A method and system for identifying key equipment in a thermal power plant

Abstract

The present invention discloses a method and system for identifying key equipment in a thermal power plant, which integrates the plant power system and the main electrical connection to evaluate the reliability of the thermal power plant; by calculating the probability that a generator set may be shut down due to a failure of the plant power equipment, the availability of the generator set is input as raw data into the calculation of the reliability of the main electrical connection, that is, the generator set is regarded as a component whose reliability is determined by the plant power system and participates in the evaluation of the main connection reliability, and finally the power supply reliability of the entire thermal power plant to the outgoing line is given; the key links and equipment of the thermal power plant can be identified, and their reliability can be systematically and completely evaluated, thereby improving the safety and reliability of the thermal power plant.

Description

Technical Field

[0001] The present invention belongs to the technical field of power plant safety, and in particular relates to a method and system for identifying key equipment in a thermal power plant. Background Art

[0002] The safe and reliable operation of the power system is a prerequisite for ensuring continuous power supply to electricity users and is the cornerstone of the national economy. The rapid development of various sectors in recent years has been inseparable from the support of the power system, and the resulting reliability issues have become increasingly important. Power plants, as the power source of the entire power system, are of paramount importance in ensuring power system reliability. Their safe and stable operation directly affects the normal operation of the power system. An incident at a power plant can directly lead to an imbalance in the power supply and may even develop into a major safety incident that threatens the entire power grid. Therefore, studying the operational reliability of power plants is a key component of evaluating power system reliability.

[0003] Currently, most existing power plants are thermal power plants. Thermal power plants are not only the most mature and common type of power plant, but also play a critical role in peak-to-valley load regulation in modern power grids, where peak-to-valley variations are increasingly pronounced. The power system's energy supply comes from power plants, which rely on auxiliary power equipment. Each thermal power unit comprises not only the main engine but also hundreds of auxiliary equipment. The proper operation of a generator set depends on the coordinated operation of auxiliary power equipment. Reliable operation of the auxiliary power system is essential for stable power plant operation. Failure of auxiliary power equipment directly impacts the generator set, potentially forcing it to shut down and potentially triggering a power grid incident. While relevant literature has examined individual components of auxiliary power systems, such as boilers, pumps, and thermal control systems, comprehensive reliability assessment of auxiliary power systems remains largely unresolved. Specific modeling and evaluation of auxiliary power systems based on reliability theory is lacking.

[0004] The main electrical connection is responsible for gathering and transmitting electrical energy within the power system and is an indispensable component of the entire electrical engineering process. Consisting primarily of circuit breakers and wiring, these connections are prevalent in power plants and substations, directly impacting the reliability of the power grid. Specifically, as the link between the power plant and the power system, a failure in the main connection can directly disconnect the generator set from the system, further preventing the outgoing line from transmitting electrical energy, leading to power loss at related load points and even causing system oscillations, seriously threatening the reliability of the power supply system. Therefore, the reliability of the main electrical connection is of great significance to power plants and is a crucial indicator for ensuring the reliability of the power supply system.

[0005] At present, the reliability assessment of thermal power plants is still limited to providing specific improvement measures, and there is no comprehensive and systematic study of the entire thermal power plant. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method and system for identifying key equipment of a thermal power plant in response to the above-mentioned deficiencies in the existing technology, so as to achieve a comprehensive evaluation of the reliability of the thermal power plant, identify important links and key equipment therein, and improve the safety and reliability of the thermal power plant.

[0007] The present invention adopts the following technical solutions:

[0008] A method for identifying key equipment in a thermal power plant comprises the following steps:

[0009] S1. Considering the equipment classification and wiring design, a typical plant power system for a thermal power plant is established.

[0010] S2. Based on the typical power supply system of the thermal power plant constructed in step S1, perform non-sequential Monte Carlo simulation and fault analysis on the power supply system to obtain a reliability assessment result of the power supply system of the thermal power plant;

[0011] S3. Considering the information layer and physical layer modeling for smart terminals, the failure rate of smart terminals in thermal power plants is obtained.

[0012] S4. Based on the intelligent terminal failure rate obtained in step S3, a sequential Monte Carlo simulation is performed on the main connection system of the power plant including the intelligent terminal to obtain reliability results of the main connection part of the thermal power plant;

[0013] S5. Input the auxiliary power system result obtained in step S2 into the sequential Monte Carlo simulation in step S4 to obtain the reliability results of the auxiliary power system and the main connection system of the thermal power plant, thereby realizing the identification of key equipment in the thermal power plant.

[0014] Specifically, step S1 is as follows:

[0015] S101. Equipment classification of typical power supply systems in thermal power plants;

[0016] S102. Based on the equipment classification in step S101, select different representative equipment for each classification, and set the unit structure according to the principle of relative independence of each unit. For the high-voltage auxiliary power system, divide the auxiliary power bus into several independent sections according to the number of boilers. The auxiliary equipment of the same unit is independently connected to the same bus and supplied by a high-voltage auxiliary power transformer. The low-voltage auxiliary power adopts the power center-motor control center wiring. Design the wiring of a typical auxiliary power system of a thermal power plant.

[0017] Specifically, step S2 is as follows:

[0018] S201. Establish a multi-level load model for the plant power system and fit the original load curve with a stepped multi-level load level.

[0019] S202. Treat each device in the auxiliary power system as an independent component, sample the component states using a non-sequential Monte Carlo simulation method, combine them to obtain the auxiliary power system state, and calculate the reliability index of each load point in the auxiliary power system;

[0020] S203. Based on the status of each load point in the system and the system wiring topology obtained in step S202, analyze whether an accident will occur and perform a predicted fault analysis. If a predicted accident occurs in the system under the corresponding state, calculate the load amount that needs to be shelved in that state through optimal power flow. If load shedding is required, the selected state is the unavailable state, and the probability of the auxiliary power system being in the unavailable state is recorded.

[0021] S204. Based on the expected fault analysis of step S203, the number of occurrences of different fault types that lead to shutdown faults is statistically obtained. Combined with the original load curve of step S201, the reliability assessment result of the thermal power plant power system is calculated.

[0022] Furthermore, in step S204, the reliability assessment results of the thermal power plant power system include:

[0023] Probability of power shortage :

[0024]

[0025] in, yes The number of times the state occurs; is the total number of samples; The load level of the system in a given load model The collection of unavailable states; is the load level duration; is the total time the load curve lasts; is the total number of levels divided into a given load level;

[0026] Expected power shortage :

[0027]

[0028] in, yes The load that needs to be removed in the state (MW); is the state during the simulation time period The number of outgoing lines.

[0029] Specifically, step S3 is as follows:

[0030] S301. Information layer modeling of intelligent terminals in thermal power plants, including station control layer, bay layer, process layer, station control bus, and process bus;

[0031] S302 , physical layer modeling of the smart terminal of the thermal power plant, and constructing the smart terminal failure rate based on the information layer of the smart terminal of the thermal power plant in step S301 .

[0032] Furthermore, in step S302, the intelligent terminal failure rate for:

[0033]

[0034] in, is the availability of the process bus, is the availability of the merged unit, is the availability of the current sensor, is the availability of the voltage sensor, is the availability of the circuit breaker, is the availability of the Ethernet switch, is the availability of three series connected smart components.

[0035] Specifically, in step S4, the reliability index used to evaluate the main electrical connection is:

[0036] Failure frequency :

[0037]

[0038] in, is the number of faults that occurred, is the total simulation time length;

[0039] Annual failure duration ;

[0040]

[0041] in, It is the collection of all outgoing line fault states. is the duration of the outgoing fault;

[0042] Mean time between failures :

[0043]

[0044] Availability and unavailability rate :

[0045]

[0046]

[0047] Specifically, in step S4, the reliability assessment of the main electrical connection part of the thermal power plant is as follows:

[0048] S401. Analyze the main wiring system network topology based on the combination method;

[0049] S402, performing component reliability merging of the main wiring system;

[0050] S403, simulating the main connection system state using a sequential Monte Carlo method;

[0051] S404. Calculate the main wiring system's related ratio. If the related ratio is less than a given value, the simulation ends. Otherwise, the simulation continues until the related ratio is less than a given value or the simulation reaches a predetermined time.

[0052] Specifically, step S5 is as follows:

[0053] The reliability of the thermal power plant is evaluated by integrating the plant power system and the main electrical connection. By calculating the probability that a failure in the plant power equipment may cause a generator set to shut down, the availability of the generator set is input as raw data into the main electrical connection reliability calculation. In other words, the generator set is regarded as a component whose reliability is determined by the plant power system and participates in the main connection reliability assessment. Ultimately, the power supply reliability of the entire thermal power plant to the outgoing line is determined.

[0054] In a second aspect, an embodiment of the present invention provides a key equipment identification system for a thermal power plant, comprising:

[0055] The system module considers equipment classification and wiring design for the auxiliary power system and establishes a typical auxiliary power system for a thermal power plant.

[0056] The analysis module performs non-sequential Monte Carlo simulation and fault analysis on the typical power supply system of a thermal power plant constructed by the system module, and obtains the reliability assessment conclusion of the power supply system of the thermal power plant;

[0057] The fault module considers modeling at both the information and physical levels for smart terminals and obtains the failure rate of smart terminals in thermal power plants.

[0058] The simulation module performs a sequential Monte Carlo simulation on the main connection system of the power plant containing the intelligent terminal based on the intelligent terminal failure rate obtained by the fault module, and obtains the reliability results of the main connection part of the thermal power plant;

[0059] The identification module inputs the plant power system results obtained by the analysis module into the timing Monte Carlo simulation of the simulation module to obtain the reliability results of the thermal power plant of the plant power system and the main connection system, thereby realizing the identification of key equipment in the thermal power plant.

[0060] Compared with the prior art, the present invention has at least the following beneficial effects:

[0061] The present invention provides a method for identifying key equipment in a thermal power plant, integrating the plant power system and the main electrical connection to assess the plant's reliability. By calculating the probability that a plant power equipment failure could cause a generator set to shut down, the availability of this generator set is used as raw data to input into the main electrical connection reliability calculation. This method treats the generator set as a component whose reliability is determined by the plant power system and participates in the main connection reliability assessment, ultimately providing the power supply reliability of the entire thermal power plant to the outgoing lines. This method can identify key links and equipment in a thermal power plant, conduct a systematic and comprehensive reliability assessment, and improve the safety and reliability of the thermal power plant.

[0062] Furthermore, with the continuous expansion of the power system, large-capacity units are becoming more and more common in actual applications. A 600MW unit was selected as an example to construct the plant power system. Related equipment and wiring topology were selected for analysis, and the object of reliability assessment was clarified, which facilitated the subsequent reliability assessment of the plant power system.

[0063] Furthermore, a non-sequential Monte Carlo simulation method was used, which has the characteristics of being able to simulate actual physical processes, being easy to operate and understand, and being convenient for engineering applications; the anticipated faults were analyzed, and the failure conditions of the plant power equipment that could cause power outages were identified, providing a basis for improving the reliability of the plant power system.

[0064] Furthermore, the reliability of the plant power system is evaluated in modules, emphasizing the non-negligibility of the plant power system. The reliability of the plant power system can be given separately, and the reliability assessment process within the thermal power plant is refined, providing a basis for subsequent reliability assessment of the thermal power plant, making the reliability assessment of the entire thermal power plant more comprehensive.

[0065] Furthermore, a physical model of the intelligent terminal was constructed from the two aspects of information layer setting and physical layer implementation, the working process of the intelligent terminal was clarified, and the impact of the introduction of the information system on the reliability of the circuit breaker was analyzed, providing a theoretical basis for the calculation of the failure rate of the intelligent terminal.

[0066] Furthermore, based on the working process and serial characteristics of the smart terminal, the components involved were connected in series to calculate the overall failure rate of the smart terminal, quantifying the adverse impact of the introduction of the information system on the reliability of the components. The failure rate of the smart terminal was significantly increased compared to that of the traditional circuit breaker, indicating the necessity of fault rate modeling analysis and recalculation of the smart terminal upgraded from the circuit breaker. This provides a basis for the subsequent reliability assessment of the main wiring system involving the smart terminal.

[0067] Furthermore, the reliability assessment of the electrical main wiring system requires adherence to certain criteria. From the perspective of power supply continuity, one of the following three criteria can be selected: 1) At least one outgoing line receives continuous and normal power supply; 2) A designated outgoing line receives continuous and normal power supply; 3) All outgoing lines receive continuous and normal power supply. The indicators selected in S4 adhere to these criteria, covering the key reliability requirements of the main wiring system and comprehensively and systematically describing the reliability level of the main wiring system of a thermal power plant. This provides a standard for subsequent reliability assessments of the main wiring system and the overall thermal power plant.

[0068] Furthermore, the time-varying factors in the system, including planned maintenance of equipment and changes in load levels, are taken into account by using the sequential Monte Carlo simulation method, which retains the system's time series and has the characteristics of being able to simulate actual physical processes and facilitate engineering applications. The minimum path method used is a commonly used analysis method in graph theory. Due to its conceptual clarity, it is often used to analyze power systems. By utilizing the necessity of each element in the basic concept of the minimum cut set, it reflects the fact that electrical components are indispensable to the performance of local power systems, thereby achieving better reliability calculation results. The combined method used to find the minimum path can decompose complex systems, avoid missing search nodes, and reduce the amount of calculation. The main connection reliability assessment process provided can independently solve the reliability of the main connection system, and can also provide tools for subsequent overall reliability assessment of thermal power plants.

[0069] Furthermore, step S5 considers the structure that the generator set is connected to both the plant transformer that supplies plant power and the main transformer of the supply system, and naturally divides the research scope of the thermal power plant into two parts. The plant power system and the main electrical connection are integrated, and models are established and reliability assessments are performed according to steps S1 to S4 respectively. Then, a comparative study is conducted on the degree of influence of the two on the reliability of the thermal power plant, which can more comprehensively evaluate the reliability of the thermal power plant.

[0070] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0071] In summary, the present invention can identify key links and equipment in a thermal power plant and conduct a systematic and complete evaluation of reliability, thereby improving the safety and reliability of the thermal power plant.

[0072] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 This is a schematic diagram of the power supply system of a thermal power plant according to the present invention;

[0074] Figure 2 Schematic diagram of the reliability evaluation process of the power system of a thermal power plant according to the present invention;

[0075] Figure 3 This is a schematic diagram of the information architecture of the intelligent terminal in the thermal power plant of the present invention;

[0076] Figure 4 The figure is a physical model and a schematic diagram of the working mechanism of the intelligent terminal in the thermal power plant of the present invention;

[0077] Figure 5 Schematic diagram of the evaluation process of the reliability of the main electrical connection of a thermal power plant according to the present invention;

[0078] Figure 6 Schematic diagram of the overall reliability assessment process of a thermal power plant according to the present invention;

[0079] Figure 7 This is a schematic diagram of the fault simulation results of the present invention. DETAILED DESCRIPTION

[0080] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0081] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0082] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0083] It should be further understood that the term "and / or" as used in the present specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items. For example, A and / or B may represent: A alone, A and B simultaneously, or B alone. In addition, the character " / " herein generally indicates that the associated items are in an "or" relationship.

[0084] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0085] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0086] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0087] The present invention provides a method for identifying key equipment in a thermal power plant, integrating the plant power system and the main electrical connection to assess the plant's reliability. By calculating the probability that a plant power equipment failure could cause a generator set to shut down, the availability of this generator set is used as raw data input into the main electrical connection reliability calculation. This method treats the generator set as a component whose reliability is determined by the plant power system and participates in the main connection reliability assessment, ultimately providing the power supply reliability of the entire thermal power plant to the outgoing lines. This method can identify key links and equipment in a thermal power plant, conduct a systematic and comprehensive reliability assessment, and improve the safety and reliability of the thermal power plant.

[0088] The present invention provides a method for identifying key equipment in a thermal power plant, comprising the following steps:

[0089] S1. Considering the equipment classification and wiring design, a typical plant power system for a thermal power plant is established.

[0090] The present invention is a model and evaluation method for the reliability of thermal power plants. A thermal power plant is a complex modern integrated structure, and its operation requires the cooperation of multiple electric machines. Steam turbines, generators and boilers are the three most important mechanical structures in a thermal power plant to maintain the generation of electricity, and there are many auxiliary systems around this main system to help it operate normally. With the increase in electric equipment, the corresponding power supply system will also become more complicated. Generally, these electrical loads are called plant loads, and the power supply system is called the plant power system. All these electric loads that ensure the safe operation of the power plant belong to the plant power range of the power plant. Taking a 600MW unit as an example, the present invention constructs a plant power system, selects relevant equipment and wiring topology for analysis, such as Figure 1 shown.

[0091] S101. Equipment classification of typical power supply systems in thermal power plants;

[0092] There are many types of equipment involved in the power supply system of a thermal power plant. According to their working parts, they can be roughly divided into the following categories, specifically:

[0093] For the excitation system, the main equipment involved include: demagnetization switch, exciter, automatic voltage regulator (AVR) and control device.

[0094] The boiler system consists of the boiler itself and various auxiliary equipment. The boiler itself includes the steam-water system, fuel system, furnace wall, and frame. Auxiliary equipment includes ventilation equipment, pulverizing equipment, water supply equipment, boiler accessories, and dust and ash removal equipment. Key equipment involved includes induced draft fans, forced draft fans, pulverized coal exhausters, coal mills, coal feeders, pulverized coal feeders, primary fans, and boiler water circulation pumps.

[0095] For the steam turbine system, the main equipment involved includes: condensate pump, circulation pump, feed water pump, feed water oil pump, standby feed water pump, industrial water pump, and regenerative heater.

[0096] For the electrical and public parts, the main equipment involved include: communication facilities, air compressors, cooling fans, transformer oil-water-cooled power supply, machine and boiler control power supply, rectifier devices, chemical water section, etc.

[0097] For accident safety loads, the main equipment involved include: AC lubricating oil pump, turning motor, jacking oil pump, floating charging device, accident alarm, thermal automatic device power supply, real-time control electronic computer.

[0098] For the chemical water treatment part, the main equipment involved include: clean water pump, intermediate water pump, desalted water pump, and self-use water pump.

[0099] S102. Design the wiring of a typical power system for a thermal power plant;

[0100] Most 600MW thermal power units currently in operation utilize a one-unit-one-furnace configuration, employing an integrated control system for the unit, furnace, and electrical system. Therefore, the present invention also utilizes the principle of relative independence when designing the plant power system, arranging the unit structure accordingly. To achieve this, a single busbar segmented wiring system was selected. Domestic power plants generally utilize 6kV and 380V voltage levels. For related equipment, loads above 200kW are powered by 6kV, while loads below 200kW are powered by 380V.

[0101] Power plants are the source of power for the entire power system, and power supply is the fundamental prerequisite for normal power plant operation, so their reliability requirements are extremely high. Beyond ensuring safe and stable operation, consideration must also be given to handling power supply during emergencies. This requires the provision of backup and safety power supplies in addition to the normal operating power supply. The starting power supply, also known as the starting / backup power supply, also serves as an emergency backup power source. To ensure rapid startup of generator sets during initial commissioning and in the event of a failure in the normal operating power supply, an additional power source capable of independently supplying power to auxiliary equipment is essential.

[0102] To ensure the reliability and economy of high-voltage auxiliary power systems, the principle of "segmentation by boiler" is generally adopted, dividing the auxiliary power busbar into several independent sections based on the number of boilers. Auxiliary equipment within the same unit is independently connected to the same busbar and supplied by a single high-voltage auxiliary transformer. Principles to be followed include relative independence, provision of a backup power source, consideration of expansion planning, and phased construction.

[0103] The segmentation of low-voltage auxiliary power is essentially the same as that of high-voltage auxiliary power busbars, with power supplied by the corresponding high-voltage auxiliary power busbars. The classification and power supply requirements for low-voltage auxiliary power loads are similar to those for high-voltage auxiliary power systems. However, due to the diverse and widespread distribution of low-voltage loads, wiring requirements require greater flexibility to adapt to practical applications. Compared to high-voltage auxiliary power loads, low-voltage loads require consideration of the concepts of safety loads and uninterruptible power supply loads. The specific approach primarily utilizes a power center-motor control center (PC-MCC) wiring scheme. The PC segment is directly powered by the low-voltage side of the low-voltage auxiliary transformer and generally serves larger loads. The MCC segment, on the other hand, primarily serves smaller loads, offering the advantage of centralized protection and operating equipment. Both utilize drawer-type switches to simplify installation and maintenance. The philosophy of this wiring scheme is to simplify wiring while directly ensuring power supply reliability.

[0104] For the common load portion, its wiring needs to be considered separately. For large-capacity units of 200MW and above, where there are a lot of common loads and large capacities, a centralized power supply is more reasonable, and a high-voltage common bus section can be established.

[0105] S2. Based on the typical power supply system of the thermal power plant constructed in step S1, perform non-sequential Monte Carlo simulation and fault analysis on the power supply system to obtain a reliability assessment result of the power supply system of the thermal power plant;

[0106] For the evaluation indicators of the plant power system, we draw on the relevant indicators of the power system, refer to the current standard "Basic Terminology of Power Reliability" DL / T 861-2004 and the international mainstream IEC 60050 standard, and divide the currently used indicators into possibility indicators and severity indicators.

[0107] Drawing on commonly used power system reliability indicators, this paper attempts to construct specific metrics that describe the impact of the auxiliary power system on thermal power plants, enabling a more comprehensive assessment of auxiliary power system reliability. After comparison, the probability of a power plant power outage caused by an auxiliary power system failure was selected as the likelihood indicator, and the amount of power not generated was selected as the severity indicator. This not only describes the likelihood of a power plant unit shutdown caused by an auxiliary power system failure, but also provides the severity of the failure, providing a more comprehensive reflection of the impact of the auxiliary power system on thermal power plant output. The specific metrics are as follows: Loss of Generation Probability (LOGP) and Expected Energy Not Generated (EENG) (in megawatt-hours per year).

[0108] See also Figure 2 The reliability assessment process of the power supply system of a thermal power plant is as follows:

[0109] S201. Establish a multi-level load model for the plant power system;

[0110] The reliability assessment of a power generation system is inseparable from its load curve. The probability that available generating capacity cannot meet the required load is the required probability of power failure. Therefore, the first step is to establish a multi-level load model suitable for Monte Carlo simulation, using a stepped multi-level load level to fit the original load curve.

[0111] Obviously, the more levels of load level division in the model, the closer the model can be to the continuous load curve. After the continuous load curve is graded in a step-by-step manner, any load point can be divided according to its nearest load level, and finally the load points that are continuous in time are converted into a discrete model suitable for non-sequential Monte Carlo simulation. It is Level load, is the total number of load level classifications, It is The duration of the load level, is the total time the load curve lasts.

[0112] S202, using non-sequential Monte Carlo simulation to select component states and obtain the auxiliary power system state;

[0113] Each device in the auxiliary power system is considered an independent component, with two states: available and unavailable. Each component conforms to the Markov state equation. Using raw system data as input, a non-sequential Monte Carlo simulation method samples the component states and combines them to obtain the auxiliary power system state.

[0114] According to the topology of the system, it is possible to analyze whether each load point has failed. It should be noted that the unavailable state of a component is not completely equivalent to the unavailable state of a load point, and analysis needs to be performed based on the specific topology. For example, if a busbar fails as an independent component, not only will the load point of the busbar itself be unavailable, but also the load points that the busbar relies on for power supply will be unavailable even if the components themselves are not faulty. The availability is calculated as:

[0115]

[0116] in, is the load point during the sampling process The number of failures that occurred, is the total number of samples.

[0117] S203. Analyze anticipated faults of the plant power system;

[0118] Based on the status of each load point in the system and the system's wiring topology, analyze whether an accident will occur and perform a preemptive fault analysis. If a preemptive accident occurs in the system under this state, the load amount that needs to be shelved in this state is given through optimal power flow calculation. If load shedding is required, the selected state is considered to be an unavailable state, and the probability of the factory power system being in an unavailable state is recorded.

[0119] S204. Calculate the reliability index of the plant power system;

[0120] Probability of power shortage :

[0121]

[0122] in, yes The number of times the state occurs; is the total number of samples; The load level of the system in a given load model The collection of unavailable states; is the load level duration; is the total time the load curve lasts; is the total number of levels divided by a given load level.

[0123] Expected power shortage (MWh / year):

[0124]

[0125] in, yes The load that needs to be removed in the state (MW); is the state during the simulation time period The number of outgoing lines.

[0126] Finally, through step S2, the failure rate of each load node in the plant power system can be obtained, thereby identifying key links and equipment.

[0127] S3. Considering the information layer and physical layer modeling for smart terminals, the failure rate of smart terminals in thermal power plants is obtained.

[0128] See also Figure 3 ,The information architecture of the intelligent terminal in the thermal power plant is as follows:

[0129] S301, information level modeling of intelligent terminals in thermal power plants;

[0130] This paper uses the IEC 61850-7-4 standard to present a typical substation communication architecture. IEC 61850 is an international standard for substation automation. By standardizing all aspects of information exchange, it improves interoperability between intelligent electronic devices (IEDs). IEC 61850 features object names that reflect the power system context, a standardized configuration language, and device self-description, offering advantages such as low cost, ambiguity elimination, and the ability to enable new functionality.

[0131] The composition and functions of each part are introduced as follows:

[0132] Station Control Layer: This layer includes the engineer station and the Supervisory Control and Data Acquisition (SCADA) system. Here, engineers can monitor the status data of various components and perform certain manual operations.

[0133] Bay layer: The bay layer includes microprocessor-based relays and bay controllers, also known as protection and control smart elements. The protection smart elements receive information transmitted by the process bus, perform precise calculations, and send action signals via Ethernet.

[0134] Process layer: This layer is directly related to physical components and includes current transformers (CTs), voltage transformers (PTs), merging units (MUs), and actuators. The voltage and current signals acquired by the sensors are digitized by the MUs and sent to the bay layer for further calculations.

[0135] Station control bus: The station control bus is used to support information exchange between the station control layer and the bay layer, so that the status data of the entire station can be used for monitoring and operation in the control center.

[0136] Process Bus: The process bus enables time-critical communication between the process and bay levels, bridging the gap between voltage and current information and trip signals from the merging unit to the protection unit.

[0137] S302, physical layer modeling of intelligent terminals in thermal power plants;

[0138] The IEC 61850 standard defines a unified modeling description for various smart terminals and an information exchange architecture between them, facilitating the analysis of component-level power information interaction mechanisms. However, in actual operation, random failures or damage to information systems can lead to information loss, control failures, and even deterioration of the power system. In other words, the construction of smart power plants is highly dependent on the reliability of information systems, reflecting the typical characteristics of cyber-physical systems (CPSs). The reliability assessment of smart power plants must be based on consideration of the impact of information systems. The interaction between information and physical systems reduces the reliability of purely physical components, necessitating detailed modeling to explore the adverse effects of the introduction of information systems on component reliability.

[0139] This invention considers upgrading circuit breakers, replacing traditional circuit breakers with intelligent terminals that incorporate information systems. These intelligent terminals can collect and upload voltage and current measurements, as well as switch status information, receive and execute action commands, and perform on-site processing based on the situation, thus reducing downtime. Because intelligent terminals integrate sensors, intelligent components, and switching elements, they can be viewed, analogously to circuit breakers, as the intersection between power system operation functions and information system support functions.

[0140] See also Figure 4 ,The physical model and action mechanism of the intelligent terminal in the thermal power plant are as follows:

[0141] Sensors CT / PT collect information and transmit it to the merging unit MU. After merging and synchronizing the electrical quantities, the unit sends the digital signals to the protection unit via the process bus PB according to specified format standards. To facilitate analysis, the Ethernet switch ES and protection intelligent components on the same protection panel are combined into a single protection unit. Typically, each protection unit is equipped with redundant protection intelligent components. Parallel protection intelligent components are connected in parallel and then in series with the Ethernet switch to form a single protection unit.

[0142] Figure 4 In the intelligent terminal model constructed in , the reliability calculation is as follows:

[0143] The mean time to failure (MTTF) and mean time to repair (MTTR) of a component are calculated as:

[0144]

[0145] in, and are two random numbers uniformly distributed between [0, 1]. =1 / is the mean time to repair of a component.

[0146] In this invention, each component (except the process bus) is considered to have two states: available and unavailable. The probability of a component being in the available or unavailable state is:

[0147]

[0148]

[0149] in, 、 and They represent the failure rate, repair rate and availability rate of the component respectively.

[0150] In the ideal case of non-blocking switches and a priority mechanism, process delays can be negligible. However, in practical applications, due to the use of traditional technologies such as wireless and Ethernet, delays must be taken into account. In wireless environments, delays can be considerable due to electromagnetic or high-voltage interference. Furthermore, packets may occasionally be dropped by the network due to errors. Process delay is defined as the delay in message transmission due to temporary heavy traffic, even if there is no physical failure on the process bus. This can cause circuit breakers to fail to operate in a timely manner, rendering intelligent terminals unavailable. Therefore, network delays are possible. To account for this possibility, delayed states are modeled as process bus states.

[0151] The measurement, communication, and control processes of smart terminals are serial in nature. Therefore, component-level terminal reliability modeling generally equates the two-state models of related information components in series. Furthermore, it is assumed that the same type of terminal has independent information systems with similar reliability parameters. Furthermore, as the aggregation element for transmitting and receiving information across the entire system, a failure of the PB will cause the failure of all information functions in the entire system and the suspension of all smart terminals.

[0152] The failure rate of the intelligent terminal constructed in the present invention is:

[0153]

[0154] S4. Based on the intelligent terminal failure rate obtained in step S3, a sequential Monte Carlo simulation is performed on the main connection system of the power plant including the intelligent terminal to obtain reliability results of the main connection part of the thermal power plant;

[0155] According to the evaluation criteria for the reliability of the main electrical connection, from the perspective of power supply continuity, one of the following three options can be selected:

[0156] 1) At least one outgoing line is continuously and normally powered;

[0157] 2) The designated outlet can continuously and normally supply power;

[0158] 3) All outgoing lines can continuously and normally supply power.

[0159] The reliability index selected by the present invention for evaluating the main electrical connection is:

[0160] 1) Failure frequency Frequency of failure (times / year) refers to the number of outgoing line failures in a year due to insufficient reliability of the main wiring system.

[0161]

[0162] in, is the number of faults that occurred, is the total simulation time length.

[0163] 2) Annual failure duration Duration of failure (hours / year) refers to the outage time in a year due to failure of the outgoing line due to insufficient reliability of the main wiring system.

[0164]

[0165] in, It is the collection of all outgoing line fault states. is the duration of the outgoing fault.

[0166] 3) Mean duration of failure Average duration of failure (hours / time) refers to the downtime of each outgoing line due to a failure of the main wiring due to failure to meet reliability requirements.

[0167]

[0168] 4) Availability The availability of main wirings is also called the power supply reliability rate of the main electrical wiring. It refers to the ratio of the time when the main wiring is in normal working state to the total operating time when the reliability requirements are met. Conversely, the ratio of the time when the main wiring is in the corresponding fault state to the total operating time when the reliability requirements are not met is the unavailability rate. .

[0169]

[0170]

[0171] See also Figure 5The evaluation process of the reliability of the main electrical connection of a thermal power plant is as follows:

[0172] S401. Analyze the main wiring system network topology based on the combination method;

[0173] Using the wiring information and component data of the main electrical wiring section of a thermal power plant as input, a combinatorial method is used to perform network topology analysis and determine the minimum cut set. It is important to note that, generally speaking, the highest order of the system's minimum cut set should be equal to the number of minimum paths. To accommodate the actual situation in power systems, when determining a higher-order cut set, a search should be conducted against lower-order cut sets. Specifically, after obtaining cut sets from order 3 to order n, it is necessary to check whether the minimum cut set has already been assigned to a lower-order cut set, i.e., the corresponding cut sets from order 2 to order n-1.

[0174] Since faults higher than the second order with extremely small probability of occurrence are not considered in actual power system research, the present invention only obtains the first-order and second-order cut sets when obtaining the minimum cut set, which correspond to single and double faults respectively, reducing unnecessary calculation amount and program running time.

[0175] S402, performing component reliability merging of the main wiring system;

[0176] When performing reliability calculations, it is necessary to simplify the main electrical wiring diagram into a clearer logic diagram. In this process, the circuit breaker, that is, the intelligent terminal in the present invention, is used as a partition, and other components such as disconnectors, current transformers, and voltage transformers are logically merged with other components and converted into a reliability component for calculation. The present invention involves the merging of the following logical components when forming the logic diagram:

[0177] The bus reliability logic element refers to the bus and the equipment connected to the bus, including voltage transformers and lightning rods, which are combined together to form a bus.

[0178] The transformer reliability logic element refers to the combination of the current transformer and the isolating switch connected to the transformer into a transformer element.

[0179] The circuit breaker reliability logic element is a circuit breaker element that combines the circuit breaker and the current transformer connected thereto into a circuit breaker element. In the present invention, the elements involved in the intelligent terminal are combined into an intelligent terminal.

[0180] S403, simulating the main connection system state using a sequential Monte Carlo method;

[0181] In the main electrical wiring system of a thermal power plant, components typically experience three states: normal operation, outage, and planned maintenance. Because planned maintenance is not a random variable but is performed on components that are not out of service due to faults, this simulation assumes that each component operates in only two states: normal operation and outage due to faults. In other words, it randomly switches between available and unavailable states.

[0182] By sampling the duration of component states to form a system state sequence, the faulty component is identified based on a particular state in the chronological system state sequence. If the faulty component in this state is essential for maintaining system availability, that is, if the faulty component belongs to the minimum cut set of load points in the topology analysis, the system is considered to be in a faulty state and cannot operate.

[0183] S404, calculating the reliability index of the main connection system and determining whether the index converges;

[0184] The operating state of the main connection system is simulated using the sequential Monte Carlo method, and the convergence criterion for calculating the reliability index is as follows. The time the main connection system is in operation is , the time in the outage state is These two states are randomly distributed. The expected value of the time the system is in the outage state is:

[0185]

[0186] The standard deviation of system outages is:

[0187]

[0188] The ratio of the standard deviation to the expected value of outages is:

[0189]

[0190] Based on the given running time before the simulation starts, the ratio of the standard deviation to the expected value of outage can be calculated , then further extending the simulation running time of the system can get the corresponding The correlation ratio R is obtained from the following formula:

[0191]

[0192] The convergence of the simulation can be determined based on the correlation ratio. If the correlation ratio is less than a given value, the simulation ends; otherwise, the simulation continues until the correlation ratio is less than a given value or the simulation reaches a predetermined time.

[0193] S5. According to the main connection system reliability assessment process of step S4, the auxiliary power system result obtained in step S2 is used as the input of step S4 to obtain the reliability results of the thermal power plant divided into the auxiliary power system and the main connection system.

[0194] See also Figure 6 The specific evaluation process of the overall reliability of a thermal power plant is as follows:

[0195] The reliability of a thermal power plant is assessed by integrating the plant power system and the main electrical connection. By calculating the probability that a generator set shutdown may occur due to a plant power equipment failure, the availability of this generator set is input as raw data into the main electrical connection reliability calculation. In other words, the generator set is considered as a component whose reliability is determined by the plant power system and participates in the main connection reliability assessment. Ultimately, the power supply reliability of the entire thermal power plant to the outgoing line is determined.

[0196] The present invention considers integrating the plant power system and electrical main connection of a thermal power plant, constructing a model and studying its reliability assessment. This has important practical significance for identifying key links and equipment in the power plant, more comprehensively assessing the reliability of the thermal power plant, and thus better ensuring the normal operation of the power grid.

[0197] In another embodiment of the present invention, a key equipment identification system for a thermal power plant is provided. The system can be used to implement the above-mentioned key equipment identification method for a thermal power plant. Specifically, the key equipment identification system for a thermal power plant includes a system module, an analysis module, a fault module, a simulation module and an identification module.

[0198] Among them, the system module, for the plant power system, considers equipment classification and wiring design, and establishes a typical plant power system for a thermal power plant;

[0199] The analysis module performs non-sequential Monte Carlo simulation and fault analysis on the typical power supply system of a thermal power plant constructed by the system module, and obtains the reliability assessment conclusion of the power supply system of the thermal power plant;

[0200] The fault module considers modeling at both the information and physical levels for smart terminals and obtains the failure rate of smart terminals in thermal power plants.

[0201] The simulation module performs a sequential Monte Carlo simulation on the main connection system of the power plant containing the intelligent terminal based on the intelligent terminal failure rate obtained by the fault module, and obtains the reliability results of the main connection part of the thermal power plant;

[0202] The identification module inputs the plant power system results obtained by the analysis module into the timing Monte Carlo simulation of the simulation module to obtain the reliability results of the thermal power plant of the plant power system and the main connection system, thereby realizing the identification of key equipment in the thermal power plant.

[0203] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0204] According to the structure selection diagram described in step S1, the two units are regarded as one group according to the wiring structure and common section in the selected calculation example. The maximum capacity of the two units is 2 600 is 1200MW, so we take 200MW as one level and make statistics based on the load level table of the power plant. Table 1 gives the multi-level load level model of the power plant.

[0205] Table 1 Multi-level load model of the thermal power plant

[0206]

[0207] Taking unit #1 as an example, the reliability indicators of each load point of the unit's auxiliary power system are calculated based on the non-sequential Monte Carlo simulation, as shown in Table 2:

[0208] Table 2 Load point reliability index of the power supply system

[0209]

[0210] By analyzing the expected accidents, we can get the number of occurrences of different types of faults that lead to shutdown failures as shown in Table 3:

[0211] Table 3 Occurrence rate of equipment failure types that lead to downtime

[0212]

[0213] The same method is used to perform the above calculations on the #2 unit power system. Further processing of the calculation results can yield the shutdown probabilities of each unit system, as shown in Table 4:

[0214] Table 4 Probability of unit shutdown due to auxiliary power system failure

[0215]

[0216] The data in Table 4 can be used to calculate the probability of two units failing, one unit failing, and two units operating normally, as shown in Table 5:

[0217] Table 5 Probability of each unit operating condition occurring (%)

[0218]

[0219] According to the calculation process in the above steps and the construction of the multi-level load level model in this section, using the probability of the units operating under the three operating conditions in Table 5, the probability of power outage in the plant power system can be calculated according to the formula and expected power shortage :

[0220]

[0221]

[0222] According to the reliability assessment results, the expected probability of power outage due to power system failure in this power plant is about 0.0002% per year, and the expected amount of power outage is 194790 .

[0223] It can be seen that the key equipment in the power system of the thermal power plant that may cause unit shutdown failures mainly include: busbar; induced draft fan failure; high-pressure heater and chemical water section.

[0224] The reliability of a thermal power plant is assessed by integrating the plant power system and the main electrical connection. By calculating the probability that a plant power equipment failure could cause a generator unit to shut down, the availability of this generator unit is used as raw data for the main electrical connection reliability calculation. This means that the generator unit is considered a component whose reliability is determined by the plant power system and participates in the main connection reliability assessment. Ultimately, the reliability of the power supply to the outgoing line of the entire thermal power plant is determined.

[0225] The auxiliary power system is combined with two different wiring modes, and the simulation results obtained are as follows: Figure 7 shown.

[0226] The above calculations reveal that while plant power system failures have a significant impact on thermal power plant reliability, main electrical wiring failures have a greater impact. Calculations based on modified component reliability data show that thermal power plants are connected to a large number of intelligent terminals, and their first-order failures account for the majority of main wiring failures. Therefore, the failure and repair rates of intelligent terminal components significantly impact the overall power supply reliability of the thermal power plant. The increased circuit breaker failure rate caused by the introduction of information components should be given greater attention in the process of intelligent power plant development.

[0227] In summary, the present invention provides a method and system for identifying key equipment in a thermal power plant. This method integrates the plant power system and the main electrical connection to assess the reliability of the thermal power plant. By calculating the probability that a plant power equipment failure will cause a generator set to shut down, the availability of this generator set is used as raw data to input into the main electrical connection reliability calculation. This method treats the generator set as a component whose reliability is determined by the plant power system and participates in the main connection reliability assessment. Ultimately, the power supply reliability of the entire thermal power plant to the outgoing lines is determined. This method can identify key links and equipment in a thermal power plant, conduct a systematic and comprehensive reliability assessment, and improve the safety and reliability of the thermal power plant.

Claims

1. A method for identifying key equipment in a thermal power plant, characterized in that: The following steps are involved: S1. Considering the equipment classification and wiring design, a typical plant power system for a thermal power plant is established. S2. Based on the typical power supply system of the thermal power plant constructed in step S1, a non-sequential Monte Carlo simulation and fault analysis are performed on the power supply system to obtain reliability assessment results of the power supply system of the thermal power plant, and the failure rate of each load node in the power supply system is obtained, thereby identifying key links and equipment; S3. Considering the modeling of information layer and physical layer for smart terminals, the failure rate of smart terminals in thermal power plants is obtained, specifically: S301. Information layer modeling of intelligent terminals in thermal power plants, including: The station control layer includes an engineer station and a data acquisition and monitoring control system, which is used to monitor the status data of different components; Bay layer, including microprocessor-based relays and bay controllers. The relays receive information transmitted by the process bus, perform calculations and send action signals via Ethernet. The process layer includes current sensors, voltage sensors, merging units, and execution equipment. The voltage and current signals obtained by the current sensors and voltage sensors are digitized by the merging units and sent to the bay layer. Station control bus, used to support information exchange between the station control layer and the bay layer; Process bus; enables time-critical communication between the process layer and the bay layer; S302: Physical layer modeling of the thermal power plant intelligent terminal. Based on the information layer of the thermal power plant intelligent terminal in step S301, the intelligent terminal failure rate is constructed. The sensors CT / PT collect information and transmit it to the merging unit MU. After merging and synchronizing the electrical quantities, the digital signals are sent to the protection unit via the process layer bus PB according to the specified format standard. S4. Based on the intelligent terminal failure rate obtained in step S3, a sequential Monte Carlo simulation is performed on the main connection system of the power plant including the intelligent terminal to obtain reliability results of the main connection part of the thermal power plant; S5. Input the plant power system result obtained in step S2 into the sequential Monte Carlo simulation of step S4. After integrating the plant power system and the main electrical connection, the reliability of the thermal power plant is evaluated. By calculating the probability that a failure of the plant power equipment may cause the generator set to shut down, the availability of the generator set is input as raw data into the main electrical connection reliability calculation. That is, the generator set is regarded as a component whose reliability is determined by the plant power system and participates in the main connection reliability evaluation. Finally, the power supply reliability of the entire thermal power plant to the outgoing line is given, and the reliability results of the thermal power plant of the plant power system and the main connection system are obtained, thereby realizing the identification of key equipment of the thermal power plant.

2. The method for identifying key equipment in a thermal power plant according to claim 1, characterized in that: Step S1 is specifically as follows: S101. Equipment classification of typical power supply systems in thermal power plants; S102. Based on the equipment classification in step S101, select different representative equipment for each classification, and set the unit structure according to the principle of relative independence of each unit. For the high-voltage auxiliary power system, divide the auxiliary power bus into several independent sections according to the number of boilers. The auxiliary equipment of the same unit is independently connected to the same bus and supplied by a high-voltage auxiliary power transformer. The low-voltage auxiliary power adopts the power center-motor control center wiring. Design the wiring of a typical auxiliary power system of a thermal power plant.

3. The method for identifying key equipment in a thermal power plant according to claim 1, characterized in that: Step S2 is specifically as follows: S201. Establish a multi-level load model for the plant power system and fit the original load curve with a stepped multi-level load level. S202. Treat each device in the auxiliary power system as an independent component, sample the component states using a non-sequential Monte Carlo simulation method, combine them to obtain the auxiliary power system state, and calculate the reliability index of each load point in the auxiliary power system; S203. Based on the status of each load point in the system and the system wiring topology obtained in step S202, analyze whether an accident will occur and perform a predicted fault analysis. If a predicted accident occurs in the system under the corresponding state, calculate the load amount that needs to be shelved in that state through optimal power flow. If load shedding is required, the selected state is the unavailable state, and the probability of the auxiliary power system being in the unavailable state is recorded. S204. Based on the expected fault analysis of step S203, the number of occurrences of different fault types that lead to shutdown faults is statistically obtained. Combined with the original load curve of step S201, the reliability assessment result of the thermal power plant power system is calculated.

4. The method for identifying key equipment in a thermal power plant according to claim 3, characterized in that: In step S204, the reliability assessment results of the thermal power plant power system include: Probability of power shortage : in, yes The number of times the state occurs; is the total number of samples; The load level of the system in a given load model The collection of unavailable states; is the load level duration; is the total time the load curve lasts; is the total number of levels divided into a given load level; Expected power shortage : in, yes The load that needs to be removed in the state (MW); is the state during the simulation time period The number of outgoing lines.

5. The method for identifying key equipment in a thermal power plant according to claim 1, characterized in that: In step S302, the intelligent terminal failure rate for: in, is the availability of the process bus, is the availability of the merged unit, is the availability of the current sensor, is the availability of the voltage sensor, is the availability of the circuit breaker, is the availability of the Ethernet switch, is the availability of three series connected smart components.

6. The method for identifying key equipment in a thermal power plant according to claim 1, characterized in that: In step S4, the reliability index used to evaluate the main electrical connection is: Failure frequency : in, is the number of faults that occurred, is the total simulation time length; Annual failure duration ; in, It is the collection of all outgoing line fault states. is the duration of the outgoing fault; Mean time between failures : Availability and unavailability rate : 。 7. The method for identifying key equipment in a thermal power plant according to claim 1, characterized in that: In step S4, the reliability assessment of the main electrical connection part of the thermal power plant is specifically as follows: S401. Analyze the main wiring system network topology based on the combination method; S402, performing component reliability merging of the main wiring system; S403, simulating the main connection system state using a sequential Monte Carlo method; S404. Calculate the main wiring system's related ratio. If the related ratio is less than a given value, the simulation ends. Otherwise, the simulation continues until the related ratio is less than a given value or the simulation reaches a predetermined time.

8. A key equipment identification system for a thermal power plant, characterized in that: include: The system module considers equipment classification and wiring design for the auxiliary power system and establishes a typical auxiliary power system for a thermal power plant. The analysis module performs non-sequential Monte Carlo simulation and fault analysis on a typical power system of a thermal power plant constructed in the system module. This module obtains reliability assessment results for the power system and the failure rate of each load node in the power system, thereby identifying key links and equipment. The fault module considers modeling at both the information and physical levels for smart terminals and obtains the failure rate of smart terminals in thermal power plants, specifically: The information layer modeling of the intelligent terminal of a thermal power plant includes: the station control layer, which includes the engineer station and the data acquisition and monitoring control system, which is used to monitor the status data of different components; the bay layer, which includes microprocessor-based relays and bay controllers. The relays receive information transmitted by the process bus, perform calculations, and send action signals through Ethernet; the process layer, which includes current sensors, voltage sensors, merging units, and execution devices. The voltage and current signals obtained by the current sensors and voltage sensors are digitized by the merging units and sent to the bay layer; the station control bus is used to support information exchange between the station control layer and the bay layer; the process bus realizes time-critical communication between the process layer and the bay layer; the physical layer modeling of the intelligent terminal of a thermal power plant, which constructs the intelligent terminal failure rate based on the information layer of the intelligent terminal of the thermal power plant. The sensor CT / PT collects information and transmits it to the merging unit MU. After the electrical quantities are merged and synchronously processed, the digital signals are sent to the protection unit through the process layer bus PB according to the specified format standard; The simulation module performs a sequential Monte Carlo simulation on the main connection system of the power plant containing the intelligent terminal based on the intelligent terminal failure rate obtained by the fault module, and obtains the reliability results of the main connection part of the thermal power plant; The identification module inputs the plant power system results obtained by the analysis module into the timing Monte Carlo simulation of the simulation module, and evaluates the reliability of the thermal power plant after integrating the plant power system and the electrical main connection. By calculating the probability that the generator set may be shut down due to the failure of the plant power equipment, the availability of the generator set is input as the original data into the electrical main connection reliability calculation, that is, the generator set is regarded as a component whose reliability is determined by the plant power system and participates in the main connection reliability evaluation. Finally, the power supply reliability of the entire thermal power plant to the outgoing line is given, and the reliability results of the thermal power plant of the plant power system and the main connection system are obtained, thereby realizing the identification of key equipment of the thermal power plant.

Images