereby minimizing hydraulic
perturbation and noise including wastage of energy.
A further object of the present invention is to propose a system for automatic
and optimum bad-sharing of a plurality of generating machines in hydro-power
plants which enhances the power generation in lean discharge phase including
saving of natural resources for example, water.

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A still further object of the present invention is to propose a system for
automatic and optimum load-sharing of a plurality of generating machines in
hydro-power plants which reduces the maintenance cost and simultaneously
increases the operating life of the machines.
SUMMARY OF THE INVENTION.
Accordingly, there is provided a system for automatic and optimum load sharing
of a plurality of generating machines in hydro power plants, the system
comprising an ALSS(automatic load-sharing system)configurator module for
providing inputs, the configurator module containing project specific data in
respect of the hydro-power plants arranged in an hierarchical order from plant
level to the unit levels. An ALSS engine module configured with on-line data in
respect of the operational parameter of each of the plurality of generating
machines, the engine module receiving project specific data from the ALSS
configurator module for generating an optimum loading pattern based on a
minimum cumulative discharge data determined via plurality of iterations on the
actual turbine performance characteristics. The engine module transmitting
command signals to a governor to load the machines optimally. An input and
output interface operably connected to the modules which together constituting
a system software. An ALSS hardware having a data acquisition means collecting
fieId-data and converting the field signals to digital signals enabling the system
software to read and compute the data. An apparatus operating under a series
of sequentially arranged instructions contained in the system software causing
the governor to actuate and optimally load individual generating machines.

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The innovated system generates a series of sequentially arranged instructions
leading to a loading of the machines sequentially corresponding to a discharge
where turbine efficiency is best . The system while suggesting the loading
pattern also takes care of the type of turbine installed at the power station
including the recommended partial bad operation.
The system provides the plant operator with the data for optimal loading of the
hydro plant based on the current load demand and the inputs available to the
units. The criterion considered for determining a specific loading pattern as
optimal is that the cumulative discharge associated with that pattern is minimal.
The load pattern generation and the subsequent instructions to the operator on
the loading of individual units is carriedout individually and separately for
different plants. The system software comprises two modules for example,
ALSS-Configurator; and ALSS-Engine.
ALSS-Configurator:
The turbine designer is required to incorporate project specific data in the
module to configure a system software for a particular hydro project. The plant
details will be provided in terms of a configuration. The hierarchy of the
configuration constitutes, a Plant followed by Units in the plant. The Plant details
include:
Name of the Plant
Location of the Plant
Number of units in the plant

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Rated Speed
Type of turbine
Rated output
Number of net working heads for which data is provided.
Head loss vs. Design curve in case no instrument for reading net heads is
available.
The individual unit data will be:
Maximum and minimum permissible load
For each head, discharge vs. Load and efficiency vs. Load curves (either or
both).
All the data for the project will be stored in project specific files which will serve
as input for the Engine module.
ALSS-Engine:
The data fed into the configurator serve as an input to the ALSS-Engine, which
shall be ultimately used by the hydro plant operator for loading the plant
optimally. It ts configured with on-line input data for a specific plant, and include:
Net head or Head Race & Tail Race Levels.
Current load demand/requirement.
Status of unit ie. Running or under shutdown.
Based on the current load demand and the on-line data in respect of the
operational parameters of the individual units, the ALSS-Engine will compute the
optimum loading pattern. The basis of optimization is the minimum cumulative
discharge coming out of a large number of iterations on the actual turbine
performance characteristics performed by the module. The module also

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computes savings that will result from adopting the optimized via-&-via non-
optimized loading pattern. The ALSS-Engine acts as a decision support tool for
the hydro plant operator to optimally operate the plant. The system software
shall be used to operate online for which a ALSS hardware is employed which
conditions and acquire the field signals from a plurality of sensors to digital
signals which can be read by the system software. The hardware is customized
for the sensors with respect to the signal characteristics. The output data from
the system software shall he fed to a microprocessor based etectro-hydraulic
governor (EHG) for actuating the strokes of the guide vane servomotors of the
plnat.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1- a typical Performance Characteristics of Turbine.
Figure 2- A block diagram of an automatic load sharing system (ALSS)
Figure 3- ALSS-Engine Software Architecture Diagram
Figure 4- Schematic showing External Interface to ALSS-Hardware
Figure 5- ALSS Hardware Configuration diagram.
DETAIL DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION:
Figure 1 - Performance Characteristics of Turbine:
Curves plotted comprise an Efficiency vs. turbine Output and a Discharge vs.
Turbine Output. The efficiency curve of the turbine increases to a peak and then
again falls in a part load regime.

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Figure 2- System Configuration diagram:
The system configuration shown in Fig.2,depicts an input interface (1), an output
interface (2) with a syster (3) software (3). The system software (3) is capable of
estimating the optimum load set point of a governor (4) for each of a plurality of
hydro generating machines so as to maximize efficiency of the overall hydro-
power plant . An ALSS Hardware (6) is disposed for conditioning and converting
the field signals from a plurality of sensors( not shown) to digital signals which
can be read by the system software (3).
Figure 3- ALSS Engine Software Architecture Diagram:
ALSS engine 3(b) is the module responsible for calculating and evaluating the
optimal load set point for the field data for each machine in a power plant (5).
The engine (3b) will use the net head, load demand (13) and the design data for
computing the optimaI load set in an evaluator (9) and will display the
intermediate results in a report generator (10) in the form of plot graphically and
will also flash the final set point. This shall generate command signal for the
Governor (4) to process the signals via a control scheme (12) and load the
machines optimally. This module (3b) also maintains the history of critical
parameters in a back-end database (11) for archival. The architecture shown in
the diagram is about the above flow operation.
Figure 4- Diagram showing External Interface to ALSS-H:
This diagram shows the flow of data from the sensors (not shown) to a data
acquisition means (7) . The field signals from the sensors are conditioned and
converted to digital signals in the data acquisition means (7), which can be read
by the system software (3) and computation work is carried out. The result is fed
to a control scheme interface (8) of each machine for loading the machines
accordingly.

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Figure 5-ALSS Hardware Configuration diagram.
This figure shows the overall ALSS Hardware configuration Including an
apparatus (14) which when loaded and operated under the instructions
contained in the system software (3) implements the invention,
EXAMPLES/PREFERRED EMBODIMENTS:
The ALSS-H system has been extensively tested with actual plant data and the
optimal loading patterns suggested by the program logic has been verified and
validated. One of a typical example is explained below:-
The main parameters of the project are as follows:
a) No. x Rating : 4x100 MW
b) Type of turbine : Vertical Francis
c) Net Heads:
i) Rated net head : 69 M
ii) Maxm. Net head : 75 M
iii) Minm. Net head : 58 H
d) Design discharge (one machine) : 169.0 M3/sec
e) Rated Speed : H2.8 rpm
f) Runner Diameter (inlet) . 4400 mm

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Suppose 75% part load demand IS there, the loading pattern of machines for
300 MW output at 69.0 M net head can have various combination as follows:

The option-1 of load distribution shows a gam of 2.7% in discharge amounting to
8.10 MW of power. Hence, among the three options, the 1st one is most
optimum with respect to load sharing among various units. This shall help power
utility to optimally utilize the generating equipment and conserve the natural
resource.

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WE CLAIM:
1. A system for automatic and optimum load sharing of a plurality of
generating machines in hydro power plants, the system comprising:-
-an ALSS(automatic load-sharing system) configurator module (3a) for
providing inputs, the configurator module(3a) containing project
specific data in respect of a hydro-power plant arranged in an
hierarchical order from plant level to the unit levels;
-an ALSS engine module. (3b) configured with on-line data in respect of
the operational parameters of each of the plurality of generating
machines, the engine module (3b) receiving project specific data from
the ALSS configurator module(3a) for generating an optimum loading
pattern based on a minimum cumulative discharge data determined via
plurality of iterations on the actual turbine performance characteristics,
the engine module (3a) transmitting command signals for a
governor(4) to bad the machines optimally;
-an input and output interface (1,2) operably connected to the
modules(3a,3b) which together constituting a system software(3);
-art ALSS hardware(6) having a data acquisition means(7) collecting
fieId-data and converting the field signals to digital signals enabling the
system software to read and compute the data;
-an apparatus(I4) operating under a series of sequentially arranged
instructions contained in the system software (3) causing the
governor(4) to actuate and optimally load individual generating
machines including display of the out putted data.

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2. The system as claimed in claim 1, wherein the engine module (3b) use a
head, load demand data (13) including the design data of the turbine for
computing an optimal load data for setting in an evaluator (9).
3. The system as claimed in claim 1, wherein the command signals are
transmitted via a control scheme interface (8) of each machine .
4. The system as claimed in claim 1, wherein a control scheme (12) is provided
to the governor (4) for processing the command signals so as to enable the
governor (4) to bad the machines in correspondence with the received signals.
5. A system for automatic and optimum load sharing of a plurality of generating
machines in hydro power plants as substantially described and illustrated herein
with reference to the accompanying drawings.