Station AC power supply system protection setting value adaptation degree evaluation method and system

Abstract

The invention discloses a station AC power supply system protection setting value adaptation degree evaluation method and system, and the method comprises the steps: current amplitude adaptation: taking the protection of the current level as a reference, when the current protection action amplitude of the protection of the current level is smaller than that of the upper level, the adaptation of the current amplitude protection of the current level is 1, and otherwise, the adaptation is 0; action time adaptability: taking the protection of the level as a reference, when the action time of the protection of the level is smaller than that of the upper level, the adaptability of the action time of the protection of the level is 1, and otherwise, the adaptability of the action time of the protection of the level is 0; sensitivity adaptability: taking the protection at the level as a reference, when the sensitivity of the switch protection is not lower than a standard requirement, the adaptability of the sensitivity of the switch protection is 1, otherwise, the adaptability of the sensitivity of the switch protection is 0; according to the evaluation of the adaptation degree of the protection setting value of the alternating-current power supply system for the station, the weights of the three dimensions of current amplitude, action time and sensitivity are respectively taken for calculation, the adaptation degree of the protection setting value is estimated from the three dimensions of the current amplitude, the action time and the sensitivity of the protection setting value, and a reliability evaluation index is formed.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system protection and control, and relates to a method and system for evaluating the adaptability of protection settings of a station-used AC power supply system. Background Art

[0002] As a core component of a substation's low-voltage power supply system, the station AC power system bears the crucial responsibility of providing a stable and reliable 400V power supply. This system plays a vital role in the normal operation of various substation equipment, ensuring the safe and stable functioning of the substation. Currently, the typical design of a station power supply system is radial, which to a certain extent meets the substation's power supply needs. However, the complex load hierarchy increases the complexity and management difficulty of the power supply system. Existing low-voltage switch protection methods generally use an overcurrent-based action criterion. This protection logic states that when an overcurrent occurs in a circuit, the protection device determines the circuit based on preset parameters such as the current operating amplitude and operating time. When the current exceeds the operating amplitude and meets the operating time conditions, the protection device activates, disconnecting the faulty circuit and ensuring the safety of the power supply system. To ensure the reliability of the power supply system, when a fault such as a short circuit occurs in a load level, protection action is required to limit the fault range to the power supply range of the switch at that level, thereby preventing the power outage from spreading and minimizing the impact on the overall operation of the substation.

[0003] The protection settings of existing station AC power systems are limited by a variety of objective factors, including design selection, equipment functionality, and the diverse load levels. These factors intertwine and lead to incompatibility with low-voltage AC power supply switch protection.

[0004] In practical applications, over-selecting the rated current of the lower-level switch is a common problem, making it difficult to adapt the current operating amplitude. Due to the higher rated current of the lower-level switch, its set current operating amplitude is also relatively high. When a fault occurs, the fault current may not reach the current operating value of the lower-level protection, and the lower-level protection will not operate. However, at this time, the current operating value of the upper-level protection is relatively low, and the fault current may reach the current operating value of the upper-level protection, causing the upper-level protection to operate and cause an over-trip. Over-tripping can expand the power outage from the power supply range of the current-level switch to the power supply range of the upper-level switch, seriously affecting the reliability and stability of the power supply system.

[0005] When the short-circuit current is large, the current operating amplitude of the lower-level protection and the upper-level protection may be reached simultaneously. However, due to functional selection limitations of the two-level protection, its operating time cannot be effectively adjusted. In this case, the upper and lower protection levels may operate simultaneously, which will also cause the scope of the accident power outage to expand. For example, in a substation, when a serious short-circuit fault occurs, the lower-level protection and the upper-level protection will detect the fault current and reach the operating amplitude almost simultaneously. However, due to the mismatch in operating time, both will disconnect the circuit at the same time, causing the local power outage that should have been controlled by the lower-level protection to expand to the larger area controlled by the upper-level protection, increasing the impact of the power outage on substation operations.

[0006] In summary, the above-mentioned problems existing in the protection of the existing station AC power supply system have seriously affected the reliability and stability of the power supply system, and an effective solution is urgently needed. Summary of the Invention

[0007] The purpose of the present invention is to solve the problem of incompatibility of low-voltage AC power supply switch protection in the prior art and to provide a method and system for evaluating the adaptability of protection setting values of a station AC power supply system.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A method for evaluating the adaptability of protection settings of a station AC power system comprises the following steps: Current amplitude adaptability calculation: Taking the current level protection as the benchmark, when the current protection action amplitude of the current level protection is smaller than that of the upper level, the adaptability of the current amplitude protection of this level is 1, otherwise it is 0; For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the current amplitudes of all load switches in this level are smaller than the current amplitudes of the upper level protection, the adaptability of the current amplitude of this level protection is recorded as F N = 1, otherwise the adaptability of the current amplitude is 0; Action time adaptability calculation: Taking the current level protection as the benchmark, when the action time of the current level protection is less than that of the upper level protection, the adaptability of the action time of the current level protection is 1, otherwise it is 0; For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the action time of all load switch protections in this level is less than the action time of the upper level protection, the adaptability of the action time of this level protection is recorded as T N =1, otherwise the adaptability is 0; Sensitivity adaptability calculation: Taking the current level of protection as the benchmark, when the sensitivity of the switch protection is not lower than the standard requirement, the adaptability of the switch protection sensitivity is 1, otherwise the adaptability of the sensitivity is 0; For a certain level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. When the sensitivity of all load switch protections at this level meets the standard requirements, the sensitivity adaptability of this level of protection is recorded as K N = 1, otherwise the adaptability is 0; Comprehensive calculation of adaptability: The adaptability evaluation of the station AC power system protection setting is calculated from three dimensions: current amplitude, action time, and sensitivity. The weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded as w T , the sensitivity weight factor is recorded as w K ,and w A + w T + w K = 1, the weight factor range is continuously adjustable between 0 and 1; Corresponding to a certain level of fixed value adaptability R N = [ w A w T w K ][ F N T N K N ] T .

[0009] In the current amplitude adaptability calculation for the secondary protection, if the current protection action amplitude of the secondary protection is smaller than the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is 1, which is recorded as F 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is 0, which is recorded as F 2（某某开关） =0.

[0010] For the third level protection, the current amplitude adaptability parameter is recorded as F 3（某某开关） Similarly, for the Nth level protection switch, its current amplitude adaptability parameter is recorded as F N（某某开关） .

[0011] In the calculation of the adaptability of the action time, if the action time of the secondary protection is less than that of the primary protection, the secondary protection can act before the upper protection in terms of action time, and the action time adaptability of the upper protection is 1, which is recorded as T 2（某某开关） =1. Wherein, the switch represents the specific name of the secondary protection switch. On the contrary, if the action time of the secondary protection is greater than or equal to the action time of the primary protection, the secondary protection cannot effectively cooperate with the upper protection in terms of action time, and its action time adaptability is 0, which is recorded as T 2（某某开关） = 0; Level 3 and higher protection: For level 3 protection, the action time adaptability parameter is recorded as T 3（某某开关） Similarly, for the Nth level protection switch, its action time adaptability parameter is recorded as T N（某某开关） .

[0012] In the station AC power supply system, considering the same fault amplitude current, the action time is the primary factor for the protection action to not exceed the level, the current protection action amplitude is the secondary factor, and the sensitivity is the general factor. With the goal of not expanding the fault range, the weight factors are set as follows: Current amplitude dimension weight factor w A =0.3, action time dimension weight factor w T =0.6, sensitivity dimension weight factor w K =0.1, and satisfies w A + w T + w K =1; R N = [ w A w T w K ][ F N T N K N ] T Corresponding to the adaptability of the secondary protection setting, for the secondary protection, that is, the low-voltage side incoming line switch of the station power transformer, when the switch protection of this level F 2=1, T 2=1, K When 2=1, R2= [0.3 0.6 0.1][1 1 1] T =1, indicating that the protection setting of this level is fully adapted in three dimensions: current amplitude, action time and sensitivity.

[0013] According to the certain level of fixed value adaptability R N ,when R N =1, it is determined that the protection setting value of this level is fully adapted; when R N <1, further analyze the current amplitude adaptability F N , action time adaptability T N , sensitivity adaptability K N The value of the dimension is determined to find out the dimension that causes insufficient adaptability, and the protection setting is optimized and adjusted according to the protection setting adjustment strategy corresponding to the dimension.

[0014] A station AC power system protection setting adaptability evaluation system includes the following modules: Current amplitude adaptability calculation module: used to determine the current amplitude adaptability of the protection at this level based on the protection at this level; if there are multiple load switches at a certain level, they are considered to be at the same level of protection based on the radial power supply topology; if the current amplitudes of all load switches at this level are smaller than the current amplitudes of the upper level protection, the current amplitude adaptability of the protection at this level is determined. F N =1, otherwise F N =0; Action time adaptability calculation module: used to determine the action time adaptability of the protection at this level based on the protection at this level; if there are multiple load switches at a certain level, they are considered as the same level of protection according to the radial power supply topology; if the action time of all load switch protections at this level is less than the action time of the upper level protection, the action time adaptability of the protection at this level is determined. T N =1, otherwise T N =0; Sensitivity adaptability calculation module: used to determine the sensitivity adaptability of the protection at this level based on the protection at this level; if there are multiple load switches at a certain level, they are considered to be at the same level of protection based on the radial power supply topology; if the sensitivity of all load switches at this level meets the standard requirements, the sensitivity adaptability of the protection at this level is determined K N =1, otherwise K N =0; Adaptability comprehensive calculation module: used to comprehensively calculate the adaptability of the station AC power system protection setting value; evaluation is performed from three dimensions: current amplitude, action time, and sensitivity. The weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded as w T , the sensitivity weight factor is recorded as w K ,and w A + w T + w K = 1, the weight factor range is continuously adjustable between 0 and 1; corresponding to a certain level of fixed value adaptability R N The calculation formula is R N =[ w A w T w K ][ F N T N K N ] T .

[0015] The system includes a multi-level protection current amplitude adaptability evaluation module for calculating the current amplitude adaptability of different levels of protection, specifically: The current amplitude adaptability calculation of the secondary protection is as follows: for the secondary protection in the station AC power system, the current protection action amplitude of the secondary protection and the corresponding current protection action amplitude of the primary protection are obtained; if the current protection action amplitude of the secondary protection is smaller than the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is determined to be 1 and recorded as F 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is determined to be 0 and recorded as F 2（某某开关） =0; The current amplitude adaptability parameter of level 3 and above protection is expressed as follows: F 3（某某开关） Similarly, for the Nth level protection switch, its current amplitude adaptability parameter is recorded as F N（某某开关）, where "switch" represents the specific protection switch name of the corresponding level.

[0016] The system includes a multi-level protection action time adaptability evaluation module for calculating the action time adaptability of different levels of protection, specifically: The adaptability calculation of the secondary protection action time is as follows: for the secondary protection in the station AC power system, the action time of the secondary protection and the action time of the corresponding primary protection are obtained; if the action time of the secondary protection is less than that of the primary protection, it indicates that the secondary protection can act before the upper protection in terms of action time. In this case, the action time adaptability of the secondary protection is determined to be 1 and recorded as T 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the action time of the secondary protection is greater than or equal to the action time of the primary protection, the secondary protection cannot effectively cooperate with the upper protection in terms of action time. At this time, the action time adaptability of the secondary protection is determined to be 0 and recorded as T 2（某某开关） =0; The adaptability parameters of the action time of level 3 and higher protection are expressed as follows: T 3（某某开关） Similarly, for the Nth level protection switch, its action time adaptability parameter is recorded as T N（某某开关） , where "switch" represents the specific protection switch name of the corresponding level.

[0017] The system includes a decision optimization module, specifically: According to a certain level of fixed value adaptability R N ,when R N =1, it is determined that the protection setting value of this level is fully adapted; when R N <1, further analyze the current amplitude adaptability F N , action time adaptability T N , sensitivity adaptability K N The value of the dimension is determined to find out the dimension that causes insufficient adaptability, and the protection setting is optimized and adjusted according to the protection setting adjustment strategy corresponding to the dimension.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The station AC power system protection setting adaptability evaluation method of the present invention estimates the protection setting adaptability from three dimensions: current amplitude, action time and sensitivity of the protection setting, and forms a reliability evaluation index.

[0019] Precise fault isolation: By comprehensively considering three dimensions: current amplitude, operating time, and sensitivity, the suitability of protection settings can be more accurately assessed. When a short circuit or other fault occurs in the downstream load supply branch of the station AC power system, the appropriate protection setting ensures that the protection device operates quickly and accurately, disconnecting only the faulty branch and preventing further escalation of the fault, thereby maintaining normal power supply to loads on other branches and effectively improving the reliability of the power supply system.

[0020] Reduced outage scope: Accurate protection setting suitability assessment helps optimize protection device parameter settings, enabling selective action when a fault occurs. This prevents widespread outages caused by inappropriate protection settings, minimizes the scope of outages, and ensures the normal operation of other important equipment within the substation, which is crucial for maintaining stable operation of the entire substation.

[0021] Providing a scientific basis: The resulting station-use AC protection setting reliability evaluation index provides a scientific theoretical basis for setting low-voltage AC protection settings in substations. While traditional protection setting methods may only consider a single factor or empirical value, the comprehensive evaluation method presented in this paper can more comprehensively reflect the actual adaptation of protection settings, resulting in more reasonable and accurate setting results.

[0022] Adapting to system changes: As the station AC power system's operating conditions, load characteristics, and other factors change, the protection settings also need to be adjusted accordingly. The evaluation method of this invention dynamically assesses the adaptability of the protection settings based on the system's actual operating conditions, providing a reference for timely adjustment of the protection settings and ensuring optimal performance of the protection device under varying operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a flow chart of the method for evaluating the adaptability of protection settings of a station AC power system according to the present invention; Figure 2 This is a topological diagram of the power supply system of the present invention. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] The present invention is described in further detail below with reference to the accompanying drawings: See also Figure 1 , is a flow chart of a method for evaluating the adaptability of a station AC power system protection setting value according to the present invention, comprising the following steps: Current amplitude adaptability calculation: Taking the current level protection as the benchmark, when the current protection action amplitude of the current level protection is smaller than that of the upper level, the adaptability of the current amplitude protection of this level is 1, otherwise it is 0; For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the current amplitudes of all load switches in this level are smaller than the current amplitudes of the upper level protection, the adaptability of the current amplitude of this level protection is recorded as F N = 1, otherwise the adaptability of the current amplitude is 0; In the current amplitude adaptability calculation for the secondary protection, if the current protection action amplitude of the secondary protection is smaller than the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is 1, which is recorded as F 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is 0, which is recorded as F 2（某某开关） = 0.

[0029] For the third level protection, the current amplitude adaptability parameter is recorded as F 3（某某开关） Similarly, for the Nth level protection switch, its current amplitude adaptability parameter is recorded asF N（某某开关） .

[0030] Action time adaptability calculation: Taking the current level protection as the benchmark, when the action time of the current level protection is less than that of the upper level protection, the adaptability of the action time of the current level protection is 1, otherwise it is 0; For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the action time of all load switch protections in this level is less than the action time of the upper level protection, the adaptability of the action time of this level protection is recorded as T N =1, otherwise the adaptability is 0; In the calculation of the adaptability of the action time, if the action time of the secondary protection is less than that of the primary protection, the secondary protection can act before the upper protection in terms of action time. The action time adaptability of the upper protection is 1, which is recorded as T 2（某某开关） = 1. Wherein, a certain switch represents the specific name of the secondary protection switch. On the contrary, if the action time of the secondary protection is greater than or equal to the action time of the primary protection, the secondary protection cannot effectively cooperate with the upper protection in terms of action time, and its action time adaptability is 0, which is recorded as T 2（某某开关） = 0; Level 3 and higher protection: For level 3 protection, the action time adaptability parameter is recorded as T 3（某某开关） Similarly, for the Nth level protection switch, its action time adaptability parameter is recorded as T N（某某开关） .

[0031] Sensitivity adaptability calculation: Taking the current level of protection as the benchmark, when the sensitivity of the switch protection is not lower than the standard requirement, the adaptability of the switch protection sensitivity is 1, otherwise the adaptability of the sensitivity is 0; For a certain level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. When the sensitivity of all load switch protections at this level meets the standard requirements, the sensitivity adaptability of this level of protection is recorded as K N = 1, otherwise the adaptability is 0; Comprehensive calculation of adaptability: The adaptability evaluation of the station AC power system protection setting is calculated from three dimensions: current amplitude, action time, and sensitivity. The weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded as w T , the sensitivity weight factor is recorded as w K ,and wA + w T + w K = 1, the weight factor range is continuously adjustable between 0 and 1; Corresponding to a certain level of fixed value adaptability R N = [ w A w T w K ][ F N T N K N ] T .

[0032] According to the certain level of fixed value adaptability R N ,when R N =1, it is determined that the protection setting value of this level is fully adapted; when R N <1, further analyze the current amplitude adaptability F N , action time adaptability T N , sensitivity adaptability K N The value of the dimension is determined to find out the dimension that causes insufficient adaptability, and the protection setting is optimized and adjusted according to the protection setting adjustment strategy corresponding to the dimension.

[0033] In the station AC power supply system, considering the same fault amplitude current, the action time is the primary factor for the protection action to not exceed the level, the current protection action amplitude is the secondary factor, and the sensitivity is the general factor. With the goal of not expanding the fault range, the weight factors are set as follows: Current amplitude dimension weight factor w A =0.3, action time dimension weight factor w T =0.6, sensitivity dimension weight factor w K =0.1, and satisfies w A + w T + w K = 1; R N = [ w A wT w K ][ F N T N K N ] T Corresponding to the adaptability of the secondary protection setting, for the secondary protection, that is, the low-voltage side incoming line switch of the station power transformer, when the switch protection of this level F 2=1, T 2=1, K When 2=1, R 2= [0.3 0.6 0.1][1 1 1] T , indicating that the protection setting of this level is fully adapted in three dimensions: current amplitude, action time and sensitivity.

[0034] according to F N 、 T N 、 K N The values of {0,1} are arranged and combined to obtain the following situations and corresponding fitness R N value: when F N =1, T N =0, K N =0, R N =[0.3 0.6 0.1][10 0] T =0.3, at this time only the current action amplitude is adapted, and the action time and sensitivity are not adapted.

[0035] when F N =0, T N =1, K N =0, R N =[0.3 0.6 0.1][01 0] T =0.6, at this time only the action time is adapted, and the current action amplitude and sensitivity are not adapted.

[0036] when F N =0, T N =0, K N =1,R N =[0.3 0.6 0.1][00 1] T =0.1, at this time only the sensitivity is adapted, and the current action amplitude and action time are not adapted.

[0037] when F N =1, T N =1, K N =0, R N =[0.3 0.6 0.1][11 0] T =0.9, at this time the current action amplitude and action time are both adapted, but the sensitivity is not adapted.

[0038] when F N =0, T N =1, K N =1, R N =[0.3 0.6 0.1][01 1] T =0.7, at this time the action time and sensitivity are both adapted, but the current action amplitude is not adapted.

[0039] when F N =1, T N =0, K N =1, R N =[0.3 0.6 0.1][10 1] T =0.4, at this time the current action amplitude and sensitivity are both adapted, but the action time is not adapted.

[0040] when F N =0, T N =0, K N =0, R N =[0.3 0.6 0.1][00 0] T =0, at this time the current action amplitude, action time and sensitivity are not suitable. Example

[0041] Taking the design structure of a typical substation AC power supply system as an example, the power supply system topology is as follows: Figure 2As shown, the station transformer protection is used as the first level protection, which can disconnect the switch at this level.

[0042] Specifically, in terms of the current amplitude of the protection setting, taking the current level protection as the benchmark, when the current protection action amplitude of the current level protection is smaller than that of the upper level, the adaptability of the current amplitude protection of this level is 1, otherwise it is 0. If the current protection action amplitude of the secondary protection is smaller than that of the primary protection, the adaptability is 1, which is recorded as F 2（某某开关） =1, when the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the adaptability is 0, which is recorded as F 2（某某开关） =0, similarly, the current amplitude adaptability parameter of the third-level protection is recorded as F 3（某某开关） , by extension, the current amplitude adaptability parameter of the Nth level protection switch is recorded as F N（某某开关） .

[0043] For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the current amplitudes of all load switches in this level are smaller than the current amplitudes of the upper level protection, the adaptability of the current amplitude of this level protection is recorded as F N =1, otherwise the adaptability is 0.

[0044] In terms of action time, taking the current level protection as the benchmark, when the action time of the current level protection is less than that of the upper level protection, the adaptability of the action time of the current level protection is 1, otherwise it is 0. If the action time of the second level protection is less than that of the first level protection, the adaptability is 1, which is recorded as T 2（某某开关） =1, when the action time of the second-level protection is greater than or equal to the action time of the first-level protection, the adaptability is 0, which is recorded as T 2（某某开关） =0, similarly, the action time adaptability parameter of the third-level protection is recorded as T 3（某某开关） , the operating time adaptability parameter of the N-level protection switch is recorded as T N（某某开关） .

[0045] For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the action time of all load switch protections in this level is less than the action time of the upper level protection, the adaptability of the action time of this level protection is recorded as T N =1, otherwise the adaptability is 0.

[0046] In terms of sensitivity, referring to the definition and calculation method of sensitivity in relevant industry standards, it is the verification of the current amplitude value of each level of switch protection. Taking the current level protection as the benchmark, when the sensitivity of the switch protection K When the sensitivity is not lower than the relevant standard requirements, the adaptability of the protection sensitivity of this switch is 1, which is recorded as K N（某某开关） =1, otherwise K N（某某开关） =0.

[0047] For a certain level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. When the sensitivity of all load switch protections at this level meets the standard requirements, the sensitivity adaptability of this level of protection is recorded as K N =1, otherwise the adaptability is 0.

[0048] The adaptability evaluation of the station AC power system protection setting is calculated from three dimensions, and the weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded as w T , the sensitivity weight factor is recorded as w K , then the corresponding level of fixed value adaptation is R N =[ w A w T w K ][ F N T N K N ] T ,in w A + w T + w K =1, the weight factor can be optimized and adjusted according to expert experience or practical experience, and the value range is continuously adjustable between 0 and 1.

[0049] Considering the same fault amplitude current, the action time is the primary factor for the protection action to not exceed the level, the current protection action amplitude is a secondary factor, and the sensitivity that can mostly meet the requirements is a general factor. Therefore, with the goal of not expanding the fault range, the weight factors can be set as follows: w A Take 0.3, w T Take 0.6, wK Take 0.1, for the secondary protection, that is, the low-voltage side incoming line switch of the station power transformer, when the switch protection of this level F 2=1, T 2=1, K 2=1, when R 2=[0.3 0.6 0.1][11 1] T =1.

[0050] An embodiment of the present invention is a station AC power system protection setting adaptability assessment system, comprising the following modules: Current amplitude adaptability calculation module: used to determine the current amplitude adaptability of the protection at this level based on the protection at this level; if there are multiple load switches at a certain level, they are considered to be at the same level of protection based on the radial power supply topology; if the current amplitudes of all load switches at this level are smaller than the current amplitudes of the upper level protection, the current amplitude adaptability of the protection at this level is determined. F N =1, otherwise F N =0; The multi-level protection current amplitude adaptability evaluation module is used to calculate the current amplitude adaptability of different levels of protection, specifically: The current amplitude adaptability calculation of the secondary protection is as follows: for the secondary protection in the station AC power system, the current protection action amplitude of the secondary protection and the corresponding current protection action amplitude of the primary protection are obtained; if the current protection action amplitude of the secondary protection is smaller than the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is determined to be 1 and recorded as F 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is determined to be 0 and recorded as F 2（某某开关） =0; The current amplitude adaptability parameter of level 3 and above protection is expressed as follows: F 3（某某开关） Similarly, for the Nth level protection switch, its current amplitude adaptability parameter is recorded as F N（某某开关） , where "switch" represents the specific protection switch name of the corresponding level.

[0051] Action time adaptability calculation module: used to determine the action time adaptability of the protection at this level based on the protection at this level; if there are multiple load switches at a certain level, they are considered as the same level of protection according to the radial power supply topology; if the action time of all load switch protections at this level is less than the action time of the upper level protection, the action time adaptability of the protection at this level is determined. T N =1, otherwise T N =0; The multi-level protection action time adaptability evaluation module is used to calculate the action time adaptability of different levels of protection, specifically: The adaptability calculation of the secondary protection action time is as follows: for the secondary protection in the station AC power system, the action time of the secondary protection and the action time of the corresponding primary protection are obtained; if the action time of the secondary protection is less than that of the primary protection, it indicates that the secondary protection can act before the upper protection in terms of action time. In this case, the action time adaptability of the secondary protection is determined to be 1 and recorded as T 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the action time of the secondary protection is greater than or equal to the action time of the primary protection, the secondary protection cannot effectively cooperate with the upper protection in terms of action time. At this time, the action time adaptability of the secondary protection is determined to be 0 and recorded as T 2（某某开关） =0; The adaptability parameters of the action time of level 3 and higher protection are expressed as follows: T 3（某某开关） Similarly, for the Nth level protection switch, its action time adaptability parameter is recorded as T N（某某开关） , where "switch" represents the specific protection switch name of the corresponding level.

[0052] Sensitivity adaptability calculation module: used to determine the sensitivity adaptability of the protection at this level based on the protection at this level; if there are multiple load switches at a certain level, they are considered to be at the same level of protection based on the radial power supply topology; if the sensitivity of all load switches at this level meets the standard requirements, the sensitivity adaptability of the protection at this level is determined K N =1, otherwise K N =0; Adaptability comprehensive calculation module: used to comprehensively calculate the adaptability of the station AC power system protection setting value; evaluation is performed from three dimensions: current amplitude, action time, and sensitivity. The weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded asw T , the sensitivity weight factor is recorded as w K ,and w A + w T + w K = 1, the weight factor range is continuously adjustable between 0 and 1; corresponding to a certain level of fixed value adaptability R N The calculation formula is R N =[ w A w T w K ][ F N T N K N ] T .

[0053] Determine the optimization module, specifically: According to a certain level of fixed value adaptability R N ,when R N =1, it is determined that the protection setting value of this level is fully adapted; when R N <1, further analyze the current amplitude adaptability F N , action time adaptability T N , sensitivity adaptability K N The value of the dimension is determined to find out the dimension that causes insufficient adaptability, and the protection setting is optimized and adjusted according to the protection setting adjustment strategy corresponding to the dimension.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the suitability of protection settings of a station AC power system, characterized in that: The following steps are involved: Current amplitude adaptability calculation: Taking the current level protection as the benchmark, when the current protection action amplitude of the current level protection is smaller than that of the upper level, the adaptability of the current amplitude protection of this level is 1, otherwise it is 0; For a level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the current amplitudes of all load switches in this level are smaller than the current amplitudes of the upper level protection, the adaptability of the current amplitude of the protection level is recorded as F N = 1, otherwise the adaptability of the current amplitude is 0; Action time adaptability calculation: Taking the current level protection as the benchmark, when the action time of the current level protection is less than that of the upper level protection, the adaptability of the action time of the current level protection is 1, otherwise it is 0; For a certain level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. Only when the action time of all load switch protections in this level is less than the action time of the upper level protection, the adaptability of the action time of this level protection is recorded as T N =1, otherwise the adaptability is 0; Sensitivity adaptability calculation: Taking the current level of protection as the benchmark, when the sensitivity of the switch protection is not lower than the standard requirement, the adaptability of the switch protection sensitivity is 1, otherwise the adaptability of the sensitivity is 0; For a certain level with multiple load switches, according to the radial power supply topology, they are considered to be the same level of protection. When the sensitivity of all load switch protections at this level meets the standard requirements, the sensitivity adaptability of this level of protection is recorded as K N = 1, otherwise the adaptability is 0; Comprehensive calculation of adaptability: The adaptability evaluation of the station AC power system protection setting is calculated from three dimensions: current amplitude, action time, and sensitivity. The weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded as w T , the sensitivity weight factor is recorded as w K ,and w A + w T + w K = 1, the weight factor range is continuously adjustable between 0 and 1; Corresponding to a certain level of fixed value adaptability R N = [ w A w T w K ][ F N T N K N ] T .

2. A method for evaluating the adaptability of protection settings of a station AC power system according to claim 1, characterized in that: In the current amplitude adaptability calculation for the secondary protection, if the current protection action amplitude of the secondary protection is smaller than the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is 1, which is recorded as F 2（某某开关） =1, where switch X represents the specific secondary protection switch name; If the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is 0, which is recorded as F 2（某某开关） = 0; For the third level protection, the current amplitude adaptability parameter is recorded as F 3（某某开关） Similarly, for the Nth level protection switch, its current amplitude adaptability parameter is recorded as F N（某某开关） .

3. The method for evaluating the adaptability of protection setting values of a station AC power system according to claim 1, wherein: In the calculation of the adaptability of the action time, if the action time of the secondary protection is less than that of the primary protection, the secondary protection can act before the upper protection in terms of action time, and the action time adaptability of the upper protection is 1, which is recorded as T 2（某某开关） = 1; where switch represents the specific secondary protection switch name; On the contrary, if the action time of the secondary protection is greater than or equal to the action time of the primary protection, the secondary protection cannot effectively cooperate with the upper protection in terms of action time, and its action time adaptability is 0, which is recorded as T 2（某某开关） = 0; Level 3 and higher protection: For level 3 protection, the action time adaptability parameter is recorded as T 3（某某开关） Similarly, for the Nth level protection switch, its action time adaptability parameter is recorded as T N（某某开关） .

4. A method for evaluating the adaptability of protection settings of a station AC power system according to claim 1, characterized in that: In the station AC power supply system, considering the same fault amplitude current, the action time is the primary factor for the protection action to not exceed the level, the current protection action amplitude is the secondary factor, and the sensitivity is the general factor. With the goal of not expanding the fault range, the weight factors are set as follows: Current amplitude dimension weight factor w A =0.3, action time dimension weight factor w T =0.6, sensitivity dimension weight factor w K =0.1, and satisfies w A + w T + w K = 1; R N = [ w A w T w K ][ F N T N K N ] T Corresponding to the adaptability of the secondary protection setting, for the secondary protection, that is, the low-voltage side incoming line switch of the station power transformer, when the switch protection of this level F 2=1, T 2=1, K When 2=1, R 2= [0.3 0.6 0.1][1 1 1] T , indicating that the protection setting of this level is fully adapted in three dimensions: current amplitude, action time and sensitivity.

5. The method for evaluating the adaptability of protection setting values of a station AC power system according to claim 1, wherein: According to the certain level of fixed value adaptability R N ,when R N =1, it is determined that the protection setting value of this level is fully adapted; when R N <1, further analyze the current amplitude adaptability F N , action time adaptability T N , sensitivity adaptability K N The value of the dimension is determined to find out the dimension that causes insufficient adaptability, and the protection setting is optimized and adjusted according to the protection setting adjustment strategy corresponding to the dimension.

6. A station AC power system protection setting adaptability evaluation system, characterized by: Includes the following modules: Current amplitude adaptability calculation module: used to determine the current amplitude adaptability of the current level protection based on the current level protection; If there are multiple load switches at a certain level, they are considered as the same level of protection according to the radial power supply topology; If the current amplitudes of all load switches protected at this level are smaller than the current amplitudes of the upper level protection, the current amplitude adaptability of the protection at this level is determined. F N =1, otherwise F N =0; Action time adaptability calculation module: used to determine the action time adaptability of the protection at this level based on the protection at this level; If there are multiple load switches at a certain level, they are considered as the same level of protection according to the radial power supply topology; if the action time of all load switch protections at this level is less than the action time of the upper level protection, the action time adaptability of the protection at this level is determined. T N =1, otherwise T N =0; Sensitivity adaptability calculation module: used to determine the sensitivity adaptability of the protection at this level based on the protection at this level. If there are multiple load switches at a certain level, they are considered to be at the same level of protection based on the radial power supply topology. If the sensitivity of all load switch protections at this level meets the standard requirements, the sensitivity adaptability of the protection at this level is determined. K N =1, otherwise K N =0; Adaptability comprehensive calculation module: used to perform comprehensive calculation on the adaptability of the protection setting value of the station AC power system; The evaluation is conducted from three dimensions: current amplitude, action time, and sensitivity. The weight factor of the current amplitude dimension is recorded as w A , the weight factor of action time is recorded as w T , the sensitivity weight factor is recorded as w K ,and w A + w T + w K = 1, the weight factor range is continuously adjustable between 0 and 1; Corresponding to a certain level of fixed value adaptability R N The calculation formula is R N =[ w A w T w K ][ F N T N K N ] T .

7. A station AC power system protection setting value adaptability evaluation system according to claim 6, characterized in that: The system includes a multi-level protection current amplitude adaptability evaluation module for calculating the current amplitude adaptability of different levels of protection, specifically: Secondary protection current amplitude adaptability calculation: For the secondary protection in the station AC power system, obtain the current protection action amplitude of the secondary protection and the corresponding current protection action amplitude of the primary protection; If the current protection action amplitude of the secondary protection is smaller than that of the primary protection, the current amplitude adaptability of the secondary protection is determined to be 1 and recorded as F 2（某某开关） =1, where switch X represents the specific secondary protection switch name; If the current protection action amplitude of the secondary protection is greater than or equal to the current protection action amplitude of the primary protection, the current amplitude adaptability of the secondary protection is determined to be 0 and recorded as F 2（某某开关） =0; The current amplitude adaptability parameter of level 3 and above protection is expressed as follows: F 3（某某开关） Similarly, for the Nth level protection switch, its current amplitude adaptability parameter is recorded as F N（某某开关） , where "switch" represents the specific protection switch name of the corresponding level.

8. The station AC power system protection setting value adaptability evaluation system according to claim 6, characterized in that: The system includes a multi-level protection action time adaptability evaluation module for calculating the action time adaptability of different levels of protection, specifically: Secondary protection action time adaptability calculation: For the secondary protection in the station AC power system, obtain the secondary protection action time and the corresponding primary protection action time; If the action time of the secondary protection is less than that of the primary protection, it indicates that the secondary protection can act before the upper protection in terms of action time. At this time, the action time adaptability of the secondary protection is determined to be 1 and recorded as T 2（某某开关） =1, where a certain switch represents the specific name of the secondary protection switch; if the action time of the secondary protection is greater than or equal to the action time of the primary protection, the secondary protection cannot effectively cooperate with the upper protection in terms of action time. At this time, the action time adaptability of the secondary protection is determined to be 0 and recorded as T 2（某某开关） =0; The adaptability parameters of the action time of level 3 and higher protection are expressed as follows: T 3（某某开关） Similarly, for the Nth level protection switch, its action time adaptability parameter is recorded as T N（某某开关） , where "switch" represents the specific protection switch name of the corresponding level.

9. A station AC power system protection setting value adaptability evaluation system according to claim 6, characterized in that: The system includes a decision optimization module, specifically: According to a certain level of fixed value adaptability R N ,when R N =1, it is determined that the protection setting value of this level is fully adapted; when R N <1, further analyze the current amplitude adaptability F N , action time adaptability T N , sensitivity adaptability K N The value of the dimension is determined to find out the dimension that causes insufficient adaptability, and the protection setting is optimized and adjusted according to the protection setting adjustment strategy corresponding to the dimension.

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