Cable position interval calculation method and device, equipment and storage medium

Abstract

The invention relates to a cable position interval calculation method and device, equipment and a storage medium. The method comprises the following steps: obtaining a harmonic voltage and a harmonic current of the head end of a target cable under a target harmonic order; determining a voltage amplification factor of the harmonic voltage according to the harmonic voltage and a harmonic voltage limit value corresponding to the tail end of the target cable; according to the harmonic current and a harmonic current limit value corresponding to the tail end of the target cable, determining a current amplification factor of the harmonic current; determining line characteristic impedance and system side harmonic impedance of the target cable; according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance, determining a voltage over-limit value interval when the harmonic voltage is conducted in the target cable; and according to the current amplification factor, the line characteristic impedance and the system characteristic impedance, determining a current over-limit value interval when the harmonic current is conducted in the target cable. By adopting the method, the over-limit value interval of harmonic waves during conduction in the cable can be determined.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a cable position interval calculation method, device, equipment and storage medium. Background Art

[0002] As new technologies such as high-voltage direct current transmission, renewable energy converters and electric vehicle charging stations are widely used in power systems, a large number of harmonics are injected into the power system, causing the waveforms of voltage and current in the power grid to be distorted, affecting the stable operation of the power grid network.

[0003] One of the important reasons for harmonic pollution in power grids is that harmonics are amplified during cable transmission. Therefore, it is important to determine the over-limit range of harmonics when they are transmitted in cables in order to avoid serious harmonic amplification range in actual engineering construction. Summary of the invention

[0004] Based on this, it is necessary to provide a cable position interval calculation method, device, equipment and storage medium to address the above technical problems, which can determine the over-limit value interval when harmonics are transmitted in the cable.

[0005] In a first aspect, the present application provides a method for calculating a cable position interval, the method comprising:

[0006] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0007] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0008] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0009] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0010] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0011] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0012] In one embodiment, determining the voltage over-limit value interval when the harmonic voltage is transmitted in the target cable according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance includes:

[0013] According to the ratio of the line characteristic impedance to the system characteristic impedance, the first intermediate variable and the second intermediate variable are determined; according to the first intermediate variable, the second intermediate variable and the voltage amplification factor, the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles is determined; according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles, the voltage over-limit value range when the harmonic voltage is conducted in the target cable is determined.

[0014] In one embodiment, determining the first intermediate variable and the second intermediate variable according to the ratio of the line characteristic impedance to the system characteristic impedance includes:

[0015] The first intermediate variable and the second intermediate variable are determined using the following formula:

[0016] ;

[0017] in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Z s is the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude of θ 1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude, θ 2 is the second intermediate variable The phase angle.

[0018] In one embodiment, determining a voltage over-limit value when a harmonic voltage is conducted in a target cable in adjacent conduction cycles according to the first intermediate variable, the second intermediate variable and the voltage amplification factor includes:

[0019] ;

[0020] in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification of the harmonic voltage, w is the angular frequency, C 0 is the capacitance per unit length at the fundamental frequency, L 0 is the inductance per unit length at the fundamental frequency.

[0021] In one embodiment, determining the current over-limit value interval when the harmonic current is conducted in the target cable according to the current amplification factor, the line characteristic impedance and the system characteristic impedance includes:

[0022] According to the ratio of the system characteristic impedance to the line characteristic impedance, the third intermediate variable and the fourth intermediate variable are determined; according to the third intermediate variable, the fourth intermediate variable and the current amplification factor, the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles is determined; according to the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0023] In one embodiment, determining the third intermediate variable and the fourth intermediate variable according to the ratio of the system characteristic impedance to the line characteristic impedance includes:

[0024] The third intermediate variable and the fourth intermediate variable are determined using the following formula:

[0025] ;

[0026] in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ 1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ 2 is the fourth intermediate variable The phase angle.

[0027] In one embodiment, determining the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles according to the third intermediate variable, the fourth intermediate variable and the current amplification factor includes:

[0028] ;

[0029] in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim It is the current amplification factor of the harmonic current.

[0030] In a second aspect, the present application further provides a cable position interval calculation device, the device comprising:

[0031] An acquisition module, used for acquiring the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0032] A multiple determination module, used to determine the voltage magnification multiple of the harmonic voltage according to the harmonic voltage and the harmonic voltage limit value corresponding to the end of the target cable; and to determine the current magnification multiple of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0033] An impedance determination module, used to determine the line characteristic impedance of the target cable and the system-side harmonic impedance;

[0034] The interval determination module is used to determine the voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance; and to determine the current over-limit value interval when the harmonic current is conducted in the target cable according to the current amplification factor, the line characteristic impedance and the system characteristic impedance.

[0035] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0036] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0037] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0038] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0039] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0040] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0041] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0042] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0043] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0044] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0045] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0046] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0047] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0048] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0049] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0050] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0051] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0052] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0053] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0054] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0055] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0056] The above-mentioned cable position interval calculation method, device, equipment and storage medium obtain the harmonic voltage and harmonic current at the head end of the target cable; then, based on the harmonic voltage and the harmonic voltage limit corresponding to the end of the target cable, determine the voltage amplification factor of the harmonic voltage, and based on the harmonic current and the harmonic current limit corresponding to the end of the target cable, determine the current amplification factor of the harmonic current; further, determine the line characteristic impedance and the system-side harmonic impedance of the target cable; then, based on the line characteristic impedance, the system-side harmonic impedance, the voltage amplification factor of the harmonic voltage and the current amplification factor of the harmonic current, determine the voltage over-limit value interval when the harmonic voltage is conducted in the target cable, and the current over-limit value interval when the harmonic current is conducted in the target cable. This scheme can first limit the harmonic amplification degree of the target cable by determining the voltage amplification factor and the current amplification factor; secondly, by determining the line characteristic impedance of the target cable and the system-side harmonic impedance, it is possible to estimate the line condition of the target cable conducting signal; furthermore, by combining the voltage amplification factor, the line characteristic impedance and the system-side harmonic impedance, it is possible to determine the voltage over-limit range when the harmonic voltage is conducted in the target cable, and by combining the current amplification factor, the line characteristic impedance and the system-side harmonic impedance, it is possible to determine the current over-limit range when the harmonic current is conducted in the target cable, thereby finally achieving accurate determination of the over-limit range when the harmonic is conducted in the target cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 An application environment diagram of a cable position interval calculation method provided in an embodiment of the present application;

[0059] Figure 2 A schematic diagram of a flow chart of a cable position interval calculation method provided in an embodiment of the present application;

[0060] Figure 3 A schematic diagram of a flow chart for determining a voltage over-limit value interval provided in an embodiment of the present application;

[0061] Figure 4 A schematic diagram of a flow chart for determining a current over-limit value interval provided in an embodiment of the present application;

[0062] Figure 5 A schematic flow chart of another cable position interval calculation method provided in an embodiment of the present application;

[0063] Figure 6 A structural block diagram of a cable position interval calculation device provided in an embodiment of the present application;

[0064] Figure 7 This is a structural block diagram of another cable position interval calculation device provided in an embodiment of the present application;

[0065] Figure 8 This is a structural block diagram of another cable position interval calculation device provided in an embodiment of the present application;

[0066] Fig. 9 This is a diagram of the internal structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0068] The cable position interval calculation method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. The terminal 102 performs harmonic analysis on the current and voltage in the target cable to obtain data such as harmonic current and harmonic voltage in the target cable; then, the server 104 obtains the data results of the harmonic analysis by the terminal 102, and analyzes it, and finally determines the voltage over-limit value interval when the harmonic voltage is conducted in the target cable and the current over-limit value interval when the harmonic current is conducted in the target cable. Among them, the terminal 102 can be, but is not limited to, various harmonic analyzers, personal computers, laptops, smart phones, tablet computers, Internet of Things devices and portable wearable devices, and the Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. Portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server 104 can be implemented with an independent server or a server cluster consisting of multiple servers.

[0069] In an exemplary embodiment, Figure 2 As shown in FIG. 1 , a cable position interval calculation method is provided, and the method is applied to Figure 1 Taking the server 104 in the example as an example, the following steps may be included:

[0070] S201, obtaining the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order.

[0071] The target harmonic order may be the order of measuring the harmonic voltage and harmonic current of the target cable; the target cable may be any cable for which the voltage over-limit value interval and the current over-limit value interval need to be determined.

[0072] Exemplarily, at each target harmonic order, a set of voltage data and current data of the target cable is obtained; then, the terminal 102 analyzes the voltage data and current data at each target harmonic order to obtain the harmonic voltage and harmonic current of the head end of the target cable at each target harmonic order; further, the server 104 obtains the analysis result from the terminal 102 to obtain the harmonic voltage and harmonic current of the head end of the target cable at the target harmonic order.

[0073] Optionally, a sampling sensor can be installed at the head end of the target cable to collect real-time voltage data and current data of the target cable through the sampling sensor; further, the terminal 102 can perform harmonic component analysis based on the voltage data and current data of the target cable acquired in real time, thereby determining the harmonic voltage and harmonic current in the target cable.

[0074] S202, determining the voltage amplification factor of the harmonic voltage according to the harmonic voltage and the harmonic voltage limit corresponding to the end of the target cable; and determining the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit corresponding to the end of the target cable.

[0075] Among them, the harmonic voltage limit can represent the maximum voltage when the harmonic voltage is conducted in the target cable; the harmonic current limit can represent the maximum current when the harmonic current is conducted in the target cable.

[0076] It should be noted that during the conduction of harmonic voltage and harmonic current in the target cable, the distributed capacitance of the target cable is very likely to interact with the impedance of the power generation system and the grid impedance, and cause harmonic amplification. If the harmonic amplification phenomenon is not controlled, it may cause the harmonic content in the entire power system to exceed the standard and cause great harm to the safe operation of the power system and equipment.

[0077] Exemplarily, the voltage magnification factor of the harmonic voltage of the target cable can be determined as the ratio of the harmonic voltage limit value corresponding to the end of the target cable and the harmonic voltage at the head end of the target cable. ; The ratio of the harmonic current limit value corresponding to the end of the target cable and the harmonic current at the head end of the target cable is determined as the current amplification factor of the harmonic current of the target cable .

[0078] S203, determining the line characteristic impedance of the target cable and the system-side harmonic impedance.

[0079] Among them, the line characteristic impedance can represent the instantaneous impedance generated when the signal is transmitted in the target cable; the system-side harmonic impedance can represent the harmonic impedance of the power system.

[0080] Exemplarily, the line characteristic impedance of the target cable is related to the parameters of the target cable, such as resistance per unit length at the fundamental frequency, conductance per unit length at the fundamental frequency, and inductance per unit length at the fundamental frequency. For example, in combination with the angular frequency of the signal conducted in the target cable, the line characteristic impedance Z of the target cable is c It can be expressed as:

[0081] (1)

[0082] Among them, R 0 It can be expressed as the resistance per unit length at the fundamental frequency, G 0 It can be expressed as the conductance per unit length at the fundamental frequency, L 0 It can be expressed as the inductance per unit length at the fundamental frequency, C 0 It can represent the capacitance per unit length at the fundamental frequency, w can represent the angular frequency, and j is a complex unit.

[0083] Furthermore, the system side harmonic impedance can be represented by the rated voltage, the system short-circuit capacity and the target harmonic order. s It can be expressed as:

[0084] (2)

[0085] Among them, real(Z s ) can be expressed as the system side harmonic impedance Z s The real part, imag(Z s ) can be expressed as the system side harmonic impedance Z s The imaginary part, V N It can represent the rated voltage, S can represent the system short-circuit capacity, and h can represent the target harmonic order.

[0086] But in actual environment, the conductance per unit length G at fundamental frequency 0 is very small, so it can be considered to be 0, and then formula (1) can also be expressed as:

[0087] (3)

[0088] S204, determining the voltage over-limit value range when the harmonic voltage is conducted in the target cable based on the voltage amplification factor, the line characteristic impedance and the system characteristic impedance; and determining the current over-limit value range when the harmonic current is conducted in the target cable based on the current amplification factor, the line characteristic impedance and the system characteristic impedance.

[0089] Among them, the voltage over-limit value interval can represent the target cable position interval corresponding to when the harmonic voltage after being transmitted and amplified in the target cable exceeds the harmonic voltage limit, and the current over-limit value interval can represent the target cable position interval corresponding to when the harmonic current after being transmitted and amplified in the target cable exceeds the harmonic current limit.

[0090] Exemplarily, the voltage amplification factor, line characteristic impedance and system characteristic impedance can be input into the voltage over-limit value interval model, and the voltage over-limit value interval model analyzes and calculates the input voltage amplification factor, line characteristic impedance and system characteristic impedance, and determines the voltage over-limit value interval when the harmonic voltage is conducted in the target cable; similarly, the current amplification factor, line characteristic impedance and system characteristic impedance are input into the current over-limit value interval model, and the current over-limit value interval model analyzes and calculates the input current amplification factor, line characteristic impedance and system characteristic impedance, and determines the current over-limit value interval when the harmonic current is conducted in the target cable.

[0091] It should be noted that the voltage over-limit value interval model and the current over-limit value interval model can be obtained based on training samples; optionally, the training samples may include a training data set and a training label set; wherein the training data set may include historical voltage amplification factors, historical line characteristic impedances, and historical system characteristic impedances; the training label set may include voltage over-limit value intervals and current over-limit value intervals corresponding to each group of training data.

[0092] The above-mentioned cable position interval calculation method obtains the harmonic voltage and harmonic current at the head end of the target cable; then, based on the harmonic voltage and the harmonic voltage limit corresponding to the end of the target cable, the voltage amplification factor of the harmonic voltage is determined, and based on the harmonic current and the harmonic current limit corresponding to the end of the target cable, the current amplification factor of the harmonic current is determined; further, the line characteristic impedance and the system-side harmonic impedance of the target cable are determined; then, based on the line characteristic impedance, the system-side harmonic impedance, the voltage amplification factor of the harmonic voltage and the current amplification factor of the harmonic current, the voltage over-limit value interval when the harmonic voltage is conducted in the target cable, and the current over-limit value interval when the harmonic current is conducted in the target cable can be determined. This scheme can first limit the harmonic amplification degree of the target cable by determining the voltage amplification factor and the current amplification factor; secondly, by determining the line characteristic impedance of the target cable and the system-side harmonic impedance, it is possible to estimate the line condition of the target cable conducting signal; furthermore, by combining the voltage amplification factor, the line characteristic impedance and the system-side harmonic impedance, it is possible to determine the voltage over-limit range when the harmonic voltage is conducted in the target cable, and by combining the current amplification factor, the line characteristic impedance and the system-side harmonic impedance, it is possible to determine the current over-limit range when the harmonic current is conducted in the target cable, thereby finally achieving accurate determination of the over-limit range when the harmonic is conducted in the target cable.

[0093] Based on the above embodiment, the present application embodiment explains the above embodiment S204 in detail. Specifically, the present application embodiment involves a process of determining the voltage over-limit value interval when the harmonic voltage is transmitted in the target cable, such as Figure 3 As shown, the specific steps include:

[0094] S301, determining a first intermediate variable and a second intermediate variable according to a ratio of a line characteristic impedance to a system characteristic impedance.

[0095] Exemplarily, the first intermediate variable and the second intermediate variable may be determined by the following formula:

[0096] (4)

[0097] in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Z s is the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude, θ 1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude, θ 2is the second intermediate variable The phase angle.

[0098] It should be noted that the first intermediate variable and the second intermediate variable can be derived according to the distributed parameter circuit of the cable. Specifically, the relationship satisfied by the distributed parameter circuit of the cable can be expressed as:

[0099] (5)

[0100] Among them, V 1 It can represent the harmonic voltage at the head end of the target cable, V 2 It can represent the harmonic voltage at the end of the target cable, I 2 It can represent the harmonic current at the end of the target cable, and γ can represent the line propagation constant. The value of the line propagation constant γ can be obtained by the unit length resistance R at the fundamental frequency. 0 , the conductivity per unit length at the fundamental frequency G 0 , inductance per unit length at fundamental frequency L 0 , Capacitance per unit length at fundamental frequency C 0 and angular frequency w, can also be expressed by line attenuation constant α and phase shift constant β, specifically it can be expressed as:

[0101] (6)

[0102] But in actual environment, the unit length conductivity G at fundamental frequency 0 is very small, so it can be considered to be 0, and then formula (6) can also be expressed as:

[0103] (7)

[0104] Furthermore, based on equations (5) and (7), the ratio of the harmonic voltage amplitude at the end of the target cable to the harmonic voltage amplitude at the beginning of the target cable can be determined as the actual harmonic voltage amplification factor K: u , which can be specifically expressed as:

[0105] (8)

[0106] Among them, the resistance per unit length at the fundamental frequency in the cable line is R 0 Very small, and the capacitance per unit length C at the fundamental frequency 0 Much smaller than the inductance per unit length L at the fundamental frequency 0 ,therefore, can be considered as 0; further, due to Therefore, it can be considered that e αl and e -αl is 0, and furthermore, formula (8) can also be expressed as:

[0107] (9)

[0108] Furthermore, based on formula (9), we can use express , express , and then we can get the first intermediate variable and the second intermediate variable .

[0109] S302, determining a voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles according to the first intermediate variable, the second intermediate variable and the voltage amplification factor.

[0110] Exemplarily, the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles may be determined by the following formula:

[0111] (10)

[0112] in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification of the harmonic voltage, w is the angular frequency, C 0 is the capacitance per unit length at the fundamental frequency, L 0 is the inductance per unit length at the fundamental frequency.

[0113] It should be noted that the detailed derivation process of formula (10) is as follows. Represented as J u , and for J u Derived, we get:

[0114] (11)

[0115] Furthermore, formula (9) can be expressed as:

[0116] (12)

[0117] Furthermore, the voltage is magnified by Combined with formula (12), the actual harmonic voltage amplification factor K can be obtained. u is the voltage gain The corresponding voltage exceeds the limit value.

[0118] S303, determining a voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles.

[0119] For example, based on the voltage over-limit value when the harmonic voltage is conducted in the target cable in two adjacent conduction cycles, for example, the voltage over-limit value when the harmonic voltage is conducted in the target cable in the conduction cycle 2(n-1)π is The voltage over-limit value when the harmonic voltage is transmitted in the target cable under the conduction period of 2nπ is , which can determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable [ ]. Where n is the number of cycles.

[0120] In the embodiment of the present application, by introducing the first intermediate variable and the second intermediate variable, the relationship between the voltage amplification factor and the voltage over-limit value range is clarified, laying the foundation for accurately determining the voltage over-limit value range when the harmonic voltage is transmitted in the target cable.

[0121] Based on the above embodiment, the present application embodiment explains the above embodiment S204 in detail. Specifically, the present application embodiment involves a process of determining the current over-limit value interval when the harmonic current is conducted in the target cable, such as Figure 4 As shown, the specific steps include:

[0122] S401, determining a third intermediate variable and a fourth intermediate variable according to a ratio of a system characteristic impedance to a line characteristic impedance.

[0123] Exemplarily, the third intermediate variable and the fourth intermediate variable may be determined by the following formula:

[0124] (13)

[0125] in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ 1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ 2 is the fourth intermediate variable The phase angle.

[0126] It should be noted that the third intermediate variable and the fourth intermediate variable can be derived according to the distributed parameter circuit of the cable. Specifically, the relationship satisfied by the distributed parameter circuit of the cable can be expressed as:

[0127] (14)

[0128] Among them, I 1 It can represent the harmonic current at the head end of the target cable.

[0129] Furthermore, based on equations (7) and (14), the ratio of the harmonic current amplitude at the end of the target cable to the harmonic current amplitude at the beginning of the target cable can be determined as the actual harmonic current amplification factor K: i , which can be specifically expressed as:

[0130] (15)

[0131] Among them, the resistance per unit length at the fundamental frequency in the cable line is R 0 Very small, and the capacitance per unit length C at the fundamental frequency 0 Much smaller than the inductance per unit length L at the fundamental frequency 0 ,therefore, can be considered as 0; further, due to Therefore, it can be considered that e αl and e -αl is 0, and further, formula (15) can also be expressed as:

[0132] (16)

[0133] Furthermore, based on formula (16), we can use express , express , and then we can get the third intermediate variable and the fourth intermediate variable .

[0134] S402, determining a current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles according to the third intermediate variable, the fourth intermediate variable and the current amplification factor.

[0135] Exemplarily, the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles may be determined by the following formula:

[0136] (17)

[0137] in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim It is the current amplification factor of the harmonic current.

[0138] It should be noted that the detailed derivation process of formula (17) is as follows. Represented as J i , and for J i Derived, we get:

[0139] (18)

[0140] Furthermore, formula (16) can be expressed as:

[0141] (19)

[0142] Furthermore, the current is magnified Combined with formula (19), the actual harmonic current amplification factor K can be obtained. i Current amplification factor The corresponding current exceeds the limit value.

[0143] S403, determining a current over-limit value interval when the harmonic current is conducted in the target cable according to the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles.

[0144] For example, based on the current over-limit value when the harmonic current is conducted in the target cable in two adjacent conduction cycles, for example, the current over-limit value when the harmonic current is conducted in the target cable in the conduction cycle 2(n-1)π is The current over-limit value when the harmonic current is conducted in the target cable under the conduction period of 2nπ is , which can determine the current over-limit range when the harmonic current is conducted in the target cable [ ]. Where n is the number of cycles.

[0145] In the embodiment of the present application, by introducing the third intermediate variable and the fourth intermediate variable, the relationship between the current amplification factor and the current over-limit value range is clarified, laying the foundation for accurately determining the current over-limit value range when the harmonic current is conducted in the target cable.

[0146] Based on the above embodiment, this embodiment provides an optional example of a cable position interval calculation method. Figure 5 As shown, the specific implementation process is as follows:

[0147] S501, obtaining the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order.

[0148] S502, determining the voltage amplification factor of the harmonic voltage according to the harmonic voltage and the harmonic voltage limit corresponding to the end of the target cable; and determining the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit corresponding to the end of the target cable.

[0149] S503, determining the line characteristic impedance of the target cable and the system-side harmonic impedance.

[0150] S504, determining a first intermediate variable and a second intermediate variable according to a ratio of the line characteristic impedance to the system characteristic impedance.

[0151] S505, determining a voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles according to the first intermediate variable, the second intermediate variable and the voltage amplification factor.

[0152] S506, determining a voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles.

[0153] S507, determining a third intermediate variable and a fourth intermediate variable according to the ratio of the system characteristic impedance to the line characteristic impedance.

[0154] S508, determining a current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles according to the third intermediate variable, the fourth intermediate variable and the current amplification factor.

[0155] S509, determining a current over-limit value interval when the harmonic current is conducted in the target cable according to the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles.

[0156] The specific process of S501-S509 can refer to the description of the above method embodiment, and its implementation principle and technical effect are similar, which will not be repeated here.

[0157] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0158] Based on the same inventive concept, the embodiment of the present application also provides a cable position interval calculation device for implementing the cable position interval calculation method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more cable position interval calculation device embodiments provided below can refer to the limitations of the cable position interval calculation method above, and will not be repeated here.

[0159] In an exemplary embodiment, Figure 6As shown, a cable position interval calculation device 1 is provided, comprising: an acquisition module 10, a multiple determination module 20, an impedance determination module 30 and an interval determination module 40, wherein:

[0160] The acquisition module 10 is used to acquire the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order.

[0161] The multiple determination module 20 is used to determine the voltage magnification multiple of the harmonic voltage according to the harmonic voltage and the harmonic voltage limit corresponding to the end of the target cable; and to determine the current magnification multiple of the harmonic current according to the harmonic current and the harmonic current limit corresponding to the end of the target cable.

[0162] The impedance determination module 30 is used to determine the line characteristic impedance and the system-side harmonic impedance of the target cable.

[0163] The interval determination module 40 is used to determine the voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance; and to determine the current over-limit value interval when the harmonic current is conducted in the target cable according to the current amplification factor, the line characteristic impedance and the system characteristic impedance.

[0164] In one embodiment, Figure 7 As shown, the interval determination module 40 specifically further includes:

[0165] The first determining unit 41 is used to determine the first intermediate variable and the second intermediate variable according to the ratio of the line characteristic impedance to the system characteristic impedance.

[0166] The second determining unit 42 is used to determine the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles according to the first intermediate variable, the second intermediate variable and the voltage amplification factor.

[0167] The third determining unit 43 is used to determine the voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles.

[0168] In one embodiment, the first determining unit 41 is further configured to:

[0169] The first intermediate variable and the second intermediate variable are determined using the following formula:

[0170] ;

[0171] in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Z sis the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude, θ 1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude, θ 2 is the second intermediate variable The phase angle.

[0172] In one embodiment, the second determining unit 42 is further configured to:

[0173] ;

[0174] in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification of the harmonic voltage, w is the angular frequency, C 0 is the capacitance per unit length at the fundamental frequency, L 0 is the inductance per unit length at the fundamental frequency.

[0175] In one embodiment, Figure 8 As shown, the interval determination module 40 specifically further includes:

[0176] The fourth determining unit 44 is used to determine the third intermediate variable and the fourth intermediate variable according to the ratio of the system characteristic impedance to the line characteristic impedance.

[0177] The fifth determining unit 45 is used to determine the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles according to the third intermediate variable, the fourth intermediate variable and the current amplification factor.

[0178] The sixth determining unit 46 is used to determine the current over-limit value interval when the harmonic current is conducted in the target cable according to the current over-limit values ​​when the harmonic current is conducted in the target cable in adjacent conduction cycles.

[0179] In one embodiment, the fourth determining unit 44 is specifically configured to:

[0180] The third intermediate variable and the fourth intermediate variable are determined using the following formula:

[0181] ;

[0182] in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ 1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ 2 is the fourth intermediate variable The phase angle.

[0183] In one embodiment, the fifth determining unit 45 is specifically configured to:

[0184] ;

[0185] in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim It is the current amplification factor of the harmonic current.

[0186] Each module in the above cable position interval calculation device can be implemented in whole or in part by software, hardware and their combination. Each module can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0187] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Fig. 9 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store target cable data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a cable position interval calculation method is implemented.

[0188] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0189] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0190] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0191] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0192] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0193] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0194] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0195] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0196] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0197] According to the ratio of the line characteristic impedance to the system characteristic impedance, the first intermediate variable and the second intermediate variable are determined; according to the first intermediate variable, the second intermediate variable and the voltage amplification factor, the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles is determined; according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles, the voltage over-limit value range when the harmonic voltage is conducted in the target cable is determined.

[0198] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0199] The first intermediate variable and the second intermediate variable are determined using the following formula:

[0200] ;

[0201] in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Z s is the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude, θ 1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude, θ 2 is the second intermediate variable The phase angle.

[0202] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0203] ;

[0204] in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification of the harmonic voltage, w is the angular frequency, C 0 is the capacitance per unit length at the fundamental frequency, L 0 is the inductance per unit length at the fundamental frequency.

[0205] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0206] According to the ratio of the system characteristic impedance to the line characteristic impedance, the third intermediate variable and the fourth intermediate variable are determined; according to the third intermediate variable, the fourth intermediate variable and the current amplification factor, the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles is determined; according to the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0207] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0208] The third intermediate variable and the fourth intermediate variable are determined using the following formula:

[0209] ;

[0210] in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ 1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ 2 is the fourth intermediate variable The phase angle.

[0211] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0212] ;

[0213] in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim It is the current amplification factor of the harmonic current.

[0214] In one embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0215] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0216] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0217] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0218] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0219] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0220] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0221] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0222] According to the ratio of the line characteristic impedance to the system characteristic impedance, the first intermediate variable and the second intermediate variable are determined; according to the first intermediate variable, the second intermediate variable and the voltage amplification factor, the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles is determined; according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles, the voltage over-limit value range when the harmonic voltage is conducted in the target cable is determined.

[0223] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0224] The first intermediate variable and the second intermediate variable are determined using the following formula:

[0225] ;

[0226] in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Zs is the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude, θ 1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude, θ 2 is the second intermediate variable The phase angle.

[0227] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0228] ;

[0229] in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification of the harmonic voltage, w is the angular frequency, C 0 is the capacitance per unit length at the fundamental frequency, L 0 is the inductance per unit length at the fundamental frequency.

[0230] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0231] According to the ratio of the system characteristic impedance to the line characteristic impedance, the third intermediate variable and the fourth intermediate variable are determined; according to the third intermediate variable, the fourth intermediate variable and the current amplification factor, the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles is determined; according to the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0232] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0233] The third intermediate variable and the fourth intermediate variable are determined using the following formula:

[0234] ;

[0235] in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ 1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ 2 is the fourth intermediate variable The phase angle.

[0236] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0237] ;

[0238] in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim It is the current amplification factor of the harmonic current.

[0239] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0240] Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order;

[0241] Determining the voltage amplification factor of the harmonic voltage based on the harmonic voltage and the corresponding harmonic voltage limit value at the end of the target cable; and,

[0242] Determine the current amplification factor of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable;

[0243] Determine the line characteristic impedance and system-side harmonic impedance of the target cable;

[0244] Determine the voltage over-limit range when the harmonic voltage is transmitted in the target cable based on the voltage amplification factor, line characteristic impedance and system characteristic impedance; and,

[0245] According to the current amplification factor, line characteristic impedance and system characteristic impedance, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0246] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0247] According to the ratio of the line characteristic impedance to the system characteristic impedance, the first intermediate variable and the second intermediate variable are determined; according to the first intermediate variable, the second intermediate variable and the voltage amplification factor, the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles is determined; according to the voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles, the voltage over-limit value range when the harmonic voltage is conducted in the target cable is determined.

[0248] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0249] The first intermediate variable and the second intermediate variable are determined using the following formula:

[0250] ;

[0251] in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Z s is the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude, θ 1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude, θ 2 is the second intermediate variable The phase angle.

[0252] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0253] ;

[0254] in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification of the harmonic voltage, w is the angular frequency, C 0 is the capacitance per unit length at the fundamental frequency, L 0 is the inductance per unit length at the fundamental frequency.

[0255] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0256] According to the ratio of the system characteristic impedance to the line characteristic impedance, the third intermediate variable and the fourth intermediate variable are determined; according to the third intermediate variable, the fourth intermediate variable and the current amplification factor, the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles is determined; according to the current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles, the current over-limit value range when the harmonic current is conducted in the target cable is determined.

[0257] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0258] The third intermediate variable and the fourth intermediate variable are determined using the following formula:

[0259] ;

[0260] in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ 1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ 2 is the fourth intermediate variable The phase angle.

[0261] In one embodiment, when the computer program is executed by a processor, the following steps are also implemented:

[0262] ;

[0263] in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim It is the current amplification factor of the harmonic current.

[0264] It should be noted that the cable information (including but not limited to harmonic voltage and harmonic current, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0265] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0266] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0267] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A cable position interval calculation method, characterized in that: The method comprises: Obtain the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order; Determining a voltage amplification factor of the harmonic voltage according to the harmonic voltage and a harmonic voltage limit value corresponding to the end of the target cable; and, Determining a current amplification factor of the harmonic current according to the harmonic current and a harmonic current limit value corresponding to an end of the target cable; Determining the line characteristic impedance and system-side harmonic impedance of the target cable; Determining a voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance; and The current over-limit value interval when the harmonic current is conducted in the target cable is determined according to the current amplification factor, the line characteristic impedance and the system characteristic impedance.

2. The method according to claim 1, characterized in that The determining, according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance, a voltage over-limit value interval when the harmonic voltage is conducted in the target cable comprises: Determining a first intermediate variable and a second intermediate variable according to a ratio of the line characteristic impedance to the system characteristic impedance; Determine, according to the first intermediate variable, the second intermediate variable and the voltage amplification factor, a voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles; According to the voltage over-limit value when the harmonic voltage is conducted in the target cable in the adjacent conduction cycles, the voltage over-limit value interval when the harmonic voltage is conducted in the target cable is determined.

3. The method according to claim 2, characterized in that The determining of the first intermediate variable and the second intermediate variable according to the ratio of the line characteristic impedance to the system characteristic impedance includes: The first intermediate variable and the second intermediate variable are determined using the following formula: ； in, is the first intermediate variable, is the second intermediate variable, Z c is the line characteristic impedance, Z s is the system characteristic impedance, β is the phase shift constant, l is the cable length of the target cable, and A is the first intermediate variable The amplitude of θ1 is the first intermediate variable The phase angle, B is the second intermediate variable The amplitude of θ2 is the second intermediate variable The phase angle.

4. The method according to claim 3, characterized in that Determining, according to the first intermediate variable, the second intermediate variable, and the voltage amplification factor, a voltage over-limit value when the harmonic voltage is conducted in the target cable in adjacent conduction cycles, comprising: ； in, is the lower value among the voltage over-limit values, is the high value of the voltage over-limit value, n∈Z, K v-lim is the voltage magnification factor of the harmonic voltage, w is the angular frequency, C0 is the capacitance per unit length at the fundamental frequency, and L0 is the inductance per unit length at the fundamental frequency.

5. The method according to claim 1, characterized in that The determining, according to the current amplification factor, the line characteristic impedance and the system characteristic impedance, a current over-limit value interval when the harmonic current is conducted in the target cable comprises: Determining a third intermediate variable and a fourth intermediate variable according to a ratio of the system characteristic impedance to the line characteristic impedance; Determining, according to the third intermediate variable, the fourth intermediate variable and the current amplification factor, a current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles; According to the current over-limit value when the harmonic current is conducted in the target cable in the adjacent conduction cycles, the current over-limit value interval when the harmonic current is conducted in the target cable is determined.

6. The method according to claim 5, characterized in that The determining of the third intermediate variable and the fourth intermediate variable according to the ratio of the system characteristic impedance to the line characteristic impedance includes: The third intermediate variable and the fourth intermediate variable are determined by the following formula: ； in, is the third intermediate variable, is the fourth intermediate variable, M is the third intermediate variable The amplitude of γ1 is the third intermediate variable The phase angle, N is the fourth intermediate variable The amplitude of γ2 is the fourth intermediate variable The phase angle.

7. The method according to claim 6, characterized in that The determining, according to the third intermediate variable, the fourth intermediate variable and the current amplification factor, a current over-limit value when the harmonic current is conducted in the target cable in adjacent conduction cycles comprises: ； in, is the lower value among the current over-limit values, is the higher value among the current over-limit values, K i-lim is the current amplification factor of the harmonic current.

8. A cable position interval calculation device, characterized in that: The device comprises: An acquisition module, used for acquiring the harmonic voltage and harmonic current at the head end of the target cable at the target harmonic order; A multiple determination module, used to determine the voltage magnification multiple of the harmonic voltage according to the harmonic voltage and the harmonic voltage limit value corresponding to the end of the target cable; and to determine the current magnification multiple of the harmonic current according to the harmonic current and the harmonic current limit value corresponding to the end of the target cable; An impedance determination module, used to determine the line characteristic impedance and system-side harmonic impedance of the target cable; The interval determination module is used to determine the voltage over-limit value interval when the harmonic voltage is conducted in the target cable according to the voltage amplification factor, the line characteristic impedance and the system characteristic impedance; and to determine the current over-limit value interval when the harmonic current is conducted in the target cable according to the current amplification factor, the line characteristic impedance and the system characteristic impedance.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

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

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