Reconstruction method for electrical control upgrading of nuclear power plant switching station without integral power failure

Abstract

The invention relates to the technical field of non-safety-level transformation of a nuclear power plant, and discloses a transformation method for electrical control upgrading of a nuclear power plant switching station without integral power failure, which comprises the following steps: S1, setting a transformation premise; s2, a transformation preparation period; s3, a transformation transition period; and S4, in a transformation ending period, the transformation is completed by using a plurality of local power failure windows. According to the transformation method for electrical control upgrading of the nuclear power plant switching station without overall power failure, in order to achieve the purpose of electrical control upgrading under the state that the nuclear power plant switching station is not overall power failure, new equipment is installed at a time, cables are laid, and pre-debugging is conducted; and a new control system is accessed in a multi-turn overhaul window step-by-step power failure manner, and an old system is synchronously stripped, so that the influence of overall power failure on normal power supply of a load can be avoided, and the economic and livelihood power utilization stability is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-safety level modification of nuclear power plants, in particular to a modification method for upgrading electrical control of non-integral power failure of a switch station of a nuclear power plant. BACKGROUND

[0002] The core control loop of the switch station of the second-generation nuclear power unit is built on integrated circuits, and the logic control link is mainly realized by relay switching circuits. Due to the large number of components, the complex overall architecture, the gradual aging of equipment, and the discontinuation of supporting spare parts, the system operation and maintenance and daily management are significantly increased in difficulty. If the modification work is carried out in the mode of full stop of the switch station, it will directly affect the stable supply of power load, and further cause adverse effects on people's livelihood protection and economic operation. Therefore, the modification work needs to be controlled in the premise of not interrupting the overall power supply of the switch station, to ensure the safe and orderly progress of the modification work, and finally realize the upgrading of electrical control technology.

[0003] There are still many problems to be solved in the current modification method of the switch station of the nuclear power plant: first, compared with conventional engineering projects, the construction period of such modification is more stringent, and the time urgency is outstanding; second, the modification work needs to be completed in the existing plant, and there are still a large number of equipment in operation in the plant, which limits the equipment arrangement space, cable laying channel and operation space of the construction personnel; third, the modification construction risk in the nuclear power scene is much higher than that in the conventional project, and if the operation space and construction process are not scientifically planned, it is easy to cause safety incidents such as accidental touching of live equipment, equipment mis-trip and system false alarm.

[0004] In view of this, we propose a modification method for upgrading electrical control of non-integral power failure of a switch station of a nuclear power plant. SUMMARY

[0005] The purpose of the present application is to provide a modification method for upgrading electrical control of non-integral power failure of a switch station of a nuclear power plant to solve the problems raised in the background art.

[0006] To achieve the above purpose, the present application provides the following technical solution: A modification method for upgrading electrical control of non-integral power failure of a switch station of a nuclear power plant, comprising the following steps: S1, before modification, install new equipment required for modification at one time, complete cable laying and pre-commissioning according to the final design, and then use multiple nuclear power normal maintenance windows to orderly partially power off, gradually strip the original analog control system of the switch station, and connect and activate the equipment of the new control system; S2, the preparation period of the transformation, the design unit completes the preliminary design, equipment procurement and overall construction drawing design, each node is well prepared for scheme review and design quality control, equipment manufacturing is completed and delivered for installation, cable is laid according to the final design, and the debugging unit completes the pre-debugging to complete the preparation stage and enter the subsequent step. Considering the particularity and difficulty of nuclear power project, 4-5 years are reserved according to the complexity of the wiring of nuclear power switch station in this stage; S3, the transition period of transformation, the transformation transition period needs to be inserted into multiple maintenance windows. In the first transition implementation period, the NCS system station control layer equipment and other public systems need to be put into operation, and the equipment is transformed according to the window, and the data interconnection with the old control and remote control system is completed. The corresponding part of the old system is synchronized to exit operation, and 3-5 years are reserved as the transition period according to the equipment maintenance plan and line power-off plan of the switch station maintenance window. S4, the end of the transformation, the transformation is completed by using multiple local power-off windows. In this stage, the old screen cabinet and related cables and transition cables are removed and finally cleaned.

[0007] In a further scheme, the method is suitable for the electrical control system of the second generation nuclear power station unit switch station using analog technology control, which is upgraded to NCS power network computer monitoring system by non-integrated power-off.

[0008] In a further scheme, the step S2 needs to determine the feasibility of the transformation equipment arrangement and cable channel, determine the related process adaptability transformation range, and judge the cost and economic benefit.

[0009] In a further scheme, the method needs to go through multiple maintenance, and the new and old control systems need to run together for a long time before the transformation is completed.

[0010] In a further scheme, the step S3 of the old system corresponding part is synchronized to exit operation according to the equipment maintenance plan and line power-off plan of the switch station maintenance window.

[0011] In a further scheme, in order to ensure the smooth implementation of the non-integrated power-off transformation, risk control needs to be carried out in the whole life cycle of the system.

[0012] In a further scheme, the step S2 of the preparation period of the transformation is synchronized with the transformation of the DC system. A new set of fixed type exhaust lead-acid storage battery and phase control type charging device are composed of a DC system, which supplies power for the new control system and gradually replaces the original DC system.

[0013] In a further scheme, the step S2 is to complete the modification of the remote control system, the PMU system and the signal protection system in the preparation period of modification, the new system establishes an independent data channel, the new and old systems synchronously upload data, and the device information migration is gradually completed through the power-off window.

[0014] In a further scheme, the step S3 is to design an independent transition drawing for each power-off window in the transition period of modification, to clearly show the interface of the new device with the unmodified and modified devices and the transition cable planning, and to add a specific letter suffix to identify the transition cable.

[0015] In a further scheme, the method can complete the upgrade of the electrical control system without overall power-off of the switch station of the nuclear power plant.

[0016] Compared with the prior art, the present application provides a modification method for electrical control upgrade of a switch station of a nuclear power plant without overall power-off, which has the following beneficial effects: 1. The modification method for electrical control upgrade of a switch station of a nuclear power plant without overall power-off is used to achieve the purpose of completing the electrical control upgrade under the condition of no overall power-off of the switch station of the nuclear power plant. The new device is installed and the cable is laid and pre-adjusted at one time, and then the new control system is connected through the power-off window in multiple rounds of maintenance, and the old system is simultaneously stripped, so as to avoid the influence of overall power-off on normal power supply of the load and to ensure the stability of economic and livelihood electricity.

[0017] 2. The modification method for electrical control upgrade of a switch station of a nuclear power plant without overall power-off is used to solve the problems of aging of the analog control system device of the second-generation nuclear power plant switch station, stoppage of spare parts and high operation and maintenance pressure. The analog control system is upgraded to an NCS power network computer monitoring system, and the related public systems such as the DC system and the remote control system are simultaneously modified, so as to realize digital transformation of the control system and reduce the operation and maintenance difficulty and risk.

[0018] 3. The modification method for electrical control upgrade of a switch station of a nuclear power plant without overall power-off is used to solve the problems of tight modification period, limited space and high construction risk of nuclear power plant modification. The power-off window is designed in the order of bus, main transformer related string and other string, and the independent transition drawing and the whole life cycle risk control are matched, so as to ensure the safe and orderly implementation of the modification process and take into account the construction quality and efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a control framework comparison chart before and after modification of the present application. Figure 2 It is a step flow chart of the present application. DETAILED DESCRIPTION

[0020] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0021] Please refer to Figures 1-2 The present application provides a technical solution: A method for upgrading the electrical control of a nuclear power plant switch station without overall power failure, comprising the following steps: S1, before the transformation, first install the new equipment required for the transformation in one go, complete the cable laying and pre-commissioning according to the final design, and then use multiple nuclear power normal maintenance windows to sequentially power down and gradually strip the original analog control system of the switch station, and connect and activate the new control system equipment; S2, transformation preparation period, the design unit completes the preliminary design, equipment procurement and overall construction drawing design, each node is well prepared for scheme review and design quality control, equipment manufacturing is completed and delivered for installation, cable laying is completed according to the final design, and pre-commissioning is completed by the commissioning unit. After the preparation phase, the subsequent steps can be completed. Considering the particularity and difficulty of nuclear power projects, 4-5 years are reserved according to the complexity of the nuclear power switch station wiring in this stage, further, step S2 needs to determine the feasibility of the transformation equipment layout and cable channel, determine the range of related process adaptability transformation, and judge the cost and economic benefit, further, step S2 implements the DC system transformation during the transformation preparation period, a new set of fixed exhaust type lead-acid storage battery and phase-controlled charging device is installed, which constitutes a DC system, and supplies power to the new control system and gradually replaces the original DC system, further, step S2 synchronously implements the transformation of the remote control system, PMU system and signal protection system during the transformation preparation period, the new system establishes an independent data channel, the new and old systems synchronously upload data, and the device information migration is gradually completed through the power failure window; S3, transition period, the transition period needs to be inserted into multiple rounds of overhaul windows, in the first transition implementation period, the NCS system station control layer equipment and other public systems need to be put into operation, and the equipment needs to be modified according to the window, and the data interconnection with the old control and remote system is completed, through multiple power outage windows, the new control system interval layer equipment is accessed, the corresponding part of the old system is synchronized to exit operation, according to the equipment maintenance plan of the switch station overhaul window and the line outage plan, further, step S3 transition period plans power outage window in the order of "bus, main transformer related string, other string", first, a single bus is powered off for modification, then the corresponding string and another bus are modified using the main transformer overhaul window, the remaining string is sequentially implemented by means of line maintenance cycle, and the transition period is designed for each power outage window, the interface between the new equipment and the unmodified and modified equipment is clear, and the transition cable planning is clear, the transition cable is added with a specific letter suffix identifier; S4, the end of the modification, after the modification is completed using multiple local power outage windows, in this stage, the old screen cabinet and related cables and transition cables are removed and finally cleaned.

[0022] Further, the method is applicable to the electrical control system of the second generation nuclear power plant unit switch station using analog technology control, which is upgraded to NCS power network computer monitoring system without overall power outage, further, the method needs to go through multiple overhauls, and the new and old control systems need to coexist for a long time before the modification is completed, further, the method needs to control the risk in the whole life cycle of the system, including the risk control in the design stage, the equipment development and production stage, the installation and debugging stage, and the operation and maintenance stage, further, the method can realize the upgrading of the electrical control system without overall power outage in the switch station of the nuclear power plant.

[0023] Embodiment one, the problems that need to be considered for the modification feasibility mainly include three aspects: modification equipment arrangement and cable channel feasibility, related process adaptability modification range, and cost and economic benefit judgment.

[0024] I. Modification equipment arrangement and cable channel feasibility Although the modification is implemented in steps without overall power outage, the new equipment required for modification needs to be installed at one time and the cable laying and pre-debugging are completed according to the final design, and the feasibility of equipment arrangement is the first problem to be solved; the modification equipment arrangement space and cable channel planning scheme are one of the key factors for implementing the modification without overall power outage, and the on-site survey work needs to be done well to ensure that there is enough space to arrange new equipment in the existing plant, if necessary, the structure of the existing plant can be modified, new equipment rooms can be opened out by changing the structure and purpose of part of the rooms, and the required equipment can be placed in the new equipment rooms, and the new equipment and the original equipment are arranged in different rooms during design to minimize the modification implementation risk.

[0025] To solve the problem of new device arrangement, the original switch station control building is structurally modified, the original overhead layer of the workshop warehouse on the second floor is removed, a new floor is built, 4 steel columns and corresponding steel beams are added as the support system, and the original structure is reinforced. The upper space divided by the new floor is combined with other original offices to form a new relay protection room, and the lower space is reasonably separated to arrange the new battery group and other devices required for the modification. There are usually a large number of cables in the operation workshop, and the pre-design needs to estimate the amount of modified cables and reasonably plan the cable channel to avoid the situation that the cable channel path is not available or the space is not enough, which affects the implementation of the project.

[0026] II. Scope of related process adaptation The switch station control system modification is mainly based on electrical engineering, but depending on the different device arrangement conditions, it may cause adaptive modification of other specialties, such as: structural changes and new room requirements for architectural and structural support, new equipment ventilation and temperature control requirements for HVAC intervention, possible changes in water system pipelines for fire and safety, and water and thermal control professionals to provide support. These should be determined whether the implementation conditions are met.

[0027] III. Cost and economic benefit judgment In addition to considering the conventional equipment purchase cost, construction and installation cost, etc., according to the characteristics of non-integrated power modification, the removal cost of related equipment and cables, the dynamic cost adjustment caused by the long implementation period of the modification, the possible building modification reinforcement and evaluation cost should also be considered. From the safety and operation point of view, the benefits brought by the modification to the power plant operation should be analyzed, and the potential social benefits should be quantified.

[0028] Example II, overall scheme design during the modification preparation period: the existing GIS related control cabinet in the relay room and the GIS on-site cabinet in the high voltage distribution device room are modified synchronously, the logic in the GIS control cabinet is realized by the new GIS control cabinet and the related wiring in the circuit breaker protection screen operation box, NCS no longer needs to control GIS through the old GIS control cabinet, which can better solve the problem of upgrading the original analog control system of the switch station Figure 1 ).

[0029] There are two possibilities for the GIS device modification scheme depending on the specific circumstances of the project. Both of these schemes are theoretically feasible, and the appropriate scheme can be selected according to the modification budget, arrangement space, etc. Scheme one: GIS primary equipment and secondary equipment are replaced at the same time; this scheme has high matching degree of primary equipment and secondary equipment, but the cost is higher; if the new plant cannot be built, the primary equipment needs to be replaced in the original position, and in the replacement process, the GIS selection is limited due to the limitation of the original space, and the requirement for layout is higher, at the same time, the old equipment needs to be removed and the new equipment needs to be installed, the power-off time is longer, and the single bus operation condition will appear for a long time during the transformation period; Scheme two: do not replace the GIS primary equipment, only replace the secondary equipment, and the replaced secondary equipment should be able to complete all the control and locking logic of the original control cabinet and on-site cabinet, the cost of this scheme is lower than that of scheme one, but the control cabinet cannot be directly used with the conventional drawing, and needs to be designed according to the original primary equipment and operation conditions to better match the original GIS primary equipment, and the design requirement is higher.

[0030] The non-integrated power-off upgrade of the switch station control system also involves the synchronous transformation of the public systems such as the remote control system, PMU and signal protection system, which can be considered according to the specific conditions of the project; the signal protection system and PMU system can establish a new data channel for the new system during the transition period, and the new and old systems can upload data to the dispatching end at the same time, and gradually through the power-off window, the relevant equipment information is moved from the old system to the new system; the background of the equipment after the transformation of the remote control system is recommended to establish an interconnection relationship with the background of the original system, and the data of the old system background is transmitted to the new system background, and the new system is transmitted to the dispatching through the new system; the new and old systems may be products of different manufacturers, if the new and old systems can complete data interconnection through protocol conversion or other ways, the new system can use the original data channel to transmit data to the dispatching side, if there is a problem in the data intercommunication between the new and old systems, the new transmission channel needs to be applied to the dispatching to ensure the transmission of data.

[0031] Example three, transition drawing design during the transition period: according to the sequence and range of the power-off equipment, the relevant drawing design of each power-off window access equipment needs to be designed, the transition drawing needs to pay attention to the interface design of the new and old equipment, the interface design of the new and old equipment, and the transition cable planning, especially the public equipment such as bus protection, interlock across the interval, the new equipment needs to be connected with the untransformed equipment, and the implementation conditions of the equipment conditions and the implementation conditions need to be paid special attention to; the transition drawing should be divided into systems with the original construction drawing file, each transition stage can be named with suffix A, B, C…… to distinguish the drawing of different transition stages, and the naming rules of the cable laid during the transition period should also be identified with the rules in the construction drawing system, such as adding a specific letter suffix, which is convenient for removing after the transition period.

[0032] The nuclear power file update during the transition period: during the transition period, special attention should be paid to the influence of the implementation window on the original nuclear power file. According to the implementation, the original nuclear power file is modified, replaced or cancelled, and other upgrading work is carried out. In addition, the operation program and maintenance outline of the power station need to be upgraded.

[0033] Risk control of non-integrated power outage modification: in order to ensure the smooth implementation of non-integrated power outage modification, risk control needs to be carried out throughout the life cycle of the system, including risk control in the design stage, equipment development and production stage, installation and commissioning stage and operation and maintenance stage.

[0034] The above has made a detailed description of the present application, but some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, the modifications or improvements without departing from the spirit of the present application are within the protection scope of the present application.

Claims

1. A method of retrofitting a nuclear power plant switchyard non-entire blackout electrical control upgrade, characterized by, The method comprises the following steps: S1, before transformation, the new equipment required for transformation is installed at one time, cable laying and pre-commissioning are completed according to the final design, and then the original analog control system of the switch station is gradually stripped off, and the new control system is connected and put into operation in an orderly manner during multiple normal maintenance windows of the nuclear power station; S2, transformation preparation period, the design unit completes the preliminary design, equipment procurement and overall construction drawing design, each node is well prepared for scheme review and design quality control, the equipment manufacturing is completed and delivered for installation, the cable is laid according to the final design, and the debugging unit completes the pre-commissioning, then the preparation phase is completed and the subsequent steps are entered, considering the particularity and transformation difficulty of the nuclear power project; S3, transformation transition period, the transformation transition period needs to be inserted into multiple maintenance windows, the NCS system station control layer equipment and other public systems need to be put into operation during the first transition implementation period, and the data interconnection between the new control and the old control and remote control system is completed according to the transformation equipment, and the new control system interval layer equipment is connected through multiple power-off windows; S4, transformation finishing period, the old screen cabinet and related cables and transition cables are removed and finally cleaned up during multiple local power-off windows.

2. The retrofit method of claim 1, wherein: The method is suitable for the electrical control system of the switch station of the second generation nuclear power station in China, which is controlled by analog technology, and is upgraded to the NCS power network computer monitoring system without overall power-off.

3. The retrofit method of claim 1, wherein: The step S2 needs to determine the feasibility of the transformation equipment arrangement and cable channel, determine the related process adaptability transformation range, and judge the cost and economic benefit.

4. The retrofit method of claim 1, wherein: The method needs to go through multiple maintenance, and the new and old control systems need to run together for a long time before the transformation is completed.

5. The retrofit method of claim 1, wherein: The old system corresponding part of the step S3 is synchronously withdrawn from operation according to the equipment maintenance plan and line power-off plan of the switch station maintenance window.

6. The retrofit method of claim 1, wherein: In order to ensure the smooth implementation of the non-integral power-off transformation, risk control needs to be carried out in the whole life cycle of the system.

7. The retrofit method of claim 1, wherein: The step S2 transformation preparation period synchronously implements the transformation of the direct current system, a new set of fixed type exhaust type lead-acid storage battery and phase control type charging device are newly installed to form a direct current system, which supplies power for the new control system and gradually replaces the original direct current system.

8. The retrofit method of claim 1, wherein: The step S2 transformation preparation period synchronously completes the transformation of the remote control system, PMU system and signal protection system, the new system establishes an independent data channel, the new and old systems synchronously upload data, and the device information migration is gradually completed through the power-off window.

9. The retrofit method of claim 1, wherein: The step S3 transformation transition period designs independent transition drawings for each power-off window, clearly defines the interface between the new equipment and the untransformed and transformed equipment and the transition cable planning, and the transition drawings and the original construction drawings are named in different systems, and the transition cables are marked with a specific letter suffix.

10. The retrofit method of upgrading the non-integral outage electrical controls of a nuclear power plant switchyard according to any one of claims 1-9, characterized in that: The method can realize the upgrading of the electrical control system without overall power-off in the switch station of the nuclear power plant.

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