Power distribution network fault simulation method, system, device, medium and product

Abstract

The application relates to the technical field of power system simulation, and discloses a power distribution network fault simulation method, system, device, medium and product. The method comprises the following steps: obtaining operation parameters of a to-be-simulated power distribution network, determining system ground capacitance and a capacitive current flowing to a fault point under single-phase arc ground fault according to the operation parameters; dynamically updating tuning parameters of an arc suppression coil according to the system ground capacitance, and determining a compensation current of the arc suppression coil based on the updated tuning parameters; determining arc light current of a current simulation step according to the capacitive current and the compensation current, and determining arc light voltage of the current simulation step according to the arc light current and arc light state of a previous simulation step; updating the arc light state of the current simulation step according to the arc light current and the arc light voltage of the current simulation step, and performing fault simulation of a subsequent simulation step based on the updated arc light state, so that a simulation result of the single-phase arc ground fault is obtained, and the authenticity and accuracy of single-phase arc ground fault simulation of the power distribution network are improved.

Description

Technical Field

[0001] This invention relates to the field of power system simulation technology, and in particular to a method, system, equipment, medium and product for simulating power distribution network faults. Background Technology

[0002] In power distribution network faults, single-phase grounding faults can be broadly classified into two categories based on their grounding characteristics: metallic grounding faults and arcing grounding faults. Metallic grounding faults refer to a direct connection between the faulty phase conductor and the ground via a conductor, with a transition resistance close to zero. Arcing grounding faults, on the other hand, refer to a connection between the fault point and the ground via an electric arc discharge, exhibiting complex characteristics such as intermittency, randomness, and nonlinearity, and accounting for over 80% of all single-phase grounding faults. If arcing grounding faults are not handled promptly, they can trigger arcing grounding overvoltages, with amplitudes reaching 3.5 times or even higher than the normal phase voltage, posing a serious threat to the insulation of power distribution network equipment and potentially leading to multi-point grounding faults or phase-to-phase short circuits, thus expanding the scope of the accident.

[0003] In existing technologies, arc suppression coils typically employ a fixed inductance model or a series RL equivalent model. Their inductance parameters remain constant during simulation, making it difficult to respond to changes in system-to-ground capacitance caused by operational variations such as line switching. In contrast, actual arc suppression coils can dynamically adjust their compensation state based on changes in system-to-ground capacitance. Furthermore, for arc grounding faults, existing technologies often treat the fault point as an equivalent fixed resistor or establish and solve the arc model and arc suppression coil model independently. This makes it difficult to describe the changes in arc resistance with fault current and the arc extinction and reignition processes when the current crosses zero, leading to discrepancies between simulation results and actual fault processes for single-phase arc grounding faults. Summary of the Invention

[0004] In view of this, in order to solve the above-mentioned technical problems, the present invention provides a method, system, equipment, medium and product for simulating power distribution network faults.

[0005] The first aspect of this invention provides a method for simulating power distribution network faults, the method comprising:

[0006] Obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters;

[0007] The tuning parameters of the arc suppression coil are dynamically updated based on the system's capacitance to ground, and the compensation current of the arc suppression coil is determined based on the updated tuning parameters.

[0008] The arc current of the current simulation step is determined based on the capacitor current and the compensation current, and the arc voltage of the current simulation step is determined based on the arc current and the arc state of the previous simulation step.

[0009] The arc state of the current simulation step is updated based on the arc current and arc voltage of the current simulation step, and the fault simulation of the subsequent simulation steps is performed based on the updated arc state to obtain the simulation results of single-phase arc grounding fault.

[0010] In one example, the operating parameters include line-to-ground capacitance parameters;

[0011] The determination of the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters includes:

[0012] The system's capacitance to ground is determined based on the line-to-ground capacitance parameters.

[0013] After a single-phase arc grounding fault occurs, the non-faulty phase that provides capacitive current to the fault point is determined based on the ground capacitance connection status of the faulty phase and the non-faulty phase, and the capacitive current flowing to the fault point is determined based on the ground capacitance corresponding to each of the non-faulty phases.

[0014] In one example, the step of dynamically updating the tuning parameters of the arc suppression coil based on the system's capacitance to ground, and determining the compensation current of the arc suppression coil based on the updated tuning parameters, includes:

[0015] The resonant inductance corresponding to the current compensation state is determined based on the system's capacitance to ground, and the tuning inductance of the arc suppression coil is determined based on the resonant inductance and the preset detuning degree.

[0016] The arc suppression coil is equivalent to a series RL model consisting of the iron loss equivalent resistance and the tuning inductor, and the arc suppression coil current is used as the state variable.

[0017] Based on the neutral-to-ground voltage, arc suppression coil current, and tuning inductance from the previous simulation step, the state equations corresponding to the series RL model are discretely solved to obtain the arc suppression coil current for the current simulation step, and the arc suppression coil current is used as the compensation current.

[0018] In one example, determining the arc current of the current simulation step based on the capacitor current and the compensation current, and determining the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step, includes:

[0019] Obtain the current difference between the capacitive current flowing to the fault point and the compensation current returning through the fault phase, and use the current difference to determine the arc current of the current simulation step;

[0020] Obtain the arc photoconductivity used to characterize the arc state in the previous simulation step, and determine the arc voltage in the current simulation step based on the arc current in the current simulation step and the arc photoconductivity in the previous simulation step.

[0021] In one example, the process of updating the arc state of the current simulation step based on the arc current and arc voltage of the current simulation step, and performing fault simulation in subsequent simulation steps based on the updated arc state, to obtain the simulation results of a single-phase arc grounding fault, includes:

[0022] The instantaneous power of the arc in the current simulation step is determined based on the arc current and arc voltage in the current simulation step.

[0023] Based on the instantaneous power of the arc, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved to obtain the arc photoconductivity of the current simulation step, and the corresponding arc resistance is determined based on the arc photoconductivity of the current simulation step.

[0024] The arc photoconductivity of the current simulation step is taken as the arc state of the current simulation step. The determination of the arc voltage and the update of the arc state are repeated according to the simulation step until the preset simulation stop condition is met. The simulation result of the single-phase arc grounding fault is formed based on the arc current, arc voltage and arc resistance obtained from each simulation step.

[0025] In one example, the step of discretizing and solving the Mayr state equation describing the dynamic characteristics of the arc based on the instantaneous arc power, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step includes:

[0026] Based on the relationship between the instantaneous arc power and the preset steady-state heat dissipation power, the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step is determined.

[0027] Based on the changing state, the Mayr state equation is discretely solved using the arc photoconductivity of the previous simulation step as the base state to obtain the arc photoconductivity of the current simulation step, and the arc photoconductivity is characterized as the arc state of the current simulation step.

[0028] Secondly, the present invention also provides a power distribution network fault simulation system, the system comprising:

[0029] The capacitor current determination module is used to obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitor current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters.

[0030] The compensation current determination module is used to dynamically update the tuning parameters of the arc suppression coil based on the system's capacitance to ground, and to determine the compensation current of the arc suppression coil based on the updated tuning parameters.

[0031] The arc voltage determination module is used to determine the arc current of the current simulation step based on the capacitor current and the compensation current, and to determine the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step.

[0032] The simulation result generation module is used to update the arc state of the current simulation step based on the arc current and arc voltage of the current simulation step, and to perform fault simulation of subsequent simulation steps based on the updated arc state, so as to obtain the simulation result of single-phase arc grounding fault.

[0033] Thirdly, the present invention also provides an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, the computer program being executed by the processor causing the processor to perform the steps of the power distribution network fault simulation method as described in the first aspect.

[0034] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the steps of the power distribution network fault simulation method as described in the first aspect.

[0035] Fifthly, the present invention also provides a computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein when the program instructions are executed by a computer, the computer performs the steps of the power distribution network fault simulation method as described in the first aspect.

[0036] As can be seen from the above technical solution, this invention determines the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters of the distribution network to be simulated. It then dynamically updates the tuning parameters of the arc suppression coil using the system-to-ground capacitance, enabling the compensation current of the arc suppression coil to adjust with changes in the distribution network's operating state. Based on this, the actual arc current is determined by the current relationship between the fault point's capacitive current and the compensation current. The current arc voltage is then determined using the arc state from the previous simulation step, and the current arc state is further updated using the current arc current and arc voltage. This allows the arc suppression coil compensation process and the changes in the arc conductivity state to form a dynamically connected solution process through continuous simulation steps. Therefore, this solution avoids the compensation deviation caused by using fixed parameters for the arc suppression coil, which cannot respond to changes in the system-to-ground capacitance, thereby improving the realism and accuracy of single-phase arc grounding fault simulation in distribution networks. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is an application environment diagram of a power distribution network fault simulation method provided in an embodiment of the present invention;

[0039] Figure 2 A flowchart of a power distribution network fault simulation method provided in an embodiment of the present invention;

[0040] Figure 3 This is a schematic diagram of the actual equivalent model of the arc suppression coil;

[0041] Figure 4 This is a schematic diagram of the simulation system.

[0042] Figure 5 This is a schematic diagram of the structure of a power distribution network fault simulation system provided in an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0045] The power distribution network fault simulation method provided in this application embodiment can be applied to, for example... Figure 1In the application environment shown, terminal 101 communicates with server 102 via a network. A data storage system can store the data that server 102 needs to process. The data storage system can be integrated onto server 102 or placed on a cloud or other network server. Terminal 101 or server 102 executes a power distribution network fault simulation method, which includes: acquiring the operating parameters of the power distribution network to be simulated; determining the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters; dynamically updating the tuning parameters of the arc suppression coil based on the system-to-ground capacitance, and determining the compensation current of the arc suppression coil based on the updated tuning parameters; determining the arc current of the current simulation step based on the capacitive current and the compensation current, and determining the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step; updating the arc state of the current simulation step based on the arc current and arc voltage of the current simulation step, and performing fault simulation for subsequent simulation steps based on the updated arc state to obtain the simulation result of a single-phase arc grounding fault.

[0046] Terminal 101 can be, but is not limited to, various personal computers, laptops, smartphones, and tablets.

[0047] Server 102 can be a standalone physical server, a server cluster or distributed system consisting of multiple physical servers, or a cloud server that provides cloud computing services.

[0048] The power distribution network to be simulated can be a 6kV to 35kV medium-voltage power distribution network. The power distribution network includes three-phase power supply, distribution lines, line-to-ground capacitance, neutral point grounding branch, and fault point, among other electrical objects. The three-phase power supply is used to establish the three-phase power supply conditions of the power distribution network to be simulated; the distribution lines can be characterized using a distributed parameter line model; the line-to-ground capacitance describes the capacitive effect of each phase line relative to the ground; the neutral point grounding branch includes an arc suppression coil connected between the neutral point of the distribution transformer and the ground; and the fault point is used to simulate a single-phase arc-to-ground fault where the faulty phase forms an electrical connection with the ground via an electric arc.

[0049] It should be noted that the simulation step in this embodiment is the time progression unit used when performing discrete calculations on the transient process of continuous faults.

[0050] like Figure 2 As shown in the embodiments of this application, a method for simulating power distribution network faults is provided, which is applied to... Figure 1 Taking terminal 101 or server 102 as an example, the explanation includes the following steps S1 to S4. Wherein:

[0051] Step S1: Obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters.

[0052] In this embodiment, the operating parameters refer to parameters used to describe the electrical operating state of the simulated distribution network before and during a fault, and which can participate in subsequent fault calculations. For example, operating parameters may include power supply phase voltage, system frequency, line-to-ground capacitance parameters, neutral-to-ground voltage, arc suppression coil parameters, and the time of fault occurrence.

[0053] In one implementation, determining the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on operating parameters includes: determining the system-to-ground capacitance based on line-to-ground capacitance parameters; after a single-phase arc grounding fault occurs, determining the non-faulty phase that provides capacitive current to the fault point based on the connection status of the ground capacitance of the faulty phase and the non-faulty phase, and determining the capacitive current flowing to the fault point based on the ground capacitance corresponding to each non-faulty phase.

[0054] In fault simulation, the line-to-ground capacitance is the equivalent parameter of the distributed capacitance formed between the distribution line and the ground. Its magnitude is related to the line type, line length, and the range of lines currently in operation. Therefore, when a line is put into or taken out of operation, the system-to-ground capacitance corresponding to the distribution network being simulated will also change.

[0055] Preferably, the current system ground capacitance can be determined based on the currently operational lines and their line-to-ground capacitance parameters. To further reflect changes in ground capacitance caused by changes in operating modes such as line switching, the system ground capacitance can also be identified online in conjunction with the current system capacitor current, and the identification result can be used as the system ground capacitance for subsequent dynamic tuning of the arc suppression coil.

[0056] When using the system capacitor current amplitude During identification, the estimated value of the capacitance to ground per phase of the system can be obtained using the following formula:

[0057]

[0058] in, This is the estimated system-to-ground capacitance value obtained at the current moment. It is the power frequency angular frequency. This is the effective value of the phase voltage.

[0059] For a single-phase arc grounding fault, taking the fault in phase A as an example, before the fault occurs, phases A, B, and C form a grounding capacitor loop through their respective grounding capacitors. After phase A forms a fault connection with the ground through the arc grounding channel, the fault point changes the connection state of the original grounding capacitor loop, and the grounding capacitors of the non-faulty phases corresponding to phases B and C provide capacitive current to the fault point.

[0060] The capacitive currents flowing from phase B and phase C to the fault point are respectively expressed as: , The total capacitive current corresponding to the fault point It can be represented as:

[0061]

[0062] in, This is the equivalent capacitance to ground for each phase; This is the initial phase angle corresponding to the occurrence of the fault.

[0063] Through the above processing, the correspondence between the current operating state of the distribution network and the capacitor current of the fault point can be established at the beginning of the fault simulation, and the change in ground capacitance caused by the change in line operating mode can be further transmitted to the arc suppression coil compensation process.

[0064] Step S2: Dynamically update the tuning parameters of the arc suppression coil based on the system's capacitance to ground, and determine the compensation current of the arc suppression coil based on the updated tuning parameters.

[0065] The arc suppression coil is connected between the neutral point of the distribution transformer and the ground. The inductive compensation current it generates is in the opposite direction to the capacitive grounding current formed by the system's ground capacitance. By adjusting the inductance of the arc suppression coil, the inductive current provided by the arc suppression coil can compensate as much as possible for the capacitive current flowing to the fault point, thereby reducing the residual current flowing through the arc grounding channel.

[0066] Step S3: Determine the arc current of the current simulation step based on the capacitor current and the compensation current, and determine the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step.

[0067] In the case of a single-phase arc grounding fault, the capacitive current flowing to the fault point and the arc suppression coil compensation current returning through the fault phase are in opposite directions.

[0068] In addition, the previous simulation step is a discrete-time advance calculation node before the current simulation step. The arc photoconductivity calculated in the previous simulation step is used to characterize the arc state before the start of the current simulation step. Based on this state and the currently determined arc current, the arc voltage corresponding to the current simulation step can be calculated through circuit relationships.

[0069] In this embodiment, the arc state is used to describe the electrical conductivity of the arc at the fault point during the arcing, cooling, and extinguishing processes.

[0070] Step S4: Update the arc state of the current simulation step according to the arc current and arc voltage of the current simulation step, and perform fault simulation of subsequent simulation steps based on the updated arc state to obtain the simulation results of single-phase arc grounding fault.

[0071] The update of the arc state is essentially an adjustment of the arc photoconductivity based on the change in arc energy in the current simulation step. The updated arc state will then serve as the basis for calculating the arc voltage in the next simulation step. By recursively calculating step by step, the entire transient process of a single-phase arc grounding fault from occurrence to development, extinction, or reignition can be obtained.

[0072] This embodiment determines the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters of the distribution network to be simulated. It then dynamically updates the tuning parameters of the arc suppression coil using the system-to-ground capacitance, allowing the compensation current of the arc suppression coil to adjust according to changes in the distribution network's operating state. Based on this, the actual arc current is determined using the current relationship between the fault point's capacitive current and the compensation current. The current arc voltage is then determined using the arc state from the previous simulation step, and the current arc state is further updated using the current arc current and arc voltage. This creates a dynamically connected solution process between the arc suppression coil compensation process and the changes in the arc conductivity state through continuous simulation steps. Therefore, this scheme avoids the compensation deviation caused by using fixed parameters for the arc suppression coil, which cannot respond to changes in the system-to-ground capacitance, thereby improving the realism and accuracy of single-phase arc grounding fault simulation in distribution networks.

[0073] In some embodiments, the tuning parameters of the arc suppression coil are dynamically updated based on the system-to-ground capacitance, and the compensation current of the arc suppression coil is determined based on the updated tuning parameters. This includes: determining the resonant inductance corresponding to the current compensation state based on the system-to-ground capacitance, and determining the tuning inductance of the arc suppression coil based on the resonant inductance and a preset detuning degree; equipping the arc suppression coil as a series RL model consisting of the iron loss equivalent resistance and the tuning inductance, and using the arc suppression coil current as the state variable; and discretizing the state equation corresponding to the series RL model based on the neutral point-to-ground voltage, the arc suppression coil current, and the tuning inductance of the previous simulation step to obtain the arc suppression coil current of the current simulation step, and using the arc suppression coil current as the compensation current.

[0074] The arc suppression coil is connected in series between the neutral point of the distribution transformer and the ground. Its inductive current i L With the capacitive grounding current i of the system C In the opposite direction, by dynamically tuning the inductance of the arc suppression coil, i L ≈i C This reduces the residual current at the fault point to below the critical value required for the arc to extinguish naturally (typically, the residual current should not exceed 5A to 10A).

[0075] In practical engineering operations, arc suppression coils are typically operated in an overcompensated manner. The detuning degree 'v' can be used to describe the relative deviation between the arc suppression coil compensation current and the system capacitive grounding current.

[0076]

[0077] in, This refers to the effective value of the power frequency inductive compensation current generated by the arc suppression coil. This represents the effective value of the system's capacitive grounding current.

[0078] For example, the detuning degree can be set to a positive value, causing the arc suppression coil to be in an overcompensated state; for instance, a detuning degree of approximately +5% to +10% can be used. These values ​​are used to illustrate the tuning method of the arc suppression coil and are not required to be used in all applications.

[0079] Based on the current system capacitance to ground, the corresponding resonant inductance under full compensation can be determined first:

[0080]

[0081] in, This is the inductance required to bring the arc suppression coil into a resonant compensation state under the current system capacitance to ground conditions.

[0082] Furthermore, the actual tuning inductor used is determined based on the preset detuning degree:

[0083]

[0084] in, For tuning the inductor.

[0085] For example, the estimated system-to-ground capacitance can be updated once at the end of each power frequency cycle, and the tuning inductor can be recalculated based on the new system-to-ground capacitance. Within a power frequency cycle, the current tuning inductor can be kept unchanged, and the state solution for multiple simulation steps within that cycle can be completed using this tuning inductor; when the operating mode, such as line switching, changes and causes a change in the system-to-ground capacitance identified in the next cycle, the corresponding tuning inductor is updated again.

[0086] Furthermore, to account for the iron loss present in the arc suppression coil core, the arc suppression coil can be equivalent to the iron loss equivalent resistance (i.e., Figure 3 The fast response resistor R in f2 The RL model formed by connecting the inductor L(t) and the dynamically tuned inductor L(t) in series is as follows: Figure 3 As shown. Where R f2 The parameters used to characterize core losses such as hysteresis loss and eddy current loss can be determined based on the parameters on the nameplate of the arc suppression coil; L(t) is updated according to the above dynamic tuning process.

[0087] With arc suppression coil current i L Using (t) as the state variable, establish the state equation for the series RL loop:

[0088]

[0089] in, The voltage between the neutral point and ground is used as the input excitation for the dynamic model of the arc suppression coil.

[0090] To enable numerical computation of this continuous state equation in fault simulations progressing step by step, it can be discretized using a forward Euler method. For the current k-th simulation step, it can be obtained from the state of the previous simulation step:

[0091]

[0092] in, This is the arc suppression coil current from the previous simulation step; This represents the neutral point-to-ground voltage from the previous simulation step. The tuning inductor is used for the propulsion process in this state; Δt is the simulation step size; To obtain the current of the arc suppression coil in the current simulation step.

[0093] What was obtained That is, the compensation current for the current simulation step is used to determine the arc current flowing through the arc grounding channel in the current simulation step.

[0094] In some embodiments, determining the arc current of the current simulation step based on the capacitor current and the compensation current, and determining the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step, includes: obtaining the current difference between the capacitor current flowing to the fault point and the compensation current returning through the fault phase, and determining the arc current of the current simulation step based on the current difference; obtaining the arc photoconductivity used to characterize the arc state in the previous simulation step, and determining the arc voltage of the current simulation step based on the arc current of the current simulation step and the arc photoconductivity of the previous simulation step.

[0095] In a single-phase arc grounding fault, the capacitive current flowing to the fault point and the arc suppression coil compensation current returning through the fault phase are in opposite directions. Therefore, a current balance relationship can be established at the fault point according to Kirchhoff's current law, and the actual arc current flowing through the arc grounding channel can be obtained based on the current difference between the two.

[0096] In the current k-th simulation step, it can be represented as:

[0097]

[0098] in, This represents the capacitor current flowing to the fault point in the current simulation step. This represents the arc current flowing through the arc grounding channel in the current simulation step.

[0099] For example, when the arc suppression coil is in a better compensation state, and When the amplitudes of the two currents are close, the resulting arc current, obtained by subtracting them, is smaller, which is beneficial for the arc to cool and extinguish near the current zero crossing. Conversely, when the compensation deviation of the arc suppression coil is large, the current difference between the two currents increases, the residual current flowing through the arc grounding channel increases, and the possibility of the arc continuing to burn increases accordingly. Therefore, the arc current simultaneously inherits the dynamic compensation result of the previous stage and serves as the excitation quantity for the Mayr arc state calculation in the next stage.

[0100] In this embodiment, the arc state is recursively calculated using the arc photoconductivity g as the state variable. In the theoretical continuous model, the arc voltage, arc current, and current arc photoconductivity of the current simulation step are interrelated. However, if the current arc voltage is calculated directly using the arc photoconductivity that has not yet been obtained in the current simulation step, and the update of the current arc photoconductivity requires the use of the current arc voltage, then an interdependence will be formed between the state variables of the current step.

[0101] To enable this coupling relationship to be explicitly solved step-by-step in the simulation, this embodiment utilizes the arc photoconductivity already determined in the previous simulation step. As a known state quantity in the current simulation step of arc voltage calculation, namely:

[0102]

[0103] in, This represents the arc voltage at the current simulation step.

[0104] In other words, at the start of the k-th simulation step, This belongs to the known state left over from the previous simulation step, so it can be determined first. reuse Continue updating g (k) This transforms the direct interdependence between the current arc voltage and the current arc photoconductivity into a recursive relationship across simulation steps, thereby updating the current arc state based on the current arc current and current arc voltage, and passing the updated state to the next simulation step.

[0105] In some embodiments, the arc state of the current simulation step is updated based on the arc current and arc voltage of the current simulation step, and the fault simulation of subsequent simulation steps is performed based on the updated arc state to obtain the simulation result of a single-phase arc grounding fault. This includes: determining the instantaneous arc power of the current simulation step based on the arc current and arc voltage of the current simulation step; discretizing and solving the Mayr state equation used to describe the dynamic characteristics of the arc based on the instantaneous arc power, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step to obtain the arc photoconductivity of the current simulation step; determining the corresponding arc resistance based on the arc photoconductivity of the current simulation step; using the arc photoconductivity of the current simulation step as the arc state of the current simulation step, and repeating the determination of the arc voltage and the update of the arc state according to the simulation steps until the preset simulation stop condition is met; and forming the simulation result of a single-phase arc grounding fault based on the arc current, arc voltage, and arc resistance obtained from each simulation step.

[0106] In this embodiment, the Mayr arc model is used to describe the dynamic process of the arc at the fault point during low current and near the current zero crossing, with the arc photoconductivity g(t) as the state variable. The Mayr state equation is:

[0107]

[0108] in, = , The instantaneous input power of the current arc column. The arc column thermal time constant is used to reflect the response speed of the arc state to changes in input power, with a typical value of 10μs~100μs; This represents the steady-state heat dissipation power of the arc column.

[0109] Furthermore, based on the instantaneous arc power, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved, including: determining the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step based on the relationship between the instantaneous arc power and the preset steady-state heat dissipation power; based on the change state, using the arc photoconductivity of the previous simulation step as the base state, the Mayr state equation is discretely solved to obtain the arc photoconductivity in the current simulation step, and the arc photoconductivity is characterized as the arc state in the current simulation step.

[0110] The energy change trend of the arc column is determined by comparing the instantaneous arc power with the preset steady-state heat dissipation power. Generally, when the instantaneous arc power is greater than the preset steady-state heat dissipation power, the arc photoconductivity of the current simulation step is increased based on the arc photoconductivity of the previous simulation step to characterize the arc column heating up and arc enhancement; when the instantaneous arc power is less than the preset steady-state heat dissipation power, the arc photoconductivity of the current simulation step is decreased based on the arc photoconductivity of the previous simulation step to characterize the arc column cooling down and changing towards the arc extinguishing state.

[0111] Specifically, when p(t) > P0, the instantaneous power of the input arc column is greater than the steady-state heat dissipation power, the state change term in the Mayr equation of state is positive, and the arc photoconductivity increases relative to the previous simulation step. In this state, the energy gained by the arc column is higher than the energy lost, the arc column temperature rises, conductivity increases, and the arc light tends to be maintained or enhanced during combustion.

[0112] When p(t)≤P0, the input power of the arc column is lower than the steady-state heat dissipation power, and the arc photoconductivity decreases relative to the previous simulation step, indicating that the arc column cools down, its conductivity decreases, and it gradually tends to extinguish.

[0113] Near the zero-crossing current, the instantaneous power of the arc approaches zero, and the arc photoconductivity decays rapidly under the Mayr model. When the arc channel can no longer maintain a conductive state, it can represent the arc entering the extinction process; if the subsequent fault recovery voltage satisfies the reignition condition again, it can also represent the subsequent reignition dynamic process.

[0114] To numerically solve the Mayr state equations step by step according to the simulation, the forward Euler discretization method can be used, and the arc photoconductivity of the current k-th simulation step can be expressed as:

[0115]

[0116] in, This is the arc photoconductivity of the previous simulation step.

[0117] The arc resistance is not a fixed resistance set independently of the arc photoconductivity, but rather changes synchronously with the current arc photoconductivity. For the current simulation step, it can be calculated according to... Determine the current arc resistance .

[0118] Therefore, when the arc photoconductivity increases with the increase of the arc column input power, the corresponding arc resistance decreases; conversely, when the arc photoconductivity decreases with the cooling of the arc column, the corresponding arc resistance increases. This is achieved by continuously recording the values ​​at each simulation step. This allows for the formation of a time-varying curve showing how the arc resistance changes during the fault process, thus distinguishing it from the approach of setting the fault point as a fixed transition resistance.

[0119] After updating the arc photoconductivity and arc resistance of the current simulation step, the arc photoconductivity g of the current simulation step will be updated. (k) The arc photoconductivity is passed to the next simulation step. In the (k+1)th simulation step, the arc photoconductivity becomes the known arc state of the previous simulation step and is used for the arc voltage. Subsequently, the instantaneous arc power of the next simulation step is determined using the arc voltage and arc current, and the arc photoconductivity is updated.

[0120] In this way, the dynamic tuning result of the arc suppression coil first changes the compensation current, which in turn changes the arc current. The arc current affects the instantaneous input power of the arc and further changes the arc photoconductivity and arc resistance. The electrical state of the fault point formed by the change in the arc conductivity state continues to be reflected in the voltage and current solution process of the subsequent simulation steps, thereby realizing the continuous coupling between the dynamic compensation process of the arc suppression coil and the dynamic process of the arc.

[0121] The simulation step size should be set to be smaller than the characteristic time scale corresponding to the arc light dynamic process. This ensures that each arc column thermal time constant contains at least several consecutive calculation steps, avoiding significant numerical oscillations or divergences during the arc photoconductivity update process.

[0122] After each simulation step is completed, the current simulation step can record at least the following fault state quantities: neutral point-to-ground voltage u. N (k) Arc current i arc (k) Arc voltage u arc (k) and arc resistance R arc (k) .

[0123] Among them, the neutral point-to-ground voltage can characterize the neutral point displacement state during a single-phase ground fault; the arc current can reflect the compensation result of the arc suppression coil for the capacitive current at the fault point; the arc voltage can reflect the voltage change at both ends of the arc grounding channel and the characteristics of arc overvoltage; and the time-varying curve of the arc resistance can reflect the nonlinear process of the arc evolving from burning to cooling and extinguishing.

[0124] After completing the current simulation step, set simulation step k+1, enter the next simulation step, and re-execute the processes of tuning parameter update, compensation current solution, arc current determination, arc voltage determination, and arc state update until the preset simulation duration is reached or the arc reaches the preset permanent extinction condition.

[0125] Finally, based on the arc current, arc voltage, and arc resistance obtained from multiple consecutive simulation steps, the time-domain simulation results of a single-phase arc grounding fault are formed, thereby obtaining the fault waveform that can characterize the arc burning, zero crossing, cooling, and extinction processes.

[0126] like Figure 4 As shown, the simulation system established in this application includes a three-phase power supply module, a line and ground capacitance module, a neutral point arc suppression coil dynamic tuning module, a phase-to-phase transition resistance module, and an arc grounding resistance Mayr model module. The three-phase power supply module provides the rated voltage U. ph (Effective value of phase voltage), three-phase symmetrical, frequency is power frequency ω=2πf (f=50Hz). The line and ground capacitance module adopt a distributed parameter line model, and each phase line end has an equivalent ground capacitance C0 (ground capacitance, unit: μF / km). Under normal operation, the three-phase ground capacitance is balanced; after a single-phase ground fault occurs in phase A, the ground capacitance of phase A is short-circuited by the fault point, and only the ground capacitances of phase B C0B and C C provide capacitive current to the fault point. The neutral point arc suppression coil dynamic tuning module is connected between the neutral point and the ground. Phase-to-phase transition resistance module: connected in series in the phase-to-phase fault circuit, such as Figure 4 The phase-to-phase transition resistance Rf is marked in the image. The Mayr model module for arc grounding resistance is located between phase A of the fault point and the ground, as shown in the image. Figure 4 The arc grounding resistor (Mayr model) is marked in the diagram. After the simulation begins, the three-phase power supply module supplies power to the line, and the line-to-ground capacitance module forms a three-phase-to-ground capacitance loop under normal operating conditions. Simultaneously, the arc suppression coil dynamic tuning module adjusts the compensation state according to the system's ground capacitance parameters. When a fault occurs at a set time, phase A forms a fault path to the ground through the Mayr arc grounding resistor. At this time, the network topology changes; the phase-to-ground capacitance of phase A is short-circuited, and the capacitive current generated by phases B and C flows to the fault point; the arc suppression coil generates an inductive current to compensate for it. During the simulation, the Mayr model dynamically updates the ground conductance according to the arc state, and the arc suppression coil dynamically tunes according to changes in system parameters. The phase-to-phase transition resistor module is activated separately when simulating phase-to-phase faults, and the transition resistor R is set... f It characterizes different degrees of phase-to-phase insulation breakdown. Each module is independently activated according to the set fault conditions and solved in combination to obtain fault voltage and current waveforms that take into account ground capacitance, dynamic tuning of the arc suppression coil, phase-to-phase transition resistance, and dynamic characteristics of the arc.

[0127] Based on the same inventive concept, this application also provides a power distribution network fault simulation system for implementing the power distribution network fault simulation method described above.

[0128] The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more distribution network fault simulation system embodiments provided below can be found in the limitations of the distribution network fault simulation method above, and will not be repeated here.

[0129] like Figure 5 As shown in the figure, this application provides a power distribution network fault simulation system, which includes:

[0130] The capacitor current determination module 100 is used to obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitor current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters.

[0131] The compensation current determination module 200 is used to dynamically update the tuning parameters of the arc suppression coil according to the system's capacitance to ground, and determine the compensation current of the arc suppression coil based on the updated tuning parameters.

[0132] Arc voltage determination module 300 is used to determine the arc current of the current simulation step based on the capacitor current and the compensation current, and to determine the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step.

[0133] The simulation result generation module 400 is used to update the arc state of the current simulation step based on the arc current and arc voltage of the current simulation step, and to perform fault simulation of subsequent simulation steps based on the updated arc state, so as to obtain the simulation results of single-phase arc grounding fault.

[0134] In some embodiments, operating parameters include line-to-ground capacitance parameters;

[0135] The capacitor current determination module 100 is used for:

[0136] Determine the system's ground capacitance based on the line-to-ground capacitance parameters;

[0137] After a single-phase arc grounding fault occurs, the non-faulty phase that provides capacitive current to the fault point is determined based on the ground capacitance connection status of the faulty phase and the non-faulty phase, and the capacitive current flowing to the fault point is determined based on the ground capacitance corresponding to each non-faulty phase.

[0138] In some embodiments, the compensation current determination module 200 is configured to:

[0139] The resonant inductance corresponding to the current compensation state is determined based on the system's capacitance to ground, and the tuning inductance of the arc suppression coil is determined based on the resonant inductance and the preset detuning degree.

[0140] The arc suppression coil is equivalent to a series RL model consisting of iron loss equivalent resistance and tuning inductance, and the arc suppression coil current is used as the state variable.

[0141] Based on the neutral-to-ground voltage, arc suppression coil current, and tuning inductance from the previous simulation step, the state equations corresponding to the series RL model are discretely solved to obtain the arc suppression coil current in the current simulation step, and the arc suppression coil current is used as the compensation current.

[0142] In some embodiments, the arc voltage determination module 300 is used for:

[0143] Obtain the current difference between the capacitor current flowing to the fault point and the compensation current returning through the fault phase, and use the current difference to determine the arc current of the current simulation step;

[0144] Obtain the arc photoconductivity used to characterize the arc state in the previous simulation step, and determine the arc voltage in the current simulation step based on the arc current in the current simulation step and the arc photoconductivity in the previous simulation step.

[0145] In some embodiments, the simulation result generation module 400 is used for:

[0146] The instantaneous power of the arc in the current simulation step is determined based on the arc current and arc voltage in the current simulation step.

[0147] Based on the instantaneous power of the arc, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved to obtain the arc photoconductivity of the current simulation step, and the corresponding arc resistance is determined based on the arc photoconductivity of the current simulation step.

[0148] The arc photoconductivity of the current simulation step is taken as the arc state of the current simulation step. The arc voltage is determined and the arc state is updated repeatedly according to the simulation step until the preset simulation stop condition is met. The simulation results of single-phase arc grounding fault are formed based on the arc current, arc voltage and arc resistance obtained from each simulation step.

[0149] In some embodiments, the simulation result generation module 400 is used for:

[0150] Based on the relationship between the instantaneous power of the arc and the preset steady-state heat dissipation power, the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step is determined.

[0151] Based on the changing state, the arc photoconductivity of the previous simulation step is used as the base state. The Mayr state equation is solved discretely to obtain the arc photoconductivity of the current simulation step, and the arc photoconductivity is represented as the arc state of the current simulation step.

[0152] This embodiment determines the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters of the distribution network to be simulated. It then dynamically updates the tuning parameters of the arc suppression coil using the system-to-ground capacitance, allowing the compensation current of the arc suppression coil to adjust according to changes in the distribution network's operating state. Based on this, the actual arc current is determined using the current relationship between the fault point's capacitive current and the compensation current. The current arc voltage is then determined using the arc state from the previous simulation step, and the current arc state is further updated using the current arc current and arc voltage. This creates a dynamically connected solution process between the arc suppression coil compensation process and the changes in the arc conductivity state through continuous simulation steps. Therefore, this scheme avoids the compensation deviation caused by using fixed parameters for the arc suppression coil, which cannot respond to changes in the system-to-ground capacitance, thereby improving the realism and accuracy of single-phase arc grounding fault simulation in distribution networks.

[0153] like Figure 6 As shown, this application provides an electronic device 10, which includes a memory 20 and a processor 30. The memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 performs the following:

[0154] Obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters;

[0155] The tuning parameters of the arc suppression coil are dynamically updated based on the system's capacitance to ground, and the compensation current of the arc suppression coil is determined based on the updated tuning parameters.

[0156] The arc current of the current simulation step is determined based on the capacitor current and the compensation current, and the arc voltage of the current simulation step is determined based on the arc current and the arc state of the previous simulation step.

[0157] The arc state of the current simulation step is updated based on the arc current and arc voltage of the current simulation step, and the fault simulation of the subsequent simulation steps is performed based on the updated arc state to obtain the simulation results of single-phase arc grounding fault.

[0158] In some embodiments, operating parameters include line-to-ground capacitance parameters;

[0159] When the computer program is executed by processor 30, processor 30 performs the following:

[0160] Determine the system's ground capacitance based on the line-to-ground capacitance parameters;

[0161] After a single-phase arc grounding fault occurs, the non-faulty phase that provides capacitive current to the fault point is determined based on the ground capacitance connection status of the faulty phase and the non-faulty phase, and the capacitive current flowing to the fault point is determined based on the ground capacitance corresponding to each non-faulty phase.

[0162] In some embodiments, when a computer program is executed by processor 30, processor 30 performs the following:

[0163] The resonant inductance corresponding to the current compensation state is determined based on the system's capacitance to ground, and the tuning inductance of the arc suppression coil is determined based on the resonant inductance and the preset detuning degree.

[0164] The arc suppression coil is equivalent to a series RL model consisting of iron loss equivalent resistance and tuning inductance, and the arc suppression coil current is used as the state variable.

[0165] Based on the neutral-to-ground voltage, arc suppression coil current, and tuning inductance from the previous simulation step, the state equations corresponding to the series RL model are discretely solved to obtain the arc suppression coil current in the current simulation step, and the arc suppression coil current is used as the compensation current.

[0166] In some embodiments, when a computer program is executed by processor 30, processor 30 performs the following:

[0167] Obtain the current difference between the capacitor current flowing to the fault point and the compensation current returning through the fault phase, and use the current difference to determine the arc current of the current simulation step;

[0168] Obtain the arc photoconductivity used to characterize the arc state in the previous simulation step, and determine the arc voltage in the current simulation step based on the arc current in the current simulation step and the arc photoconductivity in the previous simulation step.

[0169] In some embodiments, when a computer program is executed by processor 30, processor 30 performs the following:

[0170] The instantaneous power of the arc in the current simulation step is determined based on the arc current and arc voltage in the current simulation step.

[0171] Based on the instantaneous power of the arc, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved to obtain the arc photoconductivity of the current simulation step, and the corresponding arc resistance is determined based on the arc photoconductivity of the current simulation step.

[0172] The arc photoconductivity of the current simulation step is taken as the arc state of the current simulation step. The arc voltage is determined and the arc state is updated repeatedly according to the simulation step until the preset simulation stop condition is met. The simulation results of single-phase arc grounding fault are formed based on the arc current, arc voltage and arc resistance obtained from each simulation step.

[0173] In some embodiments, when a computer program is executed by processor 30, processor 30 performs the following:

[0174] Based on the relationship between the instantaneous power of the arc and the preset steady-state heat dissipation power, the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step is determined.

[0175] Based on the changing state, the arc photoconductivity of the previous simulation step is used as the base state. The Mayr state equation is solved discretely to obtain the arc photoconductivity of the current simulation step, and the arc photoconductivity is represented as the arc state of the current simulation step.

[0176] This embodiment determines the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters of the distribution network to be simulated. It then dynamically updates the tuning parameters of the arc suppression coil using the system-to-ground capacitance, allowing the compensation current of the arc suppression coil to adjust according to changes in the distribution network's operating state. Based on this, the actual arc current is determined using the current relationship between the fault point's capacitive current and the compensation current. The current arc voltage is then determined using the arc state from the previous simulation step, and the current arc state is further updated using the current arc current and arc voltage. This creates a dynamically connected solution process between the arc suppression coil compensation process and the changes in the arc conductivity state through continuous simulation steps. Therefore, this scheme avoids the compensation deviation caused by using fixed parameters for the arc suppression coil, which cannot respond to changes in the system-to-ground capacitance, thereby improving the realism and accuracy of single-phase arc grounding fault simulation in distribution networks.

[0177] This application provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements:

[0178] Obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters;

[0179] The tuning parameters of the arc suppression coil are dynamically updated based on the system's capacitance to ground, and the compensation current of the arc suppression coil is determined based on the updated tuning parameters.

[0180] The arc current of the current simulation step is determined based on the capacitor current and the compensation current, and the arc voltage of the current simulation step is determined based on the arc current and the arc state of the previous simulation step.

[0181] The arc state of the current simulation step is updated based on the arc current and arc voltage of the current simulation step, and the fault simulation of the subsequent simulation steps is performed based on the updated arc state to obtain the simulation results of single-phase arc grounding fault.

[0182] In some embodiments, operating parameters include line-to-ground capacitance parameters;

[0183] When a computer program is executed, it achieves the following:

[0184] Determine the system's ground capacitance based on the line-to-ground capacitance parameters;

[0185] After a single-phase arc grounding fault occurs, the non-faulty phase that provides capacitive current to the fault point is determined based on the ground capacitance connection status of the faulty phase and the non-faulty phase, and the capacitive current flowing to the fault point is determined based on the ground capacitance corresponding to each non-faulty phase.

[0186] In some embodiments, the computer program implements the following when executed:

[0187] The resonant inductance corresponding to the current compensation state is determined based on the system's capacitance to ground, and the tuning inductance of the arc suppression coil is determined based on the resonant inductance and the preset detuning degree.

[0188] The arc suppression coil is equivalent to a series RL model consisting of iron loss equivalent resistance and tuning inductance, and the arc suppression coil current is used as the state variable.

[0189] Based on the neutral-to-ground voltage, arc suppression coil current, and tuning inductance from the previous simulation step, the state equations corresponding to the series RL model are discretely solved to obtain the arc suppression coil current in the current simulation step, and the arc suppression coil current is used as the compensation current.

[0190] In some embodiments, the computer program implements the following when executed:

[0191] Obtain the current difference between the capacitor current flowing to the fault point and the compensation current returning through the fault phase, and use the current difference to determine the arc current of the current simulation step;

[0192] Obtain the arc photoconductivity used to characterize the arc state in the previous simulation step, and determine the arc voltage in the current simulation step based on the arc current in the current simulation step and the arc photoconductivity in the previous simulation step.

[0193] In some embodiments, the computer program implements the following when executed:

[0194] The instantaneous power of the arc in the current simulation step is determined based on the arc current and arc voltage in the current simulation step.

[0195] Based on the instantaneous power of the arc, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved to obtain the arc photoconductivity of the current simulation step, and the corresponding arc resistance is determined based on the arc photoconductivity of the current simulation step.

[0196] The arc photoconductivity of the current simulation step is taken as the arc state of the current simulation step. The arc voltage is determined and the arc state is updated repeatedly according to the simulation step until the preset simulation stop condition is met. The simulation results of single-phase arc grounding fault are formed based on the arc current, arc voltage and arc resistance obtained from each simulation step.

[0197] In some embodiments, the computer program implements the following when executed:

[0198] Based on the relationship between the instantaneous power of the arc and the preset steady-state heat dissipation power, the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step is determined.

[0199] Based on the changing state, the arc photoconductivity of the previous simulation step is used as the base state. The Mayr state equation is solved discretely to obtain the arc photoconductivity of the current simulation step, and the arc photoconductivity is represented as the arc state of the current simulation step.

[0200] This embodiment determines the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters of the distribution network to be simulated. It then dynamically updates the tuning parameters of the arc suppression coil using the system-to-ground capacitance, allowing the compensation current of the arc suppression coil to adjust according to changes in the distribution network's operating state. Based on this, the actual arc current is determined using the current relationship between the fault point's capacitive current and the compensation current. The current arc voltage is then determined using the arc state from the previous simulation step, and the current arc state is further updated using the current arc current and arc voltage. This creates a dynamically connected solution process between the arc suppression coil compensation process and the changes in the arc conductivity state through continuous simulation steps. Therefore, this scheme avoids the compensation deviation caused by using fixed parameters for the arc suppression coil, which cannot respond to changes in the system-to-ground capacitance, thereby improving the realism and accuracy of single-phase arc grounding fault simulation in distribution networks.

[0201] This application provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer performs the following:

[0202] Obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters;

[0203] The tuning parameters of the arc suppression coil are dynamically updated based on the system's capacitance to ground, and the compensation current of the arc suppression coil is determined based on the updated tuning parameters.

[0204] The arc current of the current simulation step is determined based on the capacitor current and the compensation current, and the arc voltage of the current simulation step is determined based on the arc current and the arc state of the previous simulation step.

[0205] The arc state of the current simulation step is updated based on the arc current and arc voltage of the current simulation step, and the fault simulation of the subsequent simulation steps is performed based on the updated arc state to obtain the simulation results of single-phase arc grounding fault.

[0206] In some embodiments, operating parameters include line-to-ground capacitance parameters;

[0207] When program instructions are executed by the computer, they cause the computer to perform:

[0208] Determine the system's ground capacitance based on the line-to-ground capacitance parameters;

[0209] After a single-phase arc grounding fault occurs, the non-faulty phase that provides capacitive current to the fault point is determined based on the ground capacitance connection status of the faulty phase and the non-faulty phase, and the capacitive current flowing to the fault point is determined based on the ground capacitance corresponding to each non-faulty phase.

[0210] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0211] The resonant inductance corresponding to the current compensation state is determined based on the system's capacitance to ground, and the tuning inductance of the arc suppression coil is determined based on the resonant inductance and the preset detuning degree.

[0212] The arc suppression coil is equivalent to a series RL model consisting of iron loss equivalent resistance and tuning inductance, and the arc suppression coil current is used as the state variable.

[0213] Based on the neutral-to-ground voltage, arc suppression coil current, and tuning inductance from the previous simulation step, the state equations corresponding to the series RL model are discretely solved to obtain the arc suppression coil current in the current simulation step, and the arc suppression coil current is used as the compensation current.

[0214] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0215] Obtain the current difference between the capacitor current flowing to the fault point and the compensation current returning through the fault phase, and use the current difference to determine the arc current of the current simulation step;

[0216] Obtain the arc photoconductivity used to characterize the arc state in the previous simulation step, and determine the arc voltage in the current simulation step based on the arc current in the current simulation step and the arc photoconductivity in the previous simulation step.

[0217] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0218] The instantaneous power of the arc in the current simulation step is determined based on the arc current and arc voltage in the current simulation step.

[0219] Based on the instantaneous power of the arc, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved to obtain the arc photoconductivity of the current simulation step, and the corresponding arc resistance is determined based on the arc photoconductivity of the current simulation step.

[0220] The arc photoconductivity of the current simulation step is taken as the arc state of the current simulation step. The arc voltage is determined and the arc state is updated repeatedly according to the simulation step until the preset simulation stop condition is met. The simulation results of single-phase arc grounding fault are formed based on the arc current, arc voltage and arc resistance obtained from each simulation step.

[0221] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0222] Based on the relationship between the instantaneous power of the arc and the preset steady-state heat dissipation power, the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step is determined.

[0223] Based on the changing state, the arc photoconductivity of the previous simulation step is used as the base state. The Mayr state equation is solved discretely to obtain the arc photoconductivity of the current simulation step, and the arc photoconductivity is represented as the arc state of the current simulation step.

[0224] This embodiment determines the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters of the distribution network to be simulated. It then dynamically updates the tuning parameters of the arc suppression coil using the system-to-ground capacitance, allowing the compensation current of the arc suppression coil to adjust according to changes in the distribution network's operating state. Based on this, the actual arc current is determined using the current relationship between the fault point's capacitive current and the compensation current. The current arc voltage is then determined using the arc state from the previous simulation step, and the current arc state is further updated using the current arc current and arc voltage. This creates a dynamically connected solution process between the arc suppression coil compensation process and the changes in the arc conductivity state through continuous simulation steps. Therefore, this scheme avoids the compensation deviation caused by using fixed parameters for the arc suppression coil, which cannot respond to changes in the system-to-ground capacitance, thereby improving the realism and accuracy of single-phase arc grounding fault simulation in distribution networks.

[0225] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, electronic devices, computer storage media, and computer program products described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0226] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0227] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0228] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0229] In the embodiments provided by this invention, it should be understood that the disclosed systems, electronic devices, computer storage media, computer program products, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0230] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0231] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0232] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for executing all or part of the steps of the methods described in the various embodiments of the present invention through a computer device (which may be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0233] 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.

Claims

1. A method for simulating faults in a power distribution network, characterized in that, The method includes: Obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters; The tuning parameters of the arc suppression coil are dynamically updated based on the system's capacitance to ground, and the compensation current of the arc suppression coil is determined based on the updated tuning parameters. The arc current of the current simulation step is determined based on the capacitor current and the compensation current, and the arc voltage of the current simulation step is determined based on the arc current and the arc state of the previous simulation step. The arc state of the current simulation step is updated based on the arc current and arc voltage of the current simulation step, and the fault simulation of the subsequent simulation steps is performed based on the updated arc state to obtain the simulation results of single-phase arc grounding fault.

2. The power distribution network fault simulation method according to claim 1, characterized in that, The operating parameters include the line-to-ground capacitance parameters; The determination of the system-to-ground capacitance and the capacitive current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters includes: The system's capacitance to ground is determined based on the line-to-ground capacitance parameters. After a single-phase arc grounding fault occurs, the non-faulty phase that provides capacitive current to the fault point is determined based on the ground capacitance connection status of the faulty phase and the non-faulty phase, and the capacitive current flowing to the fault point is determined based on the ground capacitance corresponding to each of the non-faulty phases.

3. The power distribution network fault simulation method according to claim 1, characterized in that, The step of dynamically updating the tuning parameters of the arc suppression coil based on the system's capacitance to ground, and determining the compensation current of the arc suppression coil based on the updated tuning parameters, includes: The resonant inductance corresponding to the current compensation state is determined based on the system's capacitance to ground, and the tuning inductance of the arc suppression coil is determined based on the resonant inductance and the preset detuning degree. The arc suppression coil is equivalent to a series RL model consisting of the iron loss equivalent resistance and the tuning inductor, and the arc suppression coil current is used as the state variable. Based on the neutral-to-ground voltage, arc suppression coil current, and tuning inductance from the previous simulation step, the state equations corresponding to the series RL model are discretely solved to obtain the arc suppression coil current for the current simulation step, and the arc suppression coil current is used as the compensation current.

4. The power distribution network fault simulation method according to claim 1, characterized in that, The step of determining the arc current of the current simulation step based on the capacitor current and the compensation current, and determining the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step, includes: Obtain the current difference between the capacitive current flowing to the fault point and the compensation current returning through the fault phase, and use the current difference to determine the arc current of the current simulation step; Obtain the arc photoconductivity used to characterize the arc state in the previous simulation step, and determine the arc voltage in the current simulation step based on the arc current in the current simulation step and the arc photoconductivity in the previous simulation step.

5. The power distribution network fault simulation method according to claim 4, characterized in that, The process involves updating the arc state of the current simulation step based on the arc current and arc voltage, and performing subsequent simulation steps based on the updated arc state to obtain the simulation results of a single-phase arc grounding fault, including: The instantaneous power of the arc in the current simulation step is determined based on the arc current and arc voltage in the current simulation step. Based on the instantaneous power of the arc, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step, the Mayr state equation used to describe the dynamic characteristics of the arc is discretely solved to obtain the arc photoconductivity of the current simulation step, and the corresponding arc resistance is determined based on the arc photoconductivity of the current simulation step. The arc photoconductivity of the current simulation step is taken as the arc state of the current simulation step. The determination of the arc voltage and the update of the arc state are repeated according to the simulation step until the preset simulation stop condition is met. The simulation result of the single-phase arc grounding fault is formed based on the arc current, arc voltage and arc resistance obtained from each simulation step.

6. The power distribution network fault simulation method according to claim 5, characterized in that, The step of discretizing and solving the Mayr state equation describing the dynamic characteristics of the arc light based on the instantaneous power of the arc light, the preset steady-state heat dissipation power, and the arc photoconductivity of the previous simulation step includes: Based on the relationship between the instantaneous arc power and the preset steady-state heat dissipation power, the change state of the arc photoconductivity in the current simulation step relative to the arc photoconductivity in the previous simulation step is determined. Based on the changing state, the Mayr state equation is discretely solved using the arc photoconductivity of the previous simulation step as the base state to obtain the arc photoconductivity of the current simulation step, and the arc photoconductivity is characterized as the arc state of the current simulation step.

7. A power distribution network fault simulation system, characterized in that, The system includes: The capacitor current determination module is used to obtain the operating parameters of the distribution network to be simulated, and determine the system ground capacitance and the capacitor current flowing to the fault point under a single-phase arc grounding fault based on the operating parameters. The compensation current determination module is used to dynamically update the tuning parameters of the arc suppression coil based on the system's capacitance to ground, and to determine the compensation current of the arc suppression coil based on the updated tuning parameters. The arc voltage determination module is used to determine the arc current of the current simulation step based on the capacitor current and the compensation current, and to determine the arc voltage of the current simulation step based on the arc current and the arc state of the previous simulation step. The simulation result generation module is used to update the arc state of the current simulation step based on the arc current and arc voltage of the current simulation step, and to perform fault simulation of subsequent simulation steps based on the updated arc state, so as to obtain the simulation result of single-phase arc grounding fault.

8. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the power distribution network fault simulation method as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it implements the steps of the power distribution network fault simulation method as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, wherein when the program instructions are executed by a computer, the computer performs the steps of the power distribution network fault simulation method as described in any one of claims 1-6.

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