Lightning arrester verification system

Abstract

The invention, which belongs to the technical field of lightning arrester verification, discloses a lightning arrester verification system comprising a power supply, a current output unit, a current generation control unit, an anti-interference unit and a protection unit. The power supply is used for generating a current required by lightning arrester verification and outputting the current to the current output unit, circuits for generating different currents in the power supply are not connected, and the current comprises an impact current, a leakage current and a measurement and control current; the current output unit is used for controlling current output, and the current generation control unit is used for controlling the current generation process of the power supply; the anti-interference unit is used for disconnecting a path for the power supply to output leakage current during the impulse current test and isolating input of a circuit for generating the impulse current in the power supply during the leakage current test; and the protection unit is used for shunting the impact current during the impact current test, and absorbing and storing the residual high voltage in the circuit when switching to the leakage current test. Interference is avoided through power isolation, and circuit protection is realized through the anti-interference unit and the protection unit.

Description

Technical Field

[0001] The invention relates to a lightning arrester calibration system, belonging to the technical field of lightning arrester calibration. Background Art

[0002] Arrester calibration is an important process of arrester quality inspection, and is widely used by power supply departments in arrester function tests and regular on-site calibration of power grids. Due to different calibration schemes, the quality of arrester calibration equipment varies. During the arrester calibration test, the arcing and discharge shock waves generated by high-voltage discharge will cause physical and psychological harm to the operator, and will cause high-voltage interference to the external power supply network, causing other equipment in the power grid to fail to work properly. The arrester calibration equipment itself is most impacted and is at risk of failure and damage. Summary of the invention

[0003] The purpose of the present invention is to provide a lightning arrester calibration system to avoid the adverse effects of lightning arrester calibration in the prior art on the power grid.

[0004] To achieve the above objectives, the present invention is implemented by adopting the following technical solutions: The present invention provides a lightning arrester calibration system, comprising: a power supply, a current output unit, a current generation control unit, an anti-interference unit, and a protection unit; The power supply is used to generate the current required for arrester calibration and output the generated current to the current output unit, and the circuits generating different currents in the power supply are not connected to each other, and the currents include impact current, leakage current and measurement and control current; The current output unit is used to control the output of the current, and the current generation control unit is used to control the process of the power supply generating current; The anti-interference unit is connected to the power supply and is used to disconnect the path of the leakage current output by the power supply during the impulse current test, and to isolate the input of the circuit for generating the impulse current in the power supply during the leakage current test; The protection unit is used to shunt the impulse current during the impulse current test, and is also used to absorb and store the residual high voltage in the circuit when switching from the impulse current test to the leakage current test.

[0005] Further, the power supply includes an impulse current generating circuit, a first measurement and control current generating circuit, an AC leakage current generating circuit, a second measurement and control current generating circuit, a DC leakage current generating circuit and a third measurement and control current generating circuit; The arrester inspection includes impulse current test, AC leakage current test and DC leakage current test; The impulse current generating circuit is used to generate the impulse current required for lightning arrester calibration; The first measurement and control current generating circuit is used to generate the first measurement and control current required in the arrester calibration, and the first measurement and control current is the measurement and control current used when the impulse current is used to perform an impulse current test; The AC leakage generating circuit is used to generate the AC leakage current required for lightning arrester calibration; The second measurement and control current generating circuit is used to generate a second measurement and control current required for lightning arrester calibration, and the second measurement and control current is a measurement and control current used when performing an AC leakage current test using the AC leakage current; The DC leakage current generating circuit is used to generate the DC leakage current required for lightning arrester calibration; The third measurement and control current generating circuit is used to generate the third measurement and control current required in the arrester calibration, and the third measurement and control current is the measurement and control current used when the DC leakage current is used to perform a DC leakage current test.

[0006] Furthermore, the impulse current generating circuit includes a power supply unit, an AC high-voltage pulse transformer, a bridge rectifier and a high-voltage pulse capacitor connected in sequence, wherein the AC high-voltage pulse transformer is used to convert the current provided by the power supply unit into an AC high voltage and transmit it to the bridge rectifier, the bridge rectifier is used to convert the AC high voltage into a DC high voltage and transmit it to the high-voltage pulse capacitor, and the high-voltage pulse capacitor is used to store the energy of the impulse current generated by the DC high voltage and output the impulse current; The first measurement and control current generating circuit, the AC leakage current generating circuit, the second measurement and control current generating circuit, the DC leakage current generating circuit and the third measurement and control current generating circuit are respectively connected to different transformers for power supply units.

[0007] Further, the current output unit includes two high-voltage reed switch relays and a self-locking switch, and each of the high-voltage reed switch relays includes a normally open contact, a normally closed contact, a common terminal and a coil; When controlling the output of current, in the current output unit, two normally open contacts are respectively connected to the positive and negative poles of the impulse current output terminal in the power supply, one normally closed contact is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and another normally closed contact is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply. The common terminal is used to output the current flowing through the high-voltage reed switch relay. The two coils are connected in parallel and controlled by a self-locking switch. When the self-locking switch is turned on, the high-voltage reed switch coil is energized and attracted. At this time, the normally open contact is connected to the common terminal, and the impact current provided by the power supply is output through the common terminal; when the self-locking switch is turned off, the high-voltage reed switch coil loses power and is released. At this time, the normally closed contact is connected to the common terminal, and the AC leakage current or DC leakage current provided by the power supply is output through the common terminal.

[0008] Further, the current generation control unit is an impulse current generation control unit, including a resistor R1, a high-voltage vacuum relay and a manual key switch, the high-voltage vacuum relay is used to control the high-voltage pulse capacitor to generate an impulse current using the DC high voltage stored in the capacitor, and the high-voltage vacuum relay includes a normally open contact, a common terminal and a coil; In the impulse current generation control unit, the normally open contact is connected in series with the resistor R1, and then connected to the positive electrode of the high-voltage pulse capacitor, the common end is connected to the negative electrode of the high-voltage pulse capacitor, one end of the coil is grounded, and the other end is connected to a DC power supply through a manual key switch; When the manual push button switch is turned on, the high-voltage vacuum relay coil is energized and its normally open contact is instantly short-circuited with the common terminal.

[0009] Further, the anti-interference unit includes an electromagnetic relay, a self-locking switch and a manual key switch, and the electromagnetic relay includes a normally open contact, a normally closed contact, a common terminal and a coil; In the anti-interference unit, the common end is connected to the live wire of the power supply outside the arrester calibration system, the normally open contact is connected to the live wire of the primary side of the AC high-voltage pulse transformer, the normally closed contact is connected to the live wire of the secondary side of the transformer in the AC leakage current generating circuit or the DC leakage circuit generating circuit, one end of the coil is connected to the self-locking switch, and the other end of the coil is grounded; The electromagnetic relay is controlled to be attracted and released by the self-locking switch. During the impact current test, the self-locking switch is pressed, the electromagnetic relay is in the attracted state, the normally open contact and the common terminal are in the on state, at this time the high-voltage pulse capacitor outputs impact current, the normally closed contact and the common terminal are in the off state, and the power supply does not output leakage current; during the leakage current test, the self-locking switch is popped up, the electromagnetic relay is in the released state, the normally closed contact and the common terminal are on, at this time the AC leakage current generating circuit outputs AC leakage current or the DC leakage current generating circuit outputs DC leakage current, and the impact current generating circuit does not output impact current.

[0010] Furthermore, it also includes a leakage measurement and control unit, which is used to control and measure the AC leakage current and DC leakage current generated by the power supply; The leakage measurement and control unit includes an ammeter, an adjustable potentiometer, a self-locking switch, two AC measurement current limiting resistors, two DC measurement current limiting resistors, a first micro-electromagnetic relay, a second micro-electromagnetic relay and a third micro-electromagnetic relay. The first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay have the same components, including a coil, two normally open contacts, two normally closed contacts and two common terminals. The three coils are connected in parallel and are all connected to the self-locking switch. The self-locking switch controls the attraction and release of the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay respectively through the three coils. On the first micro electromagnetic relay, the adjustable potentiometer is connected to the secondary side of the transformer in the AC leakage current generating circuit, the two common terminals are respectively connected to the adjustable terminal and the neutral terminal of the adjustable potentiometer, the two normally open contacts are respectively connected to the two input terminals of the bridge rectifier, a normally closed contact is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and the other normally closed contact is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply; On the second micro electromagnetic relay, two normally open contacts are respectively connected to two output terminals of the bridge rectifier, two normally closed contacts are suspended, one common terminal is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and the other common terminal is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply; On the third micro electromagnetic relay, two normally closed contacts are respectively connected to two AC measuring current limiting resistors for measuring AC leakage current, two normally open contacts are respectively connected to two DC measuring current limiting resistors, and two common terminals are connected to both ends of the ammeter input; When the first micro-electromagnetic relay is released, and the third micro-electromagnetic relay is released, the first micro-electromagnetic relay and the third micro-electromagnetic relay cooperate to complete the measurement of the AC leakage current; When the first micro-electromagnetic relay is energized, the second micro-electromagnetic relay is energized, and the third micro-electromagnetic relay is energized, the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay cooperate to complete the measurement of the DC leakage current.

[0011] Further, the protection unit includes three gas discharge tubes, three varistors, three bidirectional TVS diodes, a first sampling resistor and a second sampling resistor. The first gas discharge tube, the first varistor, and the first bidirectional TVS diode are connected in series and connected in parallel with the AC leakage generating circuit. The second gas discharge tube, the second varistor, and the second bidirectional TVS diode are connected in series and connected in parallel with the DC leakage generating circuit. The first sampling resistor and the second sampling resistor are both connected in parallel at both ends of the high-voltage pulse capacitor. The second sampling resistor is connected in parallel with the third gas discharge tube. The third varistor and the third bidirectional TVS diode are connected in series and connected in parallel with the second sampling resistor. The resistance value of the first sampling resistor is greater than the resistance value of the second sampling resistor.

[0012] Furthermore, the distance between the high-voltage devices and the low-voltage devices in the power supply, current output unit, current generation control unit, anti-interference unit, and protection unit is greater than 10 mm, and the wires through which the impact current flows in the power supply, current output unit, current generation control unit, anti-interference unit, and protection unit are all made of silicone wire with a withstand voltage rating of 30 kV or above, and grooves are opened in a set area around the high-voltage devices.

[0013] Compared with the prior art, the beneficial effects achieved by the present invention are: The present invention provides a lightning arrester calibration system, which generates different currents by setting different circuits in the power supply to achieve power isolation protection, ensure that the currents used in different tests in the lightning arrester calibration are isolated from each other, avoid mutual interference between the impact current test and the leakage test, and at the same time, the high voltage generated during the test is completely isolated from the external AC power supply; by setting an anti-interference unit to prevent other currents from flowing through the lightning arrester during a certain test, ensure that the test is not interfered by other currents; by setting a protection unit, the impact current is prevented from damaging the lightning arrester calibration system and the power grid. The present invention reduces the impact of the high voltage and large current generated by the impact current test on the operator, the lightning arrester calibration system and the power supply line through the above means, ensuring personal safety, the safety of the power supply network and the normal operation of the lightning arrester calibration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a lightning arrester calibration system provided by Embodiment 1 of the present invention; Figure 2 It is a circuit diagram of the arrester calibration system provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0016] Example 1

[0017] This embodiment provides a lightning arrester calibration system, including: a power supply, a current output unit, a current generation control unit, an anti-interference unit, and a protection unit; The power supply is used to generate the current required for arrester calibration and output the generated current to the current output unit. The circuits generating any two currents in the power supply are not connected. The currents include impact current, leakage current and measurement and control current. The current output unit is used to control the output of current, and the current generation control unit is used to control the process of the power supply generating current; The anti-interference unit is connected to the power supply and is used to disconnect the path of the leakage current output by the power supply during the impulse current test and to isolate the input of the circuit for generating the impulse current in the power supply during the leakage current test; The protection unit is used to shunt the impulse current during the impulse current test, and is also used to absorb and store the residual high voltage in the circuit when switching from the impulse current test to the leakage current test.

[0018] The present invention achieves power supply isolation protection by setting different circuits in the power supply to generate different currents, ensuring that the currents used in different tests in the arrester calibration are isolated from each other, avoiding interference between the impact current test and the leakage test, and at the same time completely isolating the high voltage generated during the test from the external AC power supply; by setting an anti-interference unit, it is prevented that other currents flow through the arrester during a certain test, ensuring that the test is not interfered by other currents; by setting a protection unit, it is prevented that the impact current causes damage to the arrester calibration system and the power grid. The present invention reduces the impact of the high voltage and large current generated by the impact current test on the operator, the arrester calibration system and the power supply line through the above means, ensuring personal safety, the safety of the power supply network and the normal operation of the arrester calibration system.

[0019] Example 2

[0020] The present embodiment provides a lightning arrester calibration system, including a power supply, a current output unit, a current generation control unit, an anti-interference unit, a protection unit and a leakage current measurement and control unit.

[0021] Power supply isolation is achieved in the power supply by adopting a transformer power supply isolation protection method. Specifically, different circuits are set in the power supply to generate different currents to achieve power supply isolation.

[0022] In order to achieve power supply isolation during the impulse current test, an impulse current generating circuit is set in the power supply. The impulse current generating circuit includes a power supply unit, an AC220V to AC8kV high-voltage pulse transformer, a bridge rectifier and a high-voltage pulse capacitor. The process of generating impulse current in the impulse current generating circuit is as follows: the current provided by the power supply unit is converted into AC high voltage by the AC220V to AC8kV high-voltage pulse transformer and then transmitted to the bridge rectifier. The bridge rectifier converts the AC high voltage into DC high voltage and transmits it to the high-voltage pulse capacitor. The DC high voltage charges the high-voltage pulse capacitor. The high-voltage pulse capacitor is charged under the action of the DC high voltage, and an impulse current is generated.

[0023] In order to achieve power supply isolation during the impulse current test, a first measurement and control current generating circuit is arranged in the power supply. The first measurement and control current generating circuit is a power supply unit and an AC220V to AC12V power transformer. The AC220V to AC12V power transformer converts the current provided by the power supply unit into a first measurement and control current. The first measurement and control current is a high-voltage measurement and control power supply, that is, the measurement and control current used when the impulse current test is performed using the impulse current.

[0024] In order to achieve power supply isolation when conducting a leakage current test, an AC leakage current generating circuit, a second measurement and control current generating circuit, a DC leakage current generating circuit and a third measurement and control current generating circuit are arranged in the power supply; the AC leakage current generating circuit is a power supply unit and an AC220V to AC220V transformer, and the AC220V to AC220V transformer converts the current provided by the power supply unit into an AC leakage current; the second measurement and control current generating circuit is a power supply unit and an AC220V to AC9V transformer, and the AC220V to AC9V transformer converts the current provided by the power supply unit into a second measurement and control current The second measurement and control current is the measurement and control current used when the AC leakage current is used to perform the AC leakage current test; the DC leakage current generating circuit is a power supply unit and a DC220V to DC220V transformer, and the DC220V to DC220V transformer converts the current provided by the power supply unit into a DC leakage current; the third measurement and control current generating circuit is a power supply unit and a DC220V to DC9V transformer, and the DC220V to DC9V transformer converts the current provided by the power supply unit into a third measurement and control current, and the third measurement and control current is the measurement and control current used when the DC leakage current is used to perform the DC leakage current test.

[0025] Through the above power supply design, it is ensured that the impulse current, AC leakage current and DC leakage current used in the impulse current test and leakage current test are isolated from each other, avoiding mutual interference between the impulse current test and the leakage current test. At the same time, the high voltage generated during the test is completely isolated from the external AC power supply.

[0026] The current output unit and the current generation control unit realize the protection of the arrester calibration system and the power grid where the arrester is located by means of relay contact isolation protection.

[0027] The high-voltage reed switch relay has a set of conversion contacts with good contact isolation performance and high-voltage switching characteristics. The isolation voltage between the contacts is above 10kV. The high-voltage reed switch relay can be used to control the high-voltage impact current or leakage current to output and switch externally. In order to improve the withstand voltage energy of the contacts, suppress arc generation, and extend the life of the contacts, the normally open contacts and normally closed contacts in the high-voltage reed switch relay are sealed in an environment filled with inert gas.

[0028] The current output unit includes two high-voltage reed switch relays and two self-locking switches. Each high-voltage reed switch relay includes a normally open contact, a normally closed contact, a common terminal and a coil. In any high-voltage reed switch relay, the normally open contact and the normally closed contact are located in the coil. When controlling the output of current, in the current output unit, one end of the two normally open contacts is respectively connected to the positive and negative electrodes of the high-voltage pulse capacitor, a normally closed contact is connected to the live wire of the AC leakage current output terminal and the positive electrode of the DC leakage current output terminal in the power supply, and the other normally closed contact is connected to the neutral wire of the AC leakage current output terminal and the negative electrode of the DC leakage current output terminal in the power supply. The two coils are connected in parallel, one end of the coil is grounded, and the other end is connected to the common end of the self-locking switch; the self-locking switch controls the attraction and release of the high-voltage reed switch relay through the coil. When the high-voltage reed switch relay is in the attracted state, the normally open contact is connected to the common end, and the impact current is output; when the high-voltage reed switch relay is in the released state, the normally closed contact is connected to the common end, and the leakage current is output.

[0029] High-voltage vacuum relays have the characteristics of high switching capacity, high relay capacity, and high anti-interference, and can control, protect, and isolate large currents in high-voltage circuits. Discharge in a vacuum through the normally open contacts of high-voltage vacuum relays will not produce discharge arcing like in the air, when the high-voltage gap distance is less than the distance corresponding to the air insulation voltage, which will interfere with the normal operation of other nearby components and cause abnormal operation of the equipment. High-voltage vacuum relays have a set of conversion contacts.

[0030] The insulation strength varies greatly with air temperature and humidity. When the high voltage is 10 kV, the distance corresponding to the air insulation voltage is 1-10 mm. In this embodiment, the distance corresponding to the air insulation voltage is 10 mm.

[0031] The current generation control unit includes a high-voltage vacuum relay and a manual key switch. The high-voltage vacuum relay is used to control the process of the power supply generating the impact current. The high-voltage vacuum relay includes a normally open contact, a common terminal and a coil. When controlling the power supply to generate current, in the current generation control unit, the normally open contact is connected to the positive electrode of the high-voltage pulse capacitor in the above impact current generation circuit, and the common terminal is connected to the negative electrode of the high-voltage pulse capacitor in the above impact current generation circuit. One end of the high-voltage vacuum relay coil is grounded, and the other end is connected to a DC 12V power supply through a manual key switch. When conducting the impact current test, after the high-voltage pulse capacitor is fully charged, the manual key switch in the current generation control unit is pressed, and the coil in the high-voltage vacuum relay is energized, and its normally open contact is attracted and turned on in the vacuum, and the high-voltage pulse capacitor is short-circuited and discharged, and a large current is generated instantly (due to the limited storage capacity of the high-voltage pulse capacitor, the energy is quickly exhausted and ends). When the manual key switch is released, the high-voltage vacuum relay loses power and its normally open contact is disconnected. The contacts of the high-voltage vacuum relay will not produce arc discharge in a near-vacuum environment, which can extend the service life of the contacts and reduce the impact of arcing on surrounding devices.

[0032] Hongfa HF115F electromagnetic relay has two sets of switching contacts, with 16A contact switching capacity, 5kV dielectric withstand voltage between coil and contact, 10mm creepage distance, meeting the reinforced insulation requirements of VDE0700 / 0631 standard. Through the two sets of contacts of the electromagnetic relay with a working voltage of 5V DC, the power supply of the impulse current test and the leakage current test are controlled respectively to avoid mutual interference between the impulse current and the leakage current.

[0033] The anti-interference unit includes an electromagnetic relay, a self-locking switch and a manual key switch. The electromagnetic relay includes a normally open contact, a normally closed contact, a common terminal and a coil. In this embodiment, the electromagnetic relay is a Hongfa HF115F electromagnetic relay.

[0034] In the anti-interference unit, one end of the normally open contact is connected to the live wire of the power supply outside the lightning arrester verification system, the common end is connected to the live wire of the primary side of the AC220V to AC8kV high-voltage pulse transformer through one end of the manual push button switch, one end of the normally closed contact is connected to the live wire of the secondary side of the transformer in the AC leakage generation unit or the DC leakage generation unit, and the self-locking switch is connected to the coil; the self-locking switch controls the attraction and release of the Hongfa HF115F electromagnetic relay through the coil. During the impulse current test, after pressing the self-locking switch, the Hongfa HF115F electromagnetic relay is controlled to be in the attraction state through the self-locking switch, and the other end of the normally open contact and the other end of the common end are in contact with AC220V power. The other end of the manual push button switch is connected to the live wire of the primary side of the AC220V to AC8kV high-voltage pulse transformer. After pressing the manual push button switch, there is an AC220V input on the primary side of the AC220V to AC8kV high-voltage pulse transformer, and the AC220V to AC8kV high-voltage pulse transformer The secondary side of the transformer outputs AC high voltage, which is then rectified by a bridge and then outputs DC high voltage. After the DC high voltage charges the high-voltage pulse capacitor, the high-voltage pulse capacitor outputs an impact current. The other end of the normally closed contact and the other end of the common end are in a disconnected state (because the Hongfa HF115F electromagnetic relay is in a energized state at this time). At this time, the power supply does not output leakage current, thus avoiding the interference of leakage current during the impact current test. During the leakage current test, after the self-locking switch is released, the Hongfa HF115F electromagnetic relay is controlled to be in a released state through the self-locking switch, and the other end of the normally closed contact and the other end of the common end are in contact. At this time, the AC leakage current generation circuit outputs AC leakage current or the DC leakage current generation circuit outputs DC leakage current. At this time, there is no input on the primary side of the AC220V to 8kV high-voltage pulse transformer, and no impact current can be generated. The impact current generation circuit does not output impact current, thus avoiding the generation of impact current due to accidental touch during the leakage current test, which may cause harm to the operator.

[0035] The leakage current measurement and control unit is used to control and measure the AC leakage current and DC leakage current generated by the power supply; the leakage current measurement and control unit includes a self-locking switch, two AC measurement current limiting resistors, two DC measurement current limiting resistors, a first micro-electromagnetic relay, a second micro-electromagnetic relay and a third micro-electromagnetic relay. The first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay have the same components, including a coil, two normally open contacts, two normally closed contacts and a common terminal. The three coils are connected in parallel and are all connected to the self-locking switch. The self-locking switch controls the attraction and release of the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay respectively through the three coils. In this embodiment, the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay are all Hongfa HFD27 micro-electromagnetic relays. The Hongfa HFD27 micro-electromagnetic relay has 2 sets of conversion contacts, adopts a bifurcated contact form, has a switching capacity of 125VA / 60W, and controls the output of the AC leakage current and the DC leakage current through the AC leakage current and DC leakage current switching relay to avoid mutual interference between the AC leakage current and the DC leakage current.

[0036] On the first miniature electromagnetic relay, two common terminals are respectively connected to the adjustable terminal and the neutral terminal of the adjustable potentiometer connected to the secondary side of the transformer in the AC leakage current generating circuit, two normally open contacts are respectively connected to the input terminal of the bridge rectifier, one normally closed contact is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and the other normally closed contact is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply. When the first miniature electromagnetic relay is released, it is used to assist in measuring the AC leakage current; when the first miniature electromagnetic relay is closed, it is used to assist in measuring the DC leakage current.

[0037] On the second micro-electromagnetic relay, two normally open contacts are respectively connected to the output ends of the bridge rectifier, two normally closed contacts are suspended, one common end is connected to the live wire of the AC leakage current output end and the positive pole of the DC leakage current output end in the power supply, and the other common end is connected to the neutral wire of the AC leakage current output end and the negative pole of the DC leakage current output end in the power supply; when the second micro-relay is energized, it is used to assist in measuring the DC leakage current.

[0038] On the third micro electromagnetic relay, two normally closed contacts are respectively connected to two AC measuring current limiting resistors for measuring AC leakage current, two normally open contacts are respectively connected to two DC measuring current limiting resistors, and two common terminals are connected to both ends of the ammeter input for measuring leakage current.

[0039] When the first micro-electromagnetic relay is released, and the third micro-electromagnetic relay is released, the first micro-electromagnetic relay and the third micro-electromagnetic relay cooperate to complete the measurement of the AC leakage current; When the first micro-electromagnetic relay is energized, the second micro-electromagnetic relay is energized, and the third micro-electromagnetic relay is energized, the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay cooperate to complete the measurement of the AC leakage current.

[0040] The protection unit includes three gas discharge tubes, three varistors, three bidirectional TVS diodes, a first sampling resistor and a second sampling resistor. The first gas discharge tube, the first varistor and the first bidirectional TVS diode are connected in series and connected in parallel with an AC leakage generation circuit. The second gas discharge tube, the second varistor and the second bidirectional TVS diode are connected in series and connected in parallel with a DC leakage generation circuit. The first sampling resistor and the second sampling resistor are both connected in parallel at both ends of the high-voltage pulse capacitor. The second sampling resistor is connected in parallel with the third gas discharge tube. The third varistor and the third bidirectional TVS diode are connected in series and connected in parallel with the second sampling resistor.

[0041] In this embodiment, the gas discharge tube is a 90V10kA gas discharge tube, which can limit the voltage to within 90V and has a maximum current capacity of 10kA; the varistor is a 10D471K varistor, 10 represents that the diameter of the zinc oxide varistor ceramic piece in the varistor is 10mm, and 471 represents that the varistor voltage value is 470V; the bidirectional TVS diode is a SIMBJ6.5CA bidirectional TVS diode, which has an SMB package, a breakdown voltage of 6.5V, and a peak power of 600W.

[0042] Through the circuit design of the protection unit, that is, by connecting a 90V10kA gas discharge tube, a 10D471K varistor and a SIMBJ6.5CA bidirectional TVS diode in parallel to the output leakage circuit, the interference of the high voltage generated during the impulse current test on the components in the circuit is reduced, and the residual high voltage when switching from the impulse current test to the leakage current test is also reduced, preventing the residual high voltage from being transmitted to the leakage current generation circuit and the leakage current measurement and control circuit. Through the circuit design of the protection unit, that is, by connecting the first sampling resistor and the second sampling resistor in parallel at both ends of the high-voltage pulse capacitor, high-voltage sampling is realized, a high-voltage large-resistance resistor (referring to the first sampling resistor) and a small-resistance metal film resistor (referring to the second sampling resistor) are used for voltage division sampling, a gas discharge tube is connected in parallel at both ends of the metal film resistor, and the varistor is connected in series with the bidirectional TVS diode and then connected in parallel with the metal film resistor. The gas discharge tube, the varistor and the bidirectional TVS diode absorb the high voltage, and the impulse current generated during the impulse current test is reduced from being transmitted to the impulse current measurement circuit.

[0043] In this embodiment, all high-voltage components on the device are kept away from other components by more than 10 mm to reduce spatial interference between the high-voltage components and other components.

[0044] In this embodiment, all wires connected to the impact current are made of silicone wires with a withstand voltage level of 30kV or above, so as to minimize the impact of the high-voltage impact current on other parts.

[0045] In this embodiment, the device installation base plate, the panel and the base plate are isolated and protected by insulating bakelite, and the closer devices are isolated by slots to isolate the influence of high-voltage devices on other devices.

[0046] Combination Figure 2 , the process of generating impulse current by the arrester verification system provided in this embodiment is described as follows: Figure 2 As shown, the live wire L of the power socket J1 is connected to one end of the primary side of the step-down transformer T2 via the rocker switch S2, and the live wire L of the power socket J1 is simultaneously connected to a group of common ends of two groups of Hongfa HF115F electromagnetic relays K1 for converting AC leakage current / DC leakage current, the neutral wire N of the power socket J1 is directly connected to the other end of the primary side of the high-voltage pulse transformer T1 and the step-down transformer T2, one end of the button S1 is connected to the normally open contact of a group of contacts of the Hongfa HF115F electromagnetic relay K1, and the other end of the button S1 is connected to one end of the primary side of the high-voltage pulse transformer T1.

[0047] The step-down transformer T2 is used to provide a 12V DC power supply. The step-down transformer T2 provides working power to the devices used to perform impulse current tests in the lightning arrester calibration system.

[0048] exist Figure 2 In the figure, the high-voltage pulse transformer T1 is a high-voltage pulse transformer that converts AC220V to AC8kV.

[0049] One end of the secondary side of the high-voltage pulse transformer T1 is connected to one end of the high-power resistor R1, the other end of the resistor R1 is connected to the positive electrode of the high-voltage rectifier diode D1, and the negative electrode of the high-voltage rectifier diode D1 is respectively connected to one end of the high-voltage pulse capacitor CHV1, the high-voltage pulse capacitor CHV2, the resistor R2 and the high-power aluminum shell resistor RJ1; the other end of the secondary side of the high-voltage pulse transformer T1 is connected to the negative electrode of the high-voltage rectifier diode D2, the positive electrode of the high-voltage rectifier diode D2 is connected to the other end of the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2, and the positive electrode of the high-voltage rectifier diode D2 is also connected to one end of the resistor R3, one end of the varistor RY1 and the high-voltage terminal N / -; the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 are connected in parallel, and the total capacitance is doubled. The high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 are divided by the high-power resistor R2 and the resistor R3; the gas discharge tube F1 is connected in series with the varistor RY1 and then in parallel at both ends of the resistor R3 for sampling by the high-voltage measurement and display unit, which can effectively prevent the high-voltage sampling voltage from being too high and damaging the high-voltage measurement unit.

[0050] The self-locking switch S3 with light has two groups of contacts. The common end of one group of contacts is connected to a 5V power supply, and the normally open contact is connected to one end of the coil of the Hongfa HF115F electromagnetic relay K1, which is used to control the AC 220V input power supply to power the high-voltage pulse transformer or isolate the 220V power output; the common end of the other group of contacts is connected to a 12V power supply, and the normally open contact is connected to one end of the coil of the high-voltage reed switch relay K2 and relay K3, which is used to control the output of the impact current or leakage current. The normally open contact of this group is connected to the positive pole of the indicator light of the self-locking switch S3 with light, and the negative pole of the indicator light is connected to the ground of the 12V power supply; the other end of the coil of the Hongfa HF115F electromagnetic relay K1 is connected to the ground of the 220V leakage current generation and leakage current monitoring DC power transformer T3, and the other end of the coil of the relay K2 and relay K3 is connected to the ground of the step-down transformer T2 power supply.

[0051] One end of the high-power aluminum shell resistor RJ1 is connected to the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 respectively, and the other end is connected in series with the high-power spring resistor RL1, and then connected to the normally open contact of the high-voltage vacuum relay K4. The common end of the high-voltage vacuum relay K4 is connected to the high-voltage terminal L / +; the negative poles of the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 are connected to the high-voltage terminal N / -.

[0052] The two ends of the secondary side of the step-down transformer T2 are respectively connected to the two AC input ends of the bridge rectifier U1; the positive output end of the bridge rectifier U1 is connected to the positive electrodes of the filter capacitor C1, the filter capacitor C2 and the input end of the three-terminal regulator U2; the negative output end of the bridge rectifier U1 is connected to the negative electrodes of the filter capacitor C1, the filter capacitor C2 and the ground end of the three-terminal regulator U2; the output end of the three-terminal regulator U2 is connected to the positive electrodes of the filter capacitor C5, the filter capacitor C6, and the negative electrodes of the filter capacitor C5, the filter capacitor C6 are grounded.

[0053] The coil of the high-voltage vacuum relay K4 is controlled by a key switch S4. One end of the key switch S4 is connected to a 12V DC power supply, the other end of the key switch S4 is connected to one end of the coil of the high-voltage vacuum relay K4, and the other end of the coil of the high-voltage vacuum relay K4 is grounded.

[0054] When the power socket J1 is powered on and the boat-type switch S2 is turned on, the step-down transformer T2 is powered on and starts to work, outputting the stepped-down voltage, which is rectified by the bridge rectifier U1 to generate an unregulated DC 12V power supply, which is filtered by the filter capacitors C1 and C2, stabilized by the three-terminal voltage regulator U2, and filtered again by the filter capacitors C5 and C6 to obtain a stable 5V DC power supply.

[0055] Press the two sets of conversion self-locking switches S3 with indicator lights, and the pin L1 of the conversion self-locking switch S3 is connected to the normally open contact to obtain a 12V DC voltage, while the pin L2 of the conversion self-locking switch S3 is grounded, and the indicator light of the conversion self-locking switch S3 is on; at the same time, the 3rd and 2nd pins of the normally open contact of the conversion self-locking switch S3 are connected, and the coil of the Hongfa HF115F electromagnetic relay K1 obtains a 5V power supply, and the coil of the Hongfa HF115F electromagnetic relay K1 is energized and attracted, and one end of the key switch S1 is connected to the live wire L of the AC220V power supply; the 4th pin of the conversion self-locking switch S3 is disconnected, the coils of relays K2 and K3 lose the 12V power supply, and their normally open contacts are disconnected, and the leakage measurement circuit is disconnected. In this embodiment Figure 2 In the figure, 1, 2, 3, 4, 5 and 6 represent pin 1, pin 2, pin 3, pin 4, pin 5 and pin 6 of the self-locking switch S3 respectively.

[0056] Press the key switch S1, the primary side of the high-voltage pulse transformer T1 obtains AC220V, starts working, and outputs high-voltage AC power. After the high-voltage AC power is limited by the high-power resistor R1, the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 are charged through the half-wave rectification composed of the high-voltage rectifier diode D1 and the high-voltage rectifier diode D2. The charging voltage gradually increases, and the time from 0V to full is 5RC, which takes 20s in this embodiment. The charging voltage is divided by the high-power resistor R2 and the metal mold resistor R3, and the sampling voltage is connected to both ends of the metal mold resistor R3. To prevent high-voltage shock, the gas discharge tube F1 is connected in series with the varistor RV1 and connected to both ends of the resistor R3, and then detected by the high-voltage measurement display unit CN1. When the voltage value of the high-voltage measurement display unit CN1 reaches the desired value, release the key switch S1 to stop charging the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2. In this way, a high-voltage charging process is completed.

[0057] When the pushbutton switch S4 is pressed, the coil of the high-voltage vacuum relay K4 is energized by a 12V power supply, and the high-voltage electricity flows from the high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 through the high-power aluminum shell resistor RJ1 and the high-power spring resistor RL1, and is output to the lightning arrester monitoring device under test. The normally open contact of the high-voltage vacuum relay K4 is connected to the high-voltage terminal. This causes the device under test to be subjected to a high-voltage shock. Because the lightning arrester monitoring device is similar to MOA oxide, the resistance value changes with the voltage in a nonlinear relationship, which is higher than its withstand voltage part, and the resistance value is close to zero ohm, generating a shock wave similar to 8 / 20μs, and its counter is activated by the high-voltage shock. The high-voltage pulse capacitor CHV1 and the high-voltage pulse capacitor CHV2 are discharged due to high voltage, and the stored energy is quickly exhausted until it drops below the residual voltage of several hundred V.

[0058] Combination Figure 2, the process of generating AC leakage, DC leakage and performing leakage verification by the lightning arrester verification system provided by this embodiment is described. On the basis of the above wiring, the other end of the boat switch S2 is also connected to one end of the primary side of the transformer T3, a group of outputs of the transformer T3 is connected to the AC input end of the rectifier bridge U3, the output end of the rectifier bridge U3 is connected to the positive electrode of the filter capacitor C7, the filter capacitor C8 and the input end of the three-terminal voltage regulator U4, and the negative electrode of the rectifier bridge U3 is grounded; the 5V output end of the three-terminal voltage regulator is connected to the positive electrode of the filter capacitor C9 and the filter capacitor C10, and the negative electrode of the three-terminal voltage regulator is grounded; another group of outputs of the transformer T3 is a 220V isolated power supply, and its two ends are respectively connected to the two ends of the adjustable potentiometer R4, and the middle tap of the adjustable potentiometer R4 is connected to the common end of another group of contacts of the Hongfa HF115F electromagnetic relay K1, and the normally closed contacts of the group of contacts are connected to the normally closed contacts of a group of contacts of the relay K5, and the normally closed contacts of the other group of contacts of the relay K5 are connected to the other end of the output isolated 220V voltage in the secondary side of the transformer T3.

[0059] Two sets of conversion self-locking switches S5 with indicator lights control the switching of AC leakage and DC leakage during calibration. The coil power supply of electromagnetic relay K5, relay K6 and relay K7 is controlled by key switch S5. Figure 2 The S in the figure indicates the connection between the key switch S5 and the electromagnetic relays K5, K6 and K7. The two AC power supplies output by the adjustable potentiometer R4 (both output through the interface ACX1) are connected to the two normally closed contacts of the electromagnetic relay K5. The two AC power supplies output by the adjustable potentiometer R4 are also connected to the two AC input terminals of the bridge rectifier U6. The two output terminals of the bridge rectifier U6 are filtered by the filter capacitor C11 and then connected to the two normally open contacts of the electromagnetic relay K5 (connected through the interface DCX+ and the interface DCX-). The common terminal of the relay K6 (interface XL1 and interface XL2) is connected to the common terminal of the relay K5 (interface XL1 and interface XL 2) Connection, the normally open contact of relay K6 is connected to the common end of relay K2 through resistor R8 (connected through interface XLO2, the common end of relay K2 is interface XL-L), and the normally open contact of relay K6 is connected to the common end of relay K3 through resistor R9 (connected through interface XLO1, the common end of relay K3 is interface XL-N); resistor R8 is connected in parallel with gas discharge tube F2, and resistor R9 is connected in parallel with gas discharge tube F3, which are used to absorb the high voltage remaining due to the impulse current test and the high voltage shock when switching to leakage verification; the normally open contact of relay K2 is connected to the high voltage terminal L / +, and the normally open contact of relay K3 is connected to the high voltage terminal N / -.

[0060] When the two sets of conversion self-locking switches S5 with indicator lights pop up, the indicator lights go out; relays K5, K6 and K7 are released; the two common ends of relay K5 are respectively connected to the middle tap of the adjustable potentiometer R4 and the isolated AC220V neutral line output by the transformer T3, the two common ends of relay K5 are connected to the middle tap of the adjustable potentiometer R4 through interfaces ACX1 and ACX2, and the two common ends of relay K6 are respectively connected to the normally closed contacts; at this time, there is 12V DC on the coils of relays K2 and K3, the common end of relay K2 is connected to the normally open contact, the common end of relay K3 is connected to the normally open contact, and the common ends of relays K2 and K3 are also connected to the high-voltage terminals L / + and N / -, respectively, to output AC current to the lightning arrester monitoring device under test, and the leakage current is changed by adjusting the knob of the adjustable potentiometer R4. The output leakage current loop is also connected in series with relay K7. When K7 is released, the AC leakage current passes through the bridge rectifier U5, converting the AC current into DC current, and then inputting it into the leakage current measurement and display unit CN2. The sampled display value is adjusted through resistors R6 and R7. By comparing the leakage current measurement and display unit CN2 with the indicated value of the device under test, the error of the device under test can be determined.

[0061] The two output ends of the bridge rectifier U5 are filtered by a filter capacitor C12, and the filter capacitor C12 and the resistor R17 are connected in parallel.

[0062] When the two sets of conversion self-locking switches S5 with indicator lights are pressed, the indicator lights are on, and relays K5, K6, and K7 are energized; the two common terminals of relay K5 are respectively connected to the normally open contacts, and the DC voltage rectified by the rectifier bridge U6 is connected to the normally open contact of relay K5, and the common terminal of relay K5 outputs a DC voltage; the two normally open contacts of relay K6 are respectively connected to the common terminal; at this time, there is still 12V on the coils of high-voltage vacuum relays K2 and K3, and the common terminals of high-voltage vacuum relays K2 and K3 are respectively connected to the normally open contacts, and the high-voltage vacuum relays K2 and K3 are respectively connected to the normally open contacts. The common end of the electrical appliance K3 is also connected to the high-voltage terminal, and a DC current is output to the lightning arrester monitoring device under test. The leakage current is changed by adjusting the knob of the adjustable potentiometer R4. The output leakage current loop is also connected in series with the relay K7. The relay K7 is energized, and the DC current is rectified again through the bridge rectifier U5 (the relay K7 and the bridge rectifier U5 are connected through the interfaces INA+ and INA-), and the input leakage current measurement and display unit CN2 is connected between the relay K7 and the leakage current measurement and display unit CN2 through the interfaces INB+ and INB-, and the sampling display value is adjusted through the resistors R5 and R7. Compare the leakage measurement display unit CN2 with the indicated value of the device under test to determine the error of the device under test.

[0063] In this embodiment Figure 2 , the resistance of resistor R1 is 1MΩ, the resistance of resistor R2 is 80MΩ, the resistance of resistor R3 is 330Ω, the resistance of resistor RJ1 is 1Ω, the resistance of resistor RL1 is 10Ω, the capacitance of high-voltage pulse capacitor CHV1 and high-voltage pulse capacitor CHV2 is 1μF, the rated voltage is 10kV, the capacitance of capacitor C1 is 1000μF, the capacitance of capacitor C2 is 100nF, the capacitance of capacitor C5 is 1000μF, the capacitance of capacitor C6 is 100nF, the capacitance of capacitor C7 is 1000μF, the capacitance of capacitor C8 is 100nF, the capacitance of capacitor C9 is 1000μF, the capacitance of capacitor C10 is 100nF, IN represents the input terminal, OUT represents the output terminal, GND represents the common terminal, AC represents the current flowing through the port is alternating current, 5VH represents the high level of 5 volts, and GNDH represents the high level common terminal.

[0064] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A lightning arrester calibration system, characterized in that: include: Power supply, current output unit, current generation control unit, anti-interference unit, protection unit; The power supply is used to generate the current required for arrester calibration and output the generated current to the current output unit, and the circuits generating different currents in the power supply are not connected to each other, and the currents include impact current, leakage current and measurement and control current; The current output unit is used to control the output of the current, and the current generation control unit is used to control the process of the power supply generating current; The anti-interference unit is connected to the power supply and is used to disconnect the path of the leakage current output by the power supply during the impulse current test, and to isolate the input of the circuit for generating the impulse current in the power supply during the leakage current test; The protection unit is used to shunt the impulse current during the impulse current test, and is also used to absorb and store the residual high voltage in the circuit when switching from the impulse current test to the leakage current test.

2. The arrester calibration system according to claim 1, characterized in that: The power supply includes an impact current generating circuit, a first measurement and control current generating circuit, an AC leakage current generating circuit, a second measurement and control current generating circuit, a DC leakage current generating circuit and a third measurement and control current generating circuit; The arrester inspection includes impulse current test, AC leakage current test and DC leakage current test; The impulse current generating circuit is used to generate the impulse current required for lightning arrester calibration; The first measurement and control current generating circuit is used to generate the first measurement and control current required in the arrester calibration, and the first measurement and control current is the measurement and control current used when the impulse current is used to perform an impulse current test; The AC leakage generating circuit is used to generate the AC leakage current required for lightning arrester calibration; The second measurement and control current generating circuit is used to generate a second measurement and control current required for lightning arrester calibration, and the second measurement and control current is a measurement and control current used when performing an AC leakage current test using the AC leakage current; The DC leakage current generating circuit is used to generate the DC leakage current required for lightning arrester calibration; The third measurement and control current generating circuit is used to generate the third measurement and control current required in the arrester calibration, and the third measurement and control current is the measurement and control current used when the DC leakage current is used to perform a DC leakage current test.

3. The arrester calibration system according to claim 2, characterized in that: The impulse current generating circuit comprises a power supply unit, an AC high-voltage pulse transformer, a bridge rectifier and a high-voltage pulse capacitor connected in sequence, wherein the AC high-voltage pulse transformer is used to convert the current provided by the power supply unit into an AC high voltage and transmit it to the bridge rectifier, the bridge rectifier is used to convert the AC high voltage into a DC high voltage and transmit it to the high-voltage pulse capacitor, and the high-voltage pulse capacitor is used to store the energy of the impulse current generated by the DC high voltage and output the impulse current; The first measurement and control current generating circuit, the AC leakage current generating circuit, the second measurement and control current generating circuit, the DC leakage current generating circuit and the third measurement and control current generating circuit are respectively connected to different transformers for power supply units.

4. The arrester calibration system according to claim 1, characterized in that: The current output unit includes two high-voltage reed switch relays and a self-locking switch, each of the high-voltage reed switch relays includes a normally open contact, a normally closed contact, a common terminal and a coil; When controlling the output of current, in the current output unit, two normally open contacts are respectively connected to the positive and negative poles of the impulse current output terminal in the power supply, one normally closed contact is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and another normally closed contact is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply. The common terminal is used to output the current flowing through the high-voltage reed switch relay. The two coils are connected in parallel and controlled by a self-locking switch. When the self-locking switch is turned on, the high-voltage reed switch coil is energized and attracted. At this time, the normally open contact is connected to the common terminal, and the impact current provided by the power supply is output through the common terminal; when the self-locking switch is turned off, the high-voltage reed switch coil loses power and is released. At this time, the normally closed contact is connected to the common terminal, and the AC leakage current or DC leakage current provided by the power supply is output through the common terminal.

5. The lightning arrester calibration system according to claim 3, characterized in that: The current generation control unit is an impact current generation control unit, including a resistor R1, a high-voltage vacuum relay and a manual key switch. The high-voltage vacuum relay is used to control the high-voltage pulse capacitor to generate an impact current using the DC high voltage stored in the capacitor. The high-voltage vacuum relay includes a normally open contact, a common terminal and a coil. In the impulse current generation control unit, the normally open contact is connected in series with the resistor R1, and then connected to the positive electrode of the high-voltage pulse capacitor, the common end is connected to the negative electrode of the high-voltage pulse capacitor, one end of the coil is grounded, and the other end is connected to a DC power supply through a manual key switch; When the manual push button switch is turned on, the high-voltage vacuum relay coil is energized and its normally open contact is instantly short-circuited with the common terminal.

6. The lightning arrester calibration system according to claim 3, characterized in that: The anti-interference unit includes an electromagnetic relay, a self-locking switch and a manual key switch, and the electromagnetic relay includes a normally open contact, a normally closed contact, a common terminal and a coil; In the anti-interference unit, the common end is connected to the live wire of the power supply outside the arrester calibration system, the normally open contact is connected to the live wire of the primary side of the AC high-voltage pulse transformer, the normally closed contact is connected to the live wire of the secondary side of the transformer in the AC leakage current generating circuit or the DC leakage circuit generating circuit, one end of the coil is connected to the self-locking switch, and the other end of the coil is grounded; The electromagnetic relay is controlled to be attracted and released by the self-locking switch. During the impact current test, the self-locking switch is pressed, the electromagnetic relay is in the attracted state, the normally open contact and the common terminal are in the on state, at this time the high-voltage pulse capacitor outputs impact current, the normally closed contact and the common terminal are in the off state, and the power supply does not output leakage current; during the leakage current test, the self-locking switch is popped up, the electromagnetic relay is in the released state, the normally closed contact and the common terminal are on, at this time the AC leakage current generating circuit outputs AC leakage current or the DC leakage current generating circuit outputs DC leakage current, and the impact current generating circuit does not output impact current.

7. The arrester calibration system according to claim 1, characterized in that: Also included is a leakage measurement and control unit, the leakage measurement and control unit is used to control and measure the AC leakage current and the DC leakage current generated by the power supply; The leakage measurement and control unit includes an ammeter, an adjustable potentiometer, a self-locking switch, two AC measurement current limiting resistors, two DC measurement current limiting resistors, a first micro-electromagnetic relay, a second micro-electromagnetic relay and a third micro-electromagnetic relay. The first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay have the same components, including a coil, two normally open contacts, two normally closed contacts and two common terminals. The three coils are connected in parallel and are all connected to the self-locking switch. The self-locking switch controls the attraction and release of the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay respectively through the three coils. On the first micro electromagnetic relay, the adjustable potentiometer is connected to the secondary side of the transformer in the AC leakage current generating circuit, the two common terminals are respectively connected to the adjustable terminal and the neutral terminal of the adjustable potentiometer, the two normally open contacts are respectively connected to the two input terminals of the bridge rectifier, a normally closed contact is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and the other normally closed contact is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply; On the second micro electromagnetic relay, two normally open contacts are respectively connected to two output terminals of the bridge rectifier, two normally closed contacts are suspended, one common terminal is connected to the live wire of the AC leakage current output terminal and the positive pole of the DC leakage current output terminal in the power supply, and the other common terminal is connected to the neutral wire of the AC leakage current output terminal and the negative pole of the DC leakage current output terminal in the power supply; On the third micro electromagnetic relay, two normally closed contacts are respectively connected to two AC measuring current limiting resistors for measuring AC leakage current, two normally open contacts are respectively connected to two DC measuring current limiting resistors, and two common terminals are connected to both ends of the ammeter input; When the first micro-electromagnetic relay is released, and the third micro-electromagnetic relay is released, the first micro-electromagnetic relay and the third micro-electromagnetic relay cooperate to complete the measurement of the AC leakage current; When the first micro-electromagnetic relay is energized, the second micro-electromagnetic relay is energized, and the third micro-electromagnetic relay is energized, the first micro-electromagnetic relay, the second micro-electromagnetic relay and the third micro-electromagnetic relay cooperate to complete the measurement of the DC leakage current.

8. The arrester calibration system according to claim 3, characterized in that: The protection unit includes three gas discharge tubes, three varistors, three bidirectional TVS diodes, a first sampling resistor and a second sampling resistor. The first gas discharge tube, the first varistor and the first bidirectional TVS diode are connected in series and connected in parallel with the AC leakage generation circuit. The second gas discharge tube, the second varistor and the second bidirectional TVS diode are connected in series and connected in parallel with the DC leakage generation circuit. The first sampling resistor and the second sampling resistor are both connected in parallel at both ends of the high-voltage pulse capacitor. The second sampling resistor is connected in parallel with the third gas discharge tube. The third varistor and the third bidirectional TVS diode are connected in series and connected in parallel with the second sampling resistor. The resistance value of the first sampling resistor is greater than the resistance value of the second sampling resistor.

9. The lightning arrester calibration system according to claim 1, characterized in that: The distance between the high-voltage devices and the low-voltage devices in the power supply, current output unit, current generation control unit, anti-interference unit, and protection unit is greater than 10 mm. The wires through which the impact current flows are made of silicone wire with a withstand voltage rating of 30 kV or above, and grooves are opened in the set area around the high-voltage devices.

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