Title of Invention

AUTOMATIC LOAD SHARING SYSTEM AMONG VARIOUS UNITS IN A HYDRO POWER PLANT

Abstract

The invention relates to 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 date in respect of the operational parameters of each of the plurality of generating machine, 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 load the machines optimally; an input an output interface (1,2) operably connected to the modules (3a,3b) which altogether constituting a system software (3); an ALSS hardware (6) having a data acquisition means (7) collecting field-data and converting the field signals to digital signals enabling the system software to read and compute the data; an apparatus (14) operating order 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 outputted data.

Full Text

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 a system for extracting optimally the mechanical power from a turbine during a part load operation of the power station. More particularly,the invention relates to a system for automatic and optimum load sharing of a plurality of generating machines in hydro power plants. PACKGRPUND OF THE INVENTION Hydropower generation depends on the available water head and discharge through the machines. The regulation of 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 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 permissible range is generally in the order of 5 to 7%. 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. An US Patent No. 4280060 discloses a teaching of a dedicated microcomputer- based control system for steam turbine-generators wherein a hierarchy of microcomputer subsystems interactive with a conventional analog electrohydraulic control system to provide control and monitoring capabilities during all operating phases of the turbine-generator. The separate microcomputer subsystems are programmed for coordinated interaction and communication through shared, dual-port read/-write memory units and each microcomputer subsystem is programmed and configured to handle a separate group of control responsibilities in a distributed control system. The microcomputer hierarchy includes an input and calculations computer having means for interfacing with analog input data sources and sensors which report on various operating parameters of the turbine-generator and from which thermal and mechanical stress and other derived quantities are calculated; a display and communications computer adapted to interface with a plant computer and with an operator control panel and other display and readout devices whereby operating personnel may interact with the control system; and a control computer, standing at the top of the hierarchy; for receiving information from the other computers, for making decisions based on that information and, through input/output ports, for providing the electro-hydraulic control system with directions for optimal control of the turbine-generator within its thermal and mechanical limitations. The dedicated supervisory controller provides a plurality of operating modes. The patent (US-4280060) on the Supervisory Contro) of Steam Turbine is centered on the design and operation of a typical Distributed Control Systems (DCS) which is not a basis for the instant applications. The instant application is mainly focused on the conservation of water resource and maximizing Power output from a Hydro Power Plants. 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 load-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. 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 parameters 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 field-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. 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 load 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 bad 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. The turbine designer is required to incorporate project specific data in the module to configure a system software for 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 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 AtSS-Engine, which shall be ultimately used by the hydro plant operator for loading the plant optimally. It is 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 computes savings that will result from adopting the optimized vis-avis 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 be fed to a microprocessor based electro-hydraulic governor (EHG) for actuating the strokes of the guide vane servomotors of the plant. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1- a typical Performance Characterstics 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 Figuje 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. The system configuration shown in Fig.2,depicts an input interface (1), an output interface (2) with a system 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 Softwate Architecture Diagram: ALSS engine 3(b) is the module responsible for calculating and evaluating the optima! load set point for the field data for each machine in a power plant (5), The engine (3b) will use the net head, bad demand (13) and the design data for computing the optimal 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 fbw operation. Figure 4- Dlagram shawing 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. FIGURE 5-ALSS Hardware Configuration diagram This figure shows the overall ALSS Hardware configuration including an apparatus (14) which when haded 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 H eads: i) Rated net head 69 M ii)Maxm. Net head : 75 M iii)Minm.Net head :S8M d) Design discharge (one machine) : 169.0 M3/sec e) Rated Speed : 142.8 rpm f) Runner Diameter (inlet) : 4400 mm 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 gain of 27% 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. 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 moduie(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 goyernor(4) to load the machines optimally; -an input and output interface(1,2) operably connected to the modules(3a,3b) which together constituting a system software(3); -an ALSS hardware(6) having a data acquisition means(7) collecting field-data and converting the field signals to digital signals enabling the system software to read and compute the data; -an apparatus(14) 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. 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 I, wherein a control scheme (12) is provided to the governor (4) for processing the command signals so as to enable the governor (4) to load 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. The invention relates to 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 date in respect of the operational parameters of each of the plurality of generating machine, 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 load the machines optimally; an input an output interface (1,2) operably connected to the modules (3a,3b) which altogether constituting a system software (3); an ALSS hardware (6) having a data acquisition means (7) collecting field-data and converting the field signals to digital signals enabling the system software to read and compute the data; an apparatus (14) operating order 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 outputted data.

Documents:

232-KOL-2006-FORM-27-1.pdf

232-KOL-2006-FORM-27.pdf

232-kol-2006-granted-abstract.pdf

232-kol-2006-granted-claims.pdf

232-kol-2006-granted-correspondence.pdf

232-kol-2006-granted-description (complete).pdf

232-kol-2006-granted-drawings.pdf

232-kol-2006-granted-examination report.pdf

232-kol-2006-granted-form 1.pdf

232-kol-2006-granted-form 18.pdf

232-kol-2006-granted-form 2.pdf

232-kol-2006-granted-form 3.pdf

232-kol-2006-granted-form 5.pdf

232-kol-2006-granted-gpa.pdf

232-kol-2006-granted-reply to examination report.pdf

232-kol-2006-granted-specification.pdf