Harmonic arc extinguishing performance simulation method of high-voltage circuit breaker and related device

Abstract

The present application relates to the technical field of harmonic current, especially to a harmonic arc extinguishing performance simulation method of high-voltage circuit breaker and related device. Wherein, the method comprises: obtaining product structure and structure parameters of high-voltage circuit breaker, and establishing a simulation model according to the product structure and structure parameters; obtaining fundamental wave environment parameters, inputting the fundamental wave environment parameters into the simulation model to obtain fundamental wave arc extinguishing performance data; obtaining harmonic environment parameters, inputting the harmonic environment parameters into the simulation model to obtain harmonic arc extinguishing performance data; calculating the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, judging whether the difference is less than a preset threshold, if yes, outputting the structure parameters of the current simulation model; if not, re-obtaining the structure parameters, updating the simulation model, the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data according to the re-obtained structure parameters, providing data support for improving the structure design of high-voltage circuit breaker in harmonic environment.

Description

Technical Field

[0001] This invention relates to the field of harmonic current technology, and in particular to a method and related apparatus for simulating the harmonic arc extinguishing performance of a high-voltage circuit breaker. Background Technology

[0002] With the gradual advancement of the construction of a new power system based on new energy sources, the proportion of new energy sources and power electronic equipment connected to the grid is increasing, and the problem of harmonics in the power system is becoming more and more obvious.

[0003] Harmonics refer to the components of a periodic non-sinusoidal alternating current that are integer multiples of the fundamental frequency (i.e., 50Hz), obtained by Fourier series decomposition. These are commonly referred to as higher harmonics. In power systems, the increasing number of nonlinear electrical devices (such as semiconductor rectifiers, inverters, frequency converters, electric traction locomotives, electric arc furnaces, induction furnaces or heaters, gas discharge lamps, various semiconductor voltage, phase, and frequency modulation devices, and various household appliances made with semiconductor components) introduces a growing number of harmonic components into the power system. The presence of harmonics leads to electric field distortion, increases eddy current losses, and affects the temperature rise and insulation characteristics of equipment.

[0004] High-voltage AC circuit breakers, as crucial equipment in power systems, function to control circuit connection or disconnection, and quickly isolate faulty sections to protect other parts. However, existing high-voltage circuit breaker structures are primarily designed based on the excitation of power frequency (50Hz) current, rarely considering the impact of different frequency harmonics superimposed on the power frequency fundamental wave on the performance of high-voltage AC circuit breakers. Therefore, it is necessary to conduct research on the basic performance of high-voltage AC circuit breakers under the influence of different frequency harmonics, providing data support for structural design to improve the adaptability of high-voltage circuit breakers in harmonic environments. Summary of the Invention

[0005] This invention provides a method and related apparatus for simulating the harmonic arc extinguishing performance of high-voltage circuit breakers, which can provide data support for structural design to improve the adaptability of high-voltage circuit breakers in harmonic environments.

[0006] This invention provides a method for simulating the harmonic arc extinguishing performance of a high-voltage circuit breaker, the method comprising:

[0007] Obtain the product structure and structural parameters of the high-voltage circuit breaker, and establish a simulation model based on the product structure and structural parameters;

[0008] Obtain the fundamental wave environment parameters and input the fundamental wave environment parameters into the simulation model to obtain the fundamental wave arc extinguishing performance data;

[0009] Obtain harmonic environment parameters, input the harmonic environment parameters into the simulation model, and obtain harmonic arc extinguishing performance data;

[0010] Calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than a preset threshold. If so, output the structural parameters of the current simulation model; otherwise, reacquire the structural parameters, and update the simulation model, the fundamental wave arc extinguishing performance data, and the harmonic arc extinguishing performance data based on the reacquired structural parameters.

[0011] Optionally, the structural parameters include the nozzle inner diameter, downstream opening angle, and the volume of the compressor chamber.

[0012] Optionally, the simulation model is a two-dimensional axisymmetric magnetohydrodynamic model. In the two-dimensional axisymmetric magnetohydrodynamic model, the contact area located below the moving contact is set as a transparent contact, and the pressure acquisition point is set in the nozzle area.

[0013] Optionally, the data types of the fundamental arc extinguishing performance data and harmonic arc extinguishing performance data include: the arc current change rate before and after zero crossing and the arc conductance before zero crossing.

[0014] Optionally, the method further includes:

[0015] Harmonic data are collected from the power system, and the harmonic environmental parameters are calculated based on the harmonic data.

[0016] Optionally, the harmonic environment parameters include harmonic current frequency and harmonic content.

[0017] Optionally, the harmonic current includes a 5th harmonic current or a 7th harmonic current; the harmonic content is 5%.

[0018] Another aspect of the present invention provides a simulation device for the harmonic arc extinguishing performance of a high-voltage circuit breaker, the device comprising:

[0019] The acquisition and creation module is used to acquire the product structure and structural parameters of the high-voltage circuit breaker, and to create a simulation model based on the product structure and structural parameters.

[0020] The first acquisition and input module is used to acquire fundamental wave environmental parameters, input the fundamental wave environmental parameters into the simulation model, and obtain fundamental wave arc extinguishing performance data;

[0021] The second acquisition and input module is used to acquire harmonic environment parameters, input the harmonic environment parameters into the simulation model, and obtain harmonic arc extinguishing performance data.

[0022] The output module is used to calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output; if not, the structural parameters are reacquired, and the simulation model, the fundamental wave arc extinguishing performance data, and the harmonic arc extinguishing performance data are updated according to the reacquired structural parameters.

[0023] Another aspect of the present invention provides an electronic device, the device comprising a processor and a memory:

[0024] The memory is used to store program code and transmit the program code to the processor;

[0025] The processor is used to execute the method described above according to the instructions in the program code.

[0026] In another aspect, the present invention provides a computer-readable storage medium for storing program code for performing the method as described above.

[0027] As can be seen from the above technical solutions, the present invention has the following advantages:

[0028] In the harmonic arc extinguishing performance simulation method of a high-voltage circuit breaker provided by the present invention, the product structure and structural parameters of the high-voltage circuit breaker are obtained, and a simulation model is established based on the product structure and structural parameters, thereby constructing a simulation model of the high-voltage circuit breaker structure that fits the actual situation and improving the reference value of the simulation data. By acquiring fundamental frequency environmental parameters and inputting them into the simulation model, fundamental frequency arc extinguishing performance data is obtained to provide feedback on the breaking performance of the high-voltage circuit breaker under fundamental frequency conditions, thus recreating the breaking process of the high-voltage circuit breaker under fundamental frequency conditions. Similarly, harmonic environmental parameters are acquired and input into the simulation model to obtain harmonic arc extinguishing performance data to provide feedback on the breaking performance of the high-voltage circuit breaker under harmonic conditions, thus recreating the breaking process of the high-voltage circuit breaker under harmonic conditions. Furthermore, by calculating the difference between the fundamental frequency arc extinguishing performance data and the harmonic arc extinguishing performance data, it is determined whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output; otherwise, the structural parameters are reacquired, and the simulation model, the fundamental frequency arc extinguishing performance data, and the harmonic arc extinguishing performance data are updated based on the reacquired structural parameters. This yields the structural parameters of the high-voltage circuit breaker most suitable for harmonic environments, providing data support for structural design that improves the adaptability of high-voltage circuit breakers in harmonic environments. Attached Figure Description

[0029] 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.

[0030] Figure 1 This is a flowchart illustrating a method for simulating the harmonic arc extinguishing performance of a high-voltage circuit breaker, as provided in Embodiment 1 of the present invention.

[0031] Figure 2 This is a flowchart illustrating a method for simulating the harmonic arc extinguishing performance of a high-voltage circuit breaker, as provided in Embodiment 2 of the present invention.

[0032] Figure 3 This is a schematic diagram of the simulation model structure provided in an embodiment of the present invention;

[0033] Figure 4 The arc current waveform diagram of the fifth harmonic provided in the embodiment of the present invention;

[0034] Figure 5 The arc current waveform diagram of the 7th harmonic provided in the embodiment of the present invention;

[0035] Figure 6 Bar graphs of arc conductivity under various harmonic conditions provided in embodiments of the present invention;

[0036] Figure 7 The diagram shows the internal temperature changes of a high-voltage circuit breaker under various harmonic conditions provided in the embodiments of the present invention; wherein, (a) is a temperature change diagram at 50Hz, (b) is a temperature change diagram at 250Hz, and (c) is a temperature change diagram at 350Hz.

[0037] Figure 8 The internal pressure variation curves of the high-voltage circuit breaker under various harmonic conditions are provided for embodiments of the present invention.

[0038] Figure 9 This is a schematic diagram of a simulation device for the harmonic arc extinguishing performance of a high-voltage circuit breaker, provided in Embodiment 3 of the present invention. Detailed Implementation

[0039] This invention provides a method and related apparatus for simulating the harmonic arc extinguishing performance of high-voltage circuit breakers, which can provide data support for structural design to improve the adaptability of high-voltage circuit breakers in harmonic environments.

[0040] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] High-voltage AC circuit breakers, as crucial equipment in power systems, are responsible for controlling the connection and disconnection of circuits, and quickly isolating faulty sections to protect other parts. Existing circuit breaker structures are primarily designed based on the excitation effect of power frequency (50Hz) current, without considering the impact of different frequency harmonics superimposed on the power frequency fundamental wave on circuit breaker performance. Compared to excitation only by the fundamental wave, the superposition of different frequency harmonics with the power frequency fundamental wave excitation increases the thermal energy of the arc gap during thermal breaking and the recovery voltage rise rate (RRRV) of the arc gap during electrical breaking. RRRV is directly proportional to di / dt. Current technology lacks effective research on the breaking performance of high-voltage circuit breakers under harmonic currents. This invention establishes a two-dimensional magnetohydrodynamic model of the physical structure of the mainstream 252kV SF6 gas circuit breaker (GCB). Based on this model, the arc combustion process under the influence of harmonic currents of different frequencies is simulated. The dynamic characteristics of the arc and the arc characteristics at the moment when the current finally crosses zero are analyzed from the dimensions of temperature, pressure and arc current, so that those skilled in the art can further carry out design improvements of high-voltage circuit breakers based on this invention.

[0042] Please see Figure 1 The present invention provides a simulation method for the harmonic arc extinguishing performance of a high-voltage circuit breaker, comprising:

[0043] 101. Obtain the product structure and structural parameters of the high-voltage circuit breaker, and establish a simulation model based on the product structure and structural parameters.

[0044] It should be noted that the high-voltage circuit breaker is a 252kV SF6 gas circuit breaker. A simulation model of the circuit breaker was established based on its actual product structure and structural parameters. In this embodiment, the simulation model was constructed based on half of the longitudinal section of the gas circuit breaker, and this simulation model represents the SF6 gas circuit breaker. The reason for adopting this approach is that the applicant fully considered the characteristics of the SF6 gas circuit breaker in the research. The arc-extinguishing chamber of the SF6 gas circuit breaker has axisymmetric characteristics. Ignoring the influence of irrelevant structures such as shielding reduces the workload of model building, improves simulation efficiency, and does not reduce the simulation effect or affect the validity of the simulation data.

[0045] After constructing the simulation model, the boundary conditions of the simulation model are set. The boundary conditions include the initial inflation pressure, initial temperature, and velocity of the solid contact point of the arc-extinguishing chamber. In this embodiment, they are specifically set as follows:

[0046] The initial inflation pressure inside the arc-extinguishing chamber was set to 0.6 MPa, and the outer edges of the chamber at both ends were designated as pressure outlets to maintain the environment within the arc-extinguishing chamber. The initial temperature of the model was 300 K, and the velocity at the solid contact point was set to 8.5 m / s.

[0047] In this embodiment, considering the effects of Joule heating, Lorentz force, and radiation, the short-circuit arc and flow field model of the gas circuit breaker is constructed using the Navier-Stokes equations for compressible fluids with energy source terms.

[0048] 102. Obtain the fundamental wave environmental parameters and input them into the simulation model to obtain the fundamental wave arc extinguishing performance data.

[0049] It should be noted that the fundamental frequency environmental parameters include the fundamental frequency current. In this embodiment, the root mean square value and frequency of the fundamental frequency current are set to 31.5kA and 50Hz, respectively.

[0050] In this embodiment, the fundamental current is input into the simulation model, and the simulation model is run to obtain the arc current change rate and arc conductivity of the gas circuit breaker when it breaks under the fundamental current.

[0051] 103. Obtain harmonic environment parameters and input them into the simulation model to obtain harmonic arc extinguishing performance data.

[0052] It should be noted that the harmonic environment parameters are used to recreate the actual harmonic environment faced by the gas circuit breaker. By inputting the harmonic environment parameters and running the simulation model, the arc current change rate and arc conductivity of the gas circuit breaker when breaking under harmonic current are obtained.

[0053] 104. Calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than the preset threshold. If yes, output the structural parameters of the current simulation model; if no, reacquire the structural parameters, and update the simulation model, fundamental wave arc extinguishing performance data, and harmonic arc extinguishing performance data based on the reacquired structural parameters.

[0054] In this embodiment, after obtaining the fundamental wave arc extinguishing performance data and harmonic arc extinguishing performance data, the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data is calculated. It is then determined whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output. At this point, the structural parameters are the optimal structural parameters and are most suitable for the current harmonic environment. If not, the structural parameters are re-acquired, and the simulation model is updated based on the re-acquired structural parameters. The fundamental wave environment parameters and harmonic environment parameters obtained in steps 102 and 103 are then re-input into the updated simulation model to obtain new fundamental wave arc extinguishing performance data and new harmonic arc extinguishing performance data. Then, the difference between the new fundamental wave arc extinguishing performance data and the new harmonic arc extinguishing performance data is calculated to obtain a new difference value. It is then determined whether the new difference value meets the preset threshold. If so, the corresponding structural parameters are output, thus obtaining the structural parameters most suitable for the current harmonic environment. If not, the structural parameters are updated continuously, and the above steps of calculating and judging the difference are repeated until the optimal structural parameters are output.

[0055] In this embodiment, a simulation method for the harmonic arc extinguishing performance of a high-voltage circuit breaker is provided. By obtaining the product structure and structural parameters of the high-voltage circuit breaker, and establishing a simulation model based on the product structure and structural parameters, a simulation model of the high-voltage circuit breaker structure that fits the actual situation is constructed, thereby improving the reference value of the simulation data. By acquiring fundamental frequency environmental parameters and inputting them into the simulation model, fundamental frequency arc extinguishing performance data is obtained to provide feedback on the breaking performance of high-voltage circuit breakers under fundamental frequency conditions, thus recreating the breaking process of high-voltage circuit breakers under fundamental frequency conditions. Similarly, by acquiring harmonic environmental parameters and inputting them into the simulation model, harmonic arc extinguishing performance data is obtained to provide feedback on the breaking performance of high-voltage circuit breakers under harmonic conditions, thus recreating the breaking process of high-voltage circuit breakers under harmonic conditions. Furthermore, by calculating the difference between the fundamental frequency arc extinguishing performance data and the harmonic arc extinguishing performance data, it is determined whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output; otherwise, the structural parameters are reacquired, and the simulation model, fundamental frequency arc extinguishing performance data, and harmonic arc extinguishing performance data are updated based on the reacquired structural parameters. This yields the structural parameters of the high-voltage circuit breaker most suitable for harmonic environments, providing data support for structural design that improves the adaptability of high-voltage circuit breakers in harmonic environments.

[0056] Please see Figure 2 Embodiment 2 of the present invention provides a method for simulating the harmonic arc extinguishing performance of a high-voltage circuit breaker, comprising:

[0057] 200. Collect harmonic data from the power system and calculate harmonic environmental parameters based on the data. Harmonic environmental parameters include harmonic current frequency and harmonic content.

[0058] It should be noted that before constructing the simulation model, harmonic data of each station in the power system were collected in advance. The harmonic data includes the frequency of harmonic current and the harmonic content rate. The proportion of each frequency current and the proportion of each harmonic content rate in the harmonic data were calculated, and the harmonic current frequency and harmonic content rate with the largest proportion were selected as harmonic environment parameters.

[0059] According to statistics, current harmonic monitoring data within the Southern Power Grid system shows that the highest frequency of harmonic currents can reach 13th order. The most prevalent harmonic current frequencies are the 5th and 7th harmonics, with the highest harmonic content accounting for 5%.

[0060] Therefore, in this embodiment, a harmonic environment is constructed with a 5th harmonic current and a harmonic content of 5%, and a 7th harmonic current and a harmonic content of 5%, respectively.

[0061] 201. Obtain the product structure and structural parameters of the high-voltage circuit breaker, and establish a simulation model based on the product structure and structural parameters.

[0062] In this embodiment, the structural parameters include the nozzle inner diameter, downstream angle, and volume of the compressor chamber of the high-voltage circuit breaker. The simulation model is a two-dimensional axisymmetric magnetohydrodynamic model. In the two-dimensional axisymmetric magnetohydrodynamic model, the contact region located below the moving contact is set as a transparent contact, and the pressure acquisition point is set in the nozzle region.

[0063] like Figure 3 As shown, the constructed two-dimensional axisymmetric magnetohydrodynamic model includes a pressure outlet 1, a solid contact 2, a nozzle region 3, a nozzle wall 4, a moving contact 5, a puffer cylinder 6, and a piston 7 at both ends of the high-voltage circuit breaker. Here, 9 represents the axis of symmetry. Since the moving contact causes arc axis displacement, to effectively apply the two-dimensional axisymmetric magnetohydrodynamic model, the area below the moving contact is designated as a "transparent contact 8". Point P1 (pressure acquisition point) is located in the nozzle region to record pressure changes during arc combustion. This ensures that the arc axis does not shift when operating the model under different harmonic conditions, allowing for a more accurate simulation of the conventional fundamental wave condition (i.e., no harmonics, ideal normal operating condition) and the condition where the fundamental wave is superimposed with harmonics of different frequencies (due to the actual nonlinear load connection causing the fundamental wave to superimpose harmonics).

[0064] 202. Obtain the fundamental wave environmental parameters and input them into the simulation model to obtain the fundamental wave arc extinguishing performance data.

[0065] It should be noted that the fundamental frequency environmental parameters include the fundamental frequency current. In this embodiment, the root mean square value and frequency of the fundamental frequency current are set to 31.5kA and 50Hz, respectively.

[0066] In this embodiment, the fundamental current is input into the simulation model, the simulation model is run, and the arc current change rate before and after zero crossing and the arc conductance before zero crossing are output. The arc conductance before zero crossing includes the arc conductance 200 ns before the current crosses zero and the arc conductance 500 ns before the current crosses zero.

[0067] 203. Obtain harmonic environment parameters and input them into the simulation model to obtain harmonic arc extinguishing performance data.

[0068] It should be noted that the fundamental frequency and higher harmonics can be represented by instantaneous non-sinusoidal current values, and the formula for the instantaneous non-sinusoidal current value is as follows:

[0069]

[0070] Where h is the harmonic number, n is the calculated harmonic number, and I mh Let be the current amplitude of the h-th harmonic;

[0071] Ψ ih The current phase angle at a specific time t; I h I is the instantaneous value of the h-th harmonic current; l This represents the instantaneous value of the fundamental current.

[0072] The individual harmonic distortion (IHD) and total harmonic distortion (THD) of a current can be expressed as:

[0073]

[0074]

[0075] The harmonic environment parameters include the harmonic current frequency and harmonic content. The harmonic current includes the 5th or 7th harmonic current; the harmonic content is 5%.

[0076] The fundamental current has a frequency of 50Hz, the 5th harmonic current is the 50Hz fundamental current with a 250Hz harmonic superimposed on it, and the 7th harmonic current is the 50Hz fundamental current with a 350Hz harmonic superimposed on it.

[0077] In this embodiment, the 5th harmonic current and 5% harmonic content, and the 7th harmonic current and 5% harmonic content are input into the simulation model, respectively. The simulation model is run, and the arc current change rate before and after zero crossing and the arc conductance before zero crossing are output. The arc conductance before zero crossing includes the arc conductance 200 ns before the current crosses zero and the arc conductance 500 ns before the current crosses zero.

[0078] like Figure 4 and Figure 5 As shown, the peak value of the power frequency current is 44.541 kA. The superimposed 5th harmonic increases the peak value of the arc current to 46.766 kA, while the superimposed 7th harmonic reduces the peak value of the arc current to 43.853 kA. Furthermore, the power frequency current crosses zero at 9.95 ms, but when affected by the 5th and 7th harmonics, the zero-crossing point is delayed to 9.958 ms and 9.961 ms, respectively.

[0079] The rate of change of arc current at the zero-crossing point is a crucial factor affecting arc extinction. Under a high rate of change, the arc energy in the arc-extinguishing chamber has no time to dissipate, and the temperature remains high. Therefore, the arc can easily reignite, hindering successful circuit breaker interruption. As shown in the figure, the di / dt value of the power frequency current is -13.99 A / µs. After the fifth harmonic is superimposed, di / dt becomes -17.49 A / µs, 25% higher than the fundamental current. After the seventh harmonic is superimposed, di / dt becomes -18.88 A / µs, 34.95% higher. Therefore, after harmonic superposition, the rate of change of arc current at the zero-crossing point increases, meaning that the harmonic environment easily hinders the circuit breaker's interruption.

[0080] On the other hand, this embodiment selects arc conductivity data to evaluate the breaking performance of the high-voltage circuit breaker when interrupting short-circuit current. The larger the arc conductivity value before zero crossing, the higher the probability of arc reignition. Specifically, the arc conductivity G200 at 200 ns before the current crosses zero and the arc conductivity G500 at 500 ns before the current crosses zero are selected. Figure 6 As shown, both G200 and G500 increase under the influence of harmonics. G200 is 1.25 times and 1.35 times the power frequency under the influence of the 5th and 7th harmonics, respectively. Therefore, it can be concluded that the presence of the 5th and 7th harmonics hinders the extinction of the electric arc to some extent.

[0081] 204. Calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than the preset threshold. If yes, output the structural parameters of the current simulation model; if no, reacquire the structural parameters, and update the simulation model, fundamental wave arc extinguishing performance data, and harmonic arc extinguishing performance data based on the reacquired structural parameters.

[0082] It should be noted that the preset threshold is 5%. When the difference is not less than 5, the corresponding structural parameters are output.

[0083] In this embodiment, after obtaining the fundamental wave arc extinguishing performance data and harmonic arc extinguishing performance data, the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data is calculated. It is then determined whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output. At this point, the structural parameters are the optimal structural parameters and are most suitable for the current harmonic environment. If not, the structural parameters are re-acquired, and the simulation model is updated based on the re-acquired structural parameters. The fundamental wave environment parameters and harmonic environment parameters obtained in steps 202 and 203 are then re-input into the updated simulation model to obtain new fundamental wave arc extinguishing performance data and new harmonic arc extinguishing performance data. Then, the difference between the new fundamental wave arc extinguishing performance data and the new harmonic arc extinguishing performance data is calculated to obtain a new difference value. It is then determined whether the new difference value meets a preset threshold. If so, the corresponding structural parameters are output, thus obtaining the structural parameters most suitable for the current harmonic environment. If not, the structural parameters are updated, and the above steps of calculating and judging the difference are repeated until the optimal structural parameters are output, providing data support for the structural design of high-voltage circuit breakers to improve their adaptability in harmonic environments.

[0084] In one specific embodiment, the preset threshold can be 1%.

[0085] It is understandable that the smaller the difference between the fundamental arc extinguishing performance data and the harmonic arc extinguishing performance data, the better. Therefore, in order to pursue better structural parameters, the preset settings can be made smaller, such as 1%. When the difference is less than 1%, the obtained structural parameters are better and more suitable for the current harmonic switching environment.

[0086] In a specific application example, when running the simulation model, in addition to obtaining the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, we also obtain the temperature distribution data and pressure distribution data of the arc extinguishing chamber.

[0087] It should be noted that the temperature distribution within the arc-extinguishing chamber directly reflects the dynamic changes in the arc morphology and, to a certain extent, the thermal ionization and conductivity of the SF6 gas circuit breaker. On the other hand, the pressure change at the nozzle reflects the blowing effect generated by the compression of the expansion cylinder during the high-voltage circuit breaker's breaking process. This blowing accelerates the energy dissipation of the arc and extinguishes it. Therefore, understanding the impact of harmonics on the temperature and pressure within the arc-extinguishing chamber of a high-voltage circuit breaker based on temperature and pressure distribution data allows us to understand the influence of harmonics on the breaking performance of the high-voltage circuit breaker.

[0088] Figure 7 This represents the temperature distribution at different harmonic frequencies. For example... Figure 7As shown, the arc combustion process under the influence of harmonics is similar to that under the fundamental current condition. With the injection of current energy, the arc undergoes the processes of initiation, intensification, peak intensity, and weakening. During arc combustion, the surrounding gas is heated, forming hot gas, which flows into the filling cylinder. As time progresses, the filling cylinder is compressed, the hot gas is blown out, and the temperature of the arc core decreases due to the increased pressure.

[0089] Under power frequency current, 5th harmonic, and 7th harmonic conditions, the highest temperatures in the arc-extinguishing chamber at the moment of current zero crossing were 11780K, 12315K, and 12744K, respectively. This demonstrates that harmonic content affects the dissipation of arc energy and leads to persistently high temperatures at the moment of current zero crossing.

[0090] Figure 8 The graph shows the pressure at point P1 changing over time, as shown below. Figure 8 As shown, the pressure change curves of the high-voltage circuit breaker under the influence of the 5th and 7th harmonics are relatively similar to those under the fundamental frequency. In the early stages, the main reason for the pressure increase is the gas expansion caused by arc heating. When hot gas flows into the pressure chamber through the nozzle, the air pressure at point P1 fluctuates. As time progresses, the filling cylinder is gradually compressed, forming a strong gas in the pressure chamber, which is then ejected from the nozzle. At this point, the pressure at point P1 rises above 1 MPa, and the gas in the pressure chamber begins to fluctuate violently. Finally, as the arc weakens, the pressure at point P1 stabilizes.

[0091] The temperature and pressure distributions within the arc-extinguishing chamber show that harmonics cause the temperature inside the chamber to rise when the current crosses zero. However, when the harmonic content in the current is low, the harmonics have little effect on the pressure inside the arc-extinguishing chamber.

[0092] As mentioned above, the addition of harmonic components alters the peak value, zero-crossing time, and rate of change of the arc current at the zero-crossing point, thus affecting the breaking performance of the high-voltage circuit breaker by influencing the arc energy input. Furthermore, due to the influence of harmonic components, the arc conductances G200 and G500 before the current crosses zero increase, raising the probability of arc reignition. Moreover, under the influence of 5% harmonic content, the temperature distribution within the arc-extinguishing chamber during arc combustion shows a similar trend, while the pressure changes are not significantly different. It is evident that harmonics affect many arc parameters during arc combustion. Compared to conditions with only power frequency fundamental wave excitation, harmonics increase the breaking difficulty of the high-voltage circuit breaker and affect the breaking success rate.

[0093] Therefore, the simulation method provided in this embodiment obtains the product structure and structural parameters of the high-voltage circuit breaker, and establishes a simulation model based on the product structure and structural parameters, thereby constructing a simulation model of the high-voltage circuit breaker structure that fits the actual situation and improving the reference value of the simulation data. By acquiring fundamental frequency environmental parameters and inputting them into the simulation model, fundamental frequency arc-extinguishing performance data is obtained to provide feedback on the breaking performance of high-voltage circuit breakers under fundamental frequency conditions, thus recreating the breaking process of high-voltage circuit breakers under fundamental frequency conditions. Similarly, by acquiring harmonic environmental parameters and inputting them into the simulation model, harmonic arc-extinguishing performance data is obtained to provide feedback on the breaking performance of high-voltage circuit breakers under harmonic conditions, thus recreating the breaking process of high-voltage circuit breakers under harmonic conditions. Furthermore, by calculating the difference between the fundamental frequency arc-extinguishing performance data and the harmonic arc-extinguishing performance data, it is determined whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output; otherwise, the structural parameters are reacquired, and the simulation model, fundamental frequency arc-extinguishing performance data, and harmonic arc-extinguishing performance data are updated based on the reacquired structural parameters. This yields the structural parameters of the high-voltage circuit breaker most suitable for harmonic environments, providing effective data support for structural design that improves the adaptability of high-voltage circuit breakers in harmonic environments.

[0094] Please see Figure 9 Embodiment 3 of the present invention provides a simulation device for the harmonic arc extinguishing performance of a high-voltage circuit breaker, comprising:

[0095] The acquisition and creation module 301 is used to acquire the product structure and structural parameters of the high-voltage circuit breaker, and to create a simulation model based on the product structure and structural parameters.

[0096] The first acquisition and input module 302 is used to acquire fundamental wave environmental parameters, input the fundamental wave environmental parameters into the simulation model, and obtain fundamental wave arc extinguishing performance data.

[0097] The second acquisition and input module 303 is used to acquire harmonic environment parameters, input the harmonic environment parameters into the simulation model, and obtain harmonic arc extinguishing performance data.

[0098] Output module 304 is used to calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than a preset threshold. If so, it outputs the structural parameters of the current simulation model; otherwise, it reacquires the structural parameters and updates the simulation model, fundamental wave arc extinguishing performance data, and harmonic arc extinguishing performance data based on the reacquired structural parameters.

[0099] In one specific embodiment, the present invention also provides an electronic device, the device including a processor and a memory:

[0100] The memory is used to store program code and transfer the program code to the processor;

[0101] The processor is used to execute the methods provided in the above embodiments according to the instructions in the program code.

[0102] In one specific embodiment, the present invention also provides a computer-readable storage medium for storing program code for performing the methods provided in the above embodiments.

[0103] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0104] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus 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, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0105] 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.

[0106] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each functional unit can be a separate physical entity, or two or more functional units can be integrated into one processing unit. The integrated unit described above can be implemented in hardware or as a software functional unit.

[0107] 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 to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0108] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application 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 this application described herein can be implemented, for example, 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.

[0109] 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 simulation method for the harmonic arc extinguishing performance of a high-voltage circuit breaker, characterized in that, The method includes: Obtain the product structure and structural parameters of the high-voltage circuit breaker, and establish a simulation model based on the product structure and structural parameters; Obtain fundamental wave environmental parameters and input them into the simulation model to obtain fundamental wave arc extinguishing performance data; the fundamental wave environmental parameters include the root mean square value and frequency of the fundamental wave current; Harmonic data from the power system are collected, and the proportion of each frequency current and the proportion of each harmonic content in the harmonic data are calculated. The harmonic current frequency and harmonic content with the largest proportion are selected as harmonic environment parameters. The harmonic environment parameters are input into the simulation model to obtain harmonic arc extinguishing performance data. The data types of the fundamental arc extinguishing performance data and the harmonic arc extinguishing performance data include: the arc current change rate before and after zero crossing and the arc conductance before zero crossing. Calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than a preset threshold. If so, output the structural parameters of the current simulation model; otherwise, reacquire the structural parameters, and update the simulation model, the fundamental wave arc extinguishing performance data, and the harmonic arc extinguishing performance data based on the reacquired structural parameters.

2. The method according to claim 1, characterized in that, The structural parameters include the nozzle inner diameter, downstream opening angle, and the volume of the compressor chamber.

3. The method according to claim 1, characterized in that, The simulation model is a two-dimensional axisymmetric magnetohydrodynamic model. In the two-dimensional axisymmetric magnetohydrodynamic model, the contact area located below the moving contact is set as a transparent contact, and the pressure acquisition point is set in the nozzle area.

4. The method according to claim 1, characterized in that, The harmonic current includes the 5th harmonic current or the 7th harmonic current; the harmonic content is 5%.

5. A simulation device for the harmonic arc extinguishing performance of a high-voltage circuit breaker, characterized in that, The device includes: The acquisition and creation module is used to acquire the product structure and structural parameters of the high-voltage circuit breaker, and to create a simulation model based on the product structure and structural parameters. The first acquisition and input module is used to acquire fundamental environmental parameters and input the fundamental environmental parameters into the simulation model to obtain fundamental arc extinguishing performance data; the fundamental environmental parameters include the root mean square value and frequency of the fundamental current; The second acquisition and input module is used to collect harmonic data in the power system, calculate the proportion of current of each frequency and the proportion of harmonic content in the harmonic data, and select the harmonic current frequency and harmonic content with the largest proportion as harmonic environment parameters. The harmonic environment parameters are input into the simulation model to obtain harmonic arc extinguishing performance data. The data types of the fundamental arc extinguishing performance data and the harmonic arc extinguishing performance data include: the arc current change rate before and after zero crossing and the arc conductance before zero crossing. The output module is used to calculate the difference between the fundamental wave arc extinguishing performance data and the harmonic arc extinguishing performance data, and determine whether the difference is less than a preset threshold. If so, the structural parameters of the current simulation model are output; if not, the structural parameters are reacquired, and the simulation model, the fundamental wave arc extinguishing performance data, and the harmonic arc extinguishing performance data are updated according to the reacquired structural parameters.

6. An electronic device, characterized in that, The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method as described in any one of claims 1-4 according to instructions in the program code.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for performing the method as described in any one of claims 1-4.

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