Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J11/00—Circuit arrangements for providing service supply to auxiliaries of stations in which electric power is generated, distributed or converted
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K3/00—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein
  • F01K3/12—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having two or more accumulators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K7/00—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating
  • F01K7/16—Steam engine plants characterised by the use of specific types of engine; Plants or engines characterised by their use of special steam systems, cycles or processes; Control means specially adapted for such systems, cycles or processes; Use of withdrawn or exhaust steam for feed-water heating the engines being only of turbine type
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
  • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
  • H02J3/381—Dispersed generators

Definitions

• the invention relates to the general field of electric power generation systems. It relates more particularly to
• ancillary auxiliary network derived from the power-removal network of the power station itself connected to the electricity transmission network supplied by the power plant and to the power generation group.
• these facilities also include a network of
• These facilities also include various devices to provide various network services through the plant.
• network service we mean the technical functionalities realized by the power plants
• EP 2595266 (A1) describes in this connection an installation for producing electrical energy comprising means for generating electrical energy intended to be connected to a distribution network and means for storing part of the electrical energy produced. in the form of energy
• the power generation plant thus described comprises a system for producing electrical energy, generated from kinetic energy stored in flywheels.
• This system is associated with the main power generation group which supplies electrical power to the electricity distribution network in order to compensate for the inertia of the steam turbine which drives the generator of the main production group. if it is necessary for the plant to provide the primary response requested by the network and, on the other hand, to supply electricity to the auxiliary network of this plant.
• This electrical energy production system is managed by a controller controlling the operation of the energy storage means and the connection thereof to the generation means and the electricity transmission network.
• the document cited further describes a system for storing energy in the form of kinetic energy.
• the storage and production of electrical energy by means of electrochemical generators can thus prove to be very competitive, in terms of cost, with respect to storage in the form of mechanical energy, especially when a large autonomy is required.
• energy storage in kinetic form is very suitable for providing high powers for short times (of the order of a minute), but it is less for longer times (of the order of a minute). several minutes to several hours).
• auxiliaries commonly called critical auxiliaries
• a power plant require to be powered for periods of up to several hours, in case of failure of the normal power source of the auxiliary network of the plant. This is for example the case of shaft line lubrication systems which, in the event of failure of the plant's auxiliary network supply, must be maintained in operation in order to ensure its shutdown and restart in good conditions.
• the power supply of the auxiliaries of a power plant is generally done, as illustrated in FIG. 1, by means of two types of distribution networks:
• a main auxiliary network medium voltage 4 and low voltage 15, of AC type, the main function of this network being to supply, from the energy transmission network 1 or the main power generation group 2, the set of medium voltage auxiliaries 6 and low voltage 16 of the plant necessary for its proper operation.
• auxiliaries are typically groups of motor pumps, actuators and auxiliary motors operating on average or low voltage, either fixed frequency or frequency variable, the frequency variation can be achieved by means of static frequency converters.
• an auxiliary network 17 called "backup”, of DC type, the main function of which is to mitigate a failure of the main auxiliary network and to allow a maintenance operation, at least temporarily, critical auxiliaries of the plant in order to ensure the shutdown of the plant and its restart in good conditions.
• the backup network of a power plant is therefore particularly constituted by a or more than one battery and other equipment operating in direct current, such as switchboards, control equipment and motors and actuators. These equipments, supplied with direct current, are coupled to the main auxiliary network 4, 15, by means of electronic circuits for converting alternating current into direct current. In normal operation of the unit, the batteries are recharged from the main auxiliary network 15. In the event of a malfunction, the batteries restore the stored electrical energy to the equipment operating in direct current.
• auxiliary networks a main auxiliary network 4, 15 of alternating current and a direct current network 17, induces a complexity of implementation of the auxiliaries and generates problems. significant costs throughout the life cycle of the plant (eg during the design, commissioning and operation phases of the plant).
• these two networks are partially redundant and the equipment operating in direct current, which constitutes in particular the emergency equipment of the critical auxiliaries, is less widespread than the equivalent equipment operating with alternating current and, therefore, generally more expensive.
• these equipment and the elements which constitute them are exclusively dedicated to the emergency function in case of failure.
• An object of the invention is to improve the capabilities of a power plant in terms of network services and operation while drastically simplifying the architecture of its auxiliary power distribution.
• the subject of the invention is an ancillary system for the supply of electrical energy.
• An additional system for the supply of electrical energy for an electricity generating station supplying an electric power transmission network, said production plant of electricity comprising at least one turbine coupled to an alternator forming a main power generation group which supplies an alternating current to an energy evacuation network connected to the transmission network, the energy evacuation network also supplying electricity a main auxiliary network, said main auxiliary network for supplying auxiliary equipment necessary for the operation of the plant.
• the system according to the invention comprises a secondary electrical energy supply unit itself comprising at least one elementary unit for storing and restoring electrical energy in continuous form.
• Said elemental unit comprises electrical energy storage elements coupled to reversible AC direct current converting means providing, on command, the charge of the storage elements from the electrical energy delivered by the main auxiliary network or the discharge of the electrical energy stored in the storage elements on said main auxiliary network.
• the secondary power generation group is sized and designed so that it can:
• the system according to the invention may have additional features.
• the secondary power supply group is sized so as to be able to supply the electricity transmission network with the time profile of electric power making it possible to compensate for the inertia of the gas turbine and / or of the steam turbine during primary response supply requests.
• the secondary power generation group comprises a plurality of elementary units each comprising at least one electrical energy storage element and a reversible AC-DC converter connected to the inputs of the storage element. .
• the assembly is coupled to the electricity transmission network or the energy evacuation network or the main auxiliary network of the plant.
• the elementary units are dimensioned to be able to produce when they are put into service simultaneously at least the requested power.
• the plant being equipped with a first auxiliary thermal generator and / or a second emergency power generating unit, the secondary electrical power supply unit is dimensioned so as to be able to deliver power to the generator. less equivalent to that of the first auxiliary heat group or that of the second auxiliary heat group or to the sum of the powers of these two groups.
• the secondary power supply group is dimensioned such that it provides sufficient power to allow itself to start the alternator of the main group, or that, the central being equipped with an auxiliary thermal generator connected, on command, to the main auxiliary network, it provides sufficient power for the addition of the power supplied by the storage means and the power supplied by the auxiliary thermal generator is sufficient to allow the alternator start of the main group.
• the elementary cell of the secondary electrical energy supply group furthermore comprises complementary means for reversible conversion of direct current to alternating current, coupled to the elements for storing electrical energy.
• These means are configured and arranged to allow the secondary power supply group to ensure, on command, the power supply of the alternator of the main group in the starting phase of the latter from the voltage available on the main auxiliary network and / or the energy available in the energy storage elements, or the load of the electrical energy storage elements and / or the supply of the main auxiliary electricity supply by withdrawing electrical energy by means of complementary conversion means directly to the terminals of the alternator when it is running.
• the complementary DC reversible conversion means are configured so as to provide, on command, a supply voltage of variable frequency for supplying the engines of auxiliary equipment likely to operate at variable speed.
• the elementary cell of the secondary electric power supply group furthermore comprises an additional additional DC-DC converter, connected in parallel to the complementary DC reversible conversion converting means, and making it possible to supply the alternator rotor of the generating set.
• the complementary means of reversible AC direct current converting means are made from IGBT switches (isolated-gate bipolar transistors) controlled by appropriate means.
• the system according to the invention further comprises control means making it possible to operate each of the reversible conversion means either as an AC-DC converter or as a DC-AC converter delivering a given fixed frequency alternating current or variable frequency.
• the subject of the invention is also a power generation plant which comprises an auxiliary system for producing electrical energy according to the invention.
• the proposed electrical energy storage and retrieval system can be advantageously configured to provide a certain time profile of primary reserve power and, once this reserve delivered primary, always be able to provide, following the power time profile required to power the critical auxiliaries of the plant for the desired duration.
• the power profile of the primary response requires the provision of a high power only for a few minutes, which does not cause a complete discharge electrochemical generators provided that they are sized for this purpose.
• FIG. 1 is a block diagram showing the structure of an ancillary network of a plant according to the state of the art with auxiliary auxiliary equipment with direct current, as well as the principle of connection of the continuous power sources and alternatives to the various equipment of the plant;
• FIG. 2 a block diagram showing the basic structure of a system according to the invention and its interconnection to the auxiliary circuit of a power plant;
• FIG. 3 a block diagram showing the device according to the invention in an alternative embodiment and interconnection allowing it to provide additional functionality. It should be noted that in the different figures, the same structural or functional element is identified by the same numerical or alphanumeric reference.
• FIG. 2 shows schematically the principle of implementation of the system according to the invention, in a first embodiment, within the power distribution network of a power plant.
• This network typically comprises an energy evacuation network
• Auxiliaries 6, 16 are constituted by the equipment necessary for the proper functioning of the plant, both the electrical and electronic management and control units, and the equipment performing tasks essential to the proper functioning of the main electricity generation group, such as for example the lubrication pumps of the main group 2 shaft line.
• auxiliary thermal generators 14 and 11 the functions of which consist respectively of:
• auxiliary heat unit 1 For the auxiliary heat unit 1 1, to provide extra energy to start the plant without power from the transport network 1.
• the ancillary electric power supply system mainly comprises a secondary power supply group 7 capable of storing electrical energy taken from the power plant network. which it is integrated and to restore this energy to this same network.
• the secondary group 7 mainly comprises one or more elementary units 8 of electrical power supply configured and arranged to be able to operate in parallel.
• FIG. 2 shows a secondary group 7 comprising a single cell 8.
• each elementary unit 8 comprises means 81 for storing electrical energy, constituted for example by electrochemical generators, in other words storage batteries. Since several elementary units can be used in parallel, it is possible to combine several storage means of different technologies in order to optimize the dimensioning and therefore the cost of the secondary group.
• Each unit 8 also comprises one or more AC / DC reversible converters 82, each converter being preferably constituted by electronic power switches, of the bipolar transistor type with insulated gate, or IGBT according to the English terminology, whose operation is managed by the control means of the system.
• the sizing of the secondary group 7 can be achieved either by sizing the different elements 81 and 82 of an elementary unit 8, or by varying the number of elementary units 8 constituting the secondary group 7 considered.
• control means make it possible to operate the converters 82 of the different elementary units 8 either as an AC-DC converter or as a DC converter.
• -AC delivering an AC current of given fixed frequency or variable frequency.
• Each elementary unit 8 is moreover permanently connected, according to the power that it must develop, to the energy transport network 1 or to the energy evacuation network 10 or to the main auxiliary network 4, via a reversible converter 82 of continuous electrical energy into alternative electrical energy (conversion AC-DC and DC-AC conversion) and, if necessary, via a voltage matching transformer 83.
• Each elementary unit 8 can also be connected to one or the other of these networks either directly at the converter (or one of the converters) 82, or via an adaptation transformer 83.
• each elementary unit 8 can be put into service separately via the control means of the system.
• the cutting into elementary units of the secondary power supply group 7 thus advantageously makes it possible, in the case where the secondary group 7 comprises several elementary units 8, to put into service only the number of elementary units corresponding to the need for inputting. expected energy.
• the power dimensioning of the secondary group 7 can thus be achieved either by sizing the different elements 81 and 82 of an elementary unit 8, or by varying the number of elementary units 8 constituting the secondary group 7 considered.
• Integration with a central unit of the system according to the invention makes it possible, by means of the control means of the system, to configure a secondary power supply group 7 to provide an auxiliary power supply.
• a secondary power supply group 7 to provide an auxiliary power supply.
• auxiliaries 6 and 16 operating as alternating current.
• the secondary power supply group 7 can be sized to provide the power time profile corresponding to the required network service and the power time profile required to supply the critical auxiliaries and to enable, at least temporarily, their power supply. maintenance in operation, so as to ensure the shutdown of the plant and its restart in good conditions.
• the control system of the storage system can control, by means of appropriate interfaces with the control system of said network, the power supply of the critical auxiliaries of the plant since energy storage elements. This characteristic of the system therefore makes it possible to drastically simplify the architecture of the auxiliary electrical distribution of the control unit by eliminating the auxiliary backup network 17, since it provides the same functionalities.
• the secondary group 7 may, for example, be sized to be able to deliver instantly to the electricity transmission network 1 an electric power at least equal to the additional power to be provided by the steam turbine of the main group 2 in case of primary response request. In this way, the inertia of the steam turbine is compensated by the speed of the response of the secondary group 7 and the main group 2 can thus operate continuously at a higher power.
• the primary response corresponds to the fraction of the nominal power of the main group 2 that it must be able to deliver to the network in a very short time.
• the primary response corresponds to the fraction of the nominal power of the main group 2 that it must be able to deliver to the network in a very short time.
• the secondary group 7 can be sized to be able to deliver, in addition to the required power time profile. for supplying the critical auxiliaries, a power at least equivalent to that of the auxiliary heat unit 1 1.
• Such a dimensioning then makes it possible advantageously to use this thermal group in order to provide network services, such as, for example, the primary response. Indeed it is possible, by means of the control system of the storage system, to quickly control the discharge of the storage elements in order to quickly provide on the auxiliary network of the plant a power equivalent to that of the black-start group 1 1, and to control the startup of it so that it replaces the storage system after its startup sequence completed.
• Such a principle can also be implemented to perform network services by means of the backup thermal generator 14, and / or to ensure uninterrupted power supply of the loads supplied by this backup group in the event of a failure of the network supply.
• main assistant The modular structure of the secondary power supply group 7, associated with the use of reversible DC conversion means 82, configurable by means of the control means of which the system according to the invention is provided makes it possible to advantageously to simplify the composition and organization of ancillary means which a power plant may need in different circumstances.
• the system for producing additional electrical energy according to the invention can be implemented to provide certain network services when the plant is at a standstill.
• the block diagram described in FIG. 2 shows that it is possible to connect the system to the electricity transmission network 1, through the group transformer 3 and the auxiliary transformer 5, so that it delivers to the transmission network the electrical energy stored in the batteries 81 of the cells 8 constituting the secondary group 7.
• the control system of this system can be interfaced directly with the control system of the transport network 1, and / or with the control system of the main group 2 to control the control and protection devices such as the group circuit breaker 22 or the line circuit breaker 23.
• the system for producing additional electrical energy according to the invention can be implemented so as to be able to provide the power demand required when starting the auxiliary motors 12, so that the thermal group of 14 (diesel group) is only dimensioned according to the permanent power of the auxiliary engines.
• the electrical energy production system annexed according to the invention can thus be implemented so as to deliver a variable frequency alternating current for restarting the auxiliary motors 12 progressively, variable frequency, to reduce the current draw during a start on dead bus set, that is to say when no more voltage is present on the main auxiliary auxiliary network 4, 15.
• This functionality can be achieved simply by means of interface signals between the system control system and the control system of said main auxiliary network, or if necessary by adding an auxiliary board dedicated to this auxiliary helper restart function on a busbar. death.
• Figure 3 shows schematically the principle of implementation of a variant of the system according to the invention within the power distribution network of a power plant.
• This embodiment variant differs from that of FIG. 2 in that the secondary power supply group 7 comprises one or more elementary units 8b each comprising one or more reversible converters 84 for continuous electrical energy in alternative electrical energy ( AC-DC conversion and DC-AC conversion).
• the second converter 84 is connected to the means 81 for storing electrical energy on the one hand and the alternator of the main group 2 and / or an auxiliary motor 12 'on the other hand.
• the secondary group 7 of the system according to the invention can be connected, depending on its power, either directly to the secondary of the transformer group 3, or to the secondary of the auxiliary transformer 4, which is still the primary of the transformer of group 3.
• the secondary power supply group 7 is sized to perform the required network service or services and so that it replaces the DC backup network by filling the corresponding function.
• the additional electrical energy production system according to the invention can also advantageously be implemented to perform functions normally supported by auxiliary equipment normally present in a power plant and to substitute totally or partially for these equipments.
• auxiliary equipment normally present in a power plant
• control system of this power generation system can be interfaced, if necessary, with the control system of the transport network 1, the control system of the main group 2 and the control system of the control system.
• auxiliary distribution network 4.15 to control the operation of the various control devices (circuit breakers, etc.) and to perform the functions required of the secondary group 7.
• the system according to the invention can be implemented, by using the static power converters 82 and 84 which equip each cell 8 of the secondary group 7, to ensure the static start of the shaft line when the central station is stationary and is not used for another function.
• the static start of the shaft line is usually done using a static frequency converter used to power the alternator in motor mode so as to rotate the shaft line of the gas turbine during its startup phase.
• the converter 82 is driven rectifier (that is to say in voltage source) to create, from the voltage present on the auxiliary network of the central 4 , a DC voltage on the internal DC bus of the secondary group 7.
• the converter 84 is then driven by UPS in such a way that it converts the DC voltage supplied by the converter 82 into a variable frequency AC voltage.
• This configuration of the system according to the invention thus makes it possible to drastically simplify the architecture of the accessories of the central unit by eliminating the static power conversion system 19 (see FIG. 1) normally dedicated to the start of the shaft line.
• the auxiliary electric power generation system according to the invention can advantageously be implemented, so as to ensure the turning function of the shaft line.
• the converter 84 is driven in an inverter so as to provide the power necessary for the rotation at very low speed of the shaft line, when the control unit is at a standstill.
• This configuration of the system according to the invention thus makes it possible to perform the turning function by feeding the turning motor by means of the energy available on the auxiliary network and / or the energy stored in the storage means of the system, allowing and to advantageously simplify the architecture of the auxiliaries of the plant.
• the electrical energy production system of the invention may also advantageously be implemented, so as to provide all or part of the power required to start the line.
• shaft using electrochemical generators 81 the electrical energy stored in the DC voltage generators (ie the batteries) 81 is converted into alternating current by the converters 82 and 84 and transferred to the alternator in motor mode so as to drive the line of rotation in rotation. shaft of the gas turbine.
• This configuration of the system according to the invention thus makes it possible to advantageously simplify the architecture of the auxiliaries of the central unit by making it possible to eliminate the auxiliary thermal unit 1 1 necessary for the start-up of the central unit on a dead busbar (that is to say when the plant must restart without power from the distribution network), or at least reduce the power of this group and therefore its cost by providing a portion of the power required by the storage elements 81.
• the system for producing additional electrical energy according to the invention may advantageously be implemented, so that the static power converter 84, (to the extent that it is not used as described previously in FIG. of the start-up phase of the plant), can be used to supply a variable frequency auxiliary motor.
• This configuration of the system thus makes it possible to advantageously simplify the architecture of the accessories of the control unit by eliminating a static frequency converter dedicated to supplying one or more variable speed auxiliary motors 12, such as for example a food pump motor. the boiler in a combined cycle plant.
• the additional electric power generation system according to the invention can also be advantageously implemented, so as to temporarily provide the power required to supply the static converter 84 by means of the electrochemical generators 81.
• This configuration of the system according to the invention thus makes it possible to provide a supply without disturbances (such as for example voltage dips) of the motor driven by means of the converter 84, even when the main auxiliary network of the plant is disturbed.
• system according to the invention can also be advantageously implemented, so that it allows to draw electrical energy from the alternator to charge the storage means 81 and / or replenish the main auxiliary network 4 of the plant by means of the converters 82 and 84 of this system in the event of failure of the supply of said main auxiliary network 4.
• the converter 84 rectifier that is to say, voltage source
• the converter 82 is in turn controlled by the inverter, so that it converts the DC voltage supplied by the converter 84 into a fixed frequency AC voltage.
• This configuration of the system according to the invention thus makes it possible to drastically simplify the architecture of the auxiliaries of the plant by eliminating the backup auxiliary heat group 14, or to increase the reliability of the supply of the main auxiliary network of the plant by means of of this additional voltage source.
• the plant in the event of incidents on the electric power transmission network 1, the plant is able to isolate itself from said network by means of the line circuit breaker 23, and to supply its auxiliaries while maintaining the main group 2 in operation.
• the electrical energy production system annexed according to the invention can advantageously be implemented, in such a way that it makes it possible to extract electrical energy from the alternator of the generator.
• main group 2 in order to replenish the main auxiliary network 4 of the plant by means of the converters 82 and 84 of this system in the event of failure of the energy storage elements 81.
• This configuration of the system according to the invention thus makes it possible to increase the reliability of the secondary power unit 7 in the event of failure of the energy storage elements 81, the power necessary to ensure the supply of the main auxiliary network 4 being in this case provided by the alternator.
• the electrical energy production system annexed according to the invention can be advantageously dimensioned and designed, so that it can supply the excitation system of the alternator of the main group 2 by means of an additional DC / DC converter connected in parallel with the converter 84.
• This configuration of the system according to the invention thus makes it possible to supply the stator as well as the rotor of the alternator so that it is possible to start the shaft line by means of the single production system, starting from the energy available in the storage elements 81 and / or on the main auxiliary network 4.
• the installation of the system according to the invention advantageously makes it possible to ensure the operation of critical auxiliaries operating in direct current that may need to be maintained, in particular in the case where the system according to the invention invention is implemented in the context of a discount operation to an existing plant.
• These DC equipment according to their quantity, can be connected directly by means of their control / protection equipment to the secondary group 7 of the system at the output of the energy storage elements 81, or at the output of the secondary group 7 by means of an additional DC converter.

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• 2015
  • 2015-08-07 EP EP15770558.3A patent/EP3332467A1/de active Pending
  • 2015-08-07 WO PCT/FR2015/052182 patent/WO2017025664A1/fr active Application Filing
  • 2015-08-07 US US15/529,045 patent/US10243366B2/en active Active

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