Fault calculation scene setting method for analyzing reliability of protection system

Abstract

The invention discloses a fault calculation scene setting method for analyzing the reliability of a protection system, and belongs to the technical field of power system relay protection. A primary equipment state set containing fault states of all primary equipment in a power grid and a secondary equipment state set combined by operation states of all secondary equipment of the power grid relay protection system are constructed, and then a fault calculation scene set used for analyzing the reliability of the protection system is obtained through combination. According to the method, the operation state of the secondary equipment of the power grid and the actual condition of the power grid are considered, a fault calculation scene set capable of comprehensively and truly reflecting the operation condition of the power grid is established, and all simulation scenes for evaluating the action behavior of the protection system under the specific fault working condition are included. The reliability of fault response of the protection system can be quantified through the action behavior result of the protection system in the preset fault calculation scene.

Description

Technical Field

[0001] This invention belongs to the field of power system relay protection technology, and more specifically, relates to a fault calculation scenario setting method for analyzing the reliability of protection systems. Background Technology

[0002] Relay protection is the first line of defense in a power system. When a fault occurs in the power system, the relay protection system is required to operate quickly and reliably, selectively isolating the fault to prevent it from further escalating and threatening the safety and stability of the system. However, due to improper protection settings or equipment failure, the protection system may fail to operate or operate erroneously, leading to a further deterioration of the system's operation and even causing serious accidents such as local power grid instability or collapse. Therefore, it is necessary to assess the reliability of the relay protection system.

[0003] The reliability of a relay protection system is reflected in its behavior when a fault occurs in the power grid. Due to the diversity and randomness of power system faults, the performance of relay protection devices varies under different fault conditions.

[0004] Therefore, to conduct an objective and quantitative analysis of the reliability of relay protection systems, the primary task is to construct fault calculation scenarios that can comprehensively and realistically reflect the operation of the power grid. Existing fault calculation scenarios for analyzing the reliability of protection systems only focus on the fault status of primary equipment in the power grid, including factors such as the type of faulty primary equipment, fault location, fault type, and transition resistance, resulting in fault calculation scenarios that are not accurate enough in reflecting the operational risks of the power grid. Summary of the Invention

[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a method for setting up fault calculation scenarios for analyzing the reliability of protection systems. Its purpose is to solve the technical problem that the fault calculation scenarios for analyzing the reliability of protection systems are not accurate enough.

[0006] To achieve the above objectives, according to one aspect of the present invention, a method for setting up fault calculation scenarios for analyzing the reliability of a protection system is provided, comprising:

[0007] Construct a primary equipment state set that includes the fault states of all primary equipment in the power grid; Construct a secondary equipment state set that includes combinations of operating states of all secondary equipment in the relay protection system corresponding to the power grid; The primary equipment state set and the secondary equipment state set are combined to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system; For each fault calculation scenario in the set of fault calculation scenarios, its occurrence frequency is the product of the occurrence rate of primary equipment fault state and the probability of occurrence of secondary equipment operating state combination under that scenario.

[0008] Furthermore, the fault calculation scenario setting method for analyzing the reliability of the protection system further includes: For any faulty primary device, the number of secondary devices that may fail in the corresponding secondary device status set is set within a first preset range. For any faulty primary device, the failure count of the corresponding secondary device in the status set is set within a second preset range.

[0009] Furthermore, the step of setting the number of secondary devices that may fail in the corresponding secondary device status set for any faulty primary device within a first preset range includes: for a given faulty primary device, limiting the secondary devices that may fail to the range of the three-level circuit breakers of the faulty primary device.

[0010] Furthermore, for any faulty primary device, the failure count of the corresponding secondary device in the status set is set within a second preset range, including: for secondary devices included in the range of a three-level circuit breaker, limiting a maximum of two devices to a failed state, and when two secondary devices fail, the two secondary devices are not directly associated with the same protection device.

[0011] Furthermore, the three-stage circuit breaker includes: Level 1 circuit breaker: A circuit breaker directly connected to the faulty primary equipment; Second-level circuit breakers: Circuit breakers that are connected to primary equipment directly adjacent to the faulty primary equipment, excluding circuit breakers within the scope of the first-level circuit breakers. Third-level circuit breakers: Circuit breakers that are connected to primary equipment directly adjacent to primary equipment within the scope of second-level circuit breakers, excluding circuit breakers within the scope of second-level circuit breakers.

[0012] Furthermore, in each fault calculation scenario, the probability of the next equipment fault state is the product of the equipment fault rate and the probability of the corresponding fault state.

[0013] Furthermore, the probability of a combination of secondary equipment operating states occurring under each fault calculation scenario is the product of the state probabilities corresponding to all secondary equipment operating states.

[0014] According to another aspect of the present invention, a fault calculation scenario setting apparatus for analyzing the reliability of a protection system is provided, comprising: The module is used to construct a primary equipment status set containing the fault states of all primary equipment in the power grid; and to construct a secondary equipment status set containing the combinations of operating states of all secondary equipment in the relay protection system corresponding to the power grid. The combination module is used to combine the primary equipment status set and the secondary equipment status set to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system; For each fault calculation scenario in the set of fault calculation scenarios, its occurrence frequency is the product of the occurrence rate of primary equipment fault state and the probability of occurrence of secondary equipment operating state combination under that scenario.

[0015] According to another aspect of the present invention, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a method for setting up a fault calculation scenario for analyzing the reliability of a protection system.

[0016] According to another aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of a fault calculation scenario setting method for analyzing the reliability of a protection system.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: (1) The fault calculation scenario setting method provided by the present invention constructs a primary equipment state set containing the fault states of all primary equipment in the power grid and a secondary equipment state set containing the combination of the operating states of all secondary equipment in the power grid relay protection system, and then combines them to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system. That is, the method of the present invention considers the operating states of the secondary equipment in the power grid and the actual situation of the power grid, and establishes a set of fault calculation scenarios that can comprehensively and realistically reflect the operating conditions of the power grid. It includes all simulated scenarios for evaluating the action behavior of the protection system under specific fault conditions. The reliability of the fault response of the protection system can be quantified by the action behavior results of the protection system under the preset fault calculation scenarios.

[0018] (2) Considering that given a primary equipment fault state, the fault response results of the protection system will differ under different secondary equipment states. In order to comprehensively analyze the reliability of the protection system's fault response, it is necessary to traverse the secondary equipment state set. If the primary equipment fault state set and the secondary equipment operating state set are directly combined without restrictions, the resulting fault calculation scenario set will be too large, making it difficult to analyze the reliability of the power grid relay protection system. In actual power grids, the number of secondary equipment is much larger than the number of primary equipment. Therefore, this invention also considers reducing the number of secondary equipment states to reduce the size of the fault calculation scenario set. Specifically, considering that the fault calculation scenario set obtained by directly combining the primary equipment state set and the secondary equipment state set is too large, based on the fact that the relay protection of each primary equipment in the actual power grid only has a certain protection range, the number of secondary equipment that may fail in the secondary equipment state set when each primary equipment fails is limited; based on the fact that the secondary equipment of current relay protection has high reliability, the failure multiple of secondary equipment is limited. Through the above measures, the number of secondary equipment states can be reduced, thereby significantly reducing the size of the fault calculation scenario set, making it practically operable to analyze the reliability of the protection system based on it. Attached Figure Description

[0019] Figure 1 This is a flowchart of a fault calculation scenario setting method for analyzing the reliability of a protection system, provided in an embodiment of the present invention. Figure 2 This is a local 110kV power grid topology diagram of a certain region provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Example 1 This embodiment provides a method for setting up fault calculation scenarios to analyze the reliability of a protection system, such as... Figure 1 As shown, it includes: S1-S3. S1: Construct a primary equipment state set containing the fault states of all primary equipment in the power grid. S2: Construct a secondary equipment state set containing the combinations of operating states of all secondary equipment in the power grid's relay protection system. S3: Combine the primary and secondary equipment state sets to obtain a set of fault calculation scenarios used to analyze the reliability of the protection system.

[0022] As an optional implementation, for each fault calculation scenario in the fault calculation scenario set, its occurrence frequency is the product of the occurrence rate of the primary equipment fault state and the probability of the combination of secondary equipment operating states in that scenario. As an optional implementation, the occurrence rate of the next primary equipment fault state in each fault calculation scenario is the product of the primary equipment fault rate and the probability of the fault state. As an optional implementation, the probability of the combination of secondary equipment operating states in each fault calculation scenario is the product of the state probabilities corresponding to all secondary equipment operating states.

[0023] Specifically, the fault calculation scenario setting method first constructs a primary equipment state set containing the fault states of all primary equipment in the power grid, and a secondary equipment state set containing the operating state combinations of all secondary equipment in the corresponding relay protection system of the power grid. Further, the primary and secondary equipment state sets are combined to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system. For each fault calculation scenario, its occurrence frequency is the product of the occurrence rate of the primary equipment fault state and the occurrence probability of the secondary equipment operating state combination under that scenario. This invention constructs a set of fault calculation scenarios for analyzing the reliability of the protection system, containing all simulated scenarios for evaluating the action behavior of the protection system under specific fault conditions. The reliability of the protection system's fault response can be quantified by the action results of the protection system under the preset fault calculation scenarios.

[0024] This invention considers the characteristics of primary and secondary equipment states in a set of fault calculation scenarios. Based on certain characteristics, some scenarios can be classified to obtain sets of fault calculation scenarios with different properties. For example, a set consisting of all fault calculation scenarios where only the primary equipment experiences a high-resistance fault, or a set consisting of all fault calculation scenarios where only the secondary equipment fails.

[0025] As an optional implementation, considering that the set of fault calculation scenarios obtained by directly combining the primary equipment state set and the secondary equipment state set is too large, it would be difficult to analyze the reliability of the power grid relay protection system. Therefore, it is necessary to limit the number of secondary devices that may fail in the secondary equipment state set when each primary equipment fails. The fault calculation scenario setting method for analyzing the reliability of the protection system further includes, before S3: simplifying the devices in the primary equipment state set and the secondary equipment state set. For any faulty primary equipment, the number of secondary devices that may fail in its corresponding secondary equipment state set is set within a first preset range; specifically, for a given faulty primary equipment, the secondary devices that may fail are limited to the three-level circuit breaker range of the faulty primary equipment. For any faulty primary equipment, the failure count of the secondary devices in its corresponding secondary equipment state set is set within a second preset range; specifically, for the secondary devices included in the three-level circuit breaker range, a maximum of two devices are limited to a failed state, and when two secondary devices fail, the two secondary devices are not directly associated with the same protection device.

[0026] This solution addresses the issue that directly combining fault calculation scenarios would result in an excessively large set, making it difficult to analyze the reliability of power grid relay protection systems. Based on the fact that the relay protection of each primary device in a real power grid only has a limited protection range, this approach restricts the number of secondary devices that might fail when a primary device fails. Furthermore, given the high reliability of current relay protection secondary devices, this approach limits the number of failure instances. These measures significantly reduce the size of the fault calculation scenario set.

[0027] As an optional implementation, the three-level circuit breaker includes: a first-level circuit breaker: a circuit breaker directly connected to the faulty primary equipment; a second-level circuit breaker: a circuit breaker connected to a primary equipment directly adjacent to the faulty primary equipment, excluding the circuit breakers within the first-level range; and a third-level circuit breaker: a circuit breaker connected to a primary equipment directly adjacent to the primary equipment within the range of the second-level circuit breaker, excluding the circuit breakers within the second-level range.

[0028] Specifically, circuit breakers directly connected to the faulty primary equipment are classified as Level 1; circuit breakers connected to primary equipment directly adjacent to the faulty primary equipment (excluding those in Level 1) are classified as Level 2; and circuit breakers connected to primary equipment directly adjacent to the primary equipment within the Level 2 circuit breaker range (excluding those in Level 2) are classified as Level 3. Clearly, the protection system for primary equipment within the aforementioned three levels of circuit breakers can cover the protection providing remote backup protection for the faulty primary equipment. Therefore, for a given faulty primary equipment in the power grid, only the potential failure of the protection devices and related secondary equipment within the three levels of circuit breakers for that faulty equipment in the power grid is considered.

[0029] The following provides simulation data for implementing a fault calculation scenario setup method for analyzing the reliability of a protection system in a real-world setting.

[0030] S1. Construct a primary equipment state set containing the fault states of all primary equipment in the power grid. (For...) Figure 2 The local power grid shown has 5 fault points on each of lines L1 to L5, 1 fault point on each of transformers T1 to T8 on both the high-voltage and low-voltage sides, and 1 fault point on each of busbars B1 to B6. Except for the low-voltage side fault points of the transformers, which only consider two-phase metallic short circuit faults and three-phase short circuit faults, the other fault points consider four types of faults: single-phase grounding, two-phase short circuit, three-phase short circuit, and two-phase short circuit to grounding. The transition resistor has 3 resistance values ​​within its resistance range.

[0031] Based on the above analysis, except for the low-voltage side fault point of the transformer which has only 2 fault states, all other fault points have 10 fault states. Figure 2 The local power grid's primary equipment state set contains 406 states. Based on the above analysis, the probability of fault location occurring in any given line fault state is 1 / 5, and the probability of transition resistance occurring is 1 / 3. Statistical data shows that the probability of a single-phase ground fault on a 110kV line is 90%, and the line L1 fault rate is 0.00756 (times / year). Therefore, the fault state... f The probability of a single-phase metallic ground fault occurring at the midpoint of line L1 is 1 / 5 × 1 / 3 × 90% = 0.06. The occurrence rate of this primary equipment fault state is 0.00756 × 0.06 = 0.0004536 (times / year).

[0032] S2. Construct a secondary equipment state set that includes all combinations of operating states of secondary equipment in the power grid relay protection system. Figure 2 In the local power grid shown, only busbars B1 to B6 with a voltage level of 110kV are equipped with busbar protection and adopt a centralized system; the longitudinal connection channels of the current differential protection of lines L1 to L5 are all directly connected by optical fiber; the protection devices of transformers T1 to T8 are all integrated main and backup systems; the number of secondary equipment in the relay protection system of this local power grid is shown in Table 1.

[0033]

[0034] against Figure 2 The secondary equipment of the local power grid shown, including merging units, protection devices, and intelligent terminals, all consider four states: normal operation, latent failure to operate, latent maloperation failure, and fault repair. The fiber optic longitudinal interconnection channel also considers normal operation, latent failure to operate, and fault repair. If any primary equipment failure in the local power grid is considered to be possible for all secondary equipment in the grid, and there is no limit to the number of secondary equipment failures, then the number of secondary equipment state sets is 4.92 ×3 5 ≈5.958×10 57 indivual.

[0035] After executing S1 and S2, the number of secondary devices that may fail in the secondary device state set when each primary device fails is limited, and the number of failure multiples of secondary devices is limited. Then, a secondary device state set containing all combinations of operating states of secondary devices in the power grid relay protection system is reconstructed.

[0036] by Figure 2 Taking line L1 as an example of a faulty primary equipment, we analyze the number of secondary equipment and state combinations within its three-level circuit breaker range. Clearly, CB1 and CB2 are first-level circuit breakers, CB3, CB5, CB11, CB17, CB19, and CB27 are second-level circuit breakers, and CB4, CB6, CB12, CB18, and CB20 are third-level circuit breakers. Therefore, the primary equipment within the three-level circuit breaker range includes lines L1~L3, transformers T1, T4, and T5, and busbars B1 and B3. Correspondingly, we only consider the potential failure of the protection devices and related secondary equipment of these primary equipment. Centered on a single line protection device, its related secondary equipment includes the bay merging unit, intelligent terminal, busbar voltage merging unit, and fiber optic longitudinal connection channel on the line side, as well as the bay merging unit and line protection device on the opposite side of the line. The secondary equipment related to a single transformer protection device includes the bay merging units, intelligent terminals, and busbar voltage merging units on each side of the corresponding transformer. The secondary equipment associated with a single busbar protection device includes the corresponding busbar voltage merging unit and the merging unit and intelligent terminal of the bay connected to that busbar. Therefore, the number of secondary equipment within the range of the three-level circuit breaker during a line L1 fault is determined to be 47. Considering only that at most two of these devices are in a failed state, and that when two secondary devices fail, they are not directly associated with the same protection device, the number of secondary equipment state combinations is 7441.

[0037] Similarly, analysis can be performed. Figure 2 The number of secondary devices and their state combinations within the range of the third-level circuit breaker when other primary devices in the local power grid fail are shown in Table 2.

[0038]

[0039] Based on the fault status of line L1 described in S1 f Considering the state space formed by the states of these 47 secondary devices, which has a combination number of 7441, the state combinations in the state space are... s Taking the case where LPR1 (the protection device on the CB1 side of L1) suffers a latent failure while the other 46 secondary devices operate normally, multiplying the probability of LPR1's latent failure by the probability of the other 46 secondary devices operating normally yields the following result: sThe probability is 0.001499.

[0040] S3. Combine the primary equipment state set and the secondary equipment state set to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system.

[0041] The obtained primary equipment status and the secondary equipment status when the primary equipment fails are combined to obtain the number of scenarios included in the fault calculation scenario set for different primary equipment, as shown in Table 3. Furthermore, by "merging" the fault calculation scenario sets of all primary equipment in Table 3, the fault calculation scenario set of the local power grid can be obtained, with a total of 2,056,600 scenarios.

[0042]

[0043] The fault state described in S1 f and the secondary equipment status combination s Fault calculation scenarios j For example, scenario j The incidence rate was: 0.0004536 × 0.001499 ≈ 6.80 × 10 -7 (Times / Year). A similar analysis was performed on each scenario in the above set of local power grid fault calculation scenarios to obtain the occurrence rate of each scenario.

[0044] It should be noted that if the primary equipment state set and the secondary equipment state set obtained in S2 are directly combined, the number of scenarios in the fault calculation scenario set will reach 406 × 5.958 × 10. 57 =2.419×10 60 Clearly, analyzing the fault response reliability of a local power grid relay protection system based on this scenario set is not feasible. Therefore, the proposed measures can significantly reduce the size of the local power grid fault calculation scenario set, making it practically feasible to analyze the reliability of the protection system based on it.

[0045] Example 2 This embodiment provides a fault calculation scenario setting device for analyzing the reliability of a protection system, including: a construction module and a combination module.

[0046] The module is used to construct a primary equipment state set containing the fault states of all primary equipment in the power grid; and to construct a secondary equipment state set containing the combination of operating states of all secondary equipment in the power grid's relay protection system.

[0047] The combination module is used to combine the primary equipment state set and the secondary equipment state set to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system; for each fault calculation scenario in the set of fault calculation scenarios, its occurrence frequency is the product of the occurrence rate of the primary equipment fault state and the occurrence probability of the combination of the secondary equipment operating states under that scenario.

[0048] Example 3 This embodiment provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of a fault calculation scenario setting method for analyzing the reliability of a protection system.

[0049] The processor in this electronic device can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The memory can be used to store computer programs and / or modules. The processor implements various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory.

[0050] Example 4 This embodiment provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of a fault calculation scenario setting method for analyzing the reliability of a protection system.

[0051] Specifically, the memory may include high-speed random access memory, as well as non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital (SD) cards, flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0052] Example 5 This invention provides a computer program product or computer program that includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of the method described in the above embodiments of this invention.

[0053] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "again" in this invention are intended to illustrate the invention and are not intended to limit the invention.

[0054] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for setting up fault calculation scenarios for analyzing the reliability of a protection system, characterized in that, include: Construct a primary equipment state set that includes the fault states of all primary equipment in the power grid; Construct a secondary equipment state set that includes combinations of operating states of all secondary equipment in the relay protection system corresponding to the power grid; The primary equipment state set and the secondary equipment state set are combined to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system; For each fault calculation scenario in the set of fault calculation scenarios, its occurrence frequency is the product of the occurrence rate of primary equipment fault state and the probability of occurrence of secondary equipment operating state combination under that scenario.

2. The fault calculation scenario setting method for analyzing the reliability of a protection system as described in claim 1, characterized in that, Also includes: For any faulty primary device, the number of secondary devices that may fail in the corresponding secondary device status set is set within a first preset range. For any faulty primary device, the failure count of the corresponding secondary device in the status set is set within a second preset range.

3. The fault calculation scenario setting method for analyzing the reliability of a protection system as described in claim 2, characterized in that, The step of setting the number of secondary devices that may fail in the corresponding secondary device status set for any faulty primary device within a first preset range includes: for a given faulty primary device, limiting the secondary devices that may fail to the range of the three-level circuit breakers of the faulty primary device.

4. The fault calculation scenario setting method for analyzing the reliability of a protection system as described in claim 2, characterized in that, The provision that for any faulty primary device, the failure count of the corresponding secondary device in the status set of the secondary device is set within a second preset range includes: for secondary devices included in the range of a three-level circuit breaker, limiting a maximum of two devices to a failed state, and when two secondary devices fail, the two secondary devices are not directly associated with the same protection device.

5. The fault calculation scenario setting method for analyzing the reliability of a protection system as described in claim 3 or 4, characterized in that, The three-level circuit breaker includes: Level 1 circuit breaker: A circuit breaker directly connected to the faulty primary equipment; Second-level circuit breakers: Circuit breakers that are connected to primary equipment directly adjacent to the faulty primary equipment, excluding circuit breakers within the scope of the first-level circuit breakers. Third-level circuit breakers: Circuit breakers that are connected to primary equipment directly adjacent to primary equipment within the scope of second-level circuit breakers, excluding circuit breakers within the scope of second-level circuit breakers.

6. The fault calculation scenario setting method for analyzing the reliability of a protection system as described in claim 1, characterized in that, In each fault calculation scenario, the probability of the next equipment fault state is the product of the equipment fault rate and the probability of the corresponding fault state.

7. The fault calculation scenario setting method for analyzing the reliability of a protection system as described in claim 1, characterized in that, The probability of a combination of secondary equipment operating states occurring in each fault calculation scenario is the product of the probabilities of all secondary equipment operating states.

8. A fault calculation scenario setting device for analyzing the reliability of a protection system, characterized in that, include: The module is used to construct a primary equipment status set containing the fault states of all primary equipment in the power grid; and to construct a secondary equipment status set containing the combinations of operating states of all secondary equipment in the relay protection system corresponding to the power grid. The combination module is used to combine the primary equipment status set and the secondary equipment status set to obtain a set of fault calculation scenarios for analyzing the reliability of the protection system; For each fault calculation scenario in the set of fault calculation scenarios, its occurrence frequency is the product of the occurrence rate of primary equipment fault state and the probability of occurrence of secondary equipment operating state combination under that scenario.

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

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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