A method and system for electrical energy distribution in a cable branch box

Abstract

The present application belongs to the technical field of power distribution control, and particularly relates to a cable branch box electric energy distribution method and system, which comprises the following steps: extracting the instantaneous waveform current sequence of each branch circuit and the physical geometric parameters of the branch bus, using the physical center distance, the effective coupling length and the instantaneous waveform current value of the adjacent branch circuit to calculate the transient space electric force between the adjacent branch buses, constraining the transient space electric force to the mechanical shear yield limit threshold of the SMC insulation support, calculating the transient distribution critical current of the target branch circuit which is ready to access a new load, comparing the starting peak current of the new load with the transient distribution critical current, and if the starting peak current exceeds the transient distribution critical current, issuing a microsecond delay distribution or soft start instruction to perform wave peak staggering scheduling. The present application converts the electric energy distribution reference into a transient mechanical tolerance constrained by mechanical strength, avoids the insulation support fracture caused by the transient peak overlap, and improves the mechanical stability of the power distribution system.

Description

Technical Field

[0001] This invention relates to the field of power distribution control technology. More specifically, this invention relates to a method and system for power distribution in a cable branch box. Background Technology

[0002] In the power distribution scenario of outdoor compact cable branch boxes, the internal space of the box is narrow, multiple copper busbars are arranged in parallel and densely, and are mechanically fixed by SMC insulation support at the bottom. Existing power distribution networks all use the effective value of current as the evaluation benchmark. Its underlying logic is to calculate the total energy transmitted by the line in order to avoid equipment overheating and aging caused by long-term high-load operation, and thus guide power distribution and load access.

[0003] However, when this existing technology is applied to compact cable branch boxes with frequent access to modern complex loads, there are obvious technical defects: modern industrial equipment or large motors generate extremely high transient peak currents the moment they are connected to the power grid. Existing distribution methods based on the effective value of the current have mathematical integration delays, which will treat these huge peaks at the microsecond level as tiny fluctuations within the safe range. At this time, if the system judges safety based on the effective value of the current and allows two adjacent branch circuits to be connected to such impact loads at the same time, the concurrent transient large currents on adjacent busbars will generate huge electromagnetic forces. This electromagnetic force is directly converted into mechanical shear force on the SMC insulation support. Once this mechanical shear force exceeds the physical fracture limit of the SMC insulation support material, the SMC insulation support will break instantly, causing the live busbars to lose physical constraints and overlap each other, resulting in a phase-to-phase short circuit explosion. This kind of power distribution accident caused by transient mechanical breakdown cannot be predicted or prevented by traditional methods of monitoring the effective value of the current. Summary of the Invention

[0004] To address the technical problem that existing power distribution methods cannot assess the mechanical damage caused by the electromagnetic force generated by transient peak current to SMC insulation support components, resulting in the potential for transient mechanical breakdown in the power distribution system, this invention provides solutions in the following aspects.

[0005] In a first aspect, the present invention provides a method for power distribution in a cable branch box, comprising: extracting the instantaneous waveform current sequence corresponding to each branch circuit, and the physical geometric parameters of the cable branch box corresponding to the branch busbar of the branch circuit, wherein the physical geometric parameters of the cable branch box include the effective coupling length and physical center-to-center distance between adjacent branch busbars; calculating the transient spatial electrodynamic force between adjacent branch busbars using the physical center-to-center distance, the effective coupling length, and the instantaneous waveform current values ​​of two adjacent branch circuits; constraining the limit value of the transient spatial electrodynamic force to the mechanical shear yield limit threshold of the SMC insulation support, and calculating the transient distribution critical current of the target branch circuit to be connected to a new load; comparing the starting peak current of the new load with the transient distribution critical current, and if the starting peak current of the new load is greater than or equal to the transient distribution critical current, issuing a delayed distribution command or a soft start command to perform peak staggered scheduling.

[0006] This invention directly calculates the transient spatial electrodynamic force between adjacent branch busbars by introducing physical geometric parameters and instantaneous waveform current values, and compares it with the mechanical shear yield limit threshold of SMC insulation support components to obtain the transient distribution critical current. When the starting peak current of a new load reaches this critical value, the current peak value is staggered on the time axis through microsecond-level peak staggering scheduling. This operation transforms the power distribution benchmark from the traditional electrical heating capacity to a transient mechanical tolerance constrained by the mechanical strength of materials, avoiding physical breakdown accidents such as busbar deformation, support fracture, and phase-to-phase short-circuit explosion caused by blindly distributing large transient currents, and maintaining the mechanical stability of the power distribution system under transient impact conditions.

[0007] Preferably, the step of extracting the instantaneous waveform current sequence corresponding to each branch circuit and the physical geometric parameters of the cable branch box of the branch busbar corresponding to the branch circuit includes: obtaining a microsecond-level sampling rate using a high-speed broadband Hall current sensor installed on each branch busbar; synchronously extracting the instantaneous waveform current sequence corresponding to each branch circuit and filtering out steady-state background signals through a digital filter configured inside the microprocessor control board based on the DSP chip; and extracting the preset physical geometric parameters of the cable branch box from the non-volatile memory of the microprocessor control board.

[0008] Preferably, the step of calculating the transient spatial electrodynamic force between adjacent branch busbars using the physical center-to-center distance, effective coupling length, and instantaneous waveform current values ​​of two adjacent branch circuits includes: In the formula, For a moment The corresponding transient spatial electrodynamic force, is the vacuum permeability constant. For effective coupling length, Pi is a constant. The physical center distance, For a moment The corresponding number Instantaneous waveform current value of the circuit. For a moment The corresponding number Instantaneous waveform current value of the circuit. This indicates taking the absolute value.

[0009] The calculation process of this invention is based on the Biot-Savart law and the Ampere force calculation model. It converts the magnetic field superposition effect between two parallel conductors into macroscopic mechanical stress that can directly cause mechanical damage to the SMC insulation support. By introducing the reciprocal relationship of the physical center distance, the attenuation characteristics of the magnetic field during spatial transmission are quantified, and the force on the charge carrier is linearly accumulated in the effective coupling length. This operation establishes a calculation model for electromagnetic stress in the calculation logic of power distribution, solves the problem that long-term Joule heat accumulation cannot assess transient structural damage, and accurately reflects the mechanical interaction of parallel branch busbars in a limited space under transient impact conditions.

[0010] Preferably, the step of constraining the limit value of transient spatial electrodynamic force to the mechanical shear yield strength threshold of the SMC insulating support, and calculating the transient distribution critical current of the target branch circuit to be connected to the new load, includes: In the formula, For a moment The corresponding transient distribution critical current, The mechanical shear yield strength threshold. is the vacuum permeability constant. For effective coupling length, Pi is a constant. The physical center distance, For a moment The corresponding number Instantaneous waveform current value of the circuit. This indicates taking the absolute value.

[0011] The calculation process of this invention constrains the limit value of transient spatial electrodynamic force to the mechanical shear yield limit threshold of the SMC insulating support. It uses the instantaneous waveform current value of the currently running branch circuit to back-calculate the upper limit of the instantaneous peak current that can be injected into the target branch circuit that is about to be connected to a new load. This operation changes the power distribution benchmark from the traditional electrical heating capacity to the transient mechanical tolerance constrained by the boundary conditions of the material mechanical strength, calculates the upper limit of the current control amplitude, and provides a physical safety boundary for subsequent peak staggered scheduling, ensuring that the amount of concurrent current injection that the system can withstand is always within the mechanical and physical strength allowable range of the insulating support.

[0012] Preferably, the step of issuing the delay allocation instruction to perform peak staggered scheduling includes: setting the delay time parameter to 300 microseconds through the timer inside the microprocessor control board to generate a microsecond-level delay allocation instruction, and issuing it to the target branch loop.

[0013] When the peak current of a new load exceeds the mechanical safety boundary, a microsecond-level delay allocation command is generated by setting a delay time parameter through a timer. This offsets the time of the new load's power injection from the transient peak of the already running branch circuit on the time axis. This operation utilizes the microsecond-level misalignment on the time axis to ensure that the current ramp-up starting point of the new load crosses the transient peak point and falls at the transient valley, avoiding transient peak overlap. This resolves the electromagnetic shock generated by concurrent startup without reducing the total allocated capacity of the system and reduces the high-amplitude electromagnetic stress on the physical structure.

[0014] Preferably, the step of issuing a soft-start command to perform peak staggered scheduling includes: issuing a soft-start command to the target branch loop using the PWM hardware output pin of the microprocessor control board. The soft-start command is generated by configuring the pulse width modulation duty cycle ramp slope of the PWM hardware output pin to be 10 percent per second.

[0015] This invention generates a soft-start command by configuring the pulse width modulation duty cycle ramp-up slope and sends it to the target branch circuit, controlling the current ramp-up rate of the new load to make it rise smoothly. This operation reduces the current ramp-up rate of the new load and keeps the transient spatial electrodynamic force generated by the product of the instantaneous waveform current values ​​of adjacent branch circuits at any time within the mechanical shear yield limit threshold, further ensuring the mechanical stability of the power distribution system under transient impact conditions.

[0016] In a second aspect, the present invention provides a power distribution system for a cable branch box, comprising a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the aforementioned power distribution method for a cable branch box is implemented.

[0017] By adopting the above technical solution, a computer program for the above-mentioned power distribution method of cable branch box is generated and stored in a memory so that it can be loaded and executed by a processor. Terminal equipment can then be made based on the memory and processor for convenient use.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. This invention upgrades power distribution control from lagging thermodynamic effective value monitoring to advanced microsecond-level electromagnetic mechanical defense. By introducing physical geometric parameters and instantaneous waveform current values ​​to construct a transient spatial electrodynamic model, it avoids physical breakdown accidents such as busbar deformation, support fracture, and phase-to-phase short circuit explosion caused by blindly distributing transient large currents.

[0020] 2. This invention converts the power distribution benchmark into a transient mechanical tolerance constrained by the mechanical shear yield limit threshold of the SMC insulation support. Through a microsecond-level peak staggered scheduling mechanism, the electromagnetic shock generated by concurrent startup is mitigated by the time axis misalignment. This significantly improves the system's ability to withstand concurrent access of high-frequency pulse loads without increasing the cost of physical structures.

[0021] 3. This invention avoids the overlap of transient peaks by coordinating microsecond-level delay allocation and soft-start command scheduling, strictly limiting transient spatial electrodynamics within the mechanical safety boundary, thereby enhancing the mechanical robustness and power supply efficiency of the power distribution system under extreme impact conditions. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating a power distribution method for a cable branch box according to the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0025] This invention discloses a method for power distribution in a cable branch box, referring to... Figure 1 This includes steps S1-S4:

[0026] S1. Extract the instantaneous waveform current sequence and the physical geometric parameters of the cable branch box.

[0027] It should be noted that each branch circuit inside the cable branch box contains a corresponding branch busbar. Due to the extremely small physical center-to-center distance between adjacent branch busbars, when a large induction motor is directly started or connected to a nonlinear sudden load, a high-amplitude transient spatial electrodynamic force will be generated between adjacent branch busbars. This transient spatial electrodynamic force will be directly applied to the SMC insulation support in the form of a mechanical bending moment. In order to accurately assess this transient mechanical impact, it is necessary to obtain high-frequency current waveforms to extract transient sudden characteristics, and at the same time obtain the geometric dimensions that determine the intensity of electromagnetic interaction between adjacent branch busbars, thereby providing basic data for subsequent application of macroscopic electromagnetic physics laws.

[0028] Specifically, each branch circuit inside the cable branch box contains a corresponding branch busbar. High-speed wideband Hall current sensors installed on each branch busbar are used, and the hardware clock divider of the high-speed wideband Hall current sensor is set to sample one million times per second to obtain a microsecond-level sampling rate. The instantaneous waveform current sequence corresponding to each branch circuit is extracted synchronously, and the steady-state background signal is filtered out by a digital filter configured inside the microprocessor control board based on the DSP chip to extract transient change features. The digital filter achieves steady-state background signal filtering by configuring the cutoff frequency to 10 kHz. Furthermore, the preset physical geometric parameters of the cable branch box are extracted from the non-volatile memory of the microprocessor control board. The physical geometric parameters of the cable branch box include the effective coupling length between adjacent branch busbars and the physical center distance.

[0029] In the physical structure of the cable branch box, the two adjacent branch busbars do not extend infinitely in space, but are arranged in a parallel manner with a constant physical center distance within a specific physical interval. The actual physical size of the overlapping part where the two branch busbars are parallel, close to each other and have electromagnetic interaction is the effective coupling length.

[0030] S2. Construct the final mapping expression for transient spatial electromotive force.

[0031] In order to pre-calculate the mechanical impact when distributing electrical energy, a mathematical mapping model between instantaneous waveform current value and transient spatial electrodynamic force is established to reflect the mechanical interaction of parallel branch busbars in a finite space under transient impact conditions, thereby realizing the conversion from electromagnetic parameters to mechanical parameters.

[0032] First, define the two adjacent branch circuits inside the cable branch box as the first... loop and the first The circuit, when the first The instantaneous waveform current value of the circuit flows through the first When the corresponding branch busbar of the loop is in use, according to the Biot-Savart law, a well-known principle in electromagnetism used to describe the magnetic induction intensity produced by a steady current at any point in space, at a distance from the first... The formula for calculating the transient magnetic induction intensity generated at the spatial location of the branch busbar center axis corresponding to the loop, where the physical center-to-center distance is equal, is as follows:

[0033]

[0034] In the formula, For a moment At a distance of The transient magnetic induction intensity generated at the spatial location of the physical center-to-center distance along the central axis of the branch busbar corresponding to the loop is measured in Tesla. Let be the vacuum permeability constant, with dimensions in Henry per meter, and its empirical value is fixed at . , For a moment The corresponding number The instantaneous waveform current value of the circuit, in amperes. Pi is a constant. The distance between the physical centers is expressed in meters; the above calculation formula is based on the Biot-Savart law, a well-known common-sense principle, and is derived from the relationship between the vacuum permeability constant and the first... The product of the instantaneous waveform current values ​​of the loop characterizes the magnetic field excitation intensity of the source current, and the spatial attenuation characteristics of the magnetic field during spatial transmission are quantified by the reciprocal relationship of the physical center distance, thereby establishing the transient magnetic induction intensity benchmark of the spatial position of the adjacent branch busbar.

[0035] Then, the The branch busbar corresponding to the loop is located within the magnetic field distribution region of the transient magnetic induction intensity. Based on the Ampere force calculation model in common electromagnetic knowledge, the first... The intermediate expression for the transient spatial electrodynamic force borne by the conductor segment of the branch busbar corresponding to the loop is:

[0036]

[0037] In the formula, For a moment The corresponding transient spatial electrodynamic force has the dimension of Newton. For a moment The corresponding number The instantaneous waveform current value of the circuit, in amperes. The transient magnetic flux density has the dimension of Tesla. The effective coupling length is measured in meters. It is a sinusoidal function, dimensionless. Let be the angle between the direction of the current and the direction of the magnetic field, with the dimension in radians; the above expression is based on Ampere's law of force, a well-known fact, and [the expression is then modified to reflect the first...] The Lorentz force experienced by the instantaneous waveform current value in the transient magnetic induction intensity is equivalent to the macroscopic Ampere force. By effectively coupling the linear integral of the charge carrier force, and combining the sinusoidal component of the angle between the current direction and the magnetic field direction, the effective force component perpendicular to the conductor axis is extracted, thereby constructing a mechanical calculation model of transient spatial electromotive force.

[0038] Next, according to the right-hand screw rule for the magnetic field of a straight conductor current, the first... The magnetic induction lines generated by the instantaneous waveform current value of the loop pass through the first When the branch busbar of the loop is in the direction of the magnetic field vector, it is in the same direction as the first branch busbar. The current axes of the branch busbars corresponding to the loop are orthogonal to each other in three-dimensional space. Substituting the condition that the angle between the current direction and the magnetic field direction is equal to 90 degrees into the sine function, we obtain that the value of the sine function is 1, i.e. Substituting this value into the aforementioned intermediate expression for simplification to eliminate trigonometric components, we obtain the simplified expression for the transient spatial electromotive force: .

[0039] Furthermore, the transient magnetic induction intensity Substituting the complete algebraic expression directly into the simplified expression for transient spatial electromotive force, and using the commutative and associative laws of multiplication, the constant terms, geometric parameters, and time-varying instantaneous waveform current values ​​are rearranged to obtain the expression after algebraic cascading and combining like terms. .

[0040] Ultimately, since the mechanical fracture of the SMC insulation support of the fixed branch busbar depends only on the absolute value of the mechanical stress applied to it, and is independent of the specific electromagnetic repulsion or attraction direction caused by the current flowing in the same or opposite directions between the conductors, the absolute value operator is applied to the product term of the instantaneous waveform current values ​​in the expression after combining like terms, and the absolute value is extracted to derive the final mapping expression of the transient spatial electromotive force as follows:

[0041]

[0042] In the formula, For a moment The corresponding transient spatial electrodynamic force has the dimension of Newton. Here is the vacuum permeability constant, with dimensions in Henry per meter. The effective coupling length is measured in meters. Pi is a constant. The distance between the physical centers is expressed in meters. For a moment The corresponding number The instantaneous waveform current value of the circuit, in amperes. For a moment The corresponding number The instantaneous waveform current value of the circuit, in amperes. This indicates taking the absolute value. For the first The instantaneous waveform current value of the circuit and the first The absolute value of the product of the instantaneous waveform current values ​​in the loop, with dimensions in ampere squared; this expression converts the superposition effect of the magnetic fields between two parallel conductors into macroscopic mechanical stress that can directly cause mechanical damage to the SMC insulation support, and determines the calculation model of electromagnetic stress in the calculation logic of power distribution, solving the problem that long-term Joule heat accumulation cannot assess transient structural damage; it indicates that when the effective coupling length increases or the first... The instantaneous waveform current value of the circuit and the first When the product of the instantaneous waveform current values ​​of the circuit increases, the transient spatial electrodynamic force increases, and the physical force generated between adjacent branch busbars increases accordingly. The mechanical shear force borne by the SMC insulation support approaches its mechanical shear yield limit threshold. At the same time, when the physical center spacing decreases, the transient spatial electrodynamic force also increases, which means that a smaller physical center spacing will exacerbate the magnetic field superposition effect.

[0043] S3. Calculate the transient distribution critical current of the target branch circuit.

[0044] Specifically, the direct manifestation of mechanical failure in cable branch boxes is the mechanical fracture of the SMC insulation support of the fixed branch busbar. In order to maintain the safety of power distribution, the transient spatial electromotive force generated between the branch busbars must always be less than the mechanical shear yield limit of the SMC insulation support. By constraining the limit value of the transient spatial electromotive force to the mechanical shear yield limit of the SMC insulation support as specified by the manufacturer, the upper limit of the instantaneous peak current that can be injected into the target branch circuit that is about to be connected to the new load is calculated by using the instantaneous waveform current value of the currently running circuit. The mechanical shear yield limit is calibrated by shearing the SMC insulation support sample with a universal testing machine until it fractures, and extracting the maximum shear stress value at the moment of fracture.

[0045] First, the maximum mechanical stress parameter that the SMC insulation support can withstand, as specified by the manufacturer, is extracted as the mechanical shear yield limit threshold. At the critical safety calculation point of power distribution, the system is brought to a state of limit equilibrium, which is the transient spatial electrodynamic force in the final mapping expression of the transient spatial electrodynamic force mentioned above. Directly replace with mechanical shear yield strength threshold The equilibrium expression is obtained as follows: Since the transient distribution critical current is being solved at this time Physically, only the positive magnitude is considered. Moving it outside the absolute value operator yields the rearranged expression: .

[0046] Then, multiply both sides of the rearranged expression by a denominator term that includes the physical center spacing, eliminate the denominator term on the right side, and simplify to obtain the expression after eliminating the fractional structure. .

[0047] Next, based on the principle of algebraic transformation, both sides of the expression after eliminating the fractional structure are simultaneously divided by the constant of vacuum permeability, the effective coupling length, and the first... The combined coefficient terms, composed of the absolute values ​​of the instantaneous waveform currents in the loop, yield the final calculation expression for the transient distribution critical current of the target branch loop to be connected to a new load:

[0048]

[0049] In the formula, For a moment The corresponding transient distribution critical current, in amperes, The mechanical shear yield strength threshold, with dimensions in Newtons. Here is the vacuum permeability constant, with dimensions in Henry per meter. The effective coupling length is measured in meters. Pi is a dimensionless constant. The distance between the physical centers is expressed in meters. For a moment The corresponding number The instantaneous waveform current value of the circuit, in amperes. This indicates taking the absolute value. For a moment The corresponding number The absolute value of the instantaneous waveform current in the circuit, in amperes; this expression transforms the energy distribution benchmark from the traditional electrical heating capacity to a transient mechanical tolerance constrained by boundary conditions of material mechanical strength, calculates the upper limit of the current control amplitude, and indicates the current limit when the current is controlled. When the absolute value of the instantaneous waveform current in the circuit increases, the transient distribution critical current decreases. In other words, when a high-amplitude peak current surge occurs in an already connected branch circuit, the upper limit of the safe current allowed to be injected into the target branch circuit will be compressed. At the same time, when the mechanical shear yield limit threshold increases, the transient distribution critical current increases. This means that the higher the mechanical physical strength of the insulation support itself, the greater the amount of concurrent current injection the system can withstand, providing a physical safety boundary for subsequent peak staggered scheduling.

[0050] It should be noted that when When this occurs, it indicates that there is no transient current impact in the adjacent circuit, and at this time, the transient distribution critical current is applied. The maximum safe current threshold preset by the system is set to the rated short-time withstand current peak value. The microprocessor control board does not need to perform peak staggering scheduling and can directly issue the conduction command.

[0051] S4. Perform microsecond-level peak staggered scheduling based on transient allocation of critical current.

[0052] This invention establishes a peak staggered scheduling mechanism, which uses the time axis misalignment to reduce high-amplitude electromagnetic stress on the physical structure and maintain the mechanical stability of the power distribution system under transient impact conditions.

[0053] Specifically, the microprocessor control board based on the DSP chip receives load access requests initiated by the smart power distribution IoT gateway, parses the electrical equipment parameters corresponding to the new load access request and extracts the starting peak current of the new load, reads the transient allocation critical current calculated by the above expression in real time, and compares the starting peak current of the new load with the transient allocation critical current in real time through the logic comparator inside the microprocessor control board. If the starting peak current of the new load is less than the transient allocation critical current, the microprocessor control board directly issues a conduction command to the target branch circuit to complete the power distribution. If the starting peak current of the new load is greater than or equal to the transient allocation critical current, it indicates that immediate power distribution will cause the system to exceed the mechanical safety boundary. The microprocessor control board immediately starts microsecond-level peak staggered scheduling, sets the delay time parameter to 300 microseconds through the timer inside the microprocessor control board to generate a microsecond-level delayed allocation command, and issues it to the target branch circuit.

[0054] Furthermore, based on microsecond-level delay allocation instructions, the microprocessor control board synchronizes the power injection time of the new load with the first... The transient peak values ​​of the instantaneous waveform current in the circuit are staggered on the time axis, or the microprocessor control board uses the PWM hardware output pin to send a soft-start command to the target branch circuit. The soft-start command is generated by configuring the pulse width modulation duty cycle ramp slope of the PWM hardware output pin to be 10 percent per second, so as to reduce the current ramp rate of the new load and keep the transient spatial electrodynamic force generated by the product of the instantaneous waveform current values ​​of adjacent branch circuits at any time within the mechanical shear yield limit threshold.

[0055] An example illustrating the execution logic of microsecond-level peak staggered scheduling: Assume the first peak in the cable branch box... The branch busbar corresponding to the circuit is at the moment of direct start-up of the heavy-duty motor, and its first... The instantaneous waveform current value of the circuit exhibits a high amplitude characteristic. At this time, the smart power distribution IoT gateway requests the first... A high-power DC inverter is connected to the branch busbar of the circuit as the target load. The microprocessor control board estimates that the peak starting current of the target load of the high-power DC inverter is 2000 amps. After comparison by the logic comparator, it is found that the peak starting current of 2000 amps is greater than the currently calculated transient allocation critical current. At this time, the microprocessor control board maintains the power supply state and issues a microsecond-level delay allocation command, which delays the connection time of the high-power DC inverter by 300 microseconds.

[0056] This invention also discloses a power distribution system for a cable branch box, including a processor and a memory. The memory stores computer program instructions, which, when executed by the processor, implement a power distribution method for a cable branch box according to the present invention.

[0057] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for power distribution in a cable branch box, characterized in that, include: Extract the instantaneous waveform current sequence corresponding to each branch circuit, as well as the physical geometric parameters of the cable branch box of the branch busbar corresponding to the branch circuit. The physical geometric parameters of the cable branch box include the effective coupling length between adjacent branch busbars and the physical center distance. The transient spatial electrodynamic force between adjacent branch busbars is calculated using the physical center-to-center distance, effective coupling length, and instantaneous waveform current values ​​of two adjacent branch circuits. The transient spatial electrodynamic force limit value is constrained to the mechanical shear yield limit threshold of the SMC insulating support, and the transient distribution critical current of the target branch circuit to be connected to the new load is calculated. The peak current of the new load at startup is compared with the critical current of transient allocation. If the peak current of the new load at startup is greater than or equal to the critical current of transient allocation, a delayed allocation command or a soft start command is issued to perform peak staggered scheduling.

2. The power distribution method for a cable branch box according to claim 1, characterized in that, The extraction of the instantaneous waveform current sequence corresponding to each branch circuit, and the physical geometric parameters of the cable branch box of the branch busbar corresponding to the branch circuit, includes: High-speed broadband Hall current sensors installed on each branch busbar are used to obtain microsecond-level sampling rates; instantaneous waveform current sequences corresponding to each branch circuit are extracted synchronously, and steady-state background signals are filtered out by digital filters configured inside the microprocessor control board based on DSP chips; preset physical geometric parameters of the cable branch box are extracted from the non-volatile memory of the microprocessor control board.

3. The power distribution method for a cable branch box according to claim 1, characterized in that, The calculation of transient spatial electrodynamic force between adjacent branch busbars using the physical center-to-center distance, effective coupling length, and instantaneous waveform current values ​​of two adjacent branch circuits includes: ； In the formula, For a moment The corresponding transient spatial electrodynamic force, is the vacuum permeability constant. For effective coupling length, Pi is a constant. The physical center distance, For a moment The corresponding number Instantaneous waveform current value of the circuit. For a moment The corresponding number Instantaneous waveform current value of the circuit. This indicates taking the absolute value.

4. The power distribution method for a cable branch box according to claim 1, characterized in that, The step of constraining the limit value of transient spatial electrodynamic force to the mechanical shear yield strength threshold of the SMC insulating support, and calculating the transient distribution critical current of the target branch circuit to be connected to the new load, includes: ； In the formula, For a moment The corresponding transient distribution critical current, The mechanical shear yield strength threshold. is the vacuum permeability constant. For effective coupling length, Pi is a constant. The physical center distance, For a moment The corresponding number Instantaneous waveform current value of the circuit. This indicates taking the absolute value.

5. A power distribution method for a cable branch box according to claim 1, characterized in that, The issuance of delay allocation instructions to execute peak staggered scheduling includes: The delay time parameter is set to 300 microseconds by the timer inside the microprocessor control board to generate microsecond-level delay allocation instructions and send them to the target branch loop.

6. The power distribution method for a cable branch box according to claim 1, characterized in that, The issuance of the soft-start command to execute peak-shifting scheduling includes: The microprocessor control board uses its PWM hardware output pin to send a soft-start command to the target branch circuit. The soft-start command is generated by configuring the PWM hardware output pin's pulse width modulation duty cycle ramp rate to be 10 percent per second.

7. A power distribution system for a cable branch box, characterized in that, include: A processor and a memory, the memory storing computer program instructions that, when executed by the processor, implement a power distribution method for a cable branch box according to any one of claims 1-6.

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