Post-arc current measuring system and method thereof

Abstract

The invention relates to the technical field of current measurement, in particular to a post-arc current measurement system and method, and a synthesis loop module comprises a test switch module, a current loop module and a voltage loop module. The current loop module is electrically connected with the test switch module and is used for providing a current source for the test switch module; the test switch module is used for sampling the zero-region post-arc current flowing through the voltage loop module after the current loop module is cut off; the voltage loop module is electrically connected with the test switch module and is used for applying recovery voltage to a test switch in the test switch module in the process of measuring the post-arc current; and the measurement analysis module is used for processing an output signal of the test switch module to obtain a post-arc current measurement result. The system can improve the accuracy of post-arc current measurement.

Description

Technical Field

[0001] The invention relates to the technical field of current measurement, and in particular to a post-arc current measurement system and method thereof. Background Art

[0002] Circuit breakers are an important part of the power system, and their safe and stable interruption is of great significance to the power system. Circuit breakers interrupt current near the zero crossing of large currents. When the current crosses zero, the conductive state of the arc gap changes. When the circuit breaker is disconnected, the free charged particles that cause the arc gap channel are called the insulating state. In the insulating state, the process in which the arc gap does not reignite is called the dielectric recovery process; because the circuit breaker is disconnected, the arc between the arc gaps is extinguished to separate the conductive circuit, and the voltage on the circuit after the disconnection is directly loaded on the two ends of the circuit breaker contacts. The voltage recovery process is called the voltage recovery process. Therefore, after the current crosses zero, there is a conflict between the voltage recovery process and the dielectric recovery process of the circuit breaker, which will cause the arc to reignite or extinguish.

[0003] After the arc current passes through zero, under the action of the transient recovery voltage, the migration movement of the plasma will form a post-arc current. The pre-arc current is generally a large current of the kiloampere level, and the post-arc current is relatively small, generally ranging from a few tenths of an ampere to several amperes, and the duration is in the μs level. The study of the post-arc current is of great significance for in-depth research on the thermal recovery characteristics of the post-arc medium and the arc reignition mechanism. The post-arc current is an important parameter in the circuit breaker breaking process. Accurately measuring the post-arc current can provide a basis for the study of the circuit breaker breaking performance. Due to the difference in the order of magnitude between the pre-arc current and the post-arc current, the measurement of the post-arc current has always been a hot topic in circuit breaker research. The difficulty in measuring the post-arc current is that the pre-arc current and the post-arc current are very different in magnitude, and the range of traditional measuring instruments cannot take both into account, so it is difficult to accurately measure the post-arc current.

[0004] At present, the methods for measuring post-arc current include measurement methods based on current transfer characteristics, which transfer the current instantly before the current passes through zero through the control of an auxiliary switch to achieve the measurement of post-arc current. However, the precise control of the switch action will lead to current measurement failure. There is also a measurement method based on a special Rogowski coil, but its integral signal requires complex calculation design and cannot obtain an accurate absolute signal. There is also a measurement method based on a tunnel magnetoresistance sensor, and its measurement accuracy is also affected by the size of the measured current and the distance from the measured current. Summary of the invention

[0005] The present invention provides a post-arc current measurement system and method thereof, aiming to solve the problem of inaccurate measurement of small post-arc current.

[0006] The objective of the present invention is achieved by the following technical solutions: A post-arc current measurement system comprises: a synthesis loop module and a measurement and analysis module; The synthetic loop module includes a test switch module, a current loop module and a voltage loop module; The current loop module is electrically connected to the test switch module and is used to provide a current source for the test switch module; The test switch module is used to sample the zero-zone post-arc current flowing through the voltage loop module after the current loop module is cut off; The voltage loop module is electrically connected to the test switch module and is used to apply a recovery voltage to the test switch in the test switch module during the post-arc current measurement process; The measurement and analysis module is used to process the output signal of the test switch module to obtain a post-arc current measurement result. As a further improvement of the present invention, the current loop module includes a first LC oscillation circuit, which includes a first capacitor and a first inductor connected in series in sequence, and is used to provide a current source with high current and low voltage; a first switch is arranged between the first capacitor and the first inductor.

[0007] As a further improvement of the present invention, the voltage loop module includes a second LC oscillation circuit, which includes a second inductor and a second capacitor connected in series in sequence, and is used to provide a high-voltage and low-current voltage source; a frequency modulation circuit is connected in parallel at both ends of the second LC oscillation circuit, and the frequency modulation circuit includes a third capacitor and a fourth capacitor connected in parallel, and the line where the third capacitor is located is also connected in series with a first resistor, and the frequency modulation circuit is used to adjust the recovery voltage.

[0008] As a further improvement of the present invention, the test switch module includes an auxiliary switch and a coaxial shunt; one end of the auxiliary switch is used to connect the current loop module, and the other end is used to connect the voltage loop module, which is used to cut off the current loop module before the large current passes through zero; the coaxial shunt is used to collect the current of the voltage source loop.

[0009] As a further improvement of the present invention, the measurement and analysis module includes a measurement submodule and a data transmission and storage submodule. The measurement submodule is used to process the data collected by the coaxial splitter; the data transmission and storage submodule is used to store and upload the data output by the measurement submodule.

[0010] As a further improvement of the present invention, the measurement submodule includes a front-stage signal processing module and a signal amplification and acquisition module; the front-stage signal processing module is used to process the output signal of the coaxial shunt, and the resistor-capacitor voltage divider is used to provide a current limiting loop with a set bandwidth; the signal amplification and acquisition module is used to amplify and acquire small signals.

[0011] As a further improvement of the present invention, the front-stage signal processing module includes a resistor-capacitor voltage divider and an anti-parallel diode, and the anti-parallel diode is connected in parallel to the high-voltage part of the resistor-capacitor voltage divider; when the current flowing through the anti-parallel diode reaches a first set current, the coaxial shunt voltage drop is greater than the diode set threshold, the diode is turned on, and the output voltage is limited; when the current flowing through the anti-parallel diode is a second set current, the coaxial shunt voltage drop is less than the conduction voltage drop of the diode, and the diode is cut off.

[0012] As a further improvement of the present invention, the signal amplification and acquisition module includes a precision amplifier, a differential driver, an analog-to-digital converter and its peripheral circuits. The precision amplifier is used to amplify the pre-stage signal output by the pre-stage signal processing module and further amplify the output voltage of the resistor-capacitor voltage divider; the differential driver is used to drive the analog-to-digital converter to convert the single-ended signal amplified by the precision amplifier into a differential signal; the analog-to-digital converter is used to convert the analog signal processed by the differential driver into a digital signal and transmit it to the data storage and transmission module.

[0013] As a further improvement of the present invention, the data transmission and storage submodule includes an FPGA main control chip, a storage module and a host computer processing module. The FPGA main control chip is used for driving and timing control of the data acquisition and storage module, and is used to store the collected data in the storage module and send the stored data to the host computer processing module. The host computer processing module receives and recovers the stored data and performs data visualization.

[0014] In a second aspect, the present invention further provides a post-arc current measurement method, based on the above-mentioned post-arc current measurement system, comprising: Connect the test switch to the test switch module, and use the current loop module to provide power to the test switch; After the current loop module is cut off, the voltage loop module is used to apply a recovery voltage to the test switch, and the zero-zone post-arc current flowing through the voltage loop module is sampled; The sampled post-arc current is processed to obtain the post-arc current measurement result.

[0015] The beneficial effects of the present invention are as follows: the post-arc current measurement system of the present invention is mainly aimed at the measurement of small post-arc currents. By testing the precise sampling function of the switch module after the current loop is cut off, the transient changes of the post-arc current in the zero zone can be captured. This high-precision measurement is essential for understanding and evaluating the electrical characteristics of the switch device after the arc is extinguished, and helps to improve the reliability and safety of the equipment design. The test switch module can accurately sample the post-arc current in the zero zone flowing through the voltage loop module after the current loop module is cut off, avoiding the influence of other interference factors on the current sampling. The post-arc measurement system of the present invention can not only realize the precise measurement of large post-arc currents, but also improve the accuracy of small current measurements through the current loop module and the voltage loop module in the synthetic loop module and the measurement and analysis module.

[0016] During the post-arc current measurement process, the voltage loop module applies a recovery voltage to the test switch in the test switch module to simulate the voltage changes in the actual working environment, so that the measurement results can better reflect the performance of the test switch in the real scene. Through the coordinated work of each module, it is possible to create more stable and controllable test conditions for the measurement of post-arc current, which is conducive to in-depth research on the characteristics and laws of post-arc current.

[0017] Preferably, the first capacitor and the first inductor in the first LC oscillation circuit are connected in series in sequence to form a stable oscillation loop, providing a high-current, low-voltage current source for the test switch module. This stable current output helps to ensure the current stability during the test and improve the accuracy and reliability of the post-arc current measurement. By setting the first switch, the on-off of the current loop can be conveniently controlled, the circuit can be quickly connected when current output is required, and the circuit can be cut off in time when it is not required, thereby improving the flexibility and controllability of the test.

[0018] Preferably, the second inductor and the second capacitor in the second LC oscillator circuit are connected in series in sequence, which can generate a high-voltage and low-current voltage source to meet the need for applying a recovery voltage to the test switch during the post-arc current measurement process. This specific voltage source characteristic helps to accurately simulate the voltage change in the actual working environment, making the measurement results more practical reference value. The output of high voltage can ensure that the test switch can withstand sufficient voltage stress when measuring the post-arc current, so as to better detect its performance under high voltage conditions. The combination of the third capacitor, the fourth capacitor and the first resistor in the frequency modulation circuit provides an effective means for adjusting the recovery voltage. By adjusting the values ​​of the capacitor and the resistor, the frequency and amplitude of the recovery voltage can be accurately controlled to meet the test requirements of different test switches. The third capacitor and the fourth capacitor in parallel can be switched or used in combination as needed, which increases the flexibility of adjusting the recovery voltage. At the same time, the first resistor connected in series can play the role of current limiting and voltage dividing to ensure the safety and stability of the adjustment process.

[0019] Preferably, the measurement submodule processes the data collected by the coaxial shunt, which can provide high-precision current measurement to ensure that the data obtained by the measurement submodule is accurate and reliable. By processing these data, key post-arc current parameters can be extracted, providing a strong basis for subsequent analysis and evaluation.

[0020] Preferably, the pre-stage signal processing module processes the output signal of the coaxial shunt, can remove noise and interference, and extract a clear and accurate post-arc current signal. This provides reliable basic data for subsequent analysis and measurement, and improves the precision and accuracy of the measurement. The signal amplification and acquisition module amplifies the small signal so that it can be accurately collected and processed by the subsequent acquisition equipment. This is particularly important for weak post-arc current signals, which can improve the signal-to-noise ratio of the signal and enhance the sensitivity of the measurement.

[0021] Preferably, in the pre-stage signal processing module, when the current flowing through the anti-parallel diode reaches the first set current, the coaxial shunt voltage drop is greater than the diode set threshold, and the diode is turned on to limit the output voltage. This function can effectively prevent the output voltage from being too high and protect the subsequent circuit from damage. Through accurate current and voltage drop judgment, it is ensured that the limiting action is performed at the right time, thereby improving the safety and stability of the measurement system. When the current flowing through the anti-parallel diode is the second set current, the coaxial shunt voltage drop is less than the diode's conduction voltage drop, and the diode is cut off. This adaptive control method can automatically adjust the conduction state of the diode according to the changes in current and voltage drop, thereby realizing dynamic regulation of the output voltage.

[0022] Preferably, the precision amplifier amplifies the pre-stage signal output by the pre-stage signal processing module, and can increase the weak signal to an amplitude suitable for subsequent processing. At the same time, the output voltage of the resistor-capacitor voltage divider is further amplified to ensure that the signal has sufficient strength for subsequent analysis and processing, thereby improving the sensitivity and accuracy of the measurement. The differential driver can provide a stable driving signal for the analog-to-digital converter, ensuring that the analog-to-digital converter can accurately convert the analog signal into a digital signal. This helps to improve the accuracy and speed of analog-to-digital conversion and provide high-quality digital signals for subsequent data processing and analysis. The analog-to-digital converter converts the analog signal processed by the differential driver into a digital signal, thereby realizing digital processing of the signal. Digital signals have the advantages of being easy to store, transmit and process, which provides convenience for subsequent data storage and transmission modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is a synthetic loop test structure diagram in an embodiment of the present invention; Figure 2 is a system function block diagram in an embodiment of the present invention; Figure 3 It is a core principle diagram of the measurement submodule in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The idea of ​​the present invention is to propose a post-arc current measurement system and method in order to solve the problem of inaccurate post-arc current measurement. The system mainly includes a synthesis loop module and a measurement analysis module (i.e. Figure 1 measurement system shown); The synthetic loop module includes a test switch module ( Figure 1 B module in the current loop module ( Figure 1 A module in the Figure 1 C module in ); The current loop module is electrically connected to the test switch module to provide a current source for the test switch module. Although the main function of the current loop module is to provide a current source for the test switch module, when measuring small currents, the current range of its output needs to include a sufficiently small current value. The current loop module has the ability to accurately control the output of tiny currents to meet test requirements.

[0027] The test switch module is used to sample the zero-zone post-arc current flowing through the voltage loop module after the current loop module is cut off; the test switch module is designed to accurately sample the zero-zone post-arc current flowing through the voltage loop module after the current loop module is cut off.

[0028] The voltage loop module is electrically connected to the test switch module, and is used to apply a recovery voltage to the test switch in the test switch module during the post-arc current measurement process; during the low current measurement process, the voltage loop module applies a recovery voltage to the test switch. The stability of this recovery voltage has an important influence on the measurement results of the low current. If the voltage fluctuates greatly, it may cause the test switch to generate additional current, thereby interfering with the accurate measurement of the low current.

[0029] The measurement and analysis module is used to process the output signal of the test switch module to obtain the post-arc current measurement result. In the measurement of small current, the measurement and analysis module has high-resolution and high-sensitivity signal processing capabilities to extract the accurate current value from the weak signal received by the test switch module.

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, wherein the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0031] Example 1 like Figure 1-Figure 3 As shown, this embodiment provides a post-arc current measurement system, including: a synthesis loop module and a measurement and analysis module. The specific structure and corresponding implementation methods are as follows.

[0032] The synthetic loop module includes a test switch module, a current loop module and a voltage loop module. The current loop module is electrically connected to the test switch module to provide a current source for the test switch module; the test switch module includes a sample switch, and the test switch module is used to sample the zero-zone post-arc current flowing through the voltage loop module after the current loop module is cut off; the voltage loop module is electrically connected to the test switch module to apply a recovery voltage to the sample switch in the test switch module during the post-arc current measurement process.

[0033] Among them, the current loop module includes a first LC oscillation circuit, which includes a first capacitor C and a first inductor L connected in series in sequence, and is used to provide a current source with high current and low voltage; a first switch G1 is arranged between the first capacitor C and the first inductor L, and the first switch is responsible for introducing the current loop.

[0034] The voltage loop module includes a second LC oscillating circuit, which includes a second inductor Ls and a second capacitor Cs connected in series, and is used to provide a high-voltage and low-current voltage source; wherein a second switch G2 is also connected in series between the second inductor Ls and the second capacitor Cs, and the voltage loop is introduced by the second switch G2. A frequency modulation loop of the voltage source is connected in parallel at both ends of the second LC oscillating circuit, and the frequency modulation loop of the voltage source includes a third capacitor Ct and a fourth capacitor Cd connected in parallel, and the line where the third capacitor is located is also connected in series with a first resistor Rt, and the frequency modulation loop is used to adjust the recovery voltage.

[0035] Specifically, the test switch module includes an auxiliary switch AB and a coaxial shunt; one end of the auxiliary switch is used to connect the current loop module, and the other end is used to connect the voltage loop module, which is used to cut off the current loop module before the large current passes zero; the coaxial shunt is used to collect the current of the voltage source loop. The test switch TO is set in parallel in the test switch module.

[0036] The auxiliary switch AB is used to cut off the current loop module before the large current passes through zero. After the test switch TO is opened, the post-arc current will flow through the voltage source loop, and the coaxial shunt is used to collect the current of the voltage source loop. The measurement and analysis module is set in parallel at both ends of the coaxial shunt, and the post-arc current can be measured through the measurement and analysis module.

[0037] During the specific implementation process, the current source loop of the synthetic loop module is first introduced. At the moment before the current passes through zero, the auxiliary switch AB is disconnected, and then the test switch TO is disconnected. The voltage source loop is introduced, and a recovery voltage is applied to the test switch. The current of the voltage source loop is measured using a coaxial shunt. After the circuit breaker is opened, the loop current is the post-arc current, and the output voltage of the coaxial shunt is connected to the measurement and analysis module.

[0038] The measurement and analysis module includes measurement submodules ( Figure 2 The measurement module in the Figure 2 The data storage and transmission module in the measurement submodule is used to process the data collected by the coaxial shunt; the data transmission and storage submodule is used to store and upload the data output by the measurement submodule.

[0039] Specifically, the measurement submodule includes a front-stage signal processing module and a signal amplification and acquisition module.

[0040] The front-stage signal processing module is used to process the output signal of the coaxial shunt; the front-stage signal processing module includes a resistor-capacitor voltage divider and an anti-parallel diode. The anti-parallel diode is connected in parallel to the high-voltage part of the resistor-capacitor voltage divider. When the current flowing through the anti-parallel diode reaches the first set current, the voltage drop of the coaxial shunt is greater than the set threshold of the diode, the diode is turned on, and the output voltage is limited; when the current flowing through the anti-parallel diode is the second set current, the voltage drop of the coaxial shunt is less than the conduction voltage drop of the diode, and the diode is cut off. Among them, the first set current is greater than the conduction threshold set by the diode, and the conduction threshold set by the diode is greater than the second set current. In the high current stage, the voltage drop of the coaxial shunt is very large, the diode is turned on, and the output voltage is limited. In the low current stage, the voltage drop of the coaxial shunt is less than the conduction voltage drop of the diode, then the diode is cut off, and the voltage across the diode is the voltage on the high-voltage side of the resistor-capacitor voltage divider, and the signal is processed by the post-stage circuit. The diode of this embodiment selects a diode with fast recovery performance, which can quickly enter the cut-off state from the conduction state.

[0041] The pre-stage signal processing module includes a resistor-capacitor voltage divider and an anti-parallel diode, which are used for preliminary processing of the output signal of the coaxial shunt in the synthesis loop module. The signal amplification and acquisition module includes a precision amplifier, a differential driver, an analog-to-digital converter and its peripheral circuits to amplify and acquire small signals.

[0042] The resistor-capacitor voltage divider is used to provide a current-limiting loop with a set bandwidth; the signal amplification and acquisition module is used to amplify and acquire small signals.

[0043] Specifically, the RC voltage divider includes resistors and capacitors on the high and low voltage sides, and its function is to provide a high-bandwidth current limiting loop for the subsequent circuit. Since the RC voltage divider needs to withstand the output voltage of the coaxial shunt in the synthesis loop module, the resistors should be metal film resistors with appropriate power, and the voltage division ratio should be as large as possible so that the subsequent circuit does not lose a large gain. The matching capacitors need to be reasonably matched according to the distributed parameters in the circuit.

[0044] The signal amplification and acquisition module includes a precision amplifier, a differential driver, and an analog-to-digital converter. The precision amplifier is used to amplify the pre-stage signal output by the pre-stage signal processing module and further amplify the output voltage of the resistor-capacitor voltage divider. The differential driver is used to drive the analog-to-digital converter to convert the single-ended signal amplified by the precision amplifier into a differential signal, thereby improving the working performance of the analog-to-digital converter. The analog-to-digital converter is used to convert the analog signal processed by the differential driver into a digital signal and transmit it to the data storage and transmission module.

[0045] The pre-stage signal processing module in the measurement submodule is the core of the entire measurement and analysis module. When the current is before the arc, the input voltage is high. The diode D1 and the diode D2 in the anti-parallel diode can be turned on when the input voltage is high, and the output voltage is limited to its conduction voltage drop. When the current is after the arc, the input voltage is small, and the anti-parallel diode D1 and the diode D2 are cut off. Among them, the diode D1 and the diode D2 in this embodiment are selected from diodes with very small reverse recovery time, such as switching diodes, whose forward current carrying capacity is weak, so the anti-parallel diodes D1 and D2 are connected in parallel in the high-voltage part of a resistor-capacitor voltage divider to limit the current flowing through it. The voltage divider ratio r is calculated as follows:

[0046] If the capacitance and resistance values ​​are properly matched, that is:

[0047] The voltage divider ratio is independent of frequency and can be written as follows:

[0048] The resistance value of the voltage-dividing resistor R1 of the RC voltage divider should be selected to ensure that the current of the diode is limited when the diode is turned on. If it is too large, the time constant in the circuit will increase. The fifth capacitor C1 and the sixth capacitor C2 in the front-stage signal processing module should be as small as possible. At the same time, the distributed parameters of the components in the circuit need to be considered to make the matching capacitor selection more reasonable and improve the bandwidth of the voltage divider. The sixth capacitor C2 is an adjustable capacitor that is adjusted according to the distributed parameters in the circuit.

[0049] In the high current stage, the diode is turned on, assuming that the diode voltage maintains its forward conduction voltage drop V F , the voltage across the sixth capacitor C2 and the voltage across the diode V F The same remains unchanged, so the current flowing through the sixth capacitor C2 is zero, and the current flowing through the second resistor R2 is:

[0050] The current flowing through the voltage divider resistor R1 is:

[0051] The current flowing through the fifth capacitor C1 is:

[0052] The current I flowing through the diode D for:

[0053] The current flowing through the diode I DIt is related to the voltage divider resistor R1, the fifth capacitor C1 and the second resistor R2. If the frequency of the input voltage is high, the diode current I D It is mainly affected by the fifth capacitor C1. The smaller the fifth capacitor C1 is, the higher the current I flowing through the diode at high frequency. D The smaller; In the low current stage, the diode is cut off, and the diode current will be transferred to the sixth capacitor C2 and the second resistor R2. The sixth capacitor C2 has a charging process. The smaller its value is, the smaller the time constant is, and the faster this process is. At this time, the measurement result is inaccurate. After steady state, the RC voltage divider works normally, and the measurement result is accurate at this time. Therefore, the value of the RC voltage divider should be as small as possible while meeting the circuit function requirements to ensure the accuracy of the measurement.

[0054] The signal amplification and acquisition module is mainly responsible for the gain compensation and acquisition of the signal after the previous signal processing module. The post-arc current is generally several hundred milliamperes to several amperes, corresponding to the output voltage of the coaxial shunt is several millivolts to tens of millivolts. The precision amplifier is used to amplify the signal to a reasonable range to ensure the measurement accuracy; the differential driver is responsible for converting the single-ended signal amplified by the precision amplifier into a differential signal to drive the analog-to-digital converter to improve its performance.

[0055] The data transmission and storage submodule includes an FPGA main control chip, a storage module and a host computer processing module. The FPGA main control chip is used to drive and control the timing of the data acquisition and storage modules, and is used to store the collected data in the storage module and send the stored data to the host computer processing module. The host computer processing module receives and recovers the stored data and performs data visualization.

[0056] Specifically, in the data storage and transmission module, FPGA is used as the main control chip to drive the analog-to-digital converter and the storage module, provide timing control, and store the collected data in the storage chip. The write rate of the storage chip should be faster than the sampling frequency of the data, or data caching should be performed, otherwise data loss will occur; finally, the data is sent to the host computer through the data interface for data recovery and visualization processing.

[0057] In summary, by testing the precise sampling function of the switch module after the current loop is cut off, the transient changes of the zero-zone post-arc current can be captured. This high-precision measurement is essential for understanding and evaluating the electrical characteristics of the switchgear after the arc is extinguished, and helps to improve the reliability and safety of the equipment design. The test switch module can accurately sample the zero-zone post-arc current flowing through the voltage loop module after the current loop module is cut off, avoiding the influence of other interference factors on the current sampling, and greatly improving the accuracy of the post-arc current measurement.

[0058] Example 2 This embodiment provides a post-arc current measurement method, based on the post-arc current measurement system described in Embodiment 1, the steps include: Connect the test switch to the test switch module, and use the current loop module to provide power to the test switch; After the current loop module is cut off, the voltage loop module is used to apply a recovery voltage to the test switch, and the zero-zone post-arc current flowing through the voltage loop module is sampled; The sampled post-arc current is processed to obtain the post-arc current measurement result.

[0059] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A post-arc current measurement system, characterized in that: include: Synthesis loop module and measurement and analysis module; The synthetic loop module includes a test switch module, a current loop module and a voltage loop module; The current loop module is electrically connected to the test switch module and is used to provide a current source for the test switch module; The test switch module is used to sample the zero-zone post-arc current flowing through the voltage loop module after the current loop module is cut off; The voltage loop module is electrically connected to the test switch module and is used to apply a recovery voltage to the test switch in the test switch module during the post-arc current measurement process; The measurement and analysis module is used to process the output signal of the test switch module to obtain a post-arc current measurement result.

2. The post-arc current measurement system according to claim 1, characterized in that: The current loop module includes a first LC oscillation circuit, which includes a first capacitor and a first inductor connected in series in sequence, and is used to provide a current source with high current and low voltage; a first switch is arranged between the first capacitor and the first inductor.

3. The post-arc current measurement system according to claim 1, characterized in that: The voltage loop module includes a second LC oscillation circuit, which includes a second inductor and a second capacitor connected in series in sequence, and is used to provide a high-voltage and low-current voltage source; a frequency modulation circuit is connected in parallel at both ends of the second LC oscillation circuit, and the frequency modulation circuit includes a third capacitor and a fourth capacitor connected in parallel, and a first resistor is also connected in series in the circuit where the third capacitor is located, and the frequency modulation circuit is used to adjust the recovery voltage.

4. The post-arc current measurement system according to claim 1, characterized in that: The test switch module includes an auxiliary switch and a coaxial shunt; one end of the auxiliary switch is used to connect the current loop module, and the other end is used to connect the voltage loop module, which is used to cut off the current loop module before the large current passes through zero; the coaxial shunt is used to collect the current of the voltage source loop.

5. The post-arc current measurement system according to claim 1, characterized in that: The measurement and analysis module includes a measurement submodule and a data transmission and storage submodule, wherein the measurement submodule is used to process the data collected by the coaxial splitter; The data transmission and storage submodule is used to store and upload the data output by the measurement submodule.

6. The post-arc current measurement system according to claim 5, characterized in that: The measurement submodule includes a front-stage signal processing module and a signal amplification and acquisition module; the front-stage signal processing module is used to process the output signal of the coaxial shunt, and the resistor-capacitor voltage divider is used to provide a current limiting loop with a set bandwidth; the signal amplification and acquisition module is used to amplify and acquire small signals.

7. The post-arc current measurement system according to claim 6, characterized in that: The pre-stage signal processing module includes a resistor-capacitor voltage divider and an anti-parallel diode, wherein the anti-parallel diode is connected in parallel to the high-voltage part of the resistor-capacitor voltage divider; when the current flowing through the anti-parallel diode reaches a first set current, the coaxial shunt voltage drop is greater than the diode set threshold, the diode is turned on, and the output voltage is limited; when the current flowing through the anti-parallel diode is a second set current, the coaxial shunt voltage drop is less than the conduction voltage drop of the diode, and the diode is cut off.

8. The post-arc current measurement system according to claim 6, characterized in that: The signal amplification and acquisition module includes a precision amplifier, a differential driver, and an analog-to-digital converter. The precision amplifier is used to amplify the pre-stage signal output by the pre-stage signal processing module and further amplify the output voltage of the resistor-capacitor voltage divider; the differential driver is used to drive the analog-to-digital converter to convert the single-ended signal amplified by the precision amplifier into a differential signal; the analog-to-digital converter is used to convert the analog signal processed by the differential driver into a digital signal and transmit it to the data storage and transmission module.

9. The post-arc current measurement system according to claim 5, characterized in that: The data transmission and storage submodule includes an FPGA main control chip, a storage module and a host computer processing module. The FPGA main control chip is used for driving and timing control of the data acquisition and storage modules, and is used to store the collected data in the storage module and send the stored data to the host computer processing module. The host computer processing module receives and recovers the stored data and performs data visualization.

10. A method for measuring post-arc current, based on the post-arc current measurement system according to any one of claims 1 to 9, characterized in that: include: Connect the test switch to the test switch module, and use the current loop module to provide power to the test switch; After the current loop module is cut off, the voltage loop module is used to apply a recovery voltage to the test switch, and the zero-zone post-arc current flowing through the voltage loop module is sampled; The sampled post-arc current is processed to obtain the post-arc current measurement result.

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