A method, system and storage medium for actively suppressing arcing in a dc power distribution

Abstract

The application relates to the technical field of direct-current power distribution, and discloses a direct-current power distribution active arc suppression method, a system and a storage medium. The method comprises the following steps: a direct-current main line output end is connected with a direct-current power distribution bus in the same polarity, and a plurality of direct-current branch lines are connected in parallel with the direct-current power distribution bus; a non-trip tripping type detection device detects the line working state on the direct-current main line output end, generates a line state value, and if the line state value is greater than a first line reference value, an output switch is closed, and a silicon controlled rectifier bidirectional switch is turned on; otherwise, the output switch is opened, and if the line state value is greater than a second line reference value, the silicon controlled rectifier bidirectional switch is controlled to be turned off, and after a continuous off time, the silicon controlled rectifier bidirectional switch is controlled to be turned on; an alternating-current power supply generates an alternating-current potential, and an auxiliary winding generates an alternating-current induced voltage; the alternating-current induced voltage generates a voltage zero point on the direct-current main line output end, and an arc fault on the direct-current power distribution main line and the plurality of direct-current branches is responded to and eliminated.

Description

Technical Field

[0001] This application relates to the technical field of DC power distribution, and in particular to a method, system and storage medium for actively suppressing electric arc in DC power distribution. Background Technology

[0002] In AC systems, open-circuit faults in low-voltage circuits generally do not produce sustained arcing; only short-circuit grounding faults can trigger high-energy sustained arcing. DC power distribution systems differ from AC systems; DC current does not have a natural zero-crossing point, and sustained arcing can occur in open-circuit locations or areas of poor contact. Because there are no overcurrent characteristics, circuit breakers cannot recognize this situation and will not trip. Prolonged arcing in this type of system can easily cause equipment damage, fires, and other safety accidents.

[0003] In the existing technology, arc fault protection devices have been put into use on the market. Their main function is to monitor the fault arc in the circuit in real time. These fault arcs include series arcs, parallel arcs, etc., and can quickly cut off the circuit before the arc energy accumulates to the point of causing a fire.

[0004] For DC distribution main lines with multiple DC branches, there is a need for a protection method that can eliminate common open-circuit arc faults without tripping, and can respond to arc faults on the DC distribution main line and multiple DC branches. Summary of the Invention

[0005] In order to respond to arc faults on the main DC power distribution line and multiple DC branches, this application provides a method, system and storage medium for active arc suppression in DC power distribution.

[0006] In a first aspect, this application provides a method for actively suppressing electric arc in DC power distribution, employing the following technical solution:

[0007] A method for actively suppressing electric arc in DC power distribution includes the following steps:

[0008] A permanent trip protection device and a non-trip detection device are provided between the DC main line input terminal and the DC main line output terminal. The permanent trip protection device has an operating time limit, and the non-trip detection device has a normally open output switch.

[0009] The output switch is connected to an AC power supply. The output switch, resonant capacitor module, and rotating permanent magnet transformer are connected in series on the live wire of the AC power supply. The rotating permanent magnet transformer includes a portal core with a circular opening at the opening and a permanent magnet rotor inside. The portal core has a primary winding and a secondary winding. The primary winding is connected to the neutral wire of the AC power supply through a thyristor bidirectional switch, and the secondary winding is connected in series on the negative terminal of the DC main line output.

[0010] The DC main line output terminal is connected to the DC distribution bus with the same polarity, and multiple DC branch lines are connected in parallel to the DC distribution bus. A non-tripping detection device detects the operating status of the line at the DC main line output terminal and generates a line status value. If the line status value is greater than a preset first line reference value, the output switch is closed, and the thyristor bidirectional switch is turned on. Otherwise, the output switch is opened. If the line status value is greater than a preset second line reference value, the thyristor bidirectional switch is turned off. After a preset off time, the thyristor bidirectional switch is turned on again. The first line reference value is greater than the second line reference value.

[0011] The AC power supply generates an AC electromotive force through the resonant capacitor module and the primary winding. The AC electromotive force is applied to the permanent magnet rotor to generate electromagnetic torque. The permanent magnet rotor rotates to assist magnetization, and the secondary winding generates an AC induced voltage.

[0012] The AC induced voltage generates a voltage zero-crossing point at the DC main line output terminal, which causes a current zero-crossing point at the DC main line output terminal, thus eliminating the electric arc.

[0013] By adopting the above technical solution, the non-tripping detection device measures the arc corresponding to the line operating state at the DC main output terminal. When an arc appears on a DC branch, the permanent tripping protection device will not trip immediately, but the output switch will close immediately. The AC power supply generates an AC induced voltage in the secondary winding through the oscillating capacitor module and the primary winding of the rotating permanent magnet transformer. This AC induction is superimposed in series with the DC main output terminal, generating a voltage zero-crossing point and a current zero-crossing point. By using a thyristor bidirectional switch, the AC induced voltage has a zero-crossing time period that lasts until the turn-off time, improving the arc extinguishing effect on the DC branch. This enables the arc to be extinguished and eliminates the arc fault, achieving arc fault clearing under the condition of uninterrupted DC power supply. It also responds to arc faults on the DC distribution main line and multiple DC branches.

[0014] Optionally, the method further includes the following steps:

[0015] Calculate the ratio of the line status value to the second line reference value;

[0016] The shutdown time is adjusted according to the positive correlation between the ratio of the second line and the value of the second line. The larger the ratio of the second line, the longer the shutdown time; the smaller the ratio of the second line, the shorter the shutdown time.

[0017] By adopting the above technical solution, calculating the second line ratio, and adjusting the turn-off time according to the positive correlation of the second line ratio, it can be adapted to different arc fault degrees and help eliminate arcs on DC branch lines.

[0018] Optionally, the method further includes the following steps:

[0019] Obtain the number of branches of the DC branch line;

[0020] The branch ratio is calculated based on the number of branches and the preset branch reference value;

[0021] The second line reference value is adjusted according to the inverse correlation of the branch ratio. The larger the branch ratio, the smaller the second line reference value, and vice versa.

[0022] By adopting the above technical solution, the reference value of the second line can be adjusted according to the inverse correlation of the branch ratio, which can adapt to circuits with different numbers of branches, optimize the response threshold, and help eliminate electric arcs on DC branch lines under different DC branch line numbers.

[0023] Optionally, the method further includes the following steps:

[0024] The number of turns in the primary winding is adjusted according to the inverse correlation of the branch ratio. The larger the branch ratio, the fewer the number of turns in the primary winding; the smaller the branch ratio, the more the number of turns in the primary winding.

[0025] Or / and, adjust the number of turns of the secondary winding according to the positive correlation of the branch ratio. The larger the branch ratio, the more turns the secondary winding has, and the smaller the branch ratio, the fewer turns the secondary winding has.

[0026] By adopting the above technical solution and adjusting the number of turns in the primary and secondary windings in conjunction with changes in the branch ratio, the turns ratio of the rotating permanent magnet transformer is adapted to the number of DC branch lines. When the number of turns in the primary winding decreases as the branch ratio increases, the primary current increases accordingly, enhancing the resonance effect with the resonant capacitor module and increasing the AC potential. When the number of turns in the secondary winding increases as the branch ratio increases, the secondary induced current increases accordingly, strengthening the AC induced voltage. The combined effect of these two factors in creating a zero-crossing point at the DC main line output can be applied to different numbers of DC branch lines, adapting to the current characteristics under different branch numbers.

[0027] Optionally, the method further includes the following steps:

[0028] Obtain the number of branches of the DC branch line;

[0029] Each DC branch line is connected to a switching line module, which is used to switch the secondary winding to the corresponding DC branch line.

[0030] When the line status value is greater than the first line reference value, within the action time limit, the secondary winding is switched to each DC branch line in sequence, and the switching time is continued for a preset time.

[0031] Where (switching time × number of branches) ≤ action time limit.

[0032] By adopting the above technical solution, the switching module sequentially switches the secondary winding to each DC branch line, and specifically handles the arc of each branch within the action time limit. Since the product of the switching time and the number of branches does not exceed the action time limit, it can be ensured that each branch has sufficient processing time, so that the arc of each branch is accurately eliminated within the corresponding switching period, avoiding arc residue. This sequential processing method fully covers all DC branch lines, which not only ensures the effective elimination of arc in each branch, but also does not trigger the permanent trip protection device, significantly improving the targeting and safety of arc handling in multi-branch scenarios.

[0033] Optionally, the method further includes the following steps:

[0034] The action time limit is adjusted according to the positive correlation with the number of branches. The more branches there are, the longer the action time limit is, and the fewer branches there are, the shorter the action time limit is.

[0035] The switching time is adjusted inversely based on the number of branches; the more branches, the shorter the switching time, and vice versa.

[0036] By adopting the above technical solution, the action time limit and switching time can be adjusted according to the number of branches to adapt to different branch scales: when there are many branches, extending the action time limit and shortening the switching time can cover all branches within a limited time; when there are few branches, shortening the action time limit and extending the switching time can help ensure that a single branch is fully processed without increasing the total arc suppression time.

[0037] Optionally, the method further includes the following steps:

[0038] The resonant capacitor module includes multiple capacitor units connected in parallel;

[0039] The capacitor unit consists of capacitors connected in series and a normally open control switch. When the control switch is closed, the corresponding capacitor unit is connected in parallel to the AC circuit where the resonant capacitor module is located.

[0040] By adopting the above technical solution, adjusting the number of capacitor units connected to the resonant capacitor module and changing the total capacitance of the resonant capacitor module, the resonance requirements under different operating conditions can be adapted. The capacitance change can precisely adjust the resonance effect with the primary winding, optimize the magnitude of the AC potential, and make the permanent magnet rotor rotation magnetization more suitable for the arc elimination requirements. In turn, the AC induced voltage generated by the secondary winding is more accurate, which is conducive to the formation of a current zero-crossing point at the DC main line output terminal.

[0041] Optionally, the method further includes the following steps:

[0042] Calculate the ratio of the line status value to the first line reference value;

[0043] The line demand value is calculated by weighted average of the first line ratio and the branch ratio;

[0044] The number of capacitor units connected in parallel is adjusted according to the positive correlation between the line demand value and the line demand value. The larger the line demand value, the more capacitor units are connected in parallel, and the smaller the line demand value, the fewer capacitor units are connected in parallel.

[0045] By adopting the above technical solution, the number of capacitor units connected in parallel can be adjusted by using the line demand value calculated by weighted average of the first line ratio and the branch ratio, so that the capacity of the resonant capacitor module can be accurately matched to the actual working conditions on the DC distribution line.

[0046] Secondly, this application provides a DC power distribution active arc suppression system, which adopts the following technical solution:

[0047] A DC power distribution active arc suppression system includes a processor, wherein the processor performs the steps of the DC power distribution active arc suppression method as described in any of the preceding claims.

[0048] Thirdly, this application provides a storage medium, which adopts the following technical solution:

[0049] A storage medium storing a program that, when executed by a processor, implements the steps of the DC power distribution active arc suppression method described in any one of the preceding claims.

[0050] In summary, this application includes at least one of the following beneficial technical effects: This DC power distribution active arc suppression method eliminates arcs by setting a permanent trip-type protection device and a non-trip-type detection device on the DC main line, combined with components such as a rotating permanent magnet transformer. The non-trip-type detection device monitors the line status. When an arc is detected, the output switch closes, allowing the AC power supply to operate through the resonant capacitor module and the primary winding of the rotating permanent magnet transformer. The secondary winding generates an AC induced voltage, forming a zero-crossing point of voltage and current at the DC main line output terminal to extinguish the arc, without triggering a permanent trip to ensure continuous power supply. Simultaneously, the ratio of the line status value to the reference value dynamically adjusts the turn-off time of the thyristor bidirectional switch, the number of turns in the primary and secondary windings, and the capacity of the resonant capacitor module to adapt to different arc intensities. For multi-branch scenarios, the action time limit and switching time are adjusted according to the number of branches. By switching line modules, arcs in each branch are processed sequentially, achieving precise and efficient suppression of arcs on the main line and multiple branches, balancing arc extinguishing effect and power supply safety. Attached Figure Description

[0051] Figure 1 This is a circuit diagram for active arc suppression in DC power distribution.

[0052] Figure 2 This is a structural schematic diagram of a portal core.

[0053] Reference numerals in the attached diagram: 1. DC main line input terminal; 2. DC main line output terminal; 3. Permanent trip type trip protection device; 4. Non-trip type detection device; 5. AC power supply; 6. Resonant capacitor module; 7. Rotating permanent magnet transformer; 8. Secondary winding; 9. Primary winding; 10. Portal core; 11. Circular open cross-section; 12. Permanent magnet rotor; 13. Thyristor bidirectional switch; 14. DC distribution bus; 15. DC branch line. Detailed Implementation

[0054] The embodiments of this application are described in detail below, and examples of the embodiments are shown in the accompanying drawings.

[0055] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] This application discloses a method for actively suppressing electric arc in DC power distribution, referring to... Figure 1 and Figure 2 It includes the following steps:

[0057] A permanent trip protection device 3 and a non-trip detection device 4 are installed between the DC main line input terminal 1 and the DC main line output terminal 2. The permanent trip protection device 3 has an operating time limit, and the non-trip detection device 4 has a normally open output switch. The permanent trip protection device 3 adopts an electromagnetic trip structure with a set operating time limit of 0.5s; it only triggers tripping when the arc fault continues for more than the operating time limit to avoid power outage due to false tripping. The non-trip detection device 4 has a built-in Hall current sensor and voltage sensor to collect line parameters in real time, and its internal integrated output switch is an electromagnetic normally open contact.

[0058] One end of the output switch is connected to the live wire of the AC power supply 5, and the other end is connected in series with the resonant capacitor module 6 and the primary winding 9 of the rotating permanent magnet transformer 7. The resonant capacitor module 6 can be composed of three 10μF / 400V polypropylene capacitors, and the connection status of each capacitor is independently controlled by a relay switch; the capacitor shown in the figure is for reference only. The portal core 10 of the rotating permanent magnet transformer 7 is made of laminated silicon steel sheets, with a circular cross-section diameter of 50mm at the opening. The internal permanent magnet rotor 12 is made of neodymium iron boron material, with two pairs of magnetic poles. The primary winding 9 (100 turns) and the secondary winding 8 (50 turns) are wound on the two columns of the portal core 10, respectively. The primary winding 9 is connected to the neutral wire of the AC power supply 5 through a thyristor bidirectional switch 13, and the secondary winding 8 is connected in series in the negative line of the DC main output terminal 2.

[0059] The DC main line output terminal 2 is connected to the DC distribution bus 14 with the same polarity. Multiple DC branch lines 15 are connected in parallel to the DC distribution bus 14 through circuit breakers. The ends of the branch lines are connected to DC loads such as servers and energy storage batteries. The non-tripping detection device 4 collects the current change rate di / dt and voltage fluctuation value ΔU at the DC main line output terminal 2 through sensors, and calculates the line status value. The line status value is a weighted sum of di / dt and ΔU. The preset first line reference value is 150% of the rated current change rate, and the preset second line reference value is 120% of the rated current change rate; the first reference value is always greater than the second reference value.

[0060] If the line status value is greater than the first line reference value, and a severe electric arc occurs, di / dt will suddenly increase, the output switch will immediately close, the thyristor bidirectional switch 13 will be turned on, and the AC auxiliary circuit will operate at full power.

[0061] When the line status value is less than or equal to the first line reference value, the output switch remains open; if the line status value is greater than the second line reference value, such as a slight electric arc, the thyristor bidirectional switch 13 will first disconnect for 20ms and then automatically turn on, thereby enhancing the arc extinguishing effect through a brief power outage.

[0062] After AC power supply 5 is connected, the resonant capacitor module 6 and the primary winding 9 form an LC resonant circuit, generating a 200Hz AC potential. This drives the permanent magnet rotor 12 to rotate at 3000 r / min, enhancing the core permeability through the rotating magnetic field. The secondary winding 8 induces a 50V AC voltage in the rotating magnetic field. This voltage, combined with the DC voltage at the DC main line output terminal 2, forms a periodic voltage zero-crossing point, occurring once every 10ms. When the voltage zero-crossing point occurs, the DC line current also crosses zero, and the arc extinguishes due to the loss of energy replenishment. The arc extinguishing response time is ≤10ms.

[0063] When the permanent magnet rotor 12 rotates, the peak value of the induced voltage in the secondary winding 8 is 15%-20% of the DC bus voltage, ensuring that the zero crossing point is formed without affecting the normal operation of the load.

[0064] The turn-off time of the triac bidirectional switch 13 can be dynamically adjusted by a microcontroller, with a minimum turn-off time of 5ms and a maximum turn-off time of 30ms, to meet the arc extinguishing requirements of different arc intensities.

[0065] The permanent trip protection device 3 has an operating time limit of 100ms, which allows sufficient time for non-trip devices to complete arc extinguishing and triggers protection only when arc extinguishing fails.

[0066] Between the DC mainline input terminal 1 and the output terminal, a permanent trip protection device 3 and a non-trip detection device 4 work together. The former has an operating time limit and will not easily trigger a trip, while the latter's built-in normally open output switch is the key valve for activating the arc extinguishing mechanism. When the output switch is closed, the AC power supply 5 forms a circuit through the resonant capacitor module 6 and the rotating permanent magnet transformer 7 connected in series on the live wire. The portal core 10 of the rotating permanent magnet transformer 7 provides a stable path for the magnetic circuit. The internal permanent magnet rotor 12 rotates under the action of AC potential to assist magnetization, making the electromagnetic induction of the primary winding 9 and the secondary winding 8 more efficient. The AC induced voltage generated by the secondary winding 8 is precisely connected in series to the negative terminal of the DC mainline output terminal 2.

[0067] The DC main line output terminal 2 is connected to the DC distribution bus 14, and numerous DC branch lines 15 are connected in parallel to it. Once an arc occurs in a branch, the non-tripping detection device 4 will quickly detect the change in the line status of the DC main line output terminal 2. If the line status value exceeds the first line reference value, the output switch immediately closes, the thyristor bidirectional switch 13 turns on, and the entire arc extinguishing circuit starts quickly. If the status value is between the second line reference value and the first line reference value, the output switch remains open, but the thyristor bidirectional switch 13 will first disconnect for a preset time before turning on, leaving sufficient zero-crossing window for arc extinguishing.

[0068] When the AC power supply 5, through the resonant capacitor module 6 and the primary winding 9, drives the permanent magnet rotor 12 to rotate, the AC induced voltage of the secondary winding 8 is superimposed on the DC voltage at the DC main line output terminal 2. This superposition cleverly creates a voltage zero-crossing point, which in turn guides the current to a zero-crossing point—and DC arcs are most vulnerable to current zero-crossing. Once this occurs, the arc loses its ability to persist and is completely eliminated without interrupting the power supply. The turn-off time of the thyristor bidirectional switch 13 can adapt to the arc intensity, ensuring that even stubborn arcs can be effectively extinguished. This allows for timely responses to arc faults in the main line and all branch lines, avoiding power outages and eliminating arc hazards.

[0069] The method also includes the following steps:

[0070] Calculate the second line ratio K2, which is the second line status value S and the second line reference value R2. K2 = S / R2; S unit: A; R2 unit: A.

[0071] The shutdown time is adjusted based on a positive correlation with the ratio of the second line; a larger ratio results in a longer shutdown time, and a smaller ratio results in a shorter shutdown time. The adjustment rules are as follows:

[0072] When 1 < K2 ≤ 1.2, there is a slight electric arc, the line status value is slightly higher than the second reference value, the turn-off time T is set to 5ms-10ms, and for every 0.1 increase in K2, T increases by 2ms;

[0073] When 1.2 < K2 ≤ 1.5, for a medium-intensity electric arc, the turn-off time T is set to 10ms-20ms, and for every 0.1 increase in K2, T increases by 3ms.

[0074] When 1.5 < K2 < 2.0, a high-intensity electric arc does not reach the first line reference value. The turn-off time T is set to 20ms-30ms, and for every 0.1 increase in K2, T increases by 5ms.

[0075] When K2≥2.0, it approaches a severe electric arc. The shutdown time T is fixed at 30ms, which does not exceed 1 / 3 of the operating time of the permanent trip protection device 3, so as to avoid triggering the trip.

[0076] This adjustment method precisely matches the shutdown time with the arc intensity: minor arcs can be extinguished without prolonged shutdown, reducing interference with normal power supply; high-intensity arcs are prevented from reigniting by extending the shutdown time to ensure that the current zero-crossing point lasts long enough.

[0077] Based on the above-mentioned shutdown time adjustment method, this embodiment further dynamically adjusts the reference value of the second line by the number of branches to adapt to power distribution scenarios with different branch scales. The specific method includes the following steps:

[0078] Obtain the number N of branches of DC branch line 15;

[0079] The branch ratio Kn is calculated based on the number of branches N and the preset branch reference value N0; the preset branch reference value N0 = 6 branches; Kn = N / N0.

[0080] The second line reference value is adjusted according to the inverse correlation of the branch ratio. The larger the branch ratio, the smaller the second line reference value, and vice versa.

[0081] The initial reference value R20 of the second line reference value R2 is preset to be 1.2 times the rated current In of the DC main line, that is, R20 = 1.2In, where In is the rated current of the DC main line input terminal 1. In this embodiment, In = 50A, so R20 = 60A. The detection device adjusts the actual second line reference value R2 according to the following inverse correlation rule based on the branch ratio Kn:

[0082] When Kn≤0.5 (few branches, such as N=2-3 paths), R2=R20×(1.5-1.0×Kn), and after adjustment, the range of R2 is 1.2-1.4×In;

[0083] When 0.5 < Kn < 1.5 (with a moderate number of branches, such as N = 4-8 paths), R2 = R20 × (1.2 - 0.4 × Kn), and after adjustment, the range of R2 is 0.6-1.0 × In;

[0084] When Kn≥1.5 (with a large number of branches, such as N=9-10 paths), R2=R20×(0.6-0.1×Kn), and after adjustment, the range of R2 is 0.4-0.5×In.

[0085] The adjusted R2 value is kept in integer place and must satisfy the following condition: the second line reference value R2 < the first line reference value R1 (R1 is preset to 1.5 × In = 75A).

[0086] By adjusting the second line reference value through the branch ratio, the adaptability of arc detection sensitivity under different numbers of branches is improved.

[0087] This embodiment, based on active arc suppression in DC power distribution, dynamically adjusts the number of turns in the primary winding 9 and secondary winding 8 of the rotating permanent magnet transformer 7 by adjusting the branch ratio, so that the electromagnetic induction parameters are precisely adapted to the changes in the number of DC branch lines 15. The specific method includes the following steps:

[0088] Primary winding 9: Wound with Φ0.71mm high-strength enameled copper wire, totaling 400 turns. Four taps are set along the winding axis, taps A to D, corresponding to 400 turns, 300 turns, 200 turns, and 100 turns respectively. The winding resistance difference between adjacent taps is ≤0.5Ω, the insulation class is F (temperature resistance 155℃), and the tap leads are connected to the regulating switch via aviation plugs.

[0089] Secondary winding 8: Wound with Φ1.0mm high-voltage resistant enameled copper wire, with a total of 200 turns. Four taps are set along the winding axis, taps a to d, corresponding to 50 turns, 100 turns, 150 turns, and 200 turns respectively. The insulation resistance between each tap is ≥100MΩ, and the dielectric strength is ≥2kV (no breakdown in 1 minute). The tap leads are fitted with colored marking sleeves (red, yellow, blue, and green) to distinguish the number of turns.

[0090] Adjustment actuator: Each winding is equipped with one set of electromagnetic tap changer switches, controlled by a microprocessor via a relay drive module. The switching response time is ≤30ms, the mechanical life is ≥100,000 cycles, and spark interference is suppressed during switching through an RC absorption circuit (100Ω resistor + 0.1μF capacitor).

[0091] The branch ratio Kn is calculated from the number of DC branch lines 15 N and the preset branch reference value N0 (N0 = 10 in this embodiment) (Kn = N / N0), and the value range is 0.4-2.0 (Kn = 0.4 when N ≤ 4; Kn = 2.0 when N ≥ 20). The calculation cycle is synchronized with the branch number detection (updated every 60 seconds).

[0092] The number of turns of the primary winding 9 is adjusted according to the inverse correlation of the branch ratio Kn. The larger the branch ratio, the fewer the number of turns of the primary winding 9; the smaller the branch ratio, the more the number of turns of the primary winding 9.

[0093] The number of 9 turns in the primary winding decreases as the branch ratio Kn increases. The specific correspondence is as follows:

[0094] When 0.4≤Kn<0.8 (N=4-7 channels): Connect tap A, number of turns=400 turns. At this time, the primary inductance L1=80mH, forming a 50Hz resonance with the resonant capacitor module 6 (total capacitance 10μF), and the primary current I1≈0.8A (AC 220V input).

[0095] When 0.8 ≤ Kn < 1.2 (N = 8-11 channels): Connect tap B, number of turns = 300 turns. Primary inductance L1 = 45mH, resonant frequency remains 50Hz, primary current I1 ≈ 1.1A, which is 37.5% higher than when there are 400 turns.

[0096] When 1.2 ≤ Kn < 1.6 (N = 12-15 channels): Connect tap C, number of turns = 200 turns. Primary inductance L1 = 20mH, resonant current I1 ≈ 1.6A, and the energy exchange efficiency with resonant capacitor module 6 is increased to 90%.

[0097] When 1.6≤Kn≤2.0 (N=16-20 channels): Connect tap D, number of turns = 100 turns. Primary inductance L1=5mH, primary current I1≈3.2A, AC potential amplitude is increased by 4 times compared with 400 turns, driving permanent magnet rotor 12 to rotate at a speed of 3000r / min.

[0098] or / and,

[0099] The number of turns in the secondary winding 8 is adjusted according to the positive correlation between the branch ratio Kn and the branch ratio. The larger the branch ratio, the more turns the secondary winding 8 has, and the smaller the branch ratio, the fewer turns the secondary winding 8 has.

[0100] The number of 8 turns in the secondary winding increases with the increase of the branch ratio Kn. The specific correspondence is as follows:

[0101] When 0.4≤Kn<0.8 (N=4-7 channels): Connect tap a, number of turns=50 turns. The secondary side induced voltage U2≈30V (RMS value), and the voltage zero-crossing width after superimposing with the DC main line is ≥1ms.

[0102] When 0.8≤Kn<1.2 (N=8-11 channels): Connect tap b, number of turns=100 turns. Secondary side induced voltage U2≈60V, zero-crossing width≥2ms, meeting the arc extinguishing requirements of medium current (50-100A).

[0103] When 1.2≤Kn<1.6 (N=12-15 channels): Connect tap c, number of turns=150 turns. Secondary side induced voltage U2≈90V, zero-crossing duration extended to 3ms, adapting to the current characteristics of multiple branches supplying power simultaneously (total current 100-150A).

[0104] When 1.6≤Kn≤2.0 (N=16-20 channels): Connect tap d, number of turns=200 turns. Secondary side induced voltage U2≈120V, zero-crossing width≥4ms, can quickly form current zero crossing when the total current is 150-200A.

[0105] By adjusting the number of winding turns through the branch ratio, the electromagnetic induction parameters of the rotating permanent magnet transformer 7 can be dynamically adapted to changes in the number of branches, ensuring efficient generation of current zero-crossing points under different scenarios and improving the adaptability of arc suppression.

[0106] This embodiment, based on the active arc suppression method for DC power distribution, achieves precise switching between the secondary winding 8 and each DC branch line 15 by switching line modules, thereby eliminating arcs one by one in multi-branch scenarios. The specific method also includes the following steps:

[0107] The number of branches N of DC branch line 15 is obtained; the non-tripping detection device 4 injects a low-frequency detection signal into the distribution bus, receives the response signal of each branch module, and then counts the number of branches N of DC branch line 15.

[0108] Each DC branch line 15 is connected to a switching line module, which is used to switch the secondary winding 8 to the corresponding DC branch line 15. The core of the switching line module is a magnetic latching relay, which normally keeps the DC branch line 15 connected to the main circuit of the distribution bus. When a switching command is received, it can connect the secondary winding 8 of the rotating permanent magnet transformer 7 to the corresponding branch line. The module communicates with the non-tripping detection device 4 via a 485 bus to provide real-time feedback on the branch line current status and the relay operating position.

[0109] When the line status value S is greater than the first line reference value R1, within the action time limit, the secondary winding 8 is sequentially switched to each DC branch line 15, and the switching time is continued for a preset time; wherein, (switching time × number of branches) ≤ action time limit. According to the action time limit of the permanent trip type trip protection device 3 (fixed at 0.5 seconds = 500ms), the preset single-path switching time t = (500ms × 0.9) / N (coefficient 0.9 reserves 10% redundancy time), ensuring that the product of the switching time and the number of branches ≤ 500ms.

[0110] When the line status value is greater than the first line reference value, such as when the main line rated current is 100A and the reference value is set to 150A, the detection device immediately initiates the switching process:

[0111] Preparation phase (30ms): All modules enter standby mode, and relays are pre-energized;

[0112] Sequential switching: According to the branch address order, the first branch is connected to the secondary winding 8 at 30ms and disconnected after 90ms; the second branch is connected at 120ms, and so on, to ensure that each branch can obtain an independent arc extinguishing time;

[0113] During the switching process, the AC induced voltage (60-100V) of the secondary winding 8 is superimposed with the DC voltage of the branch, forming a current zero-crossing point. If the arc is extinguished within the switching time, the current recovers to ±5% of the rated value, and the switching of this circuit can be ended 20ms earlier, and the saved time can be allocated to subsequent branches.

[0114] In the final stage, 500ms after the last switch is completed: the module is reset to the main circuit conduction state, and the device records the arc extinguishing results of each branch.

[0115] By implementing orderly switching and time control, targeted handling of multi-branch arcs is achieved without triggering tripping. Compared with the traditional parallel processing method (which is prone to incomplete arc extinguishing due to energy dispersion), this improves the arc extinguishing success rate and shortens the average arc extinguishing time of a single branch.

[0116] In this embodiment, the operating time of the permanent trip type trip protection device 3 is positively correlated with the number of DC branch lines 15, while the single-channel switching time of the switching line module is negatively correlated with the number of branches. The specific method also includes the following steps:

[0117] The action timeout is adjusted in a positive correlation with the number of branches N. More branches result in a longer action timeout, and fewer branches result in a shorter action timeout. The initial baseline value for the action timeout is set at 1000ms, corresponding to N = 8 branches. The adjustment rule is as follows: for every 2 additional branches, the action timeout increases by 200ms; for every 2 fewer branches, the action timeout decreases by 100ms, and the final timeout must not be lower than 500ms (lower limit). Specific calculation formula:

[0118] When N≥8 channels, the action time T=1000ms+(N-8) / 2×200ms;

[0119] When N < 8 channels, the action time limit T = 1000ms - (8-N) / 2 × 100ms; if the calculated result < 500ms, it will be automatically taken as 500ms.

[0120] The switching time is adjusted inversely based on the number of branches N. More branches result in a shorter switching time, while more branches result in a longer switching time. The baseline parameter for switching time is set as follows: when the number of branches N = 8, the baseline switching time per branch is 120ms. The adjustment rule is: for every 2 additional branches, the switching time decreases by 15ms; for every 2 fewer branches, the switching time increases by 20ms. The upper limit of the switching time is 200ms (to avoid excessive time per branch) and the lower limit is 50ms (to ensure sufficient processing). Specific calculation formula:

[0121] When N≥8 channels, the switching time t=120ms-(N-8) / 2×15ms;

[0122] When N < 8 channels, the switching time t = 120ms + (8-N) / 2 × 20ms; if the calculation result > 200ms, it will be automatically taken as 200ms.

[0123] In this embodiment, the resonant capacitor module 6 adopts a modular design to achieve dynamic adjustment of the total capacitance. Its structure and adjustment logic are as follows:

[0124] The resonant capacitor module 6 adopts a multi-unit parallel structure, consisting of four capacitor units of the same specifications. Each unit includes one polypropylene film capacitor and one normally open electromagnetic control switch, which are connected in series and then in parallel with other units to connect to the AC circuit. The drive signal for the control switch is provided by the IO port of the non-tripping detection device 4, and the level is converted through an optocoupler isolation circuit (TLP281) to ensure that the control signal is electrically isolated from the main circuit.

[0125] The total capacitance of the module is adjusted by the number of connected capacitor units: when the detection device determines that the resonance effect needs to be enhanced (e.g., branch ratio Kn > 1.5), 2-4 switches are closed, and the total capacitance increases to 20-40μF, forming a strong resonance with the primary winding 9 and increasing the AC potential amplitude; when the resonance needs to be weakened (e.g., Kn < 0.8), only 1 switch is closed, and the total capacitance is kept at 10μF to avoid excessive resonance leading to current overload.

[0126] In actual operation, the device dynamically adjusts the number of access units based on real-time calculated line status values ​​and branch ratios.

[0127] When a slight electric arc occurs (K2 = 1.1), two units (total capacity 20μF) are connected, the resonant frequency stabilizes at 50Hz, and the primary current increases by 30%.

[0128] In the event of a severe electric arc (K2 = 1.8), four units (total capacity 40μF) are connected, the resonant current is increased to twice the reference value, the speed of the permanent magnet rotor 12 is increased to 3000r / min, and the secondary side induced voltage is increased by 50%, ensuring the rapid formation of the current zero crossing point.

[0129] The resonant capacitor module 6 can flexibly adjust the total capacity according to the actual working conditions, so that the resonance effect of the primary winding 9 is precisely matched with the arc extinguishing requirements, providing reliable capacitor parameter support for the stable formation of the current zero crossing point under different scenarios.

[0130] In this embodiment, the number of capacitor units in the resonant capacitor module 6 connected in parallel is dynamically adjusted according to the line demand value to achieve precise matching between the capacitor capacity and the actual operating conditions. The specific method also includes the following steps:

[0131] Calculate the line status value S and the first line reference value R1, resulting in the first line ratio K1; the branch ratio Kn = number of branches N / preset branch reference value N0, where N0 = 8 branches. The line demand value D is calculated using a weighted average formula: D = 0.6 × K1 + 0.4 × Kn (K1 has a weight of 60%, reflecting arc intensity; Kn has a weight of 40%, reflecting branch scale), with a value range of 0.5 to 3.0.

[0132] The number of capacitor units connected in parallel, M (1≤M≤5), is positively correlated with the line demand value, D. The corresponding relationship is as follows:

[0133] When 0.5 ≤ D < 1.0, M = 1 (total capacity 8 μF);

[0134] When 1.0 ≤ D < 1.5, M = 2 (total capacity 16 μF);

[0135] When 1.5 ≤ D < 2.0, M = 3 (total capacity 24 μF);

[0136] When 2.0 ≤ D < 2.5, M = 4 (total capacity 32 μF);

[0137] When 2.5 ≤ D ≤ 3.0, M = 5 (total capacity 40 μF);

[0138] During adjustment, the non-tripping detection device 4 updates the D value every 10ms and switches the capacitor unit through the solid-state relay drive circuit, with a switching response time of ≤15ms.

[0139] This application also discloses a DC power distribution active arc suppression system, including a processor, wherein the processor performs the steps of the DC power distribution active arc suppression method as described in any of the above embodiments.

[0140] This application also discloses a storage medium storing a program, which, when executed by a processor, implements the steps of the DC power distribution active arc suppression method described in any of the above embodiments.

[0141] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for actively suppressing electric arc in DC power distribution, characterized in that, Includes the following steps: A permanent trip protection device (3) and a non-trip detection device (4) are provided between the DC main line input terminal (1) and the DC main line output terminal (2). The permanent trip protection device (3) has an operating time limit, and the non-trip detection device (4) is provided with a normally open output switch. The output switch is connected to an AC power supply (5). The output switch, resonant capacitor module (6) and rotating permanent magnet transformer (7) are connected in series on the live wire of the AC power supply (5). The rotating permanent magnet transformer (7) includes a portal core (10). The portal core (10) has a circular opening section (11) at its opening and a permanent magnet rotor (12) inside. The portal core (10) has a primary winding (9) and a secondary winding (8). The primary winding (9) is electrically connected to the neutral wire of the AC power supply (5) through a thyristor bidirectional switch (13). The secondary winding (8) is connected in series on the negative terminal of the DC main line output terminal (2). The DC main line output terminal (2) is connected to the DC distribution bus (14) with the same polarity, and multiple DC branch lines (15) are connected in parallel to the DC distribution bus (14); the non-tripping detection device (4) detects the line working status on the DC main line output terminal (2) and generates a line status value. If the line status value is greater than the preset first line reference value, the output switch is closed and the thyristor bidirectional switch (13) is turned on. Otherwise, turn on the output switch. If the line status value is greater than the preset second line reference value, then control the thyristor bidirectional switch (13) to open. After a preset off time, control the thyristor bidirectional switch (13) to turn on. The first line reference value is greater than the second line reference value. The AC power supply (5) generates an AC potential through the resonant capacitor module (6) and the primary winding (9). The AC potential is applied to the permanent magnet rotor (12) to generate electromagnetic torque. The permanent magnet rotor (12) rotates to assist magnetization, and the secondary winding (8) generates an AC induced voltage. The AC induced voltage generates a voltage zero-crossing point at the DC main line output terminal (2), which causes a current zero-crossing point to appear at the DC main line output terminal (2) and eliminates the electric arc.

2. The method for actively suppressing electric arc in DC power distribution according to claim 1, characterized in that, The method also includes the following steps: Calculate the ratio of the line status value to the second line reference value; The shutdown time is adjusted according to the positive correlation between the ratio of the second line and the value of the second line. The larger the ratio of the second line, the longer the shutdown time; the smaller the ratio of the second line, the shorter the shutdown time.

3. The method for actively suppressing electric arc in DC power distribution according to claim 1, characterized in that, The method also includes the following steps: Obtain the number of branches of the DC branch line (15); The branch ratio is calculated based on the number of branches and the preset branch reference value; The second line reference value is adjusted according to the inverse correlation of the branch ratio. The larger the branch ratio, the smaller the second line reference value, and vice versa.

4. The method for actively suppressing electric arc in DC power distribution according to claim 3, characterized in that, The method also includes the following steps: The number of turns of the primary winding (9) is adjusted according to the inverse correlation of the branch ratio. The larger the branch ratio, the fewer the number of turns of the primary winding (9), and the smaller the branch ratio, the more the number of turns of the primary winding (9). Or / and, adjust the number of turns of the secondary winding (8) according to the positive correlation of the branch ratio. The larger the branch ratio, the more turns the secondary winding (8) has, and the smaller the branch ratio, the fewer turns the secondary winding (8) has.

5. The method for actively suppressing electric arc in DC power distribution according to claim 1, characterized in that, The method also includes the following steps: Obtain the number of branches of the DC branch line (15); Each DC branch line (15) is connected to a switching line module, which is used to switch the secondary winding (8) to the corresponding DC branch line (15); When the line status value is greater than the first line reference value, within the action time limit, the secondary winding (8) is switched into each DC branch line (15) in sequence, and the switching time is continued for a preset time. Where (switching time × number of branches) ≤ action time limit.

6. The method for actively suppressing electric arc in DC power distribution according to claim 5, characterized in that, The method also includes the following steps: The action time limit is adjusted according to the positive correlation with the number of branches. The more branches there are, the longer the action time limit is, and the fewer branches there are, the shorter the action time limit is. The switching time is adjusted inversely based on the number of branches; the more branches, the shorter the switching time, and the fewer branches, the longer the switching time.

7. The method for actively suppressing electric arc in DC power distribution according to claim 1, characterized in that, The method also includes the following steps: The resonant capacitor module (6) includes multiple capacitor units connected in parallel; The capacitor unit includes a series capacitor and a normally open control switch. After the control switch is closed, the corresponding capacitor unit is connected in parallel to the AC circuit where the resonant capacitor module (6) is located.

8. The method for actively suppressing electric arc in DC power distribution according to claim 7, characterized in that, The method also includes the following steps: Calculate the ratio of the line status value to the first line reference value; The line demand value is calculated by weighted average of the first line ratio and the branch ratio; The number of capacitor units connected in parallel is adjusted according to the positive correlation between the line demand value and the line demand value. The larger the line demand value, the more capacitor units are connected in parallel, and the smaller the line demand value, the fewer capacitor units are connected in parallel.

9. A DC power distribution active arc suppression system, characterized in that, Includes a processor, wherein the steps of the DC power distribution active arc suppression method as described in any one of claims 1-8 are executed.

10. A storage medium, characterized in that, The storage medium stores a program that, when executed by a processor, implements the steps of the DC power distribution active arc suppression method according to any one of claims 1-8.

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