A method and system for designing a fast-closing channel with redundant fast closing for a large hydropower station

Abstract

This invention discloses a design method and system for a multi-redundant fast-closing channel of a high-speed gate in a giant hydropower station. The system includes: the unit's LCU PLC program determining when the fast gate should close; a computer monitoring system generating an opening signal for the fast gate based on the unit's LCU PLC program; based on the signal, the unit's LCU local cabinet's turbine protection gate closing button actuates; the turbine backup protection activates, with subsequent actions consistent with the activation of the unit's LCU local cabinet's turbine protection gate closing button; the simulation panel LCU main powerhouse local cabinet's flood control button actuates; the flood control powerhouse level switch actuates, consistent with the activation of the simulation panel LCU main powerhouse local cabinet's flood control button; and the central control room's fast gate closing button actuates, completing the fast gate closure. This invention, through the design of a dual-ring fiber optic communication network within the LCU and a remote cabinet at the inlet, eliminates the distance limitation imposed by hard-wired circuit design; the dual-ring fiber optic communication network within the LCU provides backup redundancy for each gate closing channel.

Description

Technical Field

[0001] This invention relates to the field of fast gate control for giant hydroelectric generator sets, and in particular to a design method and system for a multi-redundant fast-closing channel for a giant hydroelectric power station's fast gate. Background Technology

[0002] In hydropower stations, rapid-closing gates are crucial hydraulic engineering facilities, playing a vital role in the safe and stable operation of the generating units. They serve as the last line of defense against runaway generators and powerhouse flooding. When a generator experiences a load shedding event due to an accident, and the speed control system fails to operate, the guide vane mechanism cannot cut off the water flow, causing the generator speed to continuously increase. In this situation, an emergency rapid-closing gate operation is necessary to cut off the water flow and shut down the unit. In recent years, powerhouse flooding accidents have occurred frequently in small hydropower stations, causing severe economic losses. For large hydropower stations, the highly reliable and stable design of the rapid-closing channel is extremely important for the safe and stable operation of the generating units.

[0003] Some small hydropower stations have overly simple fast-closing channels. If the optical fiber or communication module is damaged and the channel is interrupted, the fast gate will not be able to be remotely commanded to close quickly in the event of an accident. The only solution is for operation and maintenance personnel to manually close the gate on-site, which may lead to serious consequences such as flooding of the power plant. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or existing designs of fast gate block closure channels in hydropower stations, this invention is proposed.

[0006] Therefore, the problem to be solved by this invention is how to achieve the reliability of the remote control channel for high-speed doors.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] In a first aspect, embodiments of the present invention provide a design method for a multi-redundant fast-closing channel for a giant hydropower station's fast-closing door. This method includes: the PLC program of the unit's LCU determining whether the fast-closing door should close; a computer monitoring system generating an opening signal for the fast-closing door based on the unit's LCU's PLC program; based on the signal, the unit's LCU local cabinet's turbine protection door closing button actuating; the turbine backup protection activating, with subsequent actions consistent with the activation of the unit's LCU local cabinet's turbine protection door closing button; the simulation panel LCU main powerhouse local cabinet's flooded powerhouse button actuating; the flooded powerhouse level switch actuating, consistent with the activation of the simulation panel LCU main powerhouse local cabinet's flooded powerhouse button; and the central control room's fast-closing door button actuating, completing the fast-closing door closure.

[0009] As a preferred embodiment of the multi-redundant fast-closing channel design method for the giant hydropower station's fast gate described in this invention, the following conditions are met for determining when the fast gate closes: when the unit speed is greater than 115% and the unit shear pin breaks, the fast gate closes; when the unit speed is greater than 115% and the unit's mechanical overspeed action occurs, the fast gate closes; when the fast gate opening is less than 90%, the fast gate's analog channel is normal, the fast gate gate slides down 600mm, and the fast gate's sliding and lifting fails; when both vibration alarm 1 and vibration alarm 3 occur, the fast gate closes; when the emergency shutdown process is initiated and the second step of the emergency shutdown process times out, the fast gate closes; when the fast shutdown process is initiated and the first step of the fast shutdown process times out or the shear pin breaks, the fast gate closes.

[0010] As a preferred embodiment of the design method for the multi-redundant fast-closing channel of the fast gate in the giant hydropower station described in this invention, the following steps are taken: the opening signal of the fast gate is generated according to the PLC program of the unit LCU, including the output of three signals. Two of these signals are sent to the remote I / O cabinet of the unit LCU inlet via fiber optic communication. The remote I / O cabinet of the unit inlet sends the gate closing signal to the fast gate opening and closing PLC and the fast gate closing solenoid valve through two output relays. The other signal output by the unit LCU is sent to the local cabinet of the simulation screen LCU located on the generator floor of the main powerhouse via hardwiring. The local cabinet then sends the signal to the remote cabinet of the simulation screen LCU inlet via fiber optic communication. The remote cabinet of the simulation screen LCU inlet sends two signals to the fast gate PLC and the fast gate closing solenoid valve via hardwiring.

[0011] As a preferred embodiment of the design method for the multi-redundant fast-closing channel of the fast gate in the giant hydropower station described in this invention, the fast gate lowering mechanism includes an independent control unit. Each unit's inlet fast gate is controlled by an independent control unit, which is connected to the unit's LCU inlet remote I / O cabinet via a network cable. Two gate lowering methods are adopted: manual and program control. When the PLC device of the fast gate opening and closing machine control cabinet collects the gate lowering signal through the input module, the PLC output module outputs the signal to the output relay to lower the gate.

[0012] As a preferred embodiment of the design method for the multi-redundant fast-closing channel of the fast door of the giant hydropower station described in this invention, the turbine protection door closing button of the unit LCU local cabinet includes button contacts that are hardwired to the unit LCU local cabinet and the simulation screen LCU main plant local cabinet respectively.

[0013] As a preferred embodiment of the design method for the multi-redundant fast-closing channel of the giant hydropower station described in this invention, the flooded powerhouse button of the simulation screen LCU main plant local cabinet includes button contacts that are respectively connected to the unit LCU local cabinet via hard wiring and to the simulation screen LCU inlet remote cabinet via fiber optic communication.

[0014] As a preferred embodiment of the design method for the multi-redundant fast-closing channel of the fast door of the giant hydropower station described in this invention, the fast door closing button in the central control room includes a simulation screen LCU local cabinet that sends the door closing signal to the simulation screen LCU local cabinet in the main powerhouse via optical fiber communication. The simulation screen LCU local cabinet in the main powerhouse opens a signal and sends it to the unit LCU local cabinet via hard wiring, and then sends it to the simulation screen LCU inlet remote cabinet via optical fiber communication.

[0015] Secondly, to further address the problems existing in the design of the block-closing channel of the fast gate in hydropower stations, this embodiment of the invention provides a design system for a multi-redundant fast-closing channel of a giant hydropower station fast gate, including an input module, an analog module for signal acquisition; an output module for sending the signal to the output relay to close the gate; a CPU module for program calculation and signal processing; and an optical fiber communication module for forming a dual-ring network to send the output signal to the remote I / O cabinet at the LCU inlet of the unit.

[0016] Thirdly, embodiments of the present invention provide a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program, when executed by the processor, implements any step of the design method for multi-redundant fast-closing channels of fast doors for giant hydropower stations as described in the first aspect of the present invention.

[0017] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any step of the design method for multi-redundant fast-closing channels of fast doors for giant hydropower stations as described in the first aspect of the present invention.

[0018] The beneficial effects of this invention are as follows: it eliminates some single-point opening and closing door logic, reducing the possibility of high-speed door malfunction; the linkage of the unit LCU, the simulation panel LCU, and the high-speed door hydraulic system's opening and closing machine PLC makes the closing door channels more diverse, reducing the chance of high-speed doors refusing to operate in emergency situations; through the design of the LCU's internal dual-ring network fiber optic communication and the inlet remote cabinet, distance is no longer a limitation restricting the hard-wired circuit design; the LCU's internal dual-ring network fiber optic communication provides backup redundancy for individual closing door channels. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0020] Figure 1 This is the logic diagram of the entire high-speed door closing mechanism in Example 1.

[0021] Figure 2 This refers to the various logics used in the unit's LCU program in Example 1 to determine when the fast door is closed. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0025] Example 1

[0026] Reference Figure 1 This is the first embodiment of the present invention, which provides a design method for a multi-redundant fast-closing channel for a giant hydropower station's fast gate, comprising the following steps:

[0027] S1: The PLC program of the unit's LCU determines whether the high-speed door will close.

[0028] Furthermore, the judgment conditions for the high-speed door to close include: when the unit speed is greater than 115% and the unit shear pin breaks, the high-speed door closes; when the unit speed is greater than 115% and the unit mechanical overspeed action occurs, the high-speed door closes; when the high-speed door opening is less than 90%, the high-speed door analog channel is normal, the high-speed door gate slides down 600mm and the high-speed door slides down and lifts up unsuccessfully; when both vibration alarm 1 and vibration alarm 3 occur, the high-speed door closes; when the emergency stop procedure is started and the second step of the emergency stop procedure times out, the high-speed door closes; when the rapid stop procedure is started and the first step of the rapid stop procedure times out or the shear pin breaks, the high-speed door closes.

[0029] Furthermore, the oscillation alarm is as follows: If excessive oscillation occurs during the operation of the turbine generator, it will cause serious hydraulic mechanical accidents. Giant units are equipped with oscillation sensors near the turbine shaft. When the oscillation sensor is activated, it will trigger an alarm and send it to the unit's LCU.

[0030] Furthermore, emergency shutdown refers to the process that triggers the unit's LCU emergency shutdown procedure when a giant generating unit experiences an accident such as generator protection shutdown, main transformer non-variable protection shutdown, or main transformer protection shutdown.

[0031] Among them, when a Class I mechanical accident (unit overspeed, mechanical overspeed, etc.) or a Class II mechanical accident (governor oil pressure too low, oil level too low, unit bearing temperature too high, etc.) occurs, the unit LCU rapid shutdown procedure will be triggered.

[0032] Emergency shutdown procedures can bring the unit down in a shorter time, preventing the accident from escalating.

[0033] Preferably, the hydropower station's rapid closing gate design employs an independent control unit. Each unit's inlet rapid closing gate is controlled by an independent control unit, connected to the unit's LCU inlet remote I / O cabinet via a network cable. It utilizes both manual and program-controlled gate closing methods. When the rapid closing signal is acquired by the input module of the rapid closing gate control cabinet PLC device, the PLC output module sends the signal to the output relay to close the gate. Each unit in the hydropower station has one unit LCU inlet remote I / O cabinet and two hydraulic system control cabinets arranged in the inlet rapid gate hydraulic opening and closing machine room. The left and right bank units are each equipped with one inlet simulation panel LCU inlet remote I / O cabinet.

[0034] S2: The computer monitoring system generates an opening signal for the high-speed door based on the PLC program of the unit's LCU.

[0035] Preferably, the opening signal for the high-speed door is generated according to the PLC program of the unit LCU, including the output of three signals. Two of these signals are sent to the remote I / O cabinet of the unit LCU inlet via fiber optic communication (a dual-ring network formed by Schneider PLC fiber optic communication module NRP). The remote I / O cabinet of the unit inlet sends the door closing signal to the high-speed door opening and closing PLC and the high-speed door solenoid valve through two output relays. The other signal output by the unit LCU is sent to the local cabinet of the analog panel LCU located on the generator floor of the main plant through hard wiring. From the local cabinet, it is sent to the remote cabinet of the analog panel LCU inlet via fiber optic communication. The remote cabinet of the analog panel LCU inlet sends two signals to the high-speed door PLC and the high-speed door solenoid valve through hard wiring.

[0036] The unit's LCU input module collects signals, and the program makes judgments, which activates the door closing signal from the opening module to the opening relay, and sends the signal to the high-speed door PLC and the high-speed door solenoid valve to close the door.

[0037] Furthermore, the signals that trigger the high-speed door to close are divided into: 1. Hard circuit trigger (such as the flooded factory button, the simulated screen high-speed door closing button, and the flooded factory switch action triggering the door to close); 2. LCU program judgment triggering the door to close.

[0038] S3: Based on the signal, the unit's LCU local cabinet water chiller protection door closing button is activated.

[0039] The button contacts are connected to the unit's LCU local cabinet and the analog panel LCU main plant local cabinet via hardwired connections.

[0040] Furthermore, the subsequent actions of the unit's LCU and the analog LCU are consistent with the opening signal of the high-speed door generated by the computer monitoring system based on the PLC program of the unit's LCU.

[0041] S4: Water turbine backup protection action activated, and subsequent actions are consistent with the action of the water turbine protection door closing button on the unit's LCU local cabinet.

[0042] S5: Simulate the action of the LCU main plant local cabinet flooding plant button.

[0043] Preferably, the flooding control button of the main plant local cabinet of the simulation screen LCU includes button contacts that are respectively connected to the unit LCU local cabinet via hard wiring and to the simulation screen LCU inlet remote cabinet via fiber optic communication.

[0044] Furthermore, the subsequent actions of the unit's LCU and the analog LCU are consistent with the opening signal of the high-speed door generated by the computer monitoring system based on the PLC program of the unit's LCU.

[0045] S6: The flood level switch for the waterproof factory is activated, and its operation is consistent with the operation of the flood level button on the analog panel LCU main factory local cabinet.

[0046] S7: Press the button to lower the high-speed door in the central control room to complete the closing of the high-speed door.

[0047] Preferably, the local cabinet of the simulation screen LCU sends the door closing signal to the local cabinet of the simulation screen LCU in the main plant via fiber optic communication. The local cabinet of the simulation screen LCU in the main plant then sends a signal to the local cabinet of the unit LCU via hardwire, and finally to the remote cabinet of the simulation screen LCU inlet via fiber optic communication.

[0048] Furthermore, the subsequent actions of the unit's LCU and the analog LCU are consistent with the opening signal of the high-speed door generated by the computer monitoring system based on the PLC program of the unit's LCU.

[0049] like Figure 1 The diagram shown is the logic diagram of the entire high-speed door closing mechanism. When the door closing trigger condition occurs, the signal can reach the high-speed door opening and closing machine control cabinet through multiple channels and trigger the door to close. When the channel from the main plant simulation screen LCU to the high-speed door opening and closing machine control cabinet is interrupted, the action of the simulation return screen button can realize the door closing through the unit LCU to the high-speed door opening and closing machine control cabinet.

[0050] Similarly, when the control channel from the unit's LCU to the high-speed gate is interrupted, and the water turbine protection door-lowering button is activated, the door can be lowered through the simulation panel LCU to the high-speed gate-lowering channel.

[0051] This design effectively avoids channel interruptions that could prevent the high-speed door from closing quickly, making the equipment more reliable.

[0052] This embodiment also provides a design system for a multi-redundant fast-closing channel of a giant hydropower station's fast gate, including an input module, an analog module for signal acquisition, an output module for sending the signal to the output relay to close the gate, a CPU module for program calculation and signal processing, and an optical fiber communication module for forming a dual-ring network to send the output signal to the remote I / O cabinet at the LCU inlet of the unit.

[0053] This embodiment also provides a computer device applicable to the design method of multi-redundant fast-closing channels for fast doors in giant hydropower stations, including:

[0054] The system includes a memory and a processor. The memory stores computer-executable instructions, and the processor executes these instructions to implement the design method for multi-redundant fast-closing channels of fast doors for giant hydropower stations, as proposed in the above embodiments.

[0055] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0056] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the design method for multi-redundant fast-closing channels of fast doors in giant hydropower stations as proposed in the above embodiments.

[0057] In summary, this invention eliminates some single-point opening and closing door logic, reducing the possibility of high-speed door malfunctions. The linkage between the unit's LCU, the analog LCU, and the high-speed door hydraulic system's opening and closing mechanism PLC allows for more diverse door closing channels, reducing the likelihood of high-speed doors refusing to operate in emergency situations. When the distance between the unit's LCU local cabinet and the controlled equipment is too great (exceeding 1km), hard-wired circuits may cause the controlled equipment to receive excessively low voltage, failing to drive relays. Through the design of the LCU's internal dual-ring fiber optic communication and the inlet remote cabinet, distance is no longer a limitation restricting the hard-wired circuit design. The LCU's internal dual-ring fiber optic communication provides redundancy for individual door closing channels.

[0058] Example 2

[0059] Reference Figure 2 This is the second embodiment of the present invention. Based on the first embodiment, in order to verify its beneficial effects, a specific experimental judgment process is provided for this experiment.

[0060] like Figure 2 As shown, the various logics for determining the closing of the fast door in the unit's LCU program are listed. To effectively avoid equipment malfunction, each door closing trigger condition requires two or more conditions to occur simultaneously to trigger the door to close. Furthermore, when the unit's LCU determines that any one of the following conditions is met, the fast door will be triggered to close.

[0061] The triggering conditions include the following:

[0062] Condition 1: The unit speed is greater than 115% and the unit shear pin is sheared.

[0063] Condition 2: The unit speed is greater than 115% and the unit mechanical overspeed action.

[0064] Condition 3: The opening degree of the high-speed gate is less than 90%, the analog signal channel of the high-speed gate is normal, the gate slides down 600mm, and the high-speed gate slides down and lifts up but fails.

[0065] Condition 4: Oscillation alarm 1 and oscillation alarm 3.

[0066] Condition 5: The emergency shutdown procedure is initiated, and the second step of the emergency shutdown procedure times out.

[0067] Condition 6: The rapid shutdown process is initiated, and the first step of the rapid shutdown timeout or the shear pin is sheared.

[0068] All of the above conditions prevent single-point state changes from causing the door to close, effectively preventing equipment malfunctions that could lead to the high-speed door opening accidentally.

[0069] After the overhaul of the giant power plant units, more than 20 dynamic water gate tests were conducted, and no cases of the fast gates malfunctioning and closing occurred.

[0070] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A design method for a multi-redundant fast-closing channel of a high-speed gate in a giant hydropower station, characterized in that: This includes the PLC program of the unit's LCU determining whether the high-speed door is closing; The computer monitoring system generates the opening signal of the high-speed door based on the PLC program of the unit's LCU; Based on the signal, the protection door closing button of the unit's LCU local cabinet water chiller was activated; The water chiller backup protection is activated, and subsequent actions are consistent with the action of the water chiller protection door closing button on the unit's LCU local cabinet. Simulated screen LCU main plant local cabinet flooding plant button action; The liquid level switch for the flood-proof factory building operates in accordance with the action of the flood-proof factory building button on the analog panel LCU main factory local cabinet. The button to close the high-speed door in the central control room is activated, completing the closing of the high-speed door; The conditions for determining when the high-speed door closes include: When the unit speed is greater than 115% and the unit shear pin breaks, the fast door closes. When the unit speed exceeds 115% and the unit's mechanical overspeed action occurs, the high-speed door will close. When the opening degree of the fast door is less than 90%, the analog signal channel of the fast door is normal, the fast door gate slides down 600mm and the fast door slides down and lifts up fails. When the emergency shutdown procedure is initiated and the second step of the emergency shutdown procedure times out, the high-speed door closes. When the rapid shutdown process is initiated, and the first step of the rapid shutdown times out or the shear pin is sheared, the rapid door will close. The high-speed door closing mechanism includes an independent control unit. Each unit's inlet high-speed door is controlled by an independent control unit, which is connected to the unit's LCU inlet remote I / O cabinet via a network cable. It adopts two closing methods: manual and program control. When the PLC device of the high-speed door opening and closing machine control cabinet collects the door closing signal through the input module, the PLC output module outputs the signal to the output relay to close the door.

2. The design method for multi-redundant fast-closing channels of fast gates in giant hydropower stations as described in claim 1, characterized in that: The process of generating the opening signal for the high-speed door according to the PLC program of the unit LCU includes the output of three signals, two of which are sent to the remote I / O cabinet of the unit LCU inlet via fiber optic communication. The remote I / O cabinet of the unit inlet sends the door closing signal to the high-speed door opening and closing PLC and the high-speed door solenoid valve through two output relays. Another signal from the unit's LCU is sent via hardwired to the local cabinet of the LCU in the main plant's generator floor. From there, the signal is sent via fiber optic communication to the remote cabinet at the LCU inlet of the simulation screen. The remote cabinet at the LCU inlet of the simulation screen sends two signals via hardwired to the PLC of the high-speed door and the solenoid valve for closing the high-speed door.

3. The design method for multi-redundant fast-closing channels of fast doors in giant hydropower stations as described in claim 2, characterized in that: The unit LCU local cabinet water turbine protection door button includes button contacts that are hardwired to the unit LCU local cabinet and the analog screen LCU main plant local cabinet, respectively.

4. The design method for multi-redundant fast-closing channels of fast doors in giant hydropower stations as described in claim 3, characterized in that: The flood control button of the main plant local cabinet of the simulation screen LCU includes button contacts that are respectively connected to the unit LCU local cabinet via hard wiring and to the simulation screen LCU inlet remote cabinet via fiber optic communication.

5. The design method for multi-redundant fast-closing channels of fast doors in giant hydropower stations as described in claim 4, characterized in that: The central control room's rapid door closing button includes a simulated screen LCU local cabinet that sends the door closing signal to the main plant's simulated screen LCU local cabinet via fiber optic communication. The main plant's simulated screen LCU local cabinet then outputs a signal, which is sent to the unit's LCU local cabinet via hardwire and then to the simulated screen LCU inlet remote cabinet via fiber optic communication.

6. A fast-closing channel design system employing the multi-redundant fast-closing channel design method for giant hydropower station fast doors as described in any one of claims 1 to 5, characterized in that: It also includes, Input modules and analog modules are used for signal acquisition; The output module is used to output a signal to the output relay to close the door; The CPU module is used for program calculations and signal processing. The fiber optic communication module is used to form a dual-ring network, which sends the output signal to the remote I / O cabinet at the LCU inlet of the unit.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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