CN116908628A - Heavy current arc test device - Google Patents

Abstract

The embodiment of the application provides a high-current arc test device which can solve the problem that the power of a power supply needed by the internal arc fault test of the existing high-voltage power equipment is overlarge. Wherein, the device includes: the control detection unit is used for detecting an arc current zero crossing point electric signal generated in the process of carrying out an internal arc fault test on equipment to be tested, and generating a discharge signal when the arc current zero crossing point electric signal is detected; the pulse high-voltage supply unit is connected with the control detection unit and is used for providing high-voltage pulses for the equipment to be tested under the condition that the discharge signal is received; and the power supply unit is used for providing arc current for the equipment to be tested and providing electric energy for the pulse high-voltage supply unit. The device can provide high-voltage pulse for the equipment to be tested through the pulse high-voltage supply unit at the moment of the zero crossing point of the arc current so as to reburning the arc, thereby reducing the power of the power supply required by the internal arc fault test.

Description

Heavy current arc test device

Technical Field

The application belongs to the technical field of arc tests, and particularly relates to a high-current arc test device.

Background

Internal insulation faults can be avoided in high-voltage power equipment, once the internal insulation breakdown is easy to cause serious internal arc faults, the equipment shell can be broken or even exploded due to high voltage and high current, and explosion resistance of the high-voltage power equipment can be verified by internal arc fault tests in many high-voltage electrical equipment laboratories in the world.

The existing internal arc fault test needs to adopt a power supply with no-load voltage not lower than 10kV, the power of the power supply is at least hundreds of MVA under the condition that the test current is tens of kA, so that a high-power supply cannot take a power grid as the power supply, and if an impact generator is adopted as the power supply, huge capital is required to be invested for meeting the normal work of the impact generator and the later maintenance is complex.

Disclosure of Invention

The embodiment of the application provides a high-current arc test device which can solve the problem that the power of a power supply needed by the internal arc fault test of the existing high-voltage power equipment is overlarge.

The high-current arc test device comprises:

the control detection unit is used for detecting an arc current zero crossing point electric signal generated in the process of carrying out an internal arc fault test on equipment to be tested, and generating a discharge signal when the arc current zero crossing point electric signal is detected;

the pulse high-voltage supply unit is connected with the control detection unit and is used for providing high-voltage pulses for the equipment to be tested under the condition that the discharge signal is received;

and the power supply unit is used for providing arc current for the equipment to be tested and providing electric energy for the pulse high-voltage supply unit.

Optionally, the method further comprises:

the first transformer is connected between the power supply unit and the pulse high-voltage supply unit, and the power supply unit is used for supplying electric energy to the pulse high-voltage supply unit through the first transformer;

the second transformer is connected between the power supply unit and the equipment to be tested, and the power supply unit is used for providing arc current for the equipment to be tested through the second transformer.

Alternatively to this, the method may comprise,

the control detection unit includes:

a pulse power supply unit;

the control unit is used for acquiring a loop voltage electric signal and an arc current zero crossing point electric signal according to the arc current and transmitting the loop voltage electric signal and the arc current zero crossing point electric signal to the pulse power supply unit;

the pulse power supply unit is used for outputting a first pulse electric signal when the loop voltage electric signal is a negative loop voltage electric signal and outputting a second pulse electric signal when the loop voltage electric signal is a positive loop voltage electric signal;

the voltage transformation unit is used for boosting the pulse electric signal;

and the selection unit is used for controlling the pulse high-voltage supply unit to supply the high-voltage pulse according to the boosted pulse electric signal.

Optionally, the pulse high voltage supply unit includes:

the rectification unit comprises a full-bridge rectification circuit and a low-pass filter circuit and is used for converting the alternating current provided by the first transformer into direct current;

the first charge-discharge unit or the second charge-discharge unit is used for providing the high-voltage pulse for the device to be tested based on the pulse electric signal;

and the isolation unit is used for protecting the charge-discharge unit by limiting current under the condition that the charge-discharge unit provides the high-voltage pulse.

Optionally, the selecting unit is configured to:

controlling the first charge-discharge unit to supply the high-voltage pulse in the case that the pulse electric signal is the first pulse electric signal,

and controlling the second charge-discharge unit to provide the high-voltage pulse under the condition that the pulse electric signal is the second pulse electric signal.

Alternatively to this, the method may comprise,

the first charge-discharge unit includes a first capacitor,

the second charge-discharge unit includes a second capacitor,

the first capacitor and the second capacitor are connected in series,

the isolation unit is connected in series between the low-pass filter circuit and the first capacitor,

the positive plate of the first capacitor is connected with the isolating unit,

the negative plate of the second capacitor is connected with the direct current output end of the full-bridge rectifying circuit,

the negative plate of the first capacitor and the positive plate of the second capacitor are connected with the non-grounding end of the device to be tested.

Alternatively to this, the method may comprise,

the control unit comprises a current transformer and a voltage transformer,

the current transformer is connected in series in the secondary side loop of the second transformer and is used for transmitting the electric signal of the arc current zero crossing point to the pulse power supply unit,

the voltage transformer is connected in parallel with the secondary side loop of the second transformer and is used for sending the loop voltage signal to the pulse power supply unit.

Alternatively to this, the method may comprise,

the selection unit comprises a first controllable discharge ball gap and a second controllable discharge ball gap,

the trigger electrode of the controllable discharge ball gap is connected with the transformation unit,

the cathode of the controllable discharge ball gap is connected with the voltage transformation unit and the grounding end of the equipment to be tested,

the anode of the first controllable discharge ball gap is connected with the positive plate of the first capacitor,

the anode of the second controllable discharge ball gap is connected with the cathode plate of the second capacitor,

the trigger electrode of the first controllable discharge ball gap is used for receiving the first pulse electric signal,

and the trigger electrode of the second controllable discharge ball gap is used for receiving the second pulse electric signal.

Alternatively to this, the method may comprise,

the power supply unit comprises a first power supply and a second power supply,

the first power supply is configured to supply power to the first transformer,

the second power supply is used for providing electric energy for the second transformer.

Optionally, the method further comprises:

the reactor is connected in series with the secondary side loop of the second transformer,

for regulating the arc current.

In summary, the embodiment of the application provides a high-current arc test device, which comprises: the control detection unit is used for detecting an arc current zero crossing point electric signal generated in the process of carrying out an internal arc fault test on equipment to be tested, and generating a discharge signal when the arc current zero crossing point electric signal is detected;

the pulse high-voltage supply unit is connected with the control detection unit and is used for providing high-voltage pulses for the equipment to be tested under the condition that the discharge signal is received; and the power supply unit is used for providing arc current for the equipment to be tested and providing electric energy for the pulse high-voltage supply unit. The device provided by the embodiment of the application can be used for setting the control detection unit to acquire the electric signal of the arc current zero crossing point according to the arc current under the condition of carrying out an internal arc fault test on the equipment to be tested, and controlling the pulse high-voltage supply unit to provide a high-voltage pulse for the equipment to be tested under the condition of detecting the electric signal of the arc current zero crossing point, so that an extra high-voltage pulse can be generated at two ends of an arc gap of the equipment to be tested at the moment of the arc current zero crossing point, and the arc gap can be broken down to reburning the arc. The arc gap is broken down and has a high voltage difference, and due to the influence of an inductance device, a capacitance device and a resistance device in high-voltage power equipment, a phase difference exists between alternating current and alternating voltage, at the moment when the alternating current is close to zero, namely, the moment when the arc current passes through zero, the alternating voltage is far smaller than peak voltage, at the moment, the voltage difference of the arc gap is insufficient to break down the arc, so that the temperature of the arc gap can be reduced, the dielectric strength of the arc gap can be quickly recovered, the internal arc fault test is failed, a power supply outputting high voltage is usually adopted in the conventional technology, the output voltage is usually above 10kV, the total power of the power supply is above hundreds of MVA, so that even at the moment when the arc current passes through zero, the voltage difference of the arc gap is still large enough to keep the arc gap broken down, the application additionally provides a high-voltage pulse for the arc gap under the condition of the zero crossing point of the arc current by arranging the pulse high-voltage supply unit so as to reburning the arc gap, thus a main power supply is not needed to provide voltage for puncturing the arc gap for the arc gap of the equipment to be tested at the moment of the zero crossing point of the arc current, thereby reducing the requirement of main power supply voltage for carrying out internal arc fault test on the equipment to be tested, and then reducing the requirement of main power supply power, while the pulse high-voltage supply unit only provides a high-voltage pulse for puncturing the arc gap at the moment of the zero crossing point of the arc current, so the pulse high-voltage supply unit does not consume excessive high power, and in combination, compared with the prior art, the high-current arc test device provided by the application has lower total power consumption, thus the power requirement on the power supply is lower, the investment and the maintenance cost of test equipment are reduced, there are also more choices of the type of power supply.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for the purpose of illustrating preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the figures.

In the drawings:

FIG. 1 is a schematic circuit diagram of an internal arc fault test apparatus provided by an embodiment of the present application;

fig. 2 is a schematic diagram of an application scenario of a possible high-current arc test device according to an embodiment of the present application;

FIG. 3 is a schematic diagram of another possible scenario of the application of the high-current arc test apparatus according to the embodiment of the present application;

FIG. 4 is a schematic diagram of another possible scenario of the application of the high-current arc test apparatus according to the embodiment of the present application;

FIG. 5 is a schematic diagram of an application scenario of another possible high-current arc test apparatus according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a power supply voltage and arc current waveform according to an embodiment of the present application;

fig. 7 is a schematic diagram of an application scenario of another possible high-current arc test apparatus according to an embodiment of the present application;

FIG. 8 is a schematic diagram of an application scenario of a possible high-current arc test apparatus according to an embodiment of the present application;

fig. 9 is a schematic diagram of an application scenario of another possible high-current arc test apparatus according to an embodiment of the present application;

fig. 10 is a schematic diagram of an application scenario of a possible high-current arc test apparatus according to an embodiment of the present application.

Detailed Description

The embodiment of the application provides a high-current arc test device which can solve the problem that the power of a power supply needed by the internal arc fault test of the existing high-voltage power equipment is overlarge.

The terms "first," "second," "third," "fourth" and the like in the description and in the claims and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments.

For convenience of explanation, in some cases, an internal arc fault test device may be shown in fig. 1, AC represents a power supply of an impact generator, TX represents a transformer, OTT represents a high-voltage device to be tested, D1 and D2 represent a circuit breaker, E1 represents a reactor, and GND ground belongs to a conventional arrangement, and is not described. The AC generates more than 10kV voltage on a secondary side loop of TX, loop current is more than tens of kA, in the process of performing internal arc fault test, an arc current zero crossing phenomenon can be generated due to the alternating current characteristic, and high voltage is still present on two sides of an arc gap of high-voltage equipment to be tested at the moment of a current zero crossing point by providing more than 10kV voltage, so that arc reignition is ensured, but in this way, the power supplied to a power supply needs to be more than hundreds of MVA to meet the requirement, the requirement cannot be realized in a laboratory using a power grid as the power supply, and a large amount of investment and later maintenance are required for configuring an impact generator.

In view of the above, the application provides a high-current arc test device, which can solve the problem that the power of a power supply needed by the internal arc fault test of the prior high-voltage power equipment is overlarge.

Referring to fig. 2, an application scenario schematic diagram of a high-current arc test apparatus according to an embodiment of the present application is provided, where the apparatus includes:

a control detecting unit 300 for detecting an arc current zero crossing electrical signal generated in the process of performing an internal arc fault test on the device 400 to be tested, and generating a discharge signal when the arc current zero crossing electrical signal is detected;

a pulse high voltage supply unit 200 connected to the control detection unit 300 for supplying a high voltage pulse to the device under test 400 upon receiving the discharge signal;

and a power supply unit 100 for supplying arc current to the device under test 400 and supplying power to the pulsed high voltage supply unit 200.

Illustratively, the pulse high voltage supply unit 200 and the device under test 400 are connected in parallel to the power supply unit 100, the power supply unit 100 provides the device under test 400 with an arc current for performing an internal arc fault test, the control detection unit 300 obtains an arc zero-crossing electrical signal according to the arc current, generates a discharge signal when the arc zero-crossing electrical signal is detected, and the pulse high voltage supply unit 200 can provide the device under test 400 with a high voltage pulse according to the discharge signal, so that the device under test 400 generates a high voltage in the arc gap when the arc is extinguished, and the arc gap of the device under test 400 is reburned.

It should be noted that, in order for the apparatus 400 to be tested to be able to perform an internal arc fault test, the apparatus 400 to be tested needs to maintain a high voltage in the arc gap, and at the moment of the arc zero crossing, the arc current drops to zero, the arc is extinguished, the strength of the insulating medium is quickly recovered, and if the voltage applied to the gap cannot break down the gap again at this time, the arc cannot be re-ignited and the test fails. In order to generate the arc again, the arc gap needs to be kept at a high voltage at the moment of the arc current zero crossing. By controlling the moment when the detecting unit 300 detects the zero crossing point of the arc and generating the discharge signal, the pulse high voltage supplying unit 200 can provide a high voltage pulse for the arc gap based on the discharge signal, so that the arc gap additionally obtains a high voltage pulse outside the voltage provided by the original power supplying unit 100, the voltage difference of the arc gap meets the arc reignition condition, and the arc reignition is ensured before the intensity of the insulating medium is completely recovered, so that the normal operation of the internal arc fault test is ensured.

According to the embodiment, the control detection unit is arranged to obtain the electric signal of the zero crossing point of the arc current according to the arc current, and the pulse high-voltage supply unit is controlled to provide a high-voltage pulse for the equipment to be tested under the condition that the electric signal of the zero crossing point of the arc current is detected, so that an extra high-voltage pulse can be generated at two ends of the arc gap of the equipment to be tested at the moment of the zero crossing point of the arc current, the arc gap can be broken down, so that the arc reignites, and the pulse high-voltage supply unit only provides a high-voltage pulse at the moment of the zero crossing point of the arc current to break down the arc gap, so that the pulse high-voltage supply unit does not consume excessive high power.

According to some embodiments, further comprising:

a first transformer 500 connected between the power supply unit 100 and the pulse high voltage supply unit 200, the power supply unit 100 being configured to supply the pulse high voltage supply unit 200 with electric power through the first transformer;

a second transformer 600 connected between the power supply unit and the device under test 400, wherein the power supply unit 100 is configured to provide an arc current to the device under test 400 through the second transformer 600;

fig. 3 is a schematic diagram of an application scenario of another high-current arc test apparatus according to an embodiment of the present application, where a first transformer 500 and a second transformer 600 are connected in series between a power supply unit 100 and a pulse high voltage supply unit 200, and between the power supply unit 200 and a device 400 to be tested, respectively, so that a secondary side view of the transformers can be used as power supplies of the pulse high voltage supply unit 200 and the device 400 to be tested.

It should be noted that, the secondary side of the second transformer 600 is used to provide the arc current to the device under test 400, and it is understood that the voltage across the device under test 400 is approximately equal to the no-load voltage of the second transformer 600, which is required to ensure breakdown of the arc gap, the first transformer 500 provides the pulse high voltage supply unit 200 with power, and the secondary side of the first transformer 500 outputs a higher voltage to ensure that the pulse high voltage supply unit 200 can provide a high voltage pulse to the arc gap at the moment of the arc zero crossing point.

It may be further described that the secondary side of the second transformer 600 may output a lower voltage, such as 2.5kV, which may ensure that the arc gap maintains a breakdown state at a time point of non-current zero crossing, and may provide an arc current of several tens kA, such as 60kA, and the primary side power of the transformer is approximately equal, and the secondary side of the first transformer 500 may output a high voltage, such as 50kV, according to the above numerical example, so that the pulse high voltage supply unit 200 may output a high voltage pulse to the arc gap, thereby enabling arc reignition of the arc gap at the time point of current zero crossing. The secondary side loop of the first transformer 500 charges the capacitor through the resistor, and the capacitor is full, so that the power supply is not needed to supply energy, and the average current of the secondary side loop of the first transformer 500 is very small, such as 20A, so that the lower power output of the secondary side of the first transformer 500 is ensured to be about 1MVA. The primary side power of the first transformer 500 is also approximately 1MVA, so that the power supplied by the power supply unit 100 needs to be greater than 151 MVA. It is easy to understand that in a typical practical test environment, more than one hundred MVAs of power can be directly supplied by the power grid.

According to the embodiment, the high-current arc test device provided by the application has the advantages that the transformer outputting high power and low voltage is arranged to meet the requirement of arc gap breakdown of equipment to be tested at the moment of non-arc current zero crossing point, the transformer outputting low power and high voltage is used for the pulse supply unit to generate a high-voltage pulse, the high-voltage pulse can break down the arc gap at the moment of arc current zero crossing point so as to reburning the arc, the normal operation of an internal arc fault test is ensured, meanwhile, the power requirement on a power supply is reduced, a high-power impact discharge machine is not required, the requirement of the test on the power supply can be met by using a power grid power supply or an alternating current asynchronous generator with proper power, so that the fund cost of an internal fault test is greatly reduced, and the follow-up maintenance cost is also reduced because the impact generator is not required to be configured.

According to some embodiments, the control detection unit 300 comprises:

a pulse power supply unit 340;

the control unit 310 is configured to obtain a loop voltage electrical signal and an arc current zero crossing electrical signal according to an arc current and transmit the loop voltage electrical signal and the arc current zero crossing electrical signal to the pulse power unit 340;

wherein the pulse power supply unit 340 is configured to output a first pulse electrical signal when the loop voltage electrical signal is a negative loop voltage electrical signal, and output a second pulse electrical signal when the loop voltage electrical signal is a positive loop voltage electrical signal;

a voltage transformation unit 320 for boosting the pulse electric signal;

and a selection unit 330 for controlling the pulse high voltage supply unit 200 to supply the high voltage pulse according to the boosted pulse electric signal.

As shown in fig. 4, the control unit 310 may detect a loop voltage electric signal and an arc current zero crossing electric signal from an arc current and transmit the signals to the pulse power unit 340, where the pulse power unit 340 may be configured to output a pulse electric signal when the arc current zero crossing electric signal and the loop voltage electric signal are obtained, output a first pulse electric signal when the loop voltage electric signal is obtained as a loop voltage electric signal with a negative polarity, output a second pulse electric signal when the loop voltage electric signal is obtained as a loop voltage electric signal with a positive polarity, and the voltage transforming unit 320 may boost the pulse electric signal to meet the triggering requirement of the selecting unit 330, and the selecting unit 330 may control the pulse high voltage supply unit 200 to supply a high voltage pulse to the device under test 400 according to the boosted pulse electric signal, so that the arc gap is reburned at the moment of the current zero crossing.

According to some embodiments, the pulsed high voltage supply unit 200 includes:

a rectifying unit 210 including a full-bridge rectifying circuit 211 and a low-pass filter circuit 212 for converting the alternating current supplied from the first transformer 500 into direct current;

the first charge-discharge unit 230 and the second charge-discharge unit 240, where the first charge-discharge unit 230 or the second charge-discharge unit 240 is configured to provide the high-voltage pulse to the device under test 400 based on the pulse electric signal;

and an isolation unit 220 for protecting the charge and discharge unit by limiting a current in case the charge and discharge unit supplies the high voltage pulse.

For example, fig. 5 is a schematic diagram of an application scenario of another high-current arc test apparatus provided by the present disclosure, where as shown in the drawing, the rectifying unit 210 includes a full-bridge rectifying circuit 211 and a low-pass filtering circuit 212, and the full-bridge rectifying circuit 211 is adopted to improve the utilization rate of the ac power supply, and the low-pass filtering circuit 212 can output a smooth dc current, and meanwhile, the low-pass filtering circuit 212 can adapt to the operating frequency of the ac power of the power grid. The first charge and discharge unit 230 or the second charge and discharge unit 240 may supply a high voltage pulse to the device under test 400 through discharge based on the pulse electric signal generated by the pulse power supply unit 340 to re-ignite the above-described arc gap of the device under test 400 at the time of the current zero crossing. The isolation unit 220 may limit the current to protect the charge and discharge unit in case the charge and discharge unit increases the high voltage pulse.

According to some embodiments, the selecting unit 330 is configured to:

controlling the first charge-discharge unit to supply the high-voltage pulse in the case that the pulse electric signal is the first pulse electric signal,

and controlling the second charge-discharge unit to provide the high-voltage pulse under the condition that the pulse electric signal is the second pulse electric signal.

As illustrated in fig. 5, the pulse power supply unit 340 outputs a first pulse electric signal in the case where the loop voltage electric signal is acquired as a negative polarity loop voltage electric signal, outputs a second pulse electric signal in the case where the loop voltage electric signal is acquired as a positive polarity loop voltage electric signal, the voltage transformation unit 320 may boost the pulse electric signal, the selection unit 330 controls the first charge and discharge unit 230 to discharge to provide a high voltage pulse to the device under test 400 in the case where the boosted first pulse electric signal is acquired, and controls the second charge and discharge unit 240 to discharge to provide a high voltage pulse to the device under test 400 in the case where the boosted second pulse electric signal is acquired.

It should be noted that, in the large-current arc test apparatus provided in the embodiment of the present application, by setting two charging and discharging units and discharging based on different polarities of loop voltage signals, high-voltage pulses can be provided by both an upper half-wave form and a lower half-wave form of alternating current, for convenience of description, a schematic diagram of power supply voltage and arc current waveforms is provided in the embodiment of the present application, as shown in fig. 6, the power supply voltage waveform diagram is a waveform of voltage on the secondary side of the second transformer, the voltage peak value is about 2.5kV, the arc current waveform diagram is a schematic waveform of arc current corresponding to voltage on the secondary side of the second transformer, the current peak value is about 50kA, and it can be seen that, in the case of zero crossing of arc current, the power supply voltage is smaller, that is, voltages at two ends of the arc gap of the to be tested device 400 are smaller, at this time, the arc is extinguished, in the embodiment of the present application, as shown by the pulse voltages in the power voltage waveform diagram, when the power voltage waveform corresponding to the zero crossing point of the arc current is the lower half waveform, the control unit 310 outputs the negative polarity loop voltage electric signal to the pulse power unit 340, the pulse power unit 340 outputs the first pulse electric signal, after being boosted by the voltage transformation unit 320, the selection unit 330 controls the first charge and discharge unit 330 to discharge to provide the high voltage pulse, and when the power voltage waveform corresponding to the zero crossing point of the arc current is the upper half waveform, the control unit 310 outputs the positive polarity loop voltage electric signal to the pulse power unit 340, the pulse power unit 340 outputs the second pulse electric signal, after being boosted by the voltage transformation unit 320, the selection unit 330 controls the second charge-discharge unit 330 to discharge to provide a high voltage pulse corresponding to the upper half pulse voltage in the power voltage waveform.

According to the embodiment, the two charging and discharging units provided by the application are respectively used for discharging based on the negative pole and positive pole loop voltage electric signals to provide high-voltage pulses, and can provide high-voltage pulses to reburn the arc gap under the condition that the power supply voltage is in an upper half wave or a lower half wave.

In accordance with some of the embodiments of the present application,

the first charge and discharge unit 230 includes a first capacitor C2,

the second charge and discharge unit 240 includes a second capacitor C3,

the first capacitor C2 and the second capacitor C3 are connected in series,

the isolation unit 220 is connected in series between the low-pass filter circuit and the first capacitor C2,

the positive plate of the first capacitor is connected to the separator 220,

the negative plate of the second capacitor is connected with the direct current output end of the full-bridge rectifying circuit,

the negative plate of the first capacitor and the positive plate of the second capacitor are connected to the non-grounded terminal of the device under test 400.

As shown in the schematic diagram of the application scenario of the high-current arc test apparatus provided in the embodiment of the present application, the first charge-discharge unit 100 includes a first capacitor C2, the first charge-discharge unit 100 includes a first capacitor C3, the power supply unit 100 generates an alternating current on the secondary side of the first transformer 500 through the first transformer 500, the alternating current generates a flat direct current through the full-bridge rectifying circuit 211 and the low-pass filter 212, the low-pass filter 212 may be composed of R1 and C1, the direct current generated through the low-pass filter 212 charges the capacitors C2 and C3 after passing through the isolation unit 220, the selection unit 330 controls the capacitor C2 to discharge to provide a high-voltage pulse to the arc gap of the device 400 under test when the negative loop voltage signal of the pulse power supply unit 340 is acquired, and the selection unit 330 controls the capacitor C3 to discharge to provide a high-voltage pulse to the arc gap of the device 400 under test when the positive loop voltage signal of the pulse power supply unit 340 is acquired.

It should be noted that, the isolation unit 220 may be a resistor with a very large resistance, which is schematically indicated that if the secondary side output voltage of the first transformer 500 is about 50kV, the resistance of the isolation unit 220 may be about 20kΩ, and the primary side loop circuit of the transformer 500 may be prevented from being too large under the condition that the capacitors C2 and C3 are discharged.

It is further noted that a resistor R3 may be disposed on the connection between the capacitors C2 and C3 and the device under test 400 to prevent the circuit device from being damaged by excessive instantaneous current generated by discharging the capacitors C2 and C3.

According to some embodiments, the control unit 310 includes a current transformer CT and a voltage transformer VT,

the current transformer is connected in series in the secondary side loop of the second transformer 500, and is used for transmitting the electric signal of the arc current zero crossing point to the pulse power supply unit,

the voltage transformer is connected in parallel to the secondary side loop of the second transformer 600, and is used for sending the loop voltage signal to the pulse power supply unit.

As shown in fig. 8, the control unit 310 includes a current transformer CT and a voltage transformer VT, where the voltage transformer VT is configured to detect a loop voltage electric signal, transmit a negative polarity loop voltage electric signal or a positive polarity loop voltage electric signal to the pulse power unit 340 based on an ac waveform, the current transformer CT may transmit an arc current zero crossing electric signal to the pulse power unit 340, the pulse power unit 340 outputs a pulse electric signal when acquiring the arc current zero crossing electric signal, and outputs a first pulse electric signal or a second pulse electric signal based on the negative polarity loop voltage electric signal or the positive polarity loop voltage electric signal, and the selection unit 330 controls the first charge/discharge unit 230 or the second charge/discharge unit 240 to discharge based on the first pulse electric signal or the second pulse electric signal to provide a high voltage pulse.

According to some embodiments, the selection unit 330 comprises a first controllable discharge gap G1 and a second controllable discharge gap G2,

the trigger electrode of the controllable discharge ball gap is connected with the voltage transformation unit 320,

the cathode of the controllable discharge ball gap is connected to the voltage transformation unit 320 and the ground terminal of the device under test 400,

the anode of the first controllable discharge ball gap G1 is connected with the positive plate of the first capacitor C2,

the anode of the second controllable discharge ball gap G2 is connected with the cathode plate of the second capacitor C3,

the trigger electrode of the first controllable discharge ball gap G1 is used for receiving the first pulse electric signal,

the trigger electrode of the second controllable discharge ball gap G2 is used for receiving the second pulse electric signal.

Fig. 9 is a schematic diagram of an application scenario of a high-current arc test apparatus according to an embodiment of the present application, where, as shown in the drawing, the selection unit 330 includes a first controllable discharge ball gap G1 and a second controllable discharge ball gap G2, the voltage transformation unit 320 may be a set of transformers or two sets of transformers, specifically, but not limited thereto, if a set of transformers is provided, upper and lower duplex windings are respectively arranged on two sides, and the pulse power supply unit 340 may provide pulse direct current.

It should be noted that, when the voltage transformer VT generates the negative polarity loop voltage electric signal and the current transformer CT generates the arc zero crossing electric signal, the pulse power unit 340 outputs the first pulse electric signal to the trigger electrode of the first void-capable discharge ball gap G1, the first void-capable discharge ball gap G1 breaks down, the capacitor C2 discharges to generate the high voltage pulse to the arc gap of the device 400 to be tested, and when the voltage transformer VT generates the positive polarity loop voltage electric signal and the current transformer CT generates the arc zero crossing electric signal, the pulse power unit 340 outputs the second pulse electric signal to the trigger electrode of the second void-capable discharge ball gap G2, the second void-capable discharge ball gap G2 breaks down, and the capacitor C3 discharges to generate the high voltage pulse to the arc gap of the device 400 to be tested.

In the above embodiment, by setting the pulse power supply unit 340 and the controllable discharge ball gap, the instant opening of the discharge loops of the capacitors C2 and C3 can be ensured, so that a high-voltage pulse can be generated at the moment of the arc zero crossing point, and the pulse power supply unit 300 only outputs the pulse at the moment of the arc zero crossing point, thereby saving the power resource.

According to some embodiments, the power supply unit 100 includes a first power supply P1 and a second power supply P2,

the first power supply P1 is configured to supply power to the first transformer 500,

the second power supply P2 is configured to provide electric power to the second transformer 600.

For example, fig. 10 is a schematic diagram of an application scenario of a large current arc test apparatus provided by the embodiment of the present application, where the power supply unit 100 may include a first power supply P1 and a second power supply P2, where the first power supply P1 is used to provide electric energy to the first transformer 500, the second power supply P2 is used to provide electric energy to the second transformer 600, the secondary side of the first transformer 500 outputs a higher voltage, after filtering by a full bridge rectifier and a low-pass filter composed of R1 and C1, a flat direct current is generated, and then C2 and C3 are charged by R2, the secondary side of the second transformer 600 outputs a lower voltage, but can output a large current of several tens of kA, and the secondary side of the second transformer 600 may be used as a power supply to enable the device 400 to be tested to maintain the arc gap in a breakdown state at a moment of non-current zero crossing.

In the case that the current transformer CT detects an electric signal of the secondary side arc current zero crossing point of the second transformer 600, the P3 synchronous pulse power source outputs a pulse current, and based on the voltage transformer VT, measures the voltage polarity output pulse signal of the secondary side loop of the second transformer 600, in the case that the voltage transformer VT outputs a negative polarity loop voltage signal, the controllable discharge ball gap G1 breaks down, the capacitor C2 discharges to generate a high voltage pulse to the device under test 400, so that the arc gap of the device under test 400 reignites at the arc current zero crossing point, in the case that the voltage transformer VT outputs a positive polarity loop voltage signal, the controllable discharge ball gap G2 breaks down, and the capacitor C3 discharges to generate a high voltage pulse to the device under test 400, so that the arc gap of the device under test 400 reignites at the arc current zero crossing point.

It should be noted that, the secondary side power of the first transformer 500 outputs a higher voltage so that the capacitor can generate a high voltage pulse when the capacitor discharges, and the device can set a high resistance in the secondary side loop of the first transformer 500 to control the secondary side loop current of the first transformer 500, so that the secondary side output power of the first transformer 500 is smaller, and the power of the P1 power supply is not required to be excessively large. Illustratively, the secondary side output voltage of the first transformer 500 may be 40kV, and the loop current is 25A, so that the power provided by the P1 power supply may be more than 1MVA, and thus, under the condition that the laboratory performs the internal arc fault test, the P1 power supply may select the grid power supply or the synchronous ac generator, and may meet the power requirement.

The secondary side loop of the second transformer 600 outputs a lower voltage, but needs to output several tens of kA of current to meet the arc gap breakdown requirement of the device 400 to be tested, which is schematically indicated that the secondary side output voltage of the second transformer 500 is 3kV, the arc current in the secondary side loop is 50kA, so that the secondary output power of the second transformer 500 is about 150MVA, and the power provided by the P2 power supply is greater than 150MVA, so that the power requirement can be met by the P1 power supply by selecting the grid power supply or the synchronous ac generator under the condition of internal arc fault test in the laboratory.

In summary, the high-current arc device provided by the embodiment of the application adopts the transformer outputting low voltage as the main power supply to provide arc current for the equipment to be tested, and the transformer outputting high voltage is configured as the auxiliary power supply to provide high-voltage pulse at the moment of current zero crossing, and the high-voltage pulse is used for re-igniting the arc at the moment of arc gap extinction, so that the high-current arc device can greatly reduce the power requirement required by internal arc fault test, does not need to be configured with an impact generator, and can adopt the power grid power supply as the power supply, thereby reducing equipment cost and maintenance cost and greatly reducing capital investment cost.

According to some embodiments, the high current arc device further comprises:

a reactor X3, wherein the reactor X3 is connected in series with the secondary side loop of the second transformer,

for regulating the arc current.

As shown in fig. 10, for example, a reactor X3 may be disposed in the secondary side loop of the second transformer 600, and by adjusting the size of the reactor X3, different arc currents may be generated under the condition that the no-load voltage of the second transformer 600 is unchanged, so as to meet the arc gap breakdown requirements of different devices 400 to be tested, and the application range of the device provided by the embodiment of the present application is enlarged.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

While preferred embodiments of the present description have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the disclosure.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present specification without departing from the spirit or scope of the specification. Thus, if such modifications and variations of the present specification fall within the scope of the claims and the equivalents thereof, the present specification is also intended to include such modifications and variations.

Claims (10)

1. A high current arc test apparatus comprising:

the control detection unit is used for detecting an arc current zero crossing point electric signal generated in the process of carrying out an internal arc fault test on equipment to be tested, and generating a discharge signal when the arc current zero crossing point electric signal is detected;

the pulse high-voltage supply unit is connected with the control detection unit and is used for providing high-voltage pulses for the equipment to be tested under the condition that the discharge signal is received;

and the power supply unit is used for providing arc current for the equipment to be tested and providing electric energy for the pulse high-voltage supply unit.

2. The apparatus as recited in claim 1, further comprising:

the first transformer is connected between the power supply unit and the pulse high-voltage supply unit, and the power supply unit is used for supplying electric energy to the pulse high-voltage supply unit through the first transformer;

the second transformer is connected between the power supply unit and the equipment to be tested, and the power supply unit is used for providing arc current for the equipment to be tested through the second transformer.

3. The apparatus of claim 2, wherein the device comprises a plurality of sensors,

the control detection unit includes:

a pulse power supply unit;

the control unit is used for acquiring a loop voltage electric signal and an arc current zero crossing point electric signal according to the arc current and transmitting the loop voltage electric signal and the arc current zero crossing point electric signal to the pulse power supply unit;

the pulse power supply unit is used for outputting a first pulse electric signal when the loop voltage electric signal is a negative loop voltage electric signal and outputting a second pulse electric signal when the loop voltage electric signal is a positive loop voltage electric signal;

the voltage transformation unit is used for boosting the pulse electric signal;

and the selection unit is used for controlling the pulse high-voltage supply unit to supply the high-voltage pulse according to the boosted pulse electric signal.

4. A device according to claim 3, wherein the pulsed high voltage supply unit comprises:

the rectification unit comprises a full-bridge rectification circuit and a low-pass filter circuit and is used for converting the alternating current provided by the first transformer into direct current;

the first charge-discharge unit or the second charge-discharge unit is used for providing the high-voltage pulse for the device to be tested based on the pulse electric signal;

and the isolation unit is used for protecting the charge-discharge unit by limiting current under the condition that the charge-discharge unit provides the high-voltage pulse.

5. The apparatus of claim 4, wherein the device comprises a plurality of sensors,

the selection unit is used for:

controlling the first charge-discharge unit to supply the high-voltage pulse in the case that the pulse electric signal is the first pulse electric signal,

and controlling the second charge-discharge unit to provide the high-voltage pulse under the condition that the pulse electric signal is the second pulse electric signal.

6. The apparatus of claim 5, wherein the device comprises a plurality of sensors,

the first charge-discharge unit includes a first capacitor,

the second charge-discharge unit includes a second capacitor,

the first capacitor and the second capacitor are connected in series,

the isolation unit is connected in series between the low-pass filter circuit and the first capacitor,

the positive plate of the first capacitor is connected with the isolating unit,

the negative plate of the second capacitor is connected with the direct current output end of the full-bridge rectifying circuit,

the negative plate of the first capacitor and the positive plate of the second capacitor are connected with the non-grounding end of the device to be tested.

7. The apparatus of claim 6, wherein the device comprises a plurality of sensors,

the control unit comprises a current transformer and a voltage transformer,

the current transformer is connected in series in the secondary side loop of the second transformer and is used for transmitting the electric signal of the arc current zero crossing point to the pulse power supply unit,

the voltage transformer is connected in parallel with the secondary side loop of the second transformer and is used for sending the loop voltage signal to the pulse power supply unit.

8. The apparatus of claim 7, wherein the device comprises a plurality of sensors,

the selection unit comprises a first controllable discharge ball gap and a second controllable discharge ball gap,

the trigger electrode of the controllable discharge ball gap is connected with the transformation unit,

the cathode of the controllable discharge ball gap is connected with the voltage transformation unit and the grounding end of the equipment to be tested,

the anode of the first controllable discharge ball gap is connected with the positive plate of the first capacitor,

the anode of the second controllable discharge ball gap is connected with the cathode plate of the second capacitor,

the trigger electrode of the first controllable discharge ball gap is used for receiving the first pulse electric signal,

and the trigger electrode of the second controllable discharge ball gap is used for receiving the second pulse electric signal.

9. The device according to any one of claims 2 to 8, wherein the power supply unit comprises a first power supply and a second power supply,

the first power supply is configured to supply power to the first transformer,

the second power supply is used for providing electric energy for the second transformer.

10. The apparatus according to any one of claims 2 to 8, further comprising:

the reactor is connected in series with the secondary side loop of the second transformer,

for regulating the arc current.