On-line calculation parameter setting method, system, equipment and medium

Abstract

The invention discloses a setting method, system and equipment for online calculation of parameters and a medium. The method comprises the steps that an actual fault recording file is acquired, and fault section time, fault equipment, a fault type and a short-circuit current effective value are analyzed and extracted; matching an initial online short-circuit current result according to the extracted fault recording information; calculating the deviation between the online short-circuit current and the recording value, and when the deviation is greater than a set threshold value, adjusting the motor load proportionality coefficient and re-calculating the short-circuit current until the deviation is less than the threshold value; and generating alarm information according to the deviation between the on-line short-circuit current and the recording value and the motor load proportionality coefficient setting result. According to the method, the accuracy of online short-circuit current calculation is improved, the risk that the short-circuit current exceeds the standard in actual operation of a power grid is truly reflected, and a basis is provided for scheduling operation personnel to take short-circuit current suppression measures. Therefore, the problem that online calculation and analysis of the short-circuit current cannot be accurately and reliably carried out in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the technical field of power system automation, and in particular to a method, system, device and medium for setting online calculation parameters. Background Art

[0002] With the continuous development of the power system, the scale of the power grid is expanding, the capacity and load density of substations are increasing, and large-capacity generators are connected to the power grid one after another, which makes the short-circuit current of the power system gradually increase, seriously affecting the safe and stable operation of the power grid. The accuracy of online short-circuit current calculation is the key to real-time assessment of whether the power grid is facing the risk of exceeding the short-circuit current standard, and the accuracy of the calculation result is related to the online calculation parameters. However, the current online calculation parameters are often selected from unified international standards or formulated through manual experience, which may cause a large deviation between the online calculation results and the actual values, and cannot truly reflect the actual short-circuit current level of the power grid.

[0003] The fault recorder can record the current waveform when a short-circuit fault occurs, accurately monitor the actual short-circuit fault and short-circuit current of the power grid, and by analyzing the fault recording data, the magnitude and duration of the short-circuit current can be obtained, thereby evaluating the safety of the system under fault conditions. The fault recording is used to verify the online calculation results and set the calculation parameters. By adjusting the online calculation parameters and performing iterative calculation of the short-circuit current, the deviation between the calculated value and the recorded value is within the allowable range. The online calculation parameters determined in this way are more in line with the actual power grid, which will further improve the accuracy of the online calculation results, thereby guiding the actual production operation. However, there is no effective method in the prior art that can meet this demand. Summary of the invention

[0004] The present application provides a method, system, device and medium for setting online calculation parameters, which are used to solve the problem that the prior art cannot accurately and reliably perform online calculation and analysis of short-circuit current.

[0005] In view of this, the first aspect of the present application provides a method for setting online calculation parameters, the method comprising:

[0006] S1. Obtain a fault recording file and parse and extract the fault recording file to obtain fault recording information, wherein the fault recording information includes: fault occurrence time, fault equipment, fault type, fault short-circuit current effective value and recording value;

[0007] S2. Matching the initial online short-circuit current according to the fault recording information to obtain the online short-circuit current;

[0008] S3, calculating the difference between the online short-circuit current and the recorded value, if the difference is less than a preset threshold value, executing S5, otherwise executing S4;

[0009] S4, adjusting the motor load proportional coefficient and calculating the value of the online short-circuit current, and returning to S3, until the difference between the online short-circuit current and the recorded value is less than a preset threshold value, and obtaining the setting result of the motor load proportional coefficient;

[0010] S5. Generate alarm information according to the difference between the online short-circuit current and the recorded value and the setting result.

[0011] Optionally, the method for extracting the fault type includes:

[0012] Based on the maximum value and minimum value Calculation formula to calculate the maximum value of the amplitude of the current mutation between two phases and minimum value , according to the maximum value and the minimum value Determine the type of fault;

[0013] The maximum value and minimum value The calculation formula is:

[0014] ;

[0015] In the formula, , , They are the sudden changes of short-circuit current between the two phases.

[0016] Optionally, the maximum value and the minimum value Determine the type of fault, including:

[0017] like , it is a three-phase fault;

[0018] like , it is a two-phase fault;

[0019] like , it is a single-phase fault;

[0020] In the formula, is the threshold value, is the proportionality coefficient.

[0021] Optionally, the method for extracting the effective value of the fault short-circuit current includes:

[0022] Calculate the effective value of the fault short-circuit current based on the calculation formula of the effective value of the fault short-circuit current;

[0023] The calculation formula of the effective value of the fault short-circuit current is:

[0024] ;

[0025] In the formula, is the effective value of the fault short-circuit current, The first The current value of the sampling point, is the total number of sampling points in the recording data window.

[0026] Optionally, step S2 includes:

[0027] Retrieve the section time and the fault occurrence time The closest online short-circuit current, and retrieve the current value of the online short-circuit current according to the fault device and the fault type .

[0028] Optionally, step S4 includes:

[0029] S41, if , then increase the motor load ratio coefficient and adjust its space Divide into The motor load ratio coefficient is calculated as follows: Short-circuit current value when ;

[0030] S42, if , then the motor load proportional coefficient is set to ;

[0031] S43, if ,and , , then the interval Divide into Repeat steps S41 to S43 until you get Make ;

[0032] S44, if , then lower the motor load ratio coefficient and adjust its space Divide into The motor load ratio coefficient is calculated as follows: Short-circuit current value when ;

[0033] S45, if , then the motor load proportional coefficient is set to ;

[0034] S46, if ,and , , then the interval Divide into Repeat steps S44-S46 until you get Make ;

[0035] in, is the effective value of the fault short-circuit current, is the current value of the online short-circuit current , is the preset threshold value, The motor load proportional coefficient is Calculated value of online short-circuit current at .

[0036] Optionally, step S5 includes:

[0037] S51, if When the alarm information is: the current faulty device + the effective value of the fault short-circuit current + The current value of the online short-circuit current +The first difference between the online short-circuit current and the recorded value +The preset threshold value No parameter tuning is required;

[0038] S52, if When calculating the second difference between the recorded value after parameter setting and the online short-circuit current , the alarm information is: the current faulty device + the effective value of the fault short-circuit current + The current value of the online short-circuit current +The first difference between the online short-circuit current and the recorded value + Setting value of the motor load proportional coefficient +Online short-circuit current value after parameter setting +The second difference +The preset threshold value .

[0039] A second aspect of the present application provides a system for setting online calculation parameters, the system comprising:

[0040] An acquisition unit is used to acquire a fault recording file and parse and extract the fault recording file to obtain fault recording information, wherein the fault recording information includes: fault occurrence time, fault equipment, fault type, fault short-circuit current effective value and recording value;

[0041] A matching unit, used for matching the initial online short-circuit current according to the fault recording information to obtain the online short-circuit current;

[0042] A calculation unit, used for calculating the difference between the online short-circuit current and the recorded value, and triggering the generation unit if the difference is less than a preset threshold value, otherwise triggering the adjustment unit;

[0043] An adjustment unit, used for adjusting the motor load proportional coefficient and calculating the value of the online short-circuit current, and triggering the matching unit until the difference between the online short-circuit current and the recorded value is less than a preset threshold value, thereby obtaining a setting result of the motor load proportional coefficient;

[0044] A generating unit is used to generate alarm information according to the difference between the online short-circuit current and the recorded value and the setting result.

[0045] A third aspect of the present application provides a device for setting online calculation parameters, the device comprising a processor and a memory:

[0046] The memory is used to store program code and transmit the program code to the processor;

[0047] The processor is used to execute the steps of the online calculation parameter setting method as described in the first aspect according to the instructions in the program code.

[0048] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program codes, and the program codes are used to execute the online calculation parameter setting method described in the first aspect above.

[0049] It can be seen from the above technical solutions that this application has the following advantages:

[0050] The present application provides a method for adjusting online calculation parameters, including: obtaining an actual fault recording file and parsing to extract the fault section time, fault equipment, fault type and short-circuit current effective value; matching the initial online short-circuit current result according to the extracted fault recording information; calculating the deviation between the online short-circuit current and the recording value, and when the deviation is greater than a set threshold value, adjusting the motor load proportional coefficient and recalculating the short-circuit current until the deviation is less than the threshold value; generating an alarm message according to the deviation between the online short-circuit current and the recording value and the motor load proportional coefficient adjustment result.

[0051] Compared with the prior art: the present application can automatically match the online short-circuit current result according to the short-circuit current recording value, perform iterative calculation of the short-circuit current by adjusting the online calculation parameters, gradually reduce the deviation between the short-circuit current calculation value and the fault recording value, and apply the adjusted online calculation parameters to actual production operation, thereby improving the accuracy and reliability of online short-circuit current analysis. This solves the problem that the prior art cannot accurately and reliably perform online calculation and analysis of short-circuit current. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A flow chart of a method for setting online calculation parameters provided in an embodiment of the present application;

[0053] Figure 2 A schematic diagram of the structure of an online calculation parameter setting system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0055] See also Figure 1 , a method for setting online calculation parameters provided in an embodiment of the present application includes:

[0056] Step 101, obtain a fault recording file, parse and extract the fault recording file, and obtain fault recording information, wherein the fault recording information includes: fault occurrence time, fault equipment, fault type, fault short-circuit current effective value and recording value.

[0057] In one embodiment, the method for extracting the fault type in step 101 includes:

[0058] Based on the maximum value and minimum value Calculation formula to calculate the maximum value of the amplitude of the current mutation between two phases and minimum value , according to the maximum value and minimum value Determine the type of fault;

[0059] Maximum and minimum value The calculation formula is:

[0060] ;

[0061] In the formula, , , They are the sudden changes of short-circuit current between the two phases.

[0062] Among them, according to the maximum value and minimum value Determine the type of fault, including:

[0063] like , it is a three-phase fault;

[0064] like , then it is a two-phase fault;

[0065] like , it is a single-phase fault;

[0066] In the formula, is the threshold value, is the proportionality coefficient.

[0067] In one embodiment, the method for extracting the effective value of the fault short-circuit current in step 101 includes:

[0068] Calculate the effective value of the fault short-circuit current based on the calculation formula of the effective value of the fault short-circuit current;

[0069] Among them, the calculation formula for the effective value of the fault short-circuit current is:

[0070] ;

[0071] In the formula, is the effective value of the fault short-circuit current, The first The current value of the sampling point, is the total number of sampling points in the recording data window.

[0072] Step 102: Match the initial online short-circuit current according to the fault recording information to obtain the online short-circuit current.

[0073] In one embodiment, step 102 includes:

[0074] Retrieve section time and fault occurrence time The closest online short-circuit current and retrieve the current value of the online short-circuit current based on the fault device and fault type .

[0075] Step 103, calculating the difference between the online short-circuit current and the recorded value, if the difference is less than a preset threshold value, executing step 105, otherwise executing step 104.

[0076] Step 104, adjust the motor load proportional coefficient and calculate the value of the online short-circuit current, and return to step 103 until the difference between the online short-circuit current and the recorded value is less than a preset threshold value, and obtain the setting result of the motor load proportional coefficient.

[0077] In one embodiment, step 104 includes:

[0078] S41, if , then increase the motor load ratio coefficient and adjust its space Divide into The motor load ratio coefficient is calculated as follows: Short-circuit current value when ;

[0079] S42, if , then the motor load proportional coefficient is set to ;

[0080] S43, if ,and , , then the interval Divide into Repeat steps S41 to S43 until you get Make ;

[0081] S44, if , then reduce the motor load ratio coefficient and adjust its space Divide into The motor load ratio coefficient is calculated as follows: Short-circuit current value when ;

[0082] S45, if , then the motor load proportional coefficient is set to ;

[0083] S46, if ,and , , then the interval Divide into Repeat steps S44-S46 until you get Make ;

[0084] in, is the effective value of the fault short-circuit current, is the current value of the online short-circuit current , is the preset threshold value, The motor load ratio coefficient is Calculated value of online short-circuit current at .

[0085] Step 105: Generate alarm information according to the difference between the online short-circuit current and the recorded value and the setting result.

[0086] In one embodiment, step 105 includes:

[0087] S51, if When the alarm information is: current fault device + fault short-circuit current effective value + Current value of online short-circuit current +The first difference between the online short-circuit current and the recorded value +Preset thresholds No parameter tuning is required;

[0088] S52, if When calculating the second difference between the recorded value and the online short-circuit current after the parameter setting , the alarm information is: current faulty equipment + fault short-circuit current effective value + Current value of online short-circuit current +The first difference between the online short-circuit current and the recorded value + Setting value of motor load proportional coefficient +Online short-circuit current value after parameter setting + Second Difference +Preset thresholds .

[0089] The following is a simulation example provided by this application:

[0090] In order to verify the beneficial effects of the present application, simulation demonstration is carried out through actual fault recording data and online calculation result examples. Specifically: verification is carried out based on actual power grid recording measured data and online calculation results, the measured recording file of the power grid line short-circuit fault is obtained and analyzed, and the online initial short-circuit current calculation result is matched. The deviation range of the two is 1-2kA. After the online calculation parameter motor load proportional coefficient is adjusted and iteratively calculated, the online calculation result is reduced and closer to the measured fault recording current, and the deviation range is controlled within 0.5kA. The specific simulation data are shown in Tables 1 and 2.

[0091] Table 1 Comparison between the actual fault recording results and the online initial calculation results

[0092]

[0093] Table 2 Comparison between the measured results of fault recording and the calculated results after online parameter setting

[0094]

[0095] In the embodiment of the present application, a method for setting key online calculation parameters of short-circuit current based on fault recording is provided, including: obtaining the actual fault recording file and parsing to extract the fault section time, fault equipment, fault type and short-circuit current effective value; matching the initial online short-circuit current result according to the extracted fault recording information; calculating the deviation between the online short-circuit current and the recording value, when the deviation is greater than the set threshold value, adjusting the motor load proportional coefficient and recalculating the short-circuit current until the deviation is less than the threshold value; generating an alarm message based on the deviation between the online short-circuit current and the recording value and the motor load proportional coefficient setting result. The present application improves the accuracy of online short-circuit current calculation, truly reflects the risk of short-circuit current exceeding the standard in the actual operation of the power grid, and provides a basis for dispatching and operating personnel to take short-circuit current suppression measures. This solves the problem that the existing technology cannot accurately and reliably carry out online calculation and analysis of short-circuit current.

[0096] The above is a method for adjusting online calculation parameters provided in an embodiment of the present application, and the following is a system for adjusting online calculation parameters provided in an embodiment of the present application.

[0097] See also Figure 2 , an online calculation parameter setting system provided in an embodiment of the present application includes:

[0098] The acquisition unit 201 is used to acquire the fault recording file and parse and extract the fault recording file to obtain the fault recording information, which includes: fault occurrence time, fault equipment, fault type, fault short-circuit current effective value and recording value.

[0099] The matching unit 202 is used to match the initial online short-circuit current according to the fault recording information to obtain the online short-circuit current.

[0100] The calculation unit 203 is used to calculate the difference between the online short-circuit current and the recorded value. If the difference is less than a preset threshold value, the generation unit 205 is triggered, otherwise the adjustment unit 204 is triggered.

[0101] The adjustment unit 204 is used to adjust the motor load proportional coefficient and calculate the value of the online short-circuit current, and trigger the matching unit 203 until the difference between the online short-circuit current and the recorded value is less than a preset threshold value, thereby obtaining the setting result of the motor load proportional coefficient.

[0102] The generating unit 205 is used to generate alarm information according to the difference between the online short-circuit current and the recorded value and the setting result.

[0103] Furthermore, an embodiment of the present application also provides a device for setting online calculation parameters, the device comprising a processor and a memory:

[0104] The memory is used to store program code and transmit the program code to the processor;

[0105] The processor is used to execute the steps of the online calculation parameter setting method as described in the above method embodiment according to the instructions in the program code.

[0106] Furthermore, a computer-readable storage medium is provided in an embodiment of the present application, and the computer-readable storage medium is used to store program code, and the program code is used to execute the online calculation parameter setting method described in the above method embodiment.

[0107] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0108] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0109] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0110] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0111] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0112] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0113] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0114] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for setting online calculation parameters, characterized in that: include: S1. Obtain a fault recording file and parse and extract the fault recording file to obtain fault recording information, wherein the fault recording information includes: fault occurrence time, fault equipment, fault type, fault short-circuit current effective value and recording value; S2. Matching the initial online short-circuit current according to the fault recording information to obtain the online short-circuit current; S3, calculating the difference between the online short-circuit current and the recorded value, if the difference is less than a preset threshold value, executing S5, otherwise executing S4; S4, adjusting the motor load proportional coefficient and calculating the value of the online short-circuit current, and returning to S3, until the difference between the online short-circuit current and the recorded value is less than a preset threshold value, and obtaining the setting result of the motor load proportional coefficient; S5. Generate alarm information according to the difference between the online short-circuit current and the recorded value and the setting result.

2. The method for setting online calculation parameters according to claim 1, characterized in that: The method for extracting the fault type comprises: Based on the maximum value and minimum value Calculation formula to calculate the maximum value of the amplitude of the current mutation between two phases and minimum value , according to the maximum value and the minimum value Determine the type of fault; The maximum value and minimum value The calculation formula is: ； In the formula, , , They are the sudden changes of short-circuit current between the two phases.

3. The method for setting online calculation parameters according to claim 2, characterized in that: The maximum value according to and the minimum value Determine the type of fault, including: like , it is a three-phase fault; like , then it is a two-phase fault; like , it is a single-phase fault; In the formula, is the threshold value, is the proportionality coefficient.

4. The method for setting online calculation parameters according to claim 1, characterized in that: The method for extracting the effective value of the fault short-circuit current comprises: Calculate the effective value of the fault short-circuit current based on the calculation formula of the effective value of the fault short-circuit current; The calculation formula of the effective value of the fault short-circuit current is: ； In the formula, is the effective value of the fault short-circuit current, The first The current value of the sampling point, is the total number of sampling points in the recording data window.

5. The method for setting online calculation parameters according to claim 1, characterized in that: Step S2 comprises: Retrieve the section time and the fault occurrence time The closest online short-circuit current, and retrieve the current value of the online short-circuit current according to the fault device and the fault type .

6. The method for setting online calculation parameters according to claim 5, characterized in that: Step S4 comprises: S41, if , then increase the motor load ratio coefficient and adjust its space Divide into The motor load ratio coefficient is calculated as follows: Short-circuit current value when ; S42, if , then the motor load proportional coefficient is set to ; S43, if ,and , , then the interval Divide into Repeat steps S41 to S43 until you get Make ; S44, if , then lower the motor load ratio coefficient and adjust its space Divide into The motor load ratio coefficient is calculated as follows: Short-circuit current value when ; S45, if , then the motor load proportional coefficient is set to ; S46, if ,and , , then the interval Divide into Repeat steps S44-S46 until you get Make ; in, is the effective value of the fault short-circuit current, is the current value of the online short-circuit current , is the preset threshold value, The motor load proportional coefficient is Calculated value of online short-circuit current at .

7. The method for setting online calculation parameters according to claim 6, characterized in that: Step S5 includes: S51, if When the alarm information is: the current faulty device + the effective value of the fault short-circuit current + The current value of the online short-circuit current +The first difference between the online short-circuit current and the recorded value +The preset threshold value No parameter tuning is required; S52, if When calculating the second difference between the recorded value after parameter setting and the online short-circuit current , the alarm information is: the current faulty device + the effective value of the fault short-circuit current + The current value of the online short-circuit current +The first difference between the online short-circuit current and the recorded value + Setting value of the motor load proportional coefficient +Online short-circuit current value after parameter setting +The second difference +The preset threshold value .

8. An online calculation parameter setting system, characterized in that: include: An acquisition unit is used to acquire a fault recording file and parse and extract the fault recording file to obtain fault recording information, wherein the fault recording information includes: fault occurrence time, fault equipment, fault type, fault short-circuit current effective value and recording value; A matching unit, used for matching the initial online short-circuit current according to the fault recording information to obtain the online short-circuit current; A calculation unit, used for calculating the difference between the online short-circuit current and the recorded value, and triggering the generation unit if the difference is less than a preset threshold value, otherwise triggering the adjustment unit; An adjustment unit, used for adjusting the motor load proportional coefficient and calculating the value of the online short-circuit current, and triggering the matching unit until the difference between the online short-circuit current and the recorded value is less than a preset threshold value, thereby obtaining a setting result of the motor load proportional coefficient; A generating unit is used to generate alarm information according to the difference between the online short-circuit current and the recorded value and the setting result.

9. An online parameter setting device, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the online calculation parameter setting method described in any one of claims 1-7 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program codes, and the program codes are used to execute the method for setting online calculation parameters according to any one of claims 1 to 7.

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