CN118501671B - Fault detection method and fault detection device for LC resonance circuit - Google Patents

Abstract

The present invention relates to the technical field of circuit detection, and discloses a fault detection method and a fault detection device for an LC resonant circuit, which respectively provide sweep frequency signals at the positive input terminal and the positive output terminal of the LC resonant circuit, collect the response of the negative terminal, obtain two sets of amplitude-frequency and phase-frequency characteristics, and obtain multiple fault ranges according to the qualitative characteristics in the amplitude-frequency and phase-frequency characteristics, and then obtain the final fault type according to the intersection of the multiple fault ranges. The fault detection method and the fault detection device for the LC resonant circuit provided by the present invention are based on the amplitude-frequency and phase-frequency characteristics, and can effectively and accurately locate various faults in the LC resonant circuit through qualitative analysis and reverse excitation analysis, and are not affected by the specific parameters of each component in the resonant circuit, and can be applied to the fault detection of LC resonant circuits with different parameters, and have strong versatility.

Description

A Fault Detection Method and Fault Detection Device for LC Resonance Circuit

Technical Field

The present invention relates to the technical field of electronic circuit fault detection, and in particular to a fault detection method and a fault detection device for an LC resonant circuit.

Background Art

The LC resonant circuit composed of an inductor and a capacitor is often used for resonance, filtering, and impedance matching in radio frequency equipment to improve the quality of receiving and transmitting radio frequency signals. It plays an important role in the fields of broadcasting, communication, and electronic countermeasures.

Among them, the resonant module composed of multiple stages of LC resonant circuits in series can effectively improve its resonance, filtering, impedance matching and other effects, and has good application prospects. However, with the increase of components, the failure rate will also increase. When a failure occurs, the entire resonant module is replaced, or the faulty component is replaced at a fixed point. The cost of the entire replacement is relatively high, especially in high-power applications. The cost of each component is high, and the cost of the entire replacement is even higher. Therefore, a common method is to detect the faulty component and replace the faulty component at a fixed point.

In order to detect and locate faulty components, the traditional method is to disassemble and measure the components in the network, which is blind and inconvenient because high-power inductors and capacitors are large in size. Alternatively, an excitation signal of a specific frequency is provided to obtain the output response of the resonant module under various fault conditions, and a fault comparison table is obtained based on the output response. During testing, an excitation signal of a specific frequency is provided based on the fault comparison table, and the output response is collected, which is compared with the fault comparison table to obtain the actual fault. However, each table is used for one purpose and is not universal enough. In addition, the actual performance of each component may shift due to aging, resulting in a difference between the actual detected output response and the content of the fault comparison table, resulting in insufficient actual detection accuracy.

Summary of the invention

Based on this, the purpose of the present invention is to provide a fault detection method and a fault detection device for an LC resonant circuit, so as to solve the problems of inconvenient operation and insufficient detection accuracy of LC resonant circuit fault detection in the prior art.

In one aspect, the present invention provides a fault detection method for an LC resonant circuit, wherein the LC resonant circuit comprises at least one inductor connected in series between an input positive terminal and an output positive terminal, wherein an intermediate node between the inductors, the input positive terminal, and the output positive terminal are respectively connected to a negative terminal via a capacitor, and the fault detection method comprises:

The first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature, and the second phase-frequency feature are collected in a preset order, wherein the first amplitude-frequency feature and the first phase-frequency feature are collected from the input positive end to the negative end, and the second amplitude-frequency feature and the second phase-frequency feature are collected from the output positive end to the negative end;

According to the first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature and the second phase-frequency feature, a first fault range, a second fault range, a third fault range and a fourth fault range are synchronously obtained respectively;

Obtaining a final fault type according to the intersection of the first fault range, the second fault range, the third fault range and the fourth fault range;

The step of obtaining the corresponding fault range according to the amplitude-frequency feature includes: obtaining the corresponding fault range according to the amplitude-frequency qualitative feature of the amplitude-frequency feature and a preset amplitude-frequency fault table;

The step of obtaining a corresponding fault range according to the phase-frequency characteristic includes: obtaining a corresponding fault range according to a phase-frequency qualitative characteristic of the phase-frequency characteristic and a preset phase-frequency fault table.

Optionally, the step of obtaining a final fault type according to an intersection of the first fault range, the second fault range, the third fault range and the fourth fault range further includes:

When any fault range among the first fault range, the second fault range, the third fault range and the fourth fault range is obtained according to the preset order, a fifth fault range is obtained according to the intersection of the obtained fault ranges, and the number of fault types in the fifth fault range is determined;

When the number of fault types in the fifth fault range is unique, stop collecting amplitude-frequency characteristics and phase-frequency characteristics, and use the fault types in the fifth fault range as final fault types;

When the number of fault types in the fifth fault range is not unique, the amplitude-frequency characteristics and the phase-frequency characteristics are continuously collected until the collection of the amplitude-frequency characteristics and the phase-frequency characteristics is completed, and each fault type in the final fifth fault range is taken as the final fault type.

Optionally, the amplitude-frequency qualitative characteristics include the number of peaks and the number of valleys.

Optionally, the phase-frequency qualitative characteristics include the step direction and step amplitude of each step.

Optionally, it also includes:

Performing symmetry verification on the first amplitude-frequency feature and the second amplitude-frequency feature according to the final fault type and the amplitude-frequency fault table, and re-collecting the first amplitude-frequency feature and the second amplitude-frequency feature when the symmetry verification fails, so as to re-execute the final fault type judgment;

Symmetry verification is performed on the first phase-frequency feature and the second phase-frequency feature according to the final fault type and the phase-frequency fault table, and when the symmetry verification fails, the first phase-frequency feature and the second phase-frequency feature are recollected to re-execute the final fault type judgment.

The present invention also provides a fault detection device for an LC resonant circuit, wherein the LC resonant circuit comprises at least one inductor connected in series between an input positive terminal and an output positive terminal, wherein an intermediate node between the inductors, the input positive terminal, and the output positive terminal are respectively connected to a negative terminal via a capacitor, and the fault detection device comprises: an acquisition module and a data analysis module, wherein:

The acquisition module is used to acquire a first amplitude-frequency feature, a second amplitude-frequency feature, a first phase-frequency feature, and a second phase-frequency feature according to a preset order, wherein the acquisition points of the first amplitude-frequency feature and the first phase-frequency feature are from the input positive end to the negative end, and the acquisition points of the second amplitude-frequency feature and the second phase-frequency feature are from the output positive end to the negative end;

The data analysis module is used to synchronously obtain a first fault range, a second fault range, a third fault range and a fourth fault range according to the first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature and the second phase-frequency feature respectively;

The data analysis module is further used to obtain a final fault type according to the intersection of the first fault range, the second fault range, the third fault range and the fourth fault range;

The data analysis module is also used to obtain a corresponding fault range according to the amplitude-frequency qualitative characteristics of the amplitude-frequency characteristics and a preset amplitude-frequency fault table, and to obtain a corresponding fault range according to the phase-frequency qualitative characteristics of the phase-frequency characteristics and a preset phase-frequency fault table.

Optionally, the data analysis module is further used to:

When any fault range among the first fault range, the second fault range, the third fault range and the fourth fault range is obtained according to the preset order, a fifth fault range is obtained according to the intersection of the obtained fault ranges, and the number of fault types in the fifth fault range is determined;

When the number of fault types in the fifth fault range is unique, controlling the acquisition module to stop the acquisition of amplitude-frequency characteristics and phase-frequency characteristics, and taking the fault types in the fifth fault range as final fault types;

When the number of fault types in the fifth fault range is not unique, the amplitude-frequency characteristics and the phase-frequency characteristics are continuously collected until the collection of the amplitude-frequency characteristics and the phase-frequency characteristics is completed, and each fault type in the final fifth fault range is taken as the final fault type.

Optionally, the amplitude-frequency qualitative characteristics include the number of peaks and the number of valleys.

Optionally, the phase-frequency qualitative characteristics include the step direction and step amplitude of each step.

Optionally, the data analysis module is further used to:

Performing symmetry verification on the first amplitude-frequency feature and the second amplitude-frequency feature according to the final fault type and the amplitude-frequency fault table, and controlling the acquisition module to re-acquire the first amplitude-frequency feature and the second amplitude-frequency feature when the symmetry verification fails, so as to re-execute the final fault type determination;

The first phase-frequency characteristic and the second phase-frequency characteristic are symmetry verified according to the final fault type and the phase-frequency fault table, and when the symmetry verification fails, the acquisition module is controlled to re-acquire the first phase-frequency characteristic and the second phase-frequency characteristic to re-execute the final fault type judgment.

The fault detection method of the LC resonant circuit provided by the present invention provides full-frequency excitation signals at the input positive end and the output positive end of the LC resonant circuit respectively, collects the response of the negative end, obtains two sets of amplitude-frequency characteristics and two sets of phase-frequency characteristics, and obtains multiple fault ranges according to the qualitative characteristics in the amplitude-frequency characteristics and the phase-frequency characteristics, and then obtains the final fault type according to the intersection of the multiple fault ranges, wherein the qualitative characteristics are not affected by the specific parameters of each component in the resonant circuit, and can accurately characterize various faults of LC resonant circuits with the same or different parameters, and according to the difference in amplitude-frequency characteristics and phase-frequency characteristics, as well as the difference in response under the two excitation inputs of the input positive end and the output positive end, the mirror-symmetrical and similar faults can be effectively distinguished, and the fault location accuracy is guaranteed. The fault detection method of the LC resonant circuit provided by the present invention can effectively and accurately locate various faults in the LC resonant circuit through qualitative analysis and reverse excitation analysis, which provides convenience for the fault detection of the resonant circuit of multi-stage LC series connection, and is not affected by the specific parameters of each component in the resonant circuit, and can be applicable to the fault detection of LC resonant circuits with different parameters, and has strong versatility.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the main flow of the fault detection method of the LC resonant circuit in the present invention;

FIG2 is a schematic diagram of the main module structure of the fault detection device of the LC resonant circuit in the present invention;

FIG3 is a first amplitude-frequency characteristic of a 3π-type LC resonant circuit in a normal situation in the present invention;

FIG4 is a first phase-frequency characteristic of a 3π-type LC resonant circuit in a normal situation in the present invention;

FIG5 is a first phase-frequency characteristic of a 3π-type LC resonant circuit in the present invention when C2 is open-circuited;

FIG. 6 is a first phase-frequency characteristic of the 3π-type LC resonant circuit in the present invention when C3 is open-circuited.

The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings.

DETAILED DESCRIPTION

In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and/or" used herein includes any and all combinations of one or more of the related listed items.

In order to solve the problems of inconvenient operation and insufficient detection accuracy of LC resonant circuit fault detection in the prior art, the present invention provides a fault detection method for an LC resonant circuit. Fault judgment is performed based on qualitative analysis, reverse excitation analysis and amplitude-frequency and phase-frequency joint analysis. The faulty components of a multi-stage series LC resonant circuit can be effectively located, and the method is not affected by the specific parameters of the components, does not require disassembly of the components, and is easy to operate.

Specifically, as shown in FIG. 1 and FIG. 2 , the applicable LC resonant circuit includes at least one inductor connected in series between the input positive terminal A+ and the output positive terminal B+, the intermediate node between the inductors, the input positive terminal, and the output positive terminal are respectively connected to the negative terminal through a capacitor, the first negative terminal A- and the second negative terminal B- are respectively used as the negative terminals of the input device and the output device, the two negative terminals are generally directly connected in parallel, and one is selected as the acquisition point interface in practical applications, so that under normal circumstances, the circuit structure between the input positive terminal and the output positive terminal to the negative terminal is the same, forming a multi-stage π-type topology LC resonant circuit. In this embodiment, the 3π-type topology is mainly taken as an example, and the first inductor L1, the second inductor L2 and the third inductor L3 are sequentially connected in series between the input positive terminal and the output positive terminal, and the four capacitance nodes from the input positive terminal to the output positive terminal are respectively provided with the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4, and the fault detection method includes:

Step S01: collecting a first amplitude-frequency feature, a second amplitude-frequency feature, a first phase-frequency feature, and a second phase-frequency feature according to a preset order, wherein the first amplitude-frequency feature and the first phase-frequency feature are collected from the input positive terminal to the negative terminal, and the second amplitude-frequency feature and the second phase-frequency feature are collected from the output positive terminal to the negative terminal;

Step S02: synchronously obtaining a first fault range, a second fault range, a third fault range and a fourth fault range respectively according to the first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature and the second phase-frequency feature;

Step S03: obtaining a final fault type according to the intersection of the first fault range, the second fault range, the third fault range and the fourth fault range;

The step of obtaining the corresponding fault range according to the amplitude-frequency feature includes: obtaining the corresponding fault range according to the amplitude-frequency qualitative feature of the amplitude-frequency feature and a preset amplitude-frequency fault table;

The step of obtaining a corresponding fault range according to the phase-frequency characteristic includes: obtaining a corresponding fault range according to a phase-frequency qualitative characteristic of the phase-frequency characteristic and a preset phase-frequency fault table.

In step S01, the preset order can be in the order of the first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature and the second phase-frequency feature, or the order of the first phase-frequency feature, the second phase-frequency feature, the first amplitude-frequency feature and the second amplitude-frequency feature. The acquisition order does not affect the acquired data and can be flexibly selected in practice.

For some specific faults, the fault can be directly located according to one of the first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature, and the second phase-frequency feature. When this type of fault occurs, continuing to collect other characteristic data will cause a waste of resources. In order to reduce the waste of detection resources, in this embodiment, step S02 also includes:

When any fault range among the first fault range, the second fault range, the third fault range and the fourth fault range is obtained according to the preset order, a fifth fault range is obtained according to the intersection of the obtained fault ranges, and the number of fault types in the fifth fault range is determined;

When the number of fault types in the fifth fault range is unique, stop collecting amplitude-frequency characteristics and phase-frequency characteristics, and use the fault types in the fifth fault range as final fault types;

When the number of fault types in the fifth fault range is not unique, the amplitude-frequency characteristics and the phase-frequency characteristics are continuously collected until the collection of the amplitude-frequency characteristics and the phase-frequency characteristics is completed, and each fault type in the final fifth fault range is taken as the final fault type.

As shown in Figures 3 and 4, the first amplitude-frequency characteristic and the first phase-frequency characteristic of the LC resonant circuit of the 3π type topology structure under normal conditions are respectively shown, wherein the horizontal axis is the frequency, the bandwidth reaches 0 to 1 GHz, and the vertical axis is the ratio of the output power to the input power, and the difference between the output phase and the input phase.

The amplitude-frequency qualitative characteristics generally include the number of peaks and valleys, and the phase-frequency qualitative characteristics generally include the step direction and step amplitude of each step. In most types of faults, the number of steps in the phase-frequency qualitative characteristics is consistent with the sum of the number of peaks and valleys in the amplitude-frequency characteristics. The fault comparison table for a single fault is as follows:

Fault comparison table 1:

Fault comparison table 2:

Among them, the step direction "up" represents a rising edge step, and "down" represents a falling edge step. The above fault comparison table mainly includes the characteristics of the first amplitude-frequency characteristic and the first phase-frequency characteristic. The characteristics of the second amplitude-frequency characteristic and the second phase-frequency characteristic can be obtained from the characteristics of the first amplitude-frequency characteristic and the first phase-frequency characteristic based on the principle of symmetry, and this application will not go into details here.

According to the above fault comparison table, C1 open circuit, C4 short circuit, L2 open circuit, C3 short circuit and C2 short circuit can be directly identified according to the number of peaks and valleys of the first amplitude-frequency feature.

The number of peaks and valleys of L1 open circuit and C1 short circuit in the first amplitude-frequency characteristic are the same, both of which are 0. At this time, they can be further distinguished and judged according to the second amplitude-frequency characteristic or the first phase-frequency characteristic. Among them, in the first phase-frequency characteristic, the number of phase-frequency steps of L1 open circuit and C1 short circuit is different, so they can be distinguished; in the second amplitude-frequency characteristic, the symmetrical fault of L1 open circuit is L3 open circuit, and the number of peaks and valleys are both 2, while the symmetrical fault of C1 short circuit is C4 short circuit, and the number of peaks and valleys are 2 and 3 respectively, which are different from the number of peaks and valleys of L3 open circuit. Therefore, L1 open circuit and C1 short circuit can be distinguished, and the distinction of other faults is similar.

The faults of C2 open circuit and C3 open circuit are symmetrical. The number of peaks and valleys in the first amplitude-frequency characteristic and the second amplitude-frequency characteristic, as well as the number of steps and the step direction in the first phase-frequency characteristic and the second phase-frequency characteristic are the same. However, as shown in Figures 5 and 6, the first phase-frequency characteristic when C2 is open circuit and the first phase-frequency characteristic when C3 is open circuit are respectively shown, and the step amplitudes of the phase-frequency steps are different. The step amplitudes of the four phase-frequency steps when C2 is open circuit are different, and the difference is greater than 50%. The step amplitudes of the four phase-frequency steps when C3 is open circuit are basically the same, and can be distinguished by the step amplitude in the phase-frequency qualitative characteristics. Among them, the judgment threshold for whether the step amplitudes are the same can be selected as 50%, for example. When the difference in the size of each step amplitude exceeds 50%, it can be judged that the step amplitudes are different, otherwise they are the same. In fact, other judgment thresholds can be selected according to specific circumstances, and this application does not make any special restrictions on this.

Since the fault of the LC resonant circuit with a 3π topology structure is generally a single fault, the above only shows the judgment of a single fault. In fact, a combined judgment of multiple faults can be provided according to specific needs. For multiple faults, it can be foreseen that they include a variety of completely symmetrical fault types. In this regard, whether it is the fixed-frequency and quantitative detection in the prior art or the fault detection method provided by the present application, it may be difficult to make an accurate judgment. However, the fault detection method provided by the present application can still effectively narrow the range of fault types and provide convenience for other more accurate fault detection and positioning operations.

In order to improve the accuracy of judgment and reduce misjudgment, in this embodiment, it also includes: verifying the symmetry of the first amplitude-frequency characteristic and the second amplitude-frequency characteristic according to the final fault type and the amplitude-frequency fault table, and when the symmetry verification fails, re-collecting the first amplitude-frequency characteristic and the second amplitude-frequency characteristic to re-execute the judgment of the final fault type; verifying the symmetry of the first phase-frequency characteristic and the second phase-frequency characteristic according to the final fault type and the phase-frequency fault table, and when the symmetry verification fails, re-collecting the first phase-frequency characteristic and the second phase-frequency characteristic to re-execute the judgment of the final fault type.

Specifically, for example, if an open circuit of C1 is detected, the amplitude-frequency qualitative characteristics and phase-frequency qualitative characteristics of the open circuit of C1 and the open circuit of C4 in the fault comparison table are compared with the amplitude-frequency qualitative characteristics and phase-frequency qualitative characteristics in the actually obtained first amplitude-frequency characteristic and the first phase-frequency characteristic, as well as the amplitude-frequency qualitative characteristics and phase-frequency qualitative characteristics in the second amplitude-frequency characteristic and the second phase-frequency characteristic. When the comparison is consistent, it is determined that the symmetry verification is successful. When the comparison fails, it is determined that the symmetry verification fails, and the final fault type judgment is re-executed to reduce the risk of errors in single data acquisition and detection errors, thereby making full use of multiple sets of data collected symmetrically to improve detection accuracy.

The present invention also provides a fault detection device for an LC resonant circuit, comprising an acquisition module 10 and a data analysis module 20. The acquisition module 10 is used to provide an excitation signal of the full frequency band and to collect the output response of the negative end of the resonant circuit to obtain each amplitude-frequency feature and phase-frequency feature. The data analysis module 20 obtains the amplitude-frequency qualitative feature and the phase-frequency qualitative feature according to each amplitude-frequency feature and phase-frequency feature, and then obtains the final fault type in combination with a preset fault comparison table. A current limiting resistor R0 is connected in series between the acquisition module 10 and the negative end of the LC resonant circuit to avoid the risk of overcurrent in the detection of short-circuit faults.

Specifically, the acquisition module 10 is used to collect the first amplitude-frequency characteristic, the second amplitude-frequency characteristic, the first phase-frequency characteristic and the second phase-frequency characteristic according to a preset order. The acquisition points of the first amplitude-frequency characteristic and the first phase-frequency characteristic are from the input positive end to the negative end, and the acquisition points of the second amplitude-frequency characteristic and the second phase-frequency characteristic are from the output positive end to the negative end.

The data analysis module 20 is used to synchronously obtain a first fault range, a second fault range, a third fault range and a fourth fault range respectively according to the first amplitude-frequency feature, the second amplitude-frequency feature, the first phase-frequency feature and the second phase-frequency feature;

The data analysis module 20 is also used to obtain a final fault type according to the intersection of the first fault range, the second fault range, the third fault range and the fourth fault range;

The data analysis module 20 is also used to obtain a corresponding fault range according to the amplitude-frequency qualitative characteristics of the amplitude-frequency characteristics and a preset amplitude-frequency fault table, and to obtain a corresponding fault range according to the phase-frequency qualitative characteristics of the phase-frequency characteristics and a preset phase-frequency fault table.

Among them, data collection and analysis can be achieved through a sweeper, a phase detector, a full-frequency resonant signal generator, a single-chip microcomputer, a voltage and current acquisition circuit, etc., and the specific selection can be based on cost requirements. Among them, this application adopts qualitative analysis, and the collection and identification of each qualitative feature has low requirements on the collection accuracy of the equipment, which can reduce the minimum implementation cost.

After obtaining the final fault type, the data analysis module 20 can also display the final fault type through a display, voice broadcast, etc. to display the test results, and remind the completion of the test through equipment such as indicator lights, alarms, and voice players.

In order to reduce the time and cost of data collection and analysis, the data analysis module 20 is also used to: when any fault range in the first fault range, the second fault range, the third fault range and the fourth fault range is obtained according to a preset order, the fifth fault range is obtained according to the intersection of the obtained fault ranges, and the number of fault types in the fifth fault range is determined; when the number of fault types in the fifth fault range is unique, the control acquisition module stops the acquisition of amplitude-frequency characteristics and phase-frequency characteristics, and the fault type in the fifth fault range is used as the final fault type; when the number of fault types in the fifth fault range is not unique, the amplitude-frequency characteristics and phase-frequency characteristics are continued to be collected until the amplitude-frequency characteristics and phase-frequency characteristics are collected, and each fault type in the final fifth fault range is used as the final fault type. For some specific faults, it can be directly determined according to part of the amplitude-frequency characteristics and phase-frequency characteristics, without further consuming resources, thereby reducing the consumption of detection resources and time and improving detection efficiency.

In order to improve the detection accuracy, the data analysis module 20 is also used to: perform symmetry verification on the first amplitude-frequency feature and the second amplitude-frequency feature according to the final fault type and the amplitude-frequency fault table, and when the symmetry verification fails, control the acquisition module to re-collect the first amplitude-frequency feature and the second amplitude-frequency feature to re-execute the final fault type judgment; perform symmetry verification on the first phase-frequency feature and the second phase-frequency feature according to the final fault type and the phase-frequency fault table, and when the symmetry verification fails, control the acquisition module to re-collect the first phase-frequency feature and the second phase-frequency feature to re-execute the final fault type judgment. Using symmetry features and multivariate acquisition data of phase frequency and amplitude frequency to perform symmetry verification can make full use of the acquired multivariate data, reduce the risk of false detection caused by single acquisition errors, and improve detection accuracy.

The fault detection method and the fault detection device for the LC resonant circuit provided by the present invention perform fault judgment based on qualitative analysis, reverse excitation analysis and amplitude-frequency-phase-frequency joint analysis, and can effectively locate the faulty components of the multi-stage series LC resonant circuit, and are not affected by the specific parameters of the components, do not need to disassemble the components, and are easy to operate.

At the same time, it can be understood that the present application is not only applicable to the 3π-type LC resonant circuit in the above-mentioned embodiment, but also to LC resonant circuits of other topological structures. The equivalent topological structures of various fault states at the positive input end and the positive output end are different, and their phase-frequency qualitative characteristics and amplitude-frequency qualitative characteristics will be different. Based on this characteristic, the fault detection method provided in the present application can also effectively determine the specific fault type.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

The above-mentioned embodiments only express several specific implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims (6)

1. A fault detection method for an LC resonant circuit, wherein the LC resonant circuit includes at least one inductor connected in series between an input positive terminal and an output positive terminal, and an intermediate node between the inductors, the input positive terminal, and the output positive terminal are respectively connected to a negative terminal through a capacitor, the fault detection method comprising:

Collecting a first amplitude-frequency characteristic, a second amplitude-frequency characteristic, a first phase-frequency characteristic and a second phase-frequency characteristic according to a preset sequence, wherein the collecting points of the first amplitude-frequency characteristic and the first phase-frequency characteristic are the input positive end to the negative end, and the collecting points of the second amplitude-frequency characteristic and the second phase-frequency characteristic are the output positive end to the negative end;

according to the first amplitude-frequency characteristic, the second amplitude-frequency characteristic, the first phase-frequency characteristic and the second phase-frequency characteristic, respectively and synchronously obtaining a first fault range, a second fault range, a third fault range and a fourth fault range;

obtaining a final fault type according to the intersection of the first fault range, the second fault range, the third fault range and the fourth fault range;

Carrying out symmetry verification on the first amplitude-frequency characteristic and the second amplitude-frequency characteristic according to the final fault type and an amplitude-frequency fault table, and re-collecting the first amplitude-frequency characteristic and the second amplitude-frequency characteristic when the symmetry verification fails so as to re-execute judgment of the final fault type;

Carrying out symmetry verification on the first phase frequency characteristic and the second phase frequency characteristic according to the final fault type and the phase frequency fault table, and re-collecting the first phase frequency characteristic and the second phase frequency characteristic when the symmetry verification fails so as to re-execute judgment of the final fault type;

The step of obtaining the corresponding fault range according to the amplitude-frequency characteristic comprises the following steps: obtaining a corresponding fault range according to the amplitude-frequency qualitative characteristic of the amplitude-frequency characteristic and a preset amplitude-frequency fault table;

The step of obtaining the corresponding fault range according to the phase frequency characteristics comprises the following steps: obtaining a corresponding fault range according to the phase frequency qualitative characteristic of the phase frequency characteristic and a preset phase frequency fault table;

the step of obtaining a final fault type from the intersection of the first, second, third and fourth fault ranges further comprises:

When any fault range among the first fault range, the second fault range, the third fault range and the fourth fault range is obtained according to the preset sequence, a fifth fault range is obtained according to the intersection of the obtained fault ranges, and the number of fault types in the fifth fault range is judged;

Stopping the collection of amplitude frequency characteristics and phase frequency characteristics when the number of the fault types in the fifth fault range is unique, and taking the fault types in the fifth fault range as final fault types;

And when the number of the fault types in the fifth fault range is not the same, continuing to acquire the amplitude frequency characteristic and the phase frequency characteristic until the amplitude frequency characteristic and the phase frequency characteristic are acquired, and taking each fault type in the final fifth fault range as a final fault type.

2. The method of claim 1, wherein the amplitude-frequency qualitative feature comprises a number of peaks and a number of valleys.

3. The method of claim 1, wherein the phase frequency characterization feature comprises a step direction and a step magnitude of each step.

4. A fault detection device for an LC resonant circuit, the LC resonant circuit comprising at least one inductor connected in series between an input positive terminal and an output positive terminal, an intermediate node between the inductors, the input positive terminal, and the output positive terminal being connected to a negative terminal through a capacitor, respectively, the fault detection device comprising: the system comprises an acquisition module and a data analysis module, wherein,

The acquisition module is used for acquiring a first amplitude-frequency characteristic, a second amplitude-frequency characteristic, a first phase-frequency characteristic and a second phase-frequency characteristic according to a preset sequence, wherein acquisition points of the first amplitude-frequency characteristic and the first phase-frequency characteristic are the input positive end to the negative end, and acquisition points of the second amplitude-frequency characteristic and the second phase-frequency characteristic are the output positive end to the negative end;

The data analysis module is used for synchronously obtaining a first fault range, a second fault range, a third fault range and a fourth fault range according to the first amplitude-frequency characteristic, the second amplitude-frequency characteristic, the first phase-frequency characteristic and the second phase-frequency characteristic respectively;

The data analysis module is further used for obtaining a final fault type according to the intersection of the first fault range, the second fault range, the third fault range and the fourth fault range;

The data analysis module is further configured to: obtaining a corresponding fault range according to the amplitude-frequency qualitative feature of the amplitude-frequency feature and a preset amplitude-frequency fault table, and obtaining a corresponding fault range according to the phase-frequency qualitative feature of the phase-frequency feature and a preset phase-frequency fault table;

the data analysis module is further configured to:

When any fault range among the first fault range, the second fault range, the third fault range and the fourth fault range is obtained according to the preset sequence, a fifth fault range is obtained according to the intersection of the obtained fault ranges, and the number of fault types in the fifth fault range is judged;

When the number of the fault types in the fifth fault range is unique, controlling the acquisition module to stop acquisition of amplitude frequency characteristics and phase frequency characteristics, and taking the fault type in the fifth fault range as a final fault type;

when the number of the fault types in the fifth fault range is not the same, continuing to collect the amplitude frequency characteristic and the phase frequency characteristic until the amplitude frequency characteristic and the phase frequency characteristic are collected, and taking each fault type in the final fifth fault range as a final fault type;

Wherein, the data analysis module is further configured to:

Carrying out symmetry verification on the first amplitude-frequency characteristic and the second amplitude-frequency characteristic according to the final fault type and the amplitude-frequency fault table, and controlling the acquisition module to acquire the first amplitude-frequency characteristic and the second amplitude-frequency characteristic again when the symmetry verification fails so as to execute judgment of the final fault type again;

And carrying out symmetry verification on the first phase frequency characteristic and the second phase frequency characteristic according to the final fault type and the phase frequency fault table, and controlling the acquisition module to acquire the first phase frequency characteristic and the second phase frequency characteristic again when the symmetry verification fails so as to execute judgment of the final fault type again.

5. The fault detection device for an LC tank as recited in claim 4, wherein said amplitude-frequency qualitative feature comprises a number of peaks and a number of valleys.

6. The fault detection device for an LC tank as recited in claim 4, wherein said phase frequency characterization includes a step direction and a step magnitude for each step.