CN116338278A - Switch arc voltage measuring device and measuring method - Google Patents
Switch arc voltage measuring device and measuring method Download PDFInfo
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- G01R19/0084—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring voltage only
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- G—PHYSICS
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Abstract
The invention discloses a switch arc voltage measuring device and a measuring method, wherein the measuring device comprises a measuring capacitance unit, a signal acquisition unit and a data processing unit; the measuring capacitance unit comprises a high-voltage arm measuring capacitance and a low-voltage arm measuring capacitance; the signal acquisition unit is connected with the low-voltage arm measurement capacitor and is configured to correspondingly acquire and preprocess a voltage signal input by the low-voltage arm measurement capacitor; the data processing unit is connected with the signal acquisition unit and is configured to determine arc voltage at two ends of a fracture of a switch contact to be tested according to the preprocessed voltage signal data and by combining the partial pressure proportional relation of the high-voltage arm measurement capacitor and the low-voltage arm measurement capacitor. The switching arc voltage measuring device and the measuring method can realize real-time measurement of the switching arc voltage by adopting the capacitive voltage division principle, and can not influence the normal operation and the insulation performance of the switching equipment.
Description
Technical Field
The invention relates to the technical field of voltage measurement of switching equipment, in particular to a switching arc voltage measurement device and a switching arc voltage measurement method.
Background
In recent years, the flexible direct current transmission technology is widely applied, and the extra-high voltage direct current transmission system is spotlighted by various parties by virtue of the excellent performances of the extra-high voltage direct current transmission system in the aspects of renewable energy integration, capacity expansion of a power system, power grid stability improvement and the like. The direct-current power switch equipment, in particular to a direct-current breaker with medium-high voltage level, is used as engineering backbone equipment in a direct-current power system, is responsible for completing the operation mode switching and line fault clearing of the direct-current power transmission system, and has great significance in guaranteeing the safe, economic and flexible operation of the direct-current power system. In particular, in the field of rail transit, a direct current breaker is used as an indispensable key protection device of a rail traction direct current power supply system, and along with the large-scale construction of rail transit, the rail traction direct current power supply system is widely applied, and the demand for a medium-high voltage direct current breaker with good breaking capability is also increased.
The arc voltage is an important parameter capable of reflecting the arc extinguishing performance of the medium-high voltage direct current breaker to a great extent, and meanwhile, the arc voltage can also accurately reflect the action state of the moving and static contacts of the breaker in the opening process, which is beneficial to the design and research and development of many manual zero-crossing type high-voltage and high-capacity direct current breakers. Therefore, numerous researchers and engineering designers have been interested in its measurement for many years.
However, in the current practical engineering application, because the system voltage level of the direct current breaker is higher, taking the medium and high voltage direct current breaker as an example, the system voltage is at least above kilovolts, and even up to tens of kilovolts, and in view of the fact that once the power switching equipment such as the breaker performs the opening operation, the two ends of the formed movable and static contact fracture bear corresponding system voltages, the voltage measurement at the two ends of the movable and static contact fracture obviously cannot adopt a common low voltage measurement means; however, if a measuring instrument device with a high voltage class such as a high voltage probe is adopted, the accuracy of the result is difficult to be ensured in consideration of the large measuring range and high graduation value of the high voltage probe, and the great error exists in measuring the arc voltage between the breaks formed in the breaking process of the power switching equipment such as a breaker.
The voltage divider is a measuring instrument commonly used in the field of voltage measurement and mainly comprises a resistor voltage divider, a capacitor voltage divider and a resistor-capacitor voltage divider. The resistor divider is not suitable for being connected to two ends of contacts of switching equipment such as a circuit breaker in parallel due to the self conduction characteristic; compared with a resistor voltage divider, the capacitor voltage divider has the advantages of complete circuit breaking property under the direct current working condition and no phase angle error.
In the traditional capacitive partial pressure measurement scheme, due to the consideration of safety, reliability and the like, a long distance is often reserved between an acquisition unit (or an oscilloscope) and a voltage divider, so that the acquisition unit (or the oscilloscope) and the voltage divider are connected by using a coaxial cable, the coaxial cable has a large volume and conducts alternating current, namely, the direction of the current is inverted for several times per second, the coaxial cable has certain wave impedance, and the wave impedance can cause refraction and reflection in the propagation process of the wave, so that the measurement result is disturbed.
The patent application with publication number CN 110297121A discloses a capacitive voltage divider low-voltage measuring circuit and a measuring method, which aim to solve the technical problems that a capacitive voltage divider low-voltage testing circuit in the prior art may have larger errors in voltage division ratio and amplitude; according to the technical scheme, the complex topological design and the complicated parameter adjustment method are provided, so that the influence of the coaxial cable wave impedance on voltage measurement is reduced, and the measurement error of the voltage amplitude is reduced.
The patent application with publication number CN108333421A discloses a high-voltage cable overvoltage testing device and a method thereof, wherein the device comprises a standard capacitor, a voltage measuring and recording module for measuring and recording voltage waveforms, a CPU (central processing unit) for processing the voltage waveforms and performing data calculation, and a control module, wherein one end of the standard capacitor is connected with a shielding layer of the high-voltage cable, the other end of the standard capacitor is grounded, the high-voltage end of the standard capacitor is connected with the voltage measuring and recording module, the voltage measuring and recording module is connected with the CPU, and the CPU is respectively connected with the control module. The invention is based on the fact that a capacitive voltage divider is formed by connecting a self capacitor of a cable and an externally added voltage dividing capacitor in series to divide voltage. However, the technical scheme can only be applied to cables with single-end grounding of the shielding layer, or similar application occasions capable of providing self-capacitance, and the installation of the measuring device needs to destroy the physical structure of cable products, and meanwhile, the measuring and adjusting method is complex in steps and procedures.
The above disclosure of background art is only for aiding in understanding the inventive concept and technical solution of the present invention, and it does not necessarily belong to the prior art of the present patent application, nor does it necessarily give technical teaching; the above background should not be used to assess the novelty and creativity of the present application without explicit evidence that the above-mentioned content was disclosed prior to the filing date of the present patent application.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a switch arc voltage measuring device and a measuring method, and the specific technical scheme is as follows:
in one aspect, a switch arc voltage measuring device is provided, which is used for measuring arc voltage of a fracture of a switch contact to be measured, and comprises a measuring capacitance unit, a signal acquisition unit and a data processing unit;
the measuring capacitor unit comprises a high-voltage arm measuring capacitor C1 and a low-voltage arm measuring capacitor C2, wherein one end of the high-voltage arm measuring capacitor C1 is connected with an outgoing line of the high-voltage side of the fracture of the switch contact to be measured, the other end of the high-voltage arm measuring capacitor C1 is connected with one end of the low-voltage arm measuring capacitor C2, and the other end of the low-voltage arm measuring capacitor C2 is connected with an outgoing line of the low-voltage side of the fracture of the switch contact to be measured;
the signal acquisition unit is connected with the low-voltage arm measurement capacitor C2 and is configured to acquire and preprocess voltage signals input by the low-voltage arm measurement capacitor C2 correspondingly;
the data processing unit is connected with the signal acquisition unit and is configured to determine the arc voltage at two ends of the fracture of the switch contact to be tested according to the preprocessed arc voltage signal data and by combining the partial pressure proportional relation of the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2.
Further, the measuring device further comprises an overvoltage protection unit, the signal acquisition unit is connected with the low-voltage arm measuring capacitor C2 through the overvoltage protection unit, and the overvoltage protection unit is connected in parallel to two ends of the low-voltage arm measuring capacitor C2 and consists of surge protection devices with voltage clamping functions; the action threshold of the overvoltage protection unit needs to be higher than the arc voltage, and the clamping voltage of the overvoltage protection unit is not higher than the bearing limit of the signal acquisition unit and the data processing unit.
Further, the measuring device further comprises a first resistor, a first inductor, a second resistor and a second inductor, the high-voltage side outgoing line of the fracture of the switch contact to be measured, the first resistor, the first inductor and the high-voltage arm measuring capacitor C1 are sequentially connected, the low-voltage side outgoing line of the fracture of the switch contact to be measured, the second resistor, the second inductor and the low-voltage arm measuring capacitor C2 are sequentially connected, and the low-voltage side of the fracture of the switch contact to be measured is grounded.
Further, the switch to be tested is a direct current breaker, the signal acquisition unit comprises a sampling module, a filtering module and an amplifying module which are electrically connected in sequence, the sampling module is used for sampling the voltage signal input by the low-voltage arm measurement capacitor C2, the filtering module is used for filtering the acquired voltage signal, and the amplifying module is used for properly amplifying the voltage signal after the filtering.
On the other hand, a method for measuring the arc voltage of a switch is provided, which comprises the following steps:
the measuring device is connected to two ends of a switch contact to be measured;
the voltage signal data at two ends of the capacitor C2 are measured by the low-voltage arm which is collected and preprocessed by the signal collection unit;
the data processing unit combines the voltage signal data acquired and preprocessed by the signal acquisition unit according to the partial pressure proportion relation between the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2 so as to calculate and obtain arc voltages at two ends of a fracture of the switch to be detected.
Further, the signal acquisition unit is connected to the measurement capacitor unit through an overvoltage protection unit, and when the overvoltage protection unit detects that the voltage at two ends of the low-voltage arm measurement capacitor C2 exceeds a preset threshold value, the signal acquisition unit is disconnected from the measurement capacitor unit.
Further, the time of existence of the electric arc between the start of opening the switch and the complete opening of the switch to be tested is obtained through the electric arc voltage data recorded in real time, if the time of existence of the electric arc for a single time is larger than a first preset value, the time delay of the opening action of the switch to be tested is judged, and an maintainer is required to be informed to overhaul the switch to be tested.
Further, the magnitude of the arc voltage between the start of opening and the complete opening of the switch to be tested is obtained through the arc voltage data recorded in real time, if the time that the arc voltage is smaller than the second preset value is larger than the third preset value, the risk of burning out of the switch to be tested is judged, and an maintainer is required to be informed to overhaul the switch to be tested.
Further, if the switch to be tested is in a closing state and the arc voltage is monitored, judging that the switch to be tested is not closed, and informing an maintainer of overhauling the switch to be tested; in the overhaul process, if the overhaul personnel find that the switch to be detected is actually closed, the measurement device is overhauled.
Compared with the prior art, the invention has the following advantages: by adopting the capacitive voltage division principle, the real-time measurement of the switching arc voltage can be realized, and meanwhile, the characteristics of direct current isolation and alternating current communication of the capacitor are utilized, and the measuring capacitor unit can show complete fracture characteristics for the direct current system voltage, so that the normal operation and the insulation performance of the switching equipment are not influenced.
Drawings
FIG. 1 is a schematic diagram of a switch arc voltage measurement device according to an embodiment of the present invention;
fig. 2 is a schematic diagram of an access circuit of a measurement capacitor unit in the switching arc voltage measurement device according to the embodiment of the present invention;
fig. 3 is a schematic flow chart of a switching arc voltage measurement method according to an embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures 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 of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.
In one embodiment of the invention, a switch arc voltage measuring device is provided, which is used for measuring arc voltage of a fracture of a switch contact to be measured and comprises a measuring capacitance unit, a signal acquisition unit and a data processing unit; referring to fig. 1, the measurement capacitance unit includes a high-voltage arm measurement capacitance C1 and a low-voltage arm measurement capacitance C2, wherein one end of the high-voltage arm measurement capacitance C1 is connected with an outgoing line on the high-voltage side of the fracture of the switch contact to be tested, the other end of the high-voltage arm measurement capacitance C1 is connected with one end of the low-voltage arm measurement capacitance C2, and the other end of the low-voltage arm measurement capacitance C2 is connected with an outgoing line on the low-voltage side of the fracture of the switch contact to be tested;
the signal acquisition unit is connected with the low-voltage arm measurement capacitor C2 and is configured to correspondingly acquire and preprocess a voltage signal input by the low-voltage arm measurement capacitor C2 so as to meet the requirement of further processing of subsequent data;
the data processing unit is connected with the signal acquisition unit and is configured to determine the arc voltage at two ends of the fracture of the switch contact to be tested according to the preprocessed arc voltage signal data and by combining the partial pressure proportional relation of the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2.
Specifically, the switch to be tested is a direct current breaker, the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2 are non-calibration capacitors, and the capacitor has the characteristics of stable capacitance and high voltage resistance; other specification parameters are consistent except that the capacitance values of the two are different; the signal acquisition unit comprises a sampling module, a filtering module and an amplifying module which are electrically connected in sequence, wherein the sampling module is used for sampling the voltage signal input by the low-voltage arm measurement capacitor C2, the filtering module is used for filtering the acquired voltage signal, and the amplifying module is used for properly amplifying the filtered voltage signal, so that the further processing of subsequent data is facilitated. The data processing unit comprises a microprocessor and an upper computer
In order to provide safety and power for the back-end measurement circuit, the measurement device further comprises an overvoltage protection unit and a power supply unit, wherein the signal acquisition unit is connected with the low-voltage arm measurement capacitor C2 through the overvoltage protection unit, and the overvoltage protection unit can be a piezoresistor (MOV), a transient voltage suppression diode (TVS), a Gas Discharge Tube (GDT) or formed by combining a plurality of devices in series-parallel connection; the overvoltage protection unit is connected in parallel with two ends of the low-voltage arm measurement capacitor C2 and consists of a surge protection device with a voltage clamping function; the action threshold of the overvoltage protection unit needs to be higher than the arc voltage, and the clamping voltage of the overvoltage protection unit is not higher than the bearing limit of the signal acquisition unit and the data processing unit. The power supply unit comprises a mains supply, a switching power supply or a battery pack, and supplies power to the signal acquisition unit and the data processing unit.
In order to protect the capacitance measurement unit, referring to fig. 2, the measurement device further includes a first resistor, a first inductor, a second resistor and a second inductor, the high-voltage side lead wire of the fracture of the switch contact to be measured, the first resistor, the first inductor and the high-voltage arm measurement capacitor C1 are sequentially connected, the low-voltage side lead wire of the fracture of the switch contact to be measured, the second resistor, the second inductor and the low-voltage arm measurement capacitor C2 are sequentially connected, and the low-voltage side of the fracture of the switch contact to be measured is grounded.
The switch arc voltage measuring device provided by the embodiment is small in size, convenient to install, capable of not damaging the structure of the device, particularly suitable for being installed inside the switch power equipment with limited space, and more beneficial to integrated design and development of the arc voltage measuring device and the intelligent switch power equipment body. The measuring capacitor unit has small volume, simple structure and convenient installation, is particularly suitable for being arranged in the switch power equipment with limited space, and does not damage the self structure of the power equipment; the overvoltage protection unit can effectively inhibit system voltage impact applied to two ends of the low-voltage arm measurement capacitor C2 after the switch is completely disconnected, clamps the voltages at two ends within the voltage bearing range of the rear-end measurement circuit, and solves the problem that signal transmission between the acquisition unit (or oscilloscope) and the voltage divider depends on a long-distance high-voltage cable in the traditional measurement scheme; the signal acquisition unit, the data processing unit and the power supply unit can realize modularized design, and are more beneficial to the integrated design and development of the arc voltage measuring device and the switch power equipment body.
The switch arc voltage measuring device provided by the embodiment has the following advantages: the structure of the existing equipment is not damaged; the capacitor is made into a non-standard product, has small parasitic parameters, small size and structure, high voltage resistance and good frequency response characteristic; the integrated design has the advantages that the voltage signal transmission distance is short, a coaxial cable is not required, and a common copper core wire is not required; overvoltage suppression and protection of the back-end measurement circuit are achieved through a protection unit; and data is transmitted to an upper computer, and the method is not limited to an oscilloscope.
In one embodiment of the present invention, a method for measuring arc voltage of a switch is provided, comprising the steps of:
the measuring device is connected to two ends of a switch contact to be measured; the voltage signal data at two ends of the capacitor C2 are measured by the low-voltage arm which is collected and preprocessed by the signal collection unit; the data processing unit combines the voltage signal data acquired and preprocessed by the signal acquisition unit according to the partial pressure proportion relation between the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2 so as to calculate and obtain arc voltages at two ends of a fracture of the switch to be detected. The signal acquisition unit is connected to the measurement capacitance unit through an overvoltage protection unit, and when the overvoltage protection unit detects that the voltage at two ends of the low-voltage arm measurement capacitance C2 exceeds a preset threshold value, the signal acquisition unit is disconnected from the measurement capacitance unit.
Specifically, referring to fig. 3, the measuring device is connected to two ends of a moving contact and a static contact of the switching device, and the break voltage is assumed to be U at the moment; when the switch equipment is switched on, on the premise of neglecting on-state voltage drop, U=0; when the switching device starts to break, an arc is generated between the moving contact and the fixed contact of the switching device, the break voltage U is equal to the arc voltage, the arc length is stretched along with the continuous increase of the distance between the moving contact and the fixed contact, the arc voltage gradually rises, and the arc voltage is kept constant after the stable arcing stage is entered. In the process, the measuring capacitor unit bears transient arc voltage with amplitude changing at high frequency, and dynamically changing arc voltage signals are led out in proportion according to the partial pressure proportion relation between the high-voltage arm measuring capacitor C1 and the low-voltage arm measuring capacitor C2 and sent to the signal acquisition unit at the rear end. The signal acquisition unit is directly connected with the low-voltage arm measurement capacitor C2, and correspondingly acquires and pre-processes partial pressure signals of arc voltage born by two ends of the low-voltage arm measurement capacitor C2 so as to meet the requirement of further processing of subsequent data; the data processing unit is directly connected with the signal acquisition unit and is used for receiving the voltage data of the two ends of the low-voltage arm measurement capacitor C2 after acquisition and pretreatment and determining the arc voltage of the two ends of the fracture of the switch equipment to be detected according to the partial pressure proportional relation between the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2;
when the switch equipment is switched off, the voltage at two ends of a fracture of the switch equipment is equal to the system voltage after the electric arc is extinguished, at the moment, the measurement capacitance unit directly bears the system high voltage, and the overvoltage protection unit rapidly acts. Because the capacitor has the characteristics of blocking direct current and communicating alternating current, the measuring capacitor unit shows complete fracture characteristics for direct current system voltage, so that the normal operation of the switch equipment is not influenced; and the overvoltage protection unit rapidly acts under the action of high system voltage, clamps the voltages at the two ends of the low-voltage arm measurement capacitor C2 within the bearing limit of the back-end measurement circuit, and protects the back-end measurement circuit from being damaged by the high system voltage.
According to the arc voltage data obtained by the processing of the data processing unit, the safety monitoring of the switch to be detected can be carried out, and the method specifically comprises the following steps:
and obtaining the time of the existence of the electric arc between the start of opening the switch and the complete opening of the switch to be tested through the electric arc voltage data recorded in real time, and judging that the opening action of the switch to be tested is delayed if the time of the existence of the single electric arc is greater than a first preset value, so that an maintainer needs to be informed to overhaul the switch to be tested. For example, a single arc may exist for more than 0.5 seconds, indicating that the separation mechanism of the switchgear contacts is malfunctioning, such that the switch cannot respond quickly to an open, and should be serviced. The stability of the breaking speed of the breaker is tested through a plurality of breaking tests.
And obtaining the magnitude of the arc voltage between the start of opening and the complete opening of the switch to be tested through the arc voltage data recorded in real time, and judging that the switch to be tested is burnt out if the time that the arc voltage is smaller than the second preset value is larger than the third preset value, so that an maintainer needs to be informed to overhaul the switch to be tested. For example, a single arc voltage of less than 20V for more than 0.25s indicates that the contacts of the switch are at risk of being burned out, because the smaller the arc voltage, the greater the current at the contacts thereof, and the temperature at the contacts thereof rises rapidly, if too long, so that the switch to be tested is easily damaged.
If the switch to be tested is in a closing state and the arc voltage is monitored, judging that the switch to be tested is not closed, and informing an maintainer of overhauling the switch to be tested; in the overhaul process, if the overhaul personnel find that the switch to be detected is actually closed, the measurement device is overhauled. For example, the external system has shown that the switching device has been switched on, but is still able to monitor the arc voltage, indicating that in practice the switch has not been fully switched on, or that the measuring device has failed, all requiring an inspection check.
The switching arc voltage measuring method provided by the embodiment can realize real-time measurement of switching arc voltage by adopting a capacitive voltage division principle, and simultaneously utilizes the characteristics of direct current isolation and alternating current communication of the capacitor, and the measuring capacitor unit shows complete fracture characteristics for direct current system voltage, so that normal operation and insulation performance of switching equipment are not affected.
The device and the method for measuring the arc voltage of the switch overcome the defects and the shortcomings of the existing measuring device or measuring scheme, not only can accurately measure the arc voltage between the breaks formed in the switching-off process of the switch, but also avoid the problem that the coaxial cable transmits measuring signals to interfere, and can bear the system voltage added between the breaks of the switch after the switching-off process is completed, thereby maintaining good insulating performance and not influencing the normal work and the insulating performance of the switching equipment.
The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the scope of the claims, and all equivalent structures or equivalent processes using the descriptions and drawings of the present invention are directly or indirectly applied to other related technical fields, which are also included in the scope of the present invention.
Claims (10)
1. The device is characterized by being used for measuring the arc voltage of a fracture of a switch contact to be measured and comprising a measuring capacitor unit, a signal acquisition unit and a data processing unit;
the measuring capacitor unit comprises a high-voltage arm measuring capacitor C1 and a low-voltage arm measuring capacitor C2, wherein one end of the high-voltage arm measuring capacitor C1 is connected with an outgoing line of the high-voltage side of the fracture of the switch contact to be measured, the other end of the high-voltage arm measuring capacitor C1 is connected with one end of the low-voltage arm measuring capacitor C2, and the other end of the low-voltage arm measuring capacitor C2 is connected with an outgoing line of the low-voltage side of the fracture of the switch contact to be measured;
the signal acquisition unit is connected with the low-voltage arm measurement capacitor C2 and is configured to acquire and preprocess voltage signals input by the low-voltage arm measurement capacitor C2 correspondingly;
the data processing unit is connected with the signal acquisition unit and is configured to determine the arc voltage at two ends of the fracture of the switch contact to be tested according to the preprocessed arc voltage signal data and by combining the partial pressure proportional relation of the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2.
2. The switching arc voltage measuring device according to claim 1, further comprising an overvoltage protection unit, wherein the signal acquisition unit is connected with the low-voltage arm measuring capacitor C2 through the overvoltage protection unit, and the overvoltage protection unit is connected in parallel at two ends of the low-voltage arm measuring capacitor C2 and is composed of surge protection devices with a voltage clamping function; the action threshold of the overvoltage protection unit needs to be higher than the arc voltage, and the clamping voltage of the overvoltage protection unit is not higher than the bearing limit of the signal acquisition unit and the data processing unit.
3. The device for measuring the arc voltage of a switch according to claim 1, further comprising a first resistor, a first inductor, a second resistor and a second inductor, wherein the high-voltage side lead wire of the fracture of the switch contact to be measured, the first resistor, the first inductor and the high-voltage arm measurement capacitor C1 are sequentially connected, the low-voltage side lead wire of the fracture of the switch contact to be measured, the second resistor, the second inductor and the low-voltage arm measurement capacitor C2 are sequentially connected, and the low-voltage side of the fracture of the switch contact to be measured is grounded.
4. The device for measuring arc voltage of switch according to claim 1, wherein the switch to be measured is a dc breaker, the signal collecting unit comprises a sampling module, a filtering module and an amplifying module electrically connected in sequence, the sampling module is used for sampling the voltage signal input by the low-voltage arm measuring capacitor C2, the filtering module is used for filtering the collected voltage signal, and the amplifying module is used for amplifying the voltage signal after the filtering process.
5. The method for measuring the arc voltage of the switch is characterized by comprising the following steps of:
switching the switching arc voltage measuring device according to any one of claims 1 into two ends of a switch contact to be measured;
the voltage signal data at two ends of the capacitor C2 are measured by the low-voltage arm which is collected and preprocessed by the signal collection unit;
the data processing unit combines the voltage signal data acquired and preprocessed by the signal acquisition unit according to the partial pressure proportion relation between the high-voltage arm measurement capacitor C1 and the low-voltage arm measurement capacitor C2 so as to calculate and obtain arc voltages at two ends of a fracture of the switch to be detected.
6. The method according to claim 5, wherein the signal acquisition unit is connected to the measurement capacitor unit through an overvoltage protection unit, and the signal acquisition unit is disconnected from the measurement capacitor unit when the overvoltage protection unit detects that the voltage across the low-voltage arm measurement capacitor C2 exceeds a preset threshold.
7. The method for measuring arc voltage of a switch according to claim 5, wherein the time of existence of the arc between the start of opening and the complete opening of the switch to be measured is obtained through arc voltage data recorded in real time, if the time of existence of a single arc is greater than a first preset value, the delay of the opening action of the switch to be measured is judged, and an maintainer is required to be informed to overhaul the switch to be measured.
8. The method for measuring arc voltage of a switch according to claim 5, wherein the magnitude of the arc voltage between the start of switching-off and the complete switching-off of the switch to be measured is obtained through arc voltage data recorded in real time, and if the time that the arc voltage is smaller than the second preset value is greater than the third preset value, the risk of burning out of the switch to be measured is judged, and an overhaul worker is required to be informed of overhauling the switch to be measured.
9. The method of claim 5, wherein if the switch to be tested is in a closed state and the arc voltage is detected, determining that the switch to be tested is not closed is performed, and notifying an maintainer to overhaul the switch to be tested.
10. The method according to claim 9, wherein during the maintenance, if the maintenance personnel find that the switch to be measured is actually closed, the maintenance is performed on the measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310189558.8A CN116338278A (en) | 2023-03-02 | 2023-03-02 | Switch arc voltage measuring device and measuring method |
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| CN202310189558.8A CN116338278A (en) | 2023-03-02 | 2023-03-02 | Switch arc voltage measuring device and measuring method |
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