CN212210481U - Distribution network initiative intervention type arc extinction device - Google Patents

Abstract

The utility model discloses a distribution network initiative is arc extinction device futilely in advance, including leading circuit breaker, current transformer, electrified display, overvoltage protector, low impedance current limiter, split-phase earthing switch, voltage transformer, zero sequence current transformer and intelligent control ware, intelligent control ware includes arc extinction controller and route selection unit, and voltage transformer primary part is established ties in the return circuit and directly inserts the ground net at current transformer rear end generating line, and the secondary part links to each other with the arc extinction controller, and zero sequence current transformer primary part passes through low impedance current limiter rear end, connects single-phase ground connection rear end generating line, inserts the ground net after ground cable penetrates, and the secondary part is connected to the current terminal of arc extinction controller through the wiring. The utility model discloses the alternate short circuit that causes electricity, equipment inside ground connection and earth fault and the condition such as overvoltage play the guard action to the person.

Description

Distribution network initiative intervention type arc extinction device

Technical Field

The utility model relates to an electric power system technical field, concretely relates to type arc extinguishing device is intervened to distribution network initiative.

Background

The power distribution network plays a role in directly supplying power to users in the power system, and the safety and reliability of power supply of the power distribution network have a crucial influence on the users. According to statistics, most of power failure accidents suffered by power consumers are caused by single-phase earth faults of the power distribution network, and most of electric shock injuries suffered by people and livestock also occur in the power distribution network. In recent years, with the development of national economy, the power load is greatly increased, and the requirements on the safety and reliability of power supply of power grid dispatching personnel and users are higher and higher.

The existing neutral point ungrounded mode and the neutral point arc suppression coil grounding mode have certain defects, which are specifically shown in the following aspects:

1. if single-phase earth faults occur due to electric shock of people and animals, the lines cannot be rapidly powered off, people and animals cannot be effectively protected, and the electric shock time is prolonged, so that serious injury accidents are caused.

2. The neutral point ungrounded system has no arc quenching measures, the neutral point can only compensate the power frequency reactive component in the grounding current through the arc suppression coil in the arc suppression coil grounding system, the power frequency active component and the high frequency component in the grounding current cannot be compensated, and the arc quenching effect is limited. Once an arc is generated, an arc overvoltage is caused, and a power grid cascading failure is caused. Meanwhile, the electric arc can cause accidents such as fire and the like, and great loss is caused to a power grid and users.

3. At present, as the length of an overhead line is increased and a cable line is increased, the system capacitance current is increased, and when the capacitance current is increased to a certain degree, the manufacture of an arc suppression coil is very difficult and the cost is too high. In order to solve the problem, the grounding mode of a neutral point of a partial distribution network in China is changed into grounding through a small resistor, so that the advantage of high power supply reliability of a neutral point non-effective grounding mode is sacrificed.

4. At present, the problems of single-phase earth fault line selection and fault location of a power distribution network are not well solved, fault line selection is carried out on a plurality of substations through a manual line pulling method, fault location is carried out through a manual line patrol method, power failure time is prolonged, risks of operation with faults are increased, and power supply reliability is also reduced.

In summary, the currently adopted neutral point non-effective grounding mode for the distribution network in China has advantages, but has certain defects. The intelligent power distribution network is an important component of the intelligent power distribution network, in order to improve the power supply safety, reliability and economy of the power distribution network, a brand-new grounding mode needs to be established, a comprehensive complete system integrating monitoring, protection and control is formed, and all the problems are thoroughly solved on the premise that the advantages of a neutral point non-effective grounding mode are not changed.

Disclosure of Invention

The utility model aims to solve the technical problem that a distribution network initiative intervention type arc extinguishing device is provided to solve the problem of proposing among the above-mentioned background art.

The utility model discloses a realize through following technical scheme: an active intervention type arc extinction device for a power distribution network comprises a front-mounted circuit breaker, a current transformer, a live display, an overvoltage protector, a low-impedance current limiter, a split-phase grounding switch, a voltage transformer, a zero-sequence current transformer and an intelligent controller, the intelligent controller comprises an arc extinction controller and a line selection unit, a primary part of the current transformer is connected in series in a bus loop after passing through a front-mounted circuit breaker, a secondary part of the current transformer is connected with an overvoltage protector of the device, and the current transformer is connected with the live display, the primary part of the voltage transformer is connected in series to a loop at a bus at the rear end of the current transformer and is directly connected to the grounding grid, the secondary part of the voltage transformer is connected with the arc extinction controller, the primary part of the zero sequence current transformer is connected with a bus at the rear end of the single-phase grounding through a low-impedance current limiter and is connected to the grounding grid after penetrating through a grounding cable, and the secondary part of the voltage transformer is connected to a current terminal of the arc extinction controller through a wiring.

As a preferred technical scheme, the intelligent controller is installed in a device control screen, the arc extinction controller mainly comprises a microprocessor plug board, a display board, a switch driving plug board, a switch energy storage plug board, a voltage and current sampling plug board and a power supply output plug board, a high-speed dual-core microprocessor DSP chip is adopted, and the high-speed repeated data processing capacity of the DSP is utilized to realize Fourier analysis.

As a preferred technical scheme, the line selection unit is mainly composed of a bus monitoring plug board, a voltage and current sampling plug board, an industrial control plug board and a power supply output plug board, a high-speed dual-core microprocessor DSP chip is adopted, and the high-speed repeated data processing capacity of the DSP is utilized to realize Fourier analysis.

As the preferred technical scheme, one end of an LZA switch, an LZB switch and an LAC switch in the split-phase grounding switch is connected with a bus of a transformer substation, and the other end of the split-phase grounding switch is connected with a grounding cable and a ground grid through a low-impedance current limiter.

The utility model has the advantages that:

1. single-phase earth fault arc extinction technology: by the arc extinguishing method of the ground transfer, a ground transfer loop is directly connected with a grounding grid of a substation, the loop resistance is very small, after the device acts, the ground fault is forced to have the same potential (the residual voltage is very low) with respect to the ground voltage, and the device cannot provide enough energy support for the ground fault arc, so that the arc is extinguished. Compared with an arc suppression coil, the device can completely extinguish the earth fault electric arc, reduce the probability of phase-to-phase fault caused by the earth fault electric arc and improve the reliability of power supply;

2. the line selection technology comprises the following steps: the device adopts a plurality of algorithm weight ratio strategies, particularly the capacitance and current changes of the fault line before and after the device acts are most obvious as the basis, and the fault line is accurately selected;

3. human body inductive protection technology: the protection of the human body electricity sensing is effectively realized through the judgment rapidity of the high-resistance phase selection and the switch response rapidity;

4. grounding overvoltage protection technology: the system is converted from the grounding phenomena of frequent grounding or clearance arc light and the like into the steady grounding of a fault phase, so that the accumulation effect of system overvoltage caused by repeated grounding is avoided;

5. the technology for eliminating ferromagnetic resonance: the three PT operation modes of the bus have the potential safety operation hazard due to the fact that current impact exists at a PT neutral point in the resetting process of the device. The device can effectively inhibit the PT resonance process by adopting a four PT operation mode;

6. two-phase grounding short circuit current limiting technology: under the protection state, namely after the split-phase grounding switch is switched on, one of the other two phases is suddenly grounded, so that two phases are grounded and short-circuited. When two-phase grounding short circuit fault occurs, the low-impedance current limiter which is independently designed by the device is always connected in series in a voltage loop of the fault phase, so that overlarge inter-phase short circuit current is effectively limited. The device can effectively limit the fault current below 5kA, is far lower than two-phase direct short-circuit current, quickly breaks through overcurrent protection of the device body to send a brake separating instruction, quickly disconnects the front-mounted circuit breaker and the split-phase grounding switch, and ensures that a transformer substation system and the device body are prevented from being impacted by large current.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic circuit diagram of the present invention;

fig. 2 is a first functional block diagram of the present invention;

fig. 3 is a second functional block diagram of the present invention.

The system comprises a front circuit breaker QF, a current transformer TA, an overvoltage protector FV, a voltage transformer TV, a low-impedance current limiter XD, a split-phase grounding switch LZA/LZB/LZC, a zero-sequence current transformer LTA and an intelligent controller KZ.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected" and "disposed" are to be construed broadly, and may for example be fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in figure 1, the utility model discloses an active intervention type arc extinction device for a power distribution network, which comprises a front-mounted circuit breaker, a current transformer, a live display, an overvoltage protector, a low-impedance current limiter, a split-phase grounding switch, a voltage transformer, a zero-sequence current transformer and an intelligent controller, wherein the intelligent controller comprises an arc extinction controller and a line selection unit, the primary part of the current transformer is connected in series in a bus loop after passing through the front-mounted circuit breaker, the secondary part is connected with the overvoltage protector of the device and is connected with the live display, the primary part of the voltage transformer is connected in series in the loop at the rear end bus of the current transformer and is directly connected with a grounding network, the secondary part is connected with the arc extinction controller, the primary part of the zero-sequence current transformer is connected with a single-phase grounding rear end bus through the rear end of the low, the secondary part is connected to the current terminals of the arc extinction controller by wiring.

In this embodiment, the intelligent controller is installed in the device control panel, the arc extinction controller is mainly composed of a microprocessor plug board, a display panel, a switch driving plug board, a switch energy storage plug board, a voltage and current sampling plug board and a power supply output plug board, and a high-speed dual-core microprocessor DSP chip is adopted to realize fourier analysis by utilizing the high-speed and repeated data processing capability of the DSP.

In this embodiment, the line selection unit is mainly composed of a bus monitoring plug board, a voltage and current sampling plug board, an industrial control plug board and a power supply output plug board, and adopts a high-speed dual-core microprocessor DSP chip to realize fourier analysis by using the high-speed and repeated data processing capability of the DSP.

In this embodiment, one end of each of LZA, LZB, and LAC switches in the split-phase grounding switch is connected to a bus of the substation, and the other end is connected to a grounding cable and a ground network via a low impedance current limiter.

QF is represented as a front-mounted circuit breaker and is used for a circuit breaker for normal operation and shutdown of a device, and when an interphase short-circuit fault occurs in a cabinet, the QF is matched with a line protection device and has the functions of removing the fault and avoiding accident expansion.

One end of each of the split-phase grounding switches LZA, LZB and LAC is connected with a bus of a transformer substation, and the other end of each of the split-phase grounding switches is sealed with a star and is connected with a ground net through a low-impedance current limiter and a (zero-sequence current transformer LTA) grounding cable. The system is in a switching-off state when in normal operation, namely executing elements for automatically grounding a fault phase through a low-impedance current limiter are arranged between the executing elements, and electric and program locking is arranged between the executing elements, only one-phase circuit breaker is allowed to be switched on under any condition, and when two-phase grounding short circuit occurs, the phase grounding switch has quick-break protection capability; in addition, the split-phase switch has high switching-on speed and plays a key role in quickly processing the fault phase.

The primary part of the current transformer TA is connected in series in a bus loop after passing through a front-mounted circuit breaker, and the secondary part of the current transformer TA is connected with a line protection device of the device and is mainly used for sampling input of bus overcurrent judgment.

The low-impedance current limiter XD is expressed as a low-impedance current limiter, belongs to a single-coil structure, has impedance within 1 omega, is connected in series to a grounding loop after being sealed by a split-phase grounding switch, and plays a role of inhibiting grounding current when the device is in single-phase and out-of-phase grounding faults.

FV is represented as an overvoltage protector, which is connected in series to a loop at a bus at the rear end of a current transformer and is directly connected to a grounding network, and TBP type composite overvoltage protector is used for limiting atmospheric overvoltage and operation overvoltage caused by various vacuum switches, and protecting overvoltage between phases while protecting overvoltage between phases, and when intermittent arc grounding overvoltage and ferromagnetic resonance overvoltage occur in a system, the energy of the overvoltage protector is less than 1000A2MS square wave impact energy, the overvoltage protector can play a role in protection.

KZ is the control part of the device, including arc extinction controller and route selection unit, they are installed in the device control screen, the arc extinction controller mainly is formed by microprocessor plugboard, display panel, switch driving plugboard, switch energy storage plugboard, voltage and current sampling plugboard, power supply plugboard, it adopts high-speed dual-core microprocessor DSP chip with strong function, it utilizes DSP high-speed and repeated data processing ability to implement Fourier analysis, and utilizes the secondary voltage of voltage transformer TV to make real-time acquisition and judgment, and can promptly and accurately analyze various grounding states of power network, and can adopt correspondent action, DSP signal processor can utilize self serial port to make real-time communication with touch screen, and can receive input instruction or update liquid crystal display data.

The line selection unit is mainly composed of a bus monitoring plug board, a voltage and current sampling plug board, an industrial control plug board and a power supply output plug board. The method adopts a DSP chip of a high-speed dual-core microprocessor of American TI company with powerful functions, realizes Fourier analysis by utilizing the high-speed and repeated data processing capacity of the DSP, acquires and judges all zero sequence CT incoming lines of a bus of a transformer substation and the secondary voltage of a potential transformer PT in real time, timely and accurately analyzes various grounding states of a power grid, finds out a fault line through a set algorithm, records waves of each channel by a self wave recording module, updates liquid crystal display data and alarm records, and transmits the data to a background in an RS232 or RS485 mode.

The TV is expressed as a voltage transformer, the primary part of the voltage transformer is connected in a loop in series at a bus at the rear end of a current transformer TA and is directly connected to a grounding grid, and the secondary part of the voltage transformer is connected with an arc extinction controller and is used for measuring the three-phase voltage and the zero-sequence open delta voltage of a system. Meanwhile, the voltage transformer also has a function of inhibiting ferromagnetic resonance.

The LTA is expressed as a zero sequence current transformer, the primary part of the LTA is used for connecting a single-phase grounding rear-end bus into a ground network after penetrating through a grounding cable through the rear end of a low-impedance current limiter, the secondary part of the LTA is connected to a current terminal of an arc suppression controller through a wiring for measuring the total zero sequence current of a circuit after the single-phase grounding fault is closed, and simultaneously, the LTA is matched with the arc suppression controller, when the grounding current is larger than a preset protection fixed value, the closed split-phase grounding switch is quickly separated, and equipment is protected from being impacted by large current.

First, amplitude line selection method

When the system normally operates, the zero sequence current of each line is self unbalanced current, the amplitude is very small, and the amplitude is generally below 0.02A. When grounding occurs, the zero sequence of the non-grounding loop is the capacitance current of the self loop to the ground, and the zero sequence current of the grounding loop is the sum of the zero sequence currents of other non-grounding loops. Generally, the zero sequence current of the grounding circuit is far larger than that of other non-grounding circuits, but because the amplitude of the zero sequence current is related to the grounding degree, and the capacitance current to ground of each line is affected by the environment, the climate and the line length, a large difference may be generated. When the high resistance grounding and the difference of capacitance-to-ground current of each line is large, the accuracy of the maximum amplitude line selection method is affected.

Method for selecting lines through amplitude change

The amplitude variation line selection method is an extension of the maximum amplitude line selection method, and line selection is performed by utilizing the characteristic that zero sequence current of a grounding loop is converted into self grounding capacitance current after the device is subjected to grounding protection. Before grounding protection, the zero-sequence current of the grounding loop is the sum of the zero-sequence currents of other non-grounding loops, and the zero-sequence current of the non-grounding loop is the self-grounding capacitance current; after the grounding protection, the grounding loop and the non-grounding zero sequence current are self-grounding capacitance currents. And comparing the zero sequence current ratio before and after protection, and obviously changing the zero sequence current ratio into a grounding loop.

Method for selecting lines by changing directions of three and zero sequence currents

The zero sequence current direction line selection method is a conventional line selection method, and the line selection principle is that when a single-phase earth fault occurs, the current direction of a non-earth return circuit flows from a bus to a line end, the current direction of an earth return circuit flows from a line to the bus, and the earth return circuit can be identified by judging the zero sequence current direction. When a single-phase earth fault occurs, a transient process exists, the zero-sequence current contains more high-frequency components, the action time of the earth protection of the device is less than 50ms, and if the single-phase earth fault cannot enter a stable state within 50ms, the judgment of the direction of the zero-sequence current is directly influenced. In the application of the device, the characteristic that the current direction of the grounding loop is recovered to flow from the bus to the line after the grounding protection of the device is utilized, and the process of one-step judgment and confirmation is added. And identifying a circuit with the zero sequence current direction different from other circuits before the grounding protection action, and if the zero sequence current direction of the circuit is changed after the grounding protection action, the circuit is a grounding circuit.

Fourth step, difference line selection method

The zero sequence current difference line selection method is based on the fact that when single-phase grounding occurs, zero sequence current flowing through a grounding circuit is the sum of zero sequence currents of other non-grounding circuits, after the device performs grounding protection, the grounding capacitance current of the whole system flows away from the grounding point provided by the device, and at the moment, the zero sequence current of the grounding circuit is the self grounding capacitance current. Zero sequence current of the grounding loop changes before and after the grounding protection action, and the difference value of the changes is the current flowing through the grounding protection device.

The differential value line selection method can effectively eliminate the calculation error caused by unbalanced current when the system normally operates, and can also correctly select lines for complex system wiring modes such as double circuit lines.

The above-mentioned 4 line selection methods have advantages, and when it is used, the circuit selected by adopting most rule and more than two line selection methods is ground circuit.

With the development of economy and society, more and more cable and overhead line hybrid power distribution networks are available. Due to the existence of the cable, the grounding capacitance current is large, and the arc suppression coil cannot well extinguish the arc (the residual current is large after compensation); because of the existence of the overhead line, the high-resistance grounding and the instantaneous grounding are more than those of a pure cable network, and the tripping operation is realized in a low-resistance grounding mode, so that the power supply reliability is reduced.

The problems caused by single-phase earth faults of a cable and overhead line hybrid power distribution network cannot be effectively solved by adopting a traditional arc suppression coil or small-resistance earthing device.

The arc suppression coil can not well extinguish arc (capacitance current measurement accuracy is not very high, compensation accuracy is not very high) aiming at a system with large capacitance current, intermittent overvoltage can not be completely inhibited, line selection is difficult, human body inductance electricity can not be protected, and fault isolation is difficult.

The low-resistance grounding is only suitable for a pure cable network (large capacitance current) with few instantaneous (frequent tripping) and high-resistance grounding (no action) faults, and does not solve the problem of human body inductance.

The single-phase grounding problem of the cable and overhead line hybrid power distribution network is not solved (the characteristics are that the capacitance current is large, and the instantaneous and high-resistance grounding faults are more).

The human body is required to be tripped sensitively and quickly, and the power supply reliability is reduced by the sensitive and quick tripping.

The difficulty of solving the problem of single-phase earth fault of the power distribution network is to ensure the power supply reliability and protect the personal safety, and also to quickly extinguish arcs, inhibit intermittent overvoltage, select lines and isolate faults. There is a phenomenon that one problem is solved and a new problem is brought about.

Therefore, the problems caused by the single-phase earth fault of the power distribution network, the power supply reliability and the personal safety protection are generally considered, the active intervention type arc suppression device for treating the single-phase earth fault is provided, and the active intervention type arc suppression device has important practical significance for the safe, reliable and economic operation of the power distribution network.

The device adopts the arc extinguishing method of ground transfer, and the ground transfer return circuit is directly connected with the substation grounding grid, and the loop resistance is very little, and after the device action, ground fault forces to earth equipotential (residual voltage is very low) to ground relative to the ground voltage, and compared with the arc suppression coil, the device can extinguish the ground fault electric arc completely, can reduce the probability that the ground fault electric arc causes the interphase fault, has improved the power supply reliability.

The protection method of grounding transfer and shunting of human body current is adopted, the device has high action speed (completed within 40 ms), the electric shock time of the human body is greatly shortened, the protection effect on the electric sensing personnel is realized, and the power supply to the user is not stopped.

Intermittent grounding, which is a phenomenon that instantaneous grounding occurs continuously. Is a process of changing from ground, extinction, and re-ground, and can generate a very high overvoltage. The device can change the grounding state into a stable grounding state, and the change processes of grounding, disappearance and re-grounding are not generated any more, thereby restraining the generation of intermittent grounding and overvoltage.

The key of the device for realizing rapid protection lies in accurate phase selection algorithm and rapid start, namely, the sensitivity and the accuracy of the device are ensured. When the system is grounded through a metal or grounding resistor, the amplitude and the phase of the zero sequence voltage can change according to a certain track, and the grounding phase is accurately judged by adopting a zero sequence voltage and line voltage mode angle comparison method; the theoretical calculation track and the actual sampling calculation track realize 100% accuracy of the device action. Meanwhile, a voltage slope change method is adopted to accurately judge intermittent grounding.

The fault phase line selection of the small current grounding system is influenced by factors such as small signal amplitude, unobvious zero sequence current change and the like, and particularly, the line selection is more difficult after an arc suppression coil is additionally arranged. The device adopts a unique zero sequence current maximum variation line selection principle, and creates a characteristic equation method for line selection and accurately selects a fault grounding line through the change of zero sequence current of each line before and after the device acts at the fault moment.

In order to ensure the safe operation of the system and the equipment, the device should have current-limiting and protecting measures of two-phase grounding short circuit:

under the protection state, namely after the split-phase grounding switch is switched on, one of the other two phases is suddenly grounded, so that two phases are grounded and short-circuited. As can be seen from the figure, when a two-phase grounding short-circuit fault occurs, the low-impedance current limiter XD is always connected in series in a voltage loop of the fault phase, and the overlarge inter-phase short-circuit current is effectively limited. Even if the outlet short circuit and the grounding resistance are zero, the comprehensive transformer inductive reactance, grounding grid impedance and low-impedance current limiter can effectively limit the fault current below 5kA and is far lower than the two-phase direct short circuit current, the device body overcurrent protection is used for quickly breaking to send a brake separating instruction, the front-mounted circuit breaker and the split-phase grounding switch are quickly disconnected, and the transformer substation system and the equipment body are prevented from being impacted by large current.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that are not thought of through the creative work should be covered within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the claims.

Claims (4)

1. The utility model provides a distribution network initiative intervention type arc extinguishing device which characterized in that: including leading circuit breaker, current transformer, electrified display, overvoltage protector, low impedance current limiter, split phase earthing switch, voltage transformer, zero sequence current transformer and intelligent control ware, the intelligent control ware includes arc extinction controller and route selection unit, establish ties in the bus circuit behind leading circuit breaker in current transformer primary part, the secondary part connects the overvoltage protector of this device, and current transformer is connected with electrified display, voltage transformer primary part establishes ties in the return circuit and directly inserts the ground net at current transformer rear end bus, the secondary part links to each other with the arc extinction controller, zero sequence current transformer primary part passes through low impedance current limiter rear end, connect single-phase ground connection rear end bus, insert the ground net after ground cable penetrates, the secondary part is connected to the current terminal of arc extinction controller through the wiring.

2. The active intervention type arc suppression device for the power distribution network according to claim 1, wherein: the intelligent controller is installed in the control screen of the device, the arc extinction controller is mainly composed of a microprocessor plug board, a display board, a switch driving plug board, a switch energy storage plug board, a voltage and current sampling plug board and a power supply output plug board, a high-speed dual-core microprocessor DSP chip is adopted, and the high-speed repeated data processing capacity of the DSP is utilized to realize Fourier analysis.

3. The active intervention type arc suppression device for the power distribution network according to claim 1, wherein: the line selection unit mainly comprises a bus monitoring plug board, a voltage and current sampling plug board, an industrial control plug board and a power supply output plug board, and adopts a high-speed dual-core microprocessor DSP chip to realize Fourier analysis by utilizing the high-speed and repeated data processing capability of the DSP.

4. The active intervention type arc suppression device for the power distribution network according to claim 1, wherein: one end of an LZA switch, an LZB switch and an LAC switch in the split-phase grounding switch is connected with a bus of a transformer substation, and the other end of the LZA switch, the LZB switch and the LAC switch are connected with a grounding cable and a grounding grid through a low-impedance current limiter.

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