Non-contact three-phase ac voltage phase sequence measuring device

Abstract

The application belongs to the technical field of phase sequence measurement, and particularly relates to a non-contact three-phase alternating voltage phase sequence measurement device, which comprises an internal reconstructed voltage module, an attenuation module, a filtering module, a comparison module and a main controller; the internal reconstructed voltage module comprises three, each internal reconstructed voltage module is used for forming corresponding internal reconstructed voltage of each phase in three-phase alternating voltage, and outputting the internal reconstructed voltage to the attenuation module; the attenuation module is used for attenuating and amplifying the internal reconstructed voltage of each phase; the filtering module is used for filtering the attenuated internal reconstructed voltage of each phase; the comparison module is used for generating each phase pulse signal according to the filtered internal reconstructed voltage of each phase; and the main controller is used for judging the phase sequence of alternating voltage according to the phase difference of rising edges of each phase pulse signal. The internal reconstructed voltage module is used to acquire the power frequency voltage of each phase in a non-contact conducting line mode, and the accuracy of the acquired power frequency voltage is effectively maintained.

Description

Technical Field

[0001] This application relates to the field of non-contact AC voltage phase sequence measurement technology, and in particular to a non-contact three-phase AC voltage phase sequence measurement device. Background Technology

[0002] In related technologies, phase sequence measurement of AC voltage requires disconnecting the terminals of the three-phase wires and directly connecting the three exposed alligator clips or test leads of the phase sequence meter to the three exposed live wires for measurement. In practical applications, the applicant has found the following problems: Phase sequence testing requires contact with the exposed 380V phase voltage conductors, sometimes necessitating power off before wiring and then powering on again for testing. This operation is extremely inconvenient, inefficient, and involves a large amount of manual work, while also posing a certain degree of danger.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] In view of at least one of the above technical problems, this application provides a non-contact three-phase AC voltage phase sequence measuring device, which solves the problem that when detecting phase sequence, it is necessary to contact the exposed 380V phase voltage wire, and sometimes it is necessary to disconnect the power before connecting the wire and then reconnect the power for detection. Such operation is very inconvenient, has low detection efficiency, requires a large amount of actual operation, and is also dangerous.

[0005] An embodiment of the first aspect of this application provides a non-contact three-phase AC voltage phase sequence measuring device, including an internal reconstructed voltage module, an attenuation module, a filtering module, a comparison module, and a main controller;

[0006] The internal reconfiguration voltage module includes three modules, each connected to the attenuation module. Each internal reconfiguration voltage module is used to generate the corresponding internal reconfiguration voltage in the three-phase AC voltage and output the internal reconfiguration voltage to the attenuation module.

[0007] The attenuation module is used to attenuate and amplify the reconstructed voltage within each phase;

[0008] The filtering module is used to filter the attenuated internal reconstructed voltages of each phase.

[0009] The comparison module is used to generate pulse signals for each phase based on the internal reconstructed voltage of each phase after filtering.

[0010] The main controller is used to determine the phase sequence of AC voltage based on the phase difference of the rising edges of each phase pulse signal.

[0011] This application has the following technical advantages: The measuring device disclosed in this application acquires the power frequency voltages of phases A, B, and C respectively through three internal reconstructed voltage modules. Based on these power frequency voltages, corresponding A, B, and C phase pulse signals are generated through attenuation, filtering, and comparison modules, respectively, and then the phase sequence is determined by comparison. Thus, by acquiring the power frequency voltages of each phase through non-contact conductive wires via the internal reconstructed voltage modules, the accuracy of the acquired power frequency voltages is effectively maintained. Furthermore, the cooperation of the attenuation, filtering, and comparison modules allows for rapid determination of the phase sequence among phases A, B, and C. The circuit structure of the attenuation, filtering, and comparison modules is simple, and the manufacturing cost is low.

[0012] In one implementation, the internal reconfiguration voltage module includes a signal conversion and processing circuit, a drive circuit, a power amplifier boost circuit, and a differential amplifier circuit.

[0013] The signal conversion and processing circuit is used to collect the micro current on the cable, then convert the micro current into an AC voltage signal, and then restore it into a power frequency voltage signal after shaping and filtering, and send it to the main controller to calculate the collected voltage and frequency values.

[0014] The driving circuit is used to reproduce the acquired voltage and frequency values ​​and generate a driving signal;

[0015] The power amplifier boost circuit is used to amplify the drive signal and generate the internal reconstruction voltage;

[0016] The differential amplifier circuit is used to generate a differential current based on the voltage difference between the internal reconstructed voltage and the external induced voltage, and to generate an identification voltage signal based on the differential current and send it to the main controller.

[0017] The main controller performs integration processing on the drive circuit based on the identified voltage signal.

[0018] In one implementation, the signal conversion and processing circuit includes a first current-to-voltage conversion unit, a first bandpass filter unit, and a second bandpass filter unit connected in sequence. The acquisition terminal of the first current-to-voltage conversion unit is located on the cable under test, and the second bandpass filter unit is connected to the main controller through the first analog-to-digital converter ADC1.

[0019] The driving circuit includes a first digital-to-analog converter DAC1 and a first AC filter unit connected in sequence. The first digital-to-analog converter is connected to the main controller, and the first AC filter unit is connected to the power amplifier boost circuit.

[0020] In one implementation, the power amplifier boost circuit includes a second AC filter unit, a power amplifier unit, and a boost unit connected in sequence.

[0021] The second AC filter unit is connected to the first AC filter unit;

[0022] The boost unit is connected to the differential amplifier circuit and the attenuation module, respectively.

[0023] In one implementation, the power amplification unit includes a driver, a power amplifier, and a limiter;

[0024] The first terminal of the driver is connected to the second AC filter unit, the second terminal of the driver is connected to the first terminal of the limiter through the first node N1, and the third terminal of the driver is grounded.

[0025] The second terminal of the limiter is connected to the third terminal of the power amplifier;

[0026] The second terminal of the power amplifier is connected to the first node N1, the first terminal of the power amplifier is grounded, and the fourth terminal of the power amplifier is connected to the boost unit.

[0027] In one implementation, the limiter includes a first diode and a second diode;

[0028] The power amplifier includes a first transistor and a second transistor;

[0029] In this configuration, the first terminal of the first diode is connected to the first terminal of the first transistor, and the second terminal of the first diode is connected to the first terminal of the second diode through the second node N2; the second terminal of the second diode is connected to the first node N1; the first terminal of the first transistor is the third terminal of the power amplifier, and the second terminal of the first transistor is connected to the first terminal of the second transistor through the third node N3; the third node N3 is connected to the second node N2, and the third node N3 is the fourth terminal of the power amplifier; the second terminal of the second transistor is connected to the first node N1, and the third terminal of the second transistor is grounded.

[0030] In one implementation, the differential amplifier circuit includes a differential current acquisition unit and a second current-to-voltage conversion unit connected in sequence.

[0031] The first acquisition terminal of the differential current acquisition unit is set on the cable under test, and the second acquisition terminal of the differential current acquisition unit is connected to the power amplifier boost circuit.

[0032] The second current-to-voltage conversion unit is connected to the main controller via the second analog-to-digital converter ADC2.

[0033] In one implementation, the attenuation module includes a first attenuator, a second attenuator, and a third attenuator;

[0034] The filtering module includes a first filter, a second filter, and a third filter;

[0035] The first end of the first attenuator is connected to an internal reconstructed voltage module to obtain the A-phase voltage signal, the second end of the first attenuator is connected to the second end of the third filter, and the third end of the first attenuator is connected to the first end of the first filter.

[0036] The first end of the second attenuator is connected to an internal reconfiguration voltage module to obtain the B-phase voltage signal. The second end of the second attenuator is connected to the second end of the first filter, and the third end of the second attenuator is connected to the first end of the second filter.

[0037] The first end of the third attenuator is connected to an internal reconfiguration voltage module to obtain the C-phase voltage signal. The second end of the third attenuator is connected to the second end of the second filter, and the third end of the third attenuator is connected to the first end of the third filter.

[0038] The second terminals of the first filter, the second filter, and the third filter are respectively connected to the comparison module.

[0039] In one implementation, the comparison module includes a first comparator, a second comparator, and a third comparator;

[0040] The first terminal of the first comparator is connected to the second terminal of the first filter, the first terminal of the second comparator is connected to the second terminal of the second filter, and the first terminal of the third comparator is connected to the second terminal of the third filter.

[0041] The second terminals of the first comparator, the second comparator, and the third comparator are respectively connected to the main controller.

[0042] In one implementation, the third terminal of the first comparator, the third terminal of the second comparator, and the third terminal of the third comparator are respectively connected to a reference voltage.

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a structural diagram of the phase sequence measuring device provided in the embodiments of this application;

[0046] Figure 2 This is a first structural diagram of the internal reconfigurable voltage module provided in the embodiments of this application;

[0047] Figure 3 This is a second structural diagram of the internal reconfigurable voltage module provided in the embodiments of this application;

[0048] Figure 4 This is a circuit diagram of the first current-to-voltage conversion unit provided in an embodiment of this application;

[0049] Figure 5 This is a circuit diagram of the first bandpass filter unit and the second bandpass filter unit provided in the embodiments of this application;

[0050] Figure 6 This is a circuit diagram of the driving circuit provided in the embodiments of this application;

[0051] Figure 7 This is a circuit diagram of the power amplifier boost circuit provided in the embodiments of this application;

[0052] Figure 8 This is a first structural diagram of the power amplifier unit provided in the embodiments of this application;

[0053] Figure 9 This is a second structural diagram of the power amplifier unit provided in the embodiments of this application;

[0054] Figure 10 This is a circuit diagram of the differential amplifier circuit provided in the embodiments of this application;

[0055] Figure 11 This is a structural diagram of the attenuation module, filtering module, and comparison module provided in the embodiments of this application;

[0056] Figure 12 This is a circuit diagram of the attenuation module, filtering module, and comparison module provided in the embodiments of this application; Detailed Implementation

[0057] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0058] In related technologies, phase sequence measurement of AC voltage requires disconnecting the terminals of the three-phase wires and directly connecting the three exposed alligator clips or test leads of the phase sequence meter to the three exposed live wires. In practical applications, the applicant has found the following problems: Phase sequence testing requires contact with the exposed 380V phase voltage conductors, sometimes necessitating power-off wiring and then power-on testing. This operation is inconvenient, inefficient, and involves a large amount of manual work, while also posing a certain degree of danger. The measuring device disclosed in this application acquires the power frequency voltages of phases A, B, and C through three internal reconstructed voltage modules. Based on these voltages, corresponding A, B, and C phase pulse signals are generated through attenuation, filtering, and comparison modules, respectively, and then the phase sequence is determined by comparison. In this way, the power frequency voltage of each phase is obtained by the internal reconstructed voltage module in a non-contact conductive wire manner, which effectively maintains the accuracy of the acquired power frequency voltage. Furthermore, through the cooperation of the attenuation module, the filtering module, and the comparison module, the phase sequence between phases A, B, and C can be quickly determined. Moreover, the circuit structure of the attenuation module, the filtering module, and the comparison module is simple and the manufacturing cost is low.

[0059] An embodiment of the first aspect of this application provides a non-contact three-phase AC voltage phase sequence measuring device, such as... Figures 1 to 12 As shown, it includes an internal reconfiguration voltage module 100, an attenuation module 200, a filtering module 300, a comparison module 400, and a main controller 500.

[0060] The internal reconfiguration voltage module 100 includes three modules, each of which is connected to the attenuation module 200. Each internal reconfiguration voltage module 100 is used to form a corresponding internal reconfiguration voltage in the three-phase AC voltage and output the internal reconfiguration voltage to the attenuation module 200.

[0061] The attenuation module 200 is used to attenuate and amplify the reconstructed voltage within each phase;

[0062] The filter module 300 is used to filter the attenuated internal reconstructed voltage of each phase;

[0063] The comparison module 400 is used to generate pulse signals for each phase based on the internal reconstructed voltage of each phase after filtering.

[0064] The main controller 500 is used to determine the phase sequence of AC voltage based on the phase difference of the rising edge of each phase pulse signal.

[0065] Please see Figure 1The internal reconfiguration voltage module 100 has three components, each of which collects the micro-current on one phase of the cable. The internal reconfiguration voltage module 100 generates an internal reconfiguration voltage and ultimately outputs it to the attenuation module 200 to complete the phase sequence measurement. This effectively avoids the error caused by directly collecting the induced voltage, thus obtaining a more accurate voltage for each phase of the cable. Furthermore, when acquiring the AC voltage of phases A, B, and C, for example, when measuring the AC voltage of phase A, phase B needs to be used as a reference; when measuring the AC voltage of phase B, phase C needs to be used as a reference; and when measuring the AC voltage of phase C, phase A needs to be used as a reference.

[0066] The attenuation module 200 is used to attenuate the internal reconstructed voltage of each phase and amplify the current, with the aim of reaching the voltage processing range of the main controller 500.

[0067] When the main controller 500 acquires the pulse signals of each phase, it determines the phase sequence of the AC voltage based on the phase difference of the rising edges of each phase pulse signal. Specifically, assuming the rising edge of the A-phase voltage pulse signal is used as the reference, it determines whether the rising edge of the B-phase voltage pulse signal lags behind the rising edge of the A-phase voltage pulse signal by 120°, and whether the rising edge of the C-phase voltage pulse signal lags behind the rising edge of the B-phase voltage pulse signal by 120°. If so, the three-phase voltage phase sequence is rotating in the forward direction.

[0068] If not, then determine whether the rising edge of the C-phase voltage pulse signal lags behind the rising edge of the A-phase voltage pulse signal by 120°, and whether the rising edge of the B-phase voltage pulse signal lags behind the rising edge of the C-phase voltage pulse signal by 120°. If both conditions are met, the three-phase voltage phase sequence is in reverse rotation.

[0069] In some embodiments, such as Figures 1 to 12 As shown, the internal reconfiguration voltage module 100 includes a signal conversion and processing circuit 110, a drive circuit 120, a power amplifier boost circuit 130, and a differential amplifier circuit 140.

[0070] The signal conversion and processing circuit 110 is used to collect the micro current on the cable, then convert the micro current into an AC voltage signal, and then restore it into a power frequency voltage signal after shaping and filtering, and send it to the main controller 500 to calculate the collected voltage and frequency values.

[0071] The driving circuit 120 is used to restore the acquired voltage and frequency values ​​and generate a driving signal;

[0072] The power amplifier boost circuit 130 is used to amplify the drive signal and form the internal reconstruction voltage;

[0073] The differential amplifier circuit 140 is used to generate a differential current based on the voltage difference between the internal reconstructed voltage and the external induced voltage, generate an identification voltage signal based on the differential current, and send it to the main controller 500.

[0074] The main controller 500 performs integration processing on the drive circuit 120 based on the identified voltage signal.

[0075] For the differential amplifier circuit 140, it determines whether a differential current is generated based on the internal reconstructed voltage signal and the external induced voltage. If a differential current is generated, an identification voltage signal is generated and transmitted to the main controller 500, thereby instructing the digital-to-analog converter DAC1 to take corresponding actions. The external induced voltage is the induced voltage of the cable. Specifically, the main controller 500 generates an identification voltage signal based on the differential current, and thus takes corresponding actions on the digital-to-analog converter DAC1 in three ways.

[0076] First, if the induced voltage is equal to the internally reconstructed voltage signal, i.e. the differential current is zero, then the main controller 500 does not receive the identification voltage signal; it maintains the output of the first digital-to-analog converter DAC1 and sends the internally reconstructed voltage signal to the attenuation module 200.

[0077] Secondly, the induced voltage and the internally reconstructed voltage signal are not equal, and the differential current is greater than zero. The main controller 500 receives the identification voltage signal and performs a subtraction operation on the first digital-to-analog converter DAC1, and then the first digital-to-analog converter DAC1 outputs again. Here, the sampled voltage and frequency values ​​of the cable under test are subjected to a subtraction operation, and the sampled voltage and frequency values ​​after the subtraction operation are re-output, which finally form a new internally reconstructed voltage signal in the power amplifier boost circuit 130. The new internally reconstructed voltage signal is then differentially compared with the induced voltage in the differential amplifier circuit 140. The first case is performed when the new internally reconstructed voltage signal is equal to the induced voltage. In this way, it can be effectively ensured that the internally reconstructed voltage signal is the same as the induced voltage, and then the internally reconstructed voltage signal is collected for phase sequence detection, effectively avoiding interference from other lines.

[0078] Third, the induced voltage and the internally reconstructed voltage signal are not equal, and the differential current is less than zero. The main controller 500 receives the identification voltage signal and performs an integration operation on the first digital-to-analog converter DAC1, and then the first digital-to-analog converter DAC1 outputs again. Here, the collected voltage and frequency values ​​of the cable under test are integrated, and the collected voltage and frequency values ​​after integration are re-output, which finally form a new internally reconstructed voltage signal in the power amplifier boost circuit 130. The new internally reconstructed voltage signal is differentially compared with the induced voltage again in the differential amplifier circuit 140. When the new internally reconstructed voltage signal is equal to the induced voltage, the first case is performed. In this way, it can effectively ensure that the internally reconstructed voltage signal is the same as the induced voltage, and then the internally reconstructed voltage signal is collected for phase sequence detection, effectively avoiding interference from other lines.

[0079] In some embodiments, such as Figures 1 to 12 As shown, the signal conversion and processing circuit 110 includes a first current-to-voltage conversion unit 111, a first bandpass filter unit 112, and a second bandpass filter unit 113 connected in sequence. The acquisition terminal of the first current-to-voltage conversion unit 111 is set on the cable under test, and the second bandpass filter unit 113 is connected to the main controller 500 through the first analog-to-digital converter ADC1.

[0080] The driving circuit 120 includes a first digital-to-analog converter DAC1 and a first AC filter unit 121 connected in sequence. The first digital-to-analog converter is connected to the main controller 500, and the first AC filter unit 121 is connected to the power amplifier boost circuit 130.

[0081] In the signal conversion and processing circuit 110, the acquisition terminal V1 is located on the cable under test. The first current-voltage conversion unit 111 includes, but is not limited to, an operational amplifier U4. The inverting input terminal of the operational amplifier U4 is the acquisition terminal V1, and the output terminal of the operational amplifier U4 is connected to the first bandpass filter unit 112.

[0082] The first bandpass filter unit 112 and the second bandpass filter unit 113 are common low-pass filters, which will not be described in detail here. The first bandpass filter unit 112 and the second bandpass filter unit 113 filter the acquired signal to reduce interference. The first bandpass filter unit 112 is connected to the first current-to-voltage conversion unit 111. The second bandpass filter unit 113 is connected to the main controller 500.

[0083] The first digital-to-analog converter (DAC1) is a common DAC and will not be described in detail here. The first AC filter unit 121 includes, but is not limited to, operational amplifier U100. The inverting input of operational amplifier U100 is connected to the first DAC1, and the output of operational amplifier U100 is connected to the power amplifier boost circuit 130. The operational amplifier U100 is model ADA4637-1. The output of operational amplifier U100 is connected to the power amplifier boost circuit 130.

[0084] In some embodiments, such as Figures 1 to 12 As shown, the power amplifier boost circuit 130 includes a second AC filter unit 131, a power amplifier unit 132, and a boost unit 133 connected in sequence.

[0085] The second AC filter unit 131 is connected to the first AC filter unit 121;

[0086] The boost unit 133 is connected to the differential amplifier circuit 140 and the attenuation module 200, respectively.

[0087] The second AC filter unit 131 includes, but is not limited to, operational amplifier U3A. The non-inverting input of operational amplifier U3A is connected to the first AC filter unit 121, and the output of operational amplifier U3A is connected to power amplifier unit 132. The second AC filter unit 131 is connected to the first AC filter unit 121.

[0088] For the power amplifier boost circuit 130, the second AC filter unit 131 filters the drive signal sent by the drive circuit 120 and boosts the voltage of the boost unit 133 through the power amplifier unit 132, thereby forming an internal reconstructed voltage signal.

[0089] The boost unit 133 is connected to the differential amplifier circuit 140. The boost unit 133 is also connected to the attenuation module 200. Specifically, the boost unit 133 includes a transformer T1. The first terminal of the transformer T1 is connected to the power amplifier unit 132, the second terminal of the transformer T1 is connected to the differential amplifier circuit 140, and the third terminal of the transformer T1 is connected to the attenuation module 200. The primary / secondary winding ratio of the transformer T1 is 1:385.

[0090] In some embodiments, such as Figures 1 to 12 As shown, the power amplifier unit 132 includes a driver 1321, a power amplifier 1322, and a limiter 1323;

[0091] The first terminal of the driver 1321 is connected to the second AC filter unit 131, the second terminal of the driver 1321 is connected to the first terminal of the limiter 1323 through the first node N1, and the third terminal of the driver 1321 is grounded.

[0092] The second terminal of limiter 1323 is connected to the third terminal of power amplifier 1322;

[0093] The second terminal of the power amplifier 1322 is connected to the first node N1, the first terminal of the power amplifier 1322 is grounded, and the fourth terminal of the power amplifier 1322 is connected to the boost unit 133.

[0094] The power amplifier 1322 amplifies the drive signal, thereby boosting the voltage of the boost unit 133. The limiter 1323 is used to keep the power amplifier 1322 in a static operating state, preventing crossover distortion from occurring at the output.

[0095] In some embodiments, such as Figures 1 to 12 As shown, the limiter 1323 includes a first diode D100 and a second diode D101;

[0096] The power amplifier 1322 includes a first transistor Q8050 and a second transistor Q8550;

[0097] In this configuration, the first terminal of the first diode D100 is connected to the first terminal of the first transistor Q8050, and the second terminal of the first diode D100 is connected to the first terminal of the second diode D101 through the second node N2; the second terminal of the second diode D101 is connected to the first node N1; the first terminal of the first transistor Q8050 is the third terminal of the power amplifier 1322, and the second terminal of the first transistor Q8050 is connected to the first terminal of the second transistor Q8550 through the third node N3; the third node N3 is connected to the second node N2, and the third node N3 is the fourth terminal of the power amplifier 1322; the second terminal of the second transistor Q8550 is connected to the first node N1, and the third terminal of the second transistor Q8550 is grounded.

[0098] In some embodiments, such as Figures 1 to 12 As shown, the differential amplifier circuit 140 includes a differential current acquisition unit 141 and a second current-to-voltage conversion unit 142 connected in sequence.

[0099] The first acquisition terminal of the differential current acquisition unit 141 is set on the cable under test, and the second acquisition terminal of the differential current acquisition unit 141 is connected to the power amplifier boost circuit 130.

[0100] The second current-to-voltage conversion unit 142 is connected to the main controller 500 via the second analog-to-digital converter ADC2.

[0101] The differential current acquisition unit 141 includes resistors R19, R20, and R22 connected in series. The first terminal of resistor R19 is the first input terminal J1 of the differential current acquisition unit 141, and the second terminal of resistor R19 is the first output terminal of the differential amplifier circuit 140. The second terminal of resistor R19 is connected to the second current-to-voltage conversion unit 142. The first terminal of resistor R22 is the second input terminal of the differential current acquisition unit 141, and the second terminal of resistor R22 is the second output terminal of the differential current acquisition unit 141. The second terminal of resistor R22 is also connected to the second current-to-voltage conversion unit 142. The resistance of resistor R19 is 200kΩ. The resistance of resistor R20 is 1kΩ. The resistance of resistor R22 is 200kΩ.

[0102] The second current-to-voltage conversion unit 142 includes resistors R6, R18, R106, and R7, and operational amplifier U2. The inverting input of operational amplifier U2 is connected to the differential current acquisition unit 141 via resistor R6, the non-inverting input of operational amplifier U2 is connected to the differential current acquisition unit 141 via resistor R18, the inverting input of operational amplifier U2 is connected to the output of operational amplifier U2 via resistor R106, and the output of operational amplifier U2 is connected to the main controller 500 via resistor R7. The resistance values ​​of resistors R6, R18, R106, and R7 are all 100kΩ. The second current-to-voltage conversion unit 142 is connected to the main controller 500.

[0103] In some embodiments, such as Figures 1 to 12 As shown, the attenuation module 200 includes a first attenuator 210, a second attenuator 220 and a third attenuator 230;

[0104] The filtering module 300 includes a first filter 310, a second filter 320, and a third filter 330;

[0105] The first end of the first attenuator 210 is connected to an internal reconstructed voltage module 100 to acquire the A-phase voltage signal. The second end of the first attenuator 210 is connected to the second end of the third filter 330, and the third end of the first attenuator 210 is connected to the first end of the first filter 310.

[0106] The first end of the second attenuator 220 is connected to an internal reconfiguration voltage module 100 to obtain the B-phase voltage signal. The second end of the second attenuator 220 is connected to the second end of the first filter 310, and the third end of the second attenuator 220 is connected to the first end of the second filter 320.

[0107] The first end of the third attenuator 230 is connected to an internal reconfiguration voltage module 100 to acquire the C-phase voltage signal. The second end of the third attenuator 230 is connected to the second end of the second filter 320, and the third end of the third attenuator 230 is connected to the first end of the third filter 330.

[0108] The second terminals of the first filter 310, the second filter 320, and the third filter 330 are respectively connected to the comparison module 400.

[0109] Specifically, the first terminal of the first attenuator 210 is used to acquire the A-phase voltage signal. The first terminal of the second attenuator 220 is used to acquire the B-phase voltage signal. The first terminal of the third attenuator 230 is used to acquire the C-phase voltage signal.

[0110] The first attenuator 210, the second attenuator 220, and the third attenuator 230 are used to attenuate and amplify the current of the acquired voltage signal, respectively. Attenuation of the acquired voltage signal is necessary to meet the voltage processing range of the main controller 500.

[0111] Taking the A-phase voltage signal as an example, the A-phase voltage signal passes through the first attenuator 210, outputting an attenuated A-phase voltage signal. This signal is then filtered by the first filter 310 before being input to the first comparator, which outputs an A-phase voltage pulse signal. The main controller 500 acquires the A-phase voltage pulse signal. Similarly, the main controller 500 also acquires the B-phase and C-phase voltage pulse signals.

[0112] In some embodiments, such as Figures 1 to 12 As shown, the comparison module 400 includes a first comparator 410, a second comparator 420, and a third comparator 430;

[0113] The first terminal of the first comparator 410 is connected to the second terminal of the first filter 310, the first terminal of the second comparator 420 is connected to the second terminal of the second filter 320, and the first terminal of the third comparator 430 is connected to the second terminal of the third filter 330.

[0114] The second terminals of the first comparator 410, the second comparator 420, and the third comparator 430 are respectively connected to the main controller 500.

[0115] In some embodiments, such as Figures 1 to 12 As shown, the third terminal of the first comparator 410, the third terminal of the second comparator 420, and the third terminal of the third comparator 430 are respectively connected to the reference voltage.

[0116] The reference voltage VREF serves as a reference point. Taking the first comparator 410 as an example, the phase A voltage attenuation signal, after filtering, is input to the first comparator 410. The filtered phase A voltage attenuation signal is then compared with the reference voltage VREF. If the phase A voltage attenuation signal exceeds the reference voltage VREF, the first comparator 410 outputs a high level; if the phase A voltage attenuation signal is lower than the reference voltage VREF, the first comparator 410 outputs a low level. Ultimately, the first comparator 410 outputs a phase A voltage pulse signal. Similarly, the principles of the second comparator 420 and the third comparator 430 are the same as those of the first comparator 410, and will not be elaborated upon here.

[0117] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0118] It should also be understood that, in the embodiments of the present invention, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.

[0119] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0120] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0121] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, or they may be electrical, mechanical, or other forms of connection.

[0122] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0123] The above are merely preferred embodiments of this application and do not constitute any limitation on this application. Any person skilled in the art can make many possible variations and modifications to the technical solution of this application, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this application. Therefore, all equivalent changes made based on the shape, structure, and principle of this application without departing from the content of the technical solution of this application should be covered within the protection scope of this application.

Claims

1. A non-contact three-phase AC voltage phase sequence measuring device, characterized in that, It includes an internal reconfigurable voltage module, attenuation module, filtering module, comparison module, and main controller; The internal reconfiguration voltage module has three modules, each connected to the attenuation module. Each internal reconfiguration voltage module is used to generate a corresponding internal reconfiguration voltage in the three-phase AC voltage and output the internal reconfiguration voltage to the attenuation module. The attenuation module is used to attenuate the reconstructed voltage within each phase and amplify the current. The filtering module is used to filter the attenuated internal reconstructed voltage of each phase. The comparison module is used to generate pulse signals for each phase based on the internal reconstructed voltage of each phase after filtering. The main controller is used to determine the phase sequence of the AC voltage based on the phase difference of the rising edges of each phase pulse signal. The internal reconfiguration voltage module includes a signal conversion and processing circuit, a drive circuit, a power amplifier boost circuit, and a differential amplifier circuit. The signal conversion and processing circuit is used to collect the micro current on the cable, then convert the micro current into an AC voltage signal, and then restore it into a power frequency voltage signal after shaping and filtering, and send it to the main controller to calculate the collected voltage and frequency values. The driving circuit is used to restore the acquired voltage and frequency values ​​and generate a driving signal; The power amplifier boost circuit is used to amplify the drive signal and form an internal reconstruction voltage; The differential amplifier circuit is used to generate a differential current based on the voltage difference between the internal reconstructed voltage and the external induced voltage, generate an identification voltage signal based on the differential current, and send it to the main controller. The main controller performs integration processing on the drive circuit based on the identified voltage signal.

2. The non-contact three-phase AC voltage phase sequence measuring device according to claim 1, characterized in that, The signal conversion and processing circuit includes a first current-to-voltage conversion unit, a first bandpass filter unit, and a second bandpass filter unit connected in sequence. The acquisition terminal of the first current-to-voltage conversion unit is set on the cable under test, and the second bandpass filter unit is connected to the main controller through a first analog-to-digital converter ADC1. The driving circuit includes a first digital-to-analog converter (DAC1) and a first AC filter unit connected in sequence. The first DAC1 is connected to the main controller, and the first AC filter unit is connected to the power amplifier boost circuit.

3. The non-contact three-phase AC voltage phase sequence measuring device according to claim 2, characterized in that, The power amplifier boost circuit includes a second AC filter unit, a power amplifier unit, and a boost unit connected in sequence. The second AC filter unit is connected to the first AC filter unit; The boost unit is connected to the differential amplifier circuit and the attenuation module, respectively.

4. The non-contact three-phase AC voltage phase sequence measuring device according to claim 3, characterized in that, The power amplification unit includes a driver, a power amplifier, and a limiter; The first end of the driver is connected to the second AC filter unit, the second end of the driver is connected to the first end of the limiter through the first node N1, and the third end of the driver is grounded. The second end of the limiter is connected to the third end of the power amplifier; The second terminal of the power amplifier is connected to the first node N1, the first terminal of the power amplifier is grounded, and the fourth terminal of the power amplifier is connected to the boost unit.

5. The non-contact three-phase AC voltage phase sequence measuring device according to claim 4, characterized in that, The limiter includes a first diode and a second diode; The power amplifier includes a first transistor and a second transistor; Wherein, the first end of the first diode is connected to the first end of the first transistor, and the second end of the first diode is connected to the first end of the second diode through the second node N2; the second end of the second diode is connected to the first node N1; the first end of the first transistor is the third end of the power amplifier, and the second end of the first transistor is connected to the first end of the second transistor through the third node N3; the third node N3 is connected to the second node N2, and the third node N3 is the fourth end of the power amplifier; the second end of the second transistor is connected to the first node N1, and the third end of the second transistor is grounded.

6. The non-contact three-phase AC voltage phase sequence measuring device according to claim 1, characterized in that, The differential amplifier circuit includes a differential current acquisition unit and a second current-to-voltage conversion unit connected in sequence; The first acquisition terminal of the differential current acquisition unit is set on the cable under test, and the second acquisition terminal of the differential current acquisition unit is connected to the power amplifier boost circuit. The second current-to-voltage conversion unit is connected to the main controller via the second analog-to-digital converter ADC2.

7. The non-contact three-phase AC voltage phase sequence measuring device according to claim 1, characterized in that, The attenuation module includes a first attenuator, a second attenuator, and a third attenuator; The filtering module includes a first filter, a second filter, and a third filter; Wherein, the first end of the first attenuator is connected to an internal reconstructed voltage module for acquiring the A-phase voltage signal, the second end of the first attenuator is connected to the second end of the third filter, and the third end of the first attenuator is connected to the first end of the first filter; The first end of the second attenuator is connected to an internal reconstructed voltage module to acquire the B-phase voltage signal, the second end of the second attenuator is connected to the second end of the first filter, and the third end of the second attenuator is connected to the first end of the second filter. The first end of the third attenuator is connected to an internal reconfiguration voltage module for acquiring the C-phase voltage signal, the second end of the third attenuator is connected to the second end of the second filter, and the third end of the third attenuator is connected to the first end of the third filter. The second terminals of the first filter, the second filter, and the third filter are respectively connected to the comparison module.

8. The non-contact three-phase AC voltage phase sequence measuring device according to claim 7, characterized in that, The comparison module includes a first comparator, a second comparator, and a third comparator; The first terminal of the first comparator is connected to the second terminal of the first filter, the first terminal of the second comparator is connected to the second terminal of the second filter, and the first terminal of the third comparator is connected to the second terminal of the third filter. The second terminals of the first comparator, the second comparator, and the third comparator are respectively connected to the main controller.

9. The non-contact three-phase AC voltage phase sequence measuring device according to claim 8, characterized in that, The third terminals of the first comparator, the second comparator, and the third comparator are respectively connected to the reference voltage.

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