An IGBT state monitoring and fault prediction method for single-phase half-bridge inverter

Abstract

A method for IGBT state monitoring and fault prediction suitable for a single-phase half-bridge inverter includes: using a voltage sensor to collect voltage data during the operation of the inverter; reconstructing the voltage data output by the inverter according to the positive and negative half cycles to obtain two sets of data corresponding to different IGBT switches; calculating the characteristic parameters of the IGBT according to the reconstructed voltage data; monitoring the IGBT operating state according to the calculated characteristic parameters of the IGBT; using a prediction algorithm to perform time-series extrapolation on the calculated characteristic parameters of the IGBT to obtain the prediction results of the characteristic parameters of the IGBT, performing threshold determination on the prediction results, and realizing early warning of potential IGBT faults. The present invention can realize online monitoring of the operating state of the IGBT, and can effectively improve the operating safety of the system; the present invention can realize early warning of potential IGBT faults, and can effectively avoid losses caused by sudden failures of the IGBT. The present invention can distinguish different IGBTs on the bridge arm, and then accurately locate the position of the potential IGBT fault.

Description

Technical Field

[0001] The present invention relates to the field of IGBT state monitoring and fault prediction, and in particular to an IGBT state monitoring and fault prediction method suitable for a single-phase half-bridge inverter. Background Art

[0002] Over the years, with the rapid development of power electronics technology, PWM inverter technology with modern switching devices IGBT as the core has been increasingly widely used in AC motor drive systems. However, power semiconductor devices such as IGBT are the devices with the highest failure rate in power electronic circuits and are the weak link in the system that is prone to failure. Therefore, studying the state monitoring and fault prediction methods for the switch tube of the inverter to achieve accurate prediction and location of potential faults of the switch tube is conducive to reducing the downtime caused by inverter switch tube failures and improving the efficiency of equipment use, which has very important economic value. Summary of the invention

[0003] In view of the above problems, the present invention is proposed to provide an IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter, which overcomes the above problems or at least partially solves the above problems.

[0004] In order to solve the above technical problems, the embodiments of the present application disclose the following technical solutions:

[0005] An IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter, comprising:

[0006] S100. Using a voltage sensor to collect voltage data during the operation of the inverter;

[0007] S200. Reconstruct the voltage data output by the inverter according to the positive and negative half cycles to obtain two sets of data corresponding to different IGBT switch tubes;

[0008] S300. Calculate characteristic parameters of the IGBT according to the reconstructed voltage data;

[0009] S400. Monitoring the operating state of the IGBT according to the calculated characteristic parameters of the IGBT;

[0010] S500. Use a prediction algorithm to perform time-series extrapolation on the calculated characteristic parameters of the IGBT to obtain prediction results of the characteristic parameters of the IGBT, perform threshold determination on the prediction results, and implement early warning of potential faults of the IGBT.

[0011] Furthermore, the specific process of S100 is: the voltage sensor collects the voltage data output by the inverter according to the sampling frequency f1, and the data collected by the voltage sensor is saved in chronological order:

[0012] U t =[u t1 ,u t2 ,…,u ti ,…,u tn ].

[0013] Furthermore, in S200, two sets of data corresponding to different IGBT switch tubes are obtained, wherein the positive half cycle corresponds to the switch tube S1, and the reconstructed data is:

[0014]

[0015]

[0016] Where T is the sampling period.

[0017] Furthermore, in S200, two sets of data corresponding to different IGBT switch tubes are obtained. The negative half cycle corresponds to the switch tube S2, and the reconstructed data is:

[0018]

[0019]

[0020] Where T is the sampling period.

[0021] Further, in S300, the characteristic parameter of the IGBT is the phase difference between the output voltage waveform and the modulation wave, and the calculation method thereof includes:

[0022] When calculating the characteristic parameters of the switch tube S1 corresponding to the positive half cycle, the data sampling points closest to both sides of the zero crossing point are determined as follows: and The voltage values ​​corresponding to the two sampling points have opposite signs;

[0023] Calculate the time coordinate corresponding to the zero-crossing point:

[0024]

[0025] The zero-crossing point coordinates corresponding to the calculated positive half-cycle reconstructed data are saved in chronological order and recorded as:

[0026]

[0027] Get the corresponding modulation wave zero-crossing point coordinates, recorded as:

[0028]

[0029] Calculate the corresponding phase offset:

[0030]

[0031] Furthermore, in S300, the characteristic parameter of the IGBT is the phase difference between the output voltage waveform and the modulation wave, and the calculation method thereof further includes:

[0032] When calculating the characteristic parameters of the switch tube S2 corresponding to the negative half cycle, the data sampling points closest to both sides of the zero crossing point are determined as follows: and The voltage values ​​corresponding to the two sampling points have opposite signs;

[0033] Calculate the time coordinate corresponding to the zero-crossing point:

[0034]

[0035] The zero-crossing point coordinates corresponding to the calculated positive half-cycle reconstructed data are saved in chronological order and recorded as:

[0036]

[0037] Get the corresponding modulation wave zero-crossing point coordinates, recorded as:

[0038]

[0039] Calculate the corresponding phase offset:

[0040]

[0041] Furthermore, in S400, the operating state of the IGBT is monitored according to the calculated characteristic parameters of the IGBT, specifically: the aging degree p of the IGBT is determined according to the calculated phase offset θ; and the operating state of the IGBT is determined according to the calculated change rate k of the phase offset θ.

[0042] Furthermore, the calculation formula of the aging degree p of the IGBT is:

[0043]

[0044] Among them, θ p is the currently measured phase offset, θ b is the phase shift in the initial state, θ e is the IGBT failure threshold.

[0045] Furthermore, the calculation formula for the change rate k of the phase offset θ is:

[0046]

[0047] Among them, θ i and θ j Respectively represent ti and t j The phase offset obtained at the moment.

[0048] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0049] The present invention uses the phase offset of the inverter output voltage waveform as a characteristic parameter to characterize the aging degree of the IGBT, and realizes online monitoring of the IGBT operating state by collecting the inverter output voltage data, which can effectively improve the operating safety of the system; the present invention uses a prediction algorithm to perform time-series extrapolation on the offset of the inverter output phase, and performs threshold judgment on the prediction result to realize early warning of potential IGBT failures, which can effectively avoid the loss caused by sudden failures of the IGBT. The present invention can distinguish different IGBTs on the bridge arm by separating and reconstructing the positive and negative half-waves of the output voltage, and then accurately locate the position of the potential IGBT failure.

[0050] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0052] Figure 1 This is a flow chart of an IGBT state monitoring and fault prediction method suitable for a single-phase half-bridge inverter in Example 1 of the present invention. DETAILED DESCRIPTION

[0053] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0054] In order to solve the problems existing in the prior art, an embodiment of the present invention provides an IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter.

[0055] Example 1

[0056] This embodiment discloses an IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter. Figure 1 ,include:

[0057] S100. Using a voltage sensor to collect voltage data during the operation of the inverter; specifically, the voltage sensor collects voltage data output by the inverter at a sampling frequency f1, and saves the data collected by the voltage sensor in chronological order:

[0058] U t =[u t1 ,u t2 ,…,u ti ,…,u tn ]

[0059] S200. Reconstruct the voltage data output by the inverter according to the positive and negative half cycles to obtain two sets of data corresponding to different IGBT switch tubes;

[0060] In this embodiment, two sets of data corresponding to different IGBT switches are obtained, including the switch S1 corresponding to the positive half cycle and the switch S2 corresponding to the negative half cycle; wherein the positive half cycle corresponds to the switch S1, and the reconstructed data thereof is:

[0061]

[0062]

[0063] Where T is the sampling period.

[0064] The negative half cycle corresponds to the switch tube S2, and its reconstructed data is:

[0065]

[0066]

[0067] Where T is the sampling period.

[0068] S300. Calculate the characteristic parameters of the IGBT according to the reconstructed voltage data; specifically, in this embodiment, calculate the characteristic parameters of the IGBT, including calculating the characteristic parameters of the switch tube S1 corresponding to the positive half cycle and the characteristic parameters of the switch tube S2 corresponding to the negative half cycle; when calculating the characteristic parameters of the switch tube S1 corresponding to the positive half cycle, the calculation method includes:

[0069] Determine the data sampling points closest to both sides of the zero crossing point and The voltage values ​​corresponding to the two sampling points have opposite signs;

[0070] Calculate the time coordinate corresponding to the zero-crossing point:

[0071]

[0072] The zero-crossing point coordinates corresponding to the calculated positive half-cycle reconstructed data are saved in chronological order and recorded as:

[0073]

[0074] Get the corresponding modulation wave zero-crossing point coordinates, recorded as:

[0075]

[0076] Calculate the corresponding phase offset:

[0077]

[0078] It can be understood that when calculating the characteristic parameters of the switch tube S2 corresponding to the negative half cycle, the calculation method also includes:

[0079] Determine the data sampling points closest to both sides of the zero crossing point and The voltage values ​​corresponding to the two sampling points have opposite signs;

[0080] Calculate the time coordinate corresponding to the zero-crossing point:

[0081]

[0082] The zero-crossing point coordinates corresponding to the calculated positive half-cycle reconstructed data are saved in chronological order and recorded as:

[0083]

[0084] Get the corresponding modulation wave zero-crossing point coordinates, recorded as:

[0085]

[0086] Calculate the corresponding phase offset:

[0087]

[0088] S400. Monitor the operating state of the IGBT based on the calculated characteristic parameters of the IGBT; in this embodiment, the operating state of the IGBT is monitored, specifically: the aging degree p of the IGBT is determined based on the calculated phase offset θ; and the operating state of the IGBT is determined based on the calculated change rate k of the phase offset θ.

[0089] Specifically, the calculation formula for the aging degree p of IGBT is:

[0090]

[0091] Among them, θ p is the currently measured phase offset, θ b is the phase shift in the initial state, θe is the IGBT failure threshold.

[0092] The calculation formula for the change rate k of the phase offset θ is:

[0093]

[0094] Among them, θ i and θ j Respectively represent t i and t j The phase offset obtained at the moment.

[0095] S500. Use a prediction algorithm to perform time-series extrapolation on the calculated characteristic parameters of the IGBT to obtain prediction results of the characteristic parameters of the IGBT, perform threshold determination on the prediction results, and implement early warning of potential faults of the IGBT.

[0096] Specifically, the prediction algorithm of the autoregressive model is used to perform time series extrapolation on the calculated phase offset θ to obtain its predicted value:

[0097] θ p =[θ t+1 ,θ t+2 ,…,θ t+n ]

[0098] The prediction result is compared with the set capacitor fault threshold. If the prediction value exceeds the set fault threshold, a fault warning and fault prediction time are issued.

[0099] The present embodiment discloses an IGBT state monitoring and fault prediction method suitable for a single-phase half-bridge inverter, comprising: using a voltage sensor to collect voltage data during the operation of the inverter; reconstructing the voltage data output by the inverter according to the positive and negative half cycles to obtain two sets of data corresponding to different IGBT switches; calculating characteristic parameters of the IGBT based on the reconstructed voltage data; monitoring the operating state of the IGBT based on the calculated characteristic parameters of the IGBT; using a prediction algorithm to perform time-series extrapolation on the calculated characteristic parameters of the IGBT to obtain prediction results of the characteristic parameters of the IGBT, performing threshold judgment on the prediction results, and realizing early warning of potential faults of the IGBT.

[0100] This embodiment uses the phase offset of the inverter output voltage waveform as a characteristic parameter to characterize the aging degree of the IGBT. By collecting the inverter output voltage data, the online monitoring of the IGBT operating state can be realized, which can effectively improve the operating safety of the system. The present invention uses a prediction algorithm to perform a timing extrapolation on the inverter output phase offset, and performs a threshold determination on the prediction result to realize an early warning of potential IGBT failures, which can effectively avoid the loss caused by sudden failures of the IGBT. The present invention can distinguish different IGBTs on the bridge arm by separating and reconstructing the positive and negative half-waves of the output voltage, and then accurately locate the position of the potential IGBT failure.

[0101] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0102] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0103] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0104] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0105] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0106] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. An IGBT state monitoring and fault prediction method suitable for a single-phase half-bridge inverter, characterized in that: include: S100. Using a voltage sensor to collect voltage data during the operation of the inverter; S200. Reconstruct the voltage data output by the inverter according to the positive and negative half cycles to obtain two sets of data corresponding to different IGBT switch tubes; wherein the positive half cycle corresponds to the switch tube S1, and the negative half cycle corresponds to the switch tube S2; S300. Calculate the characteristic parameters of the IGBT according to the reconstructed voltage data; wherein the characteristic parameters of the IGBT are the phase difference between the output voltage waveform and the modulation wave; S400. Based on the calculated characteristic parameters of the IGBT, the operating state of the IGBT is monitored; specifically: the aging degree p of the IGBT is determined based on the calculated phase offset θ; and the operating state of the IGBT is determined based on the calculated rate of change k of the phase offset θ; S500. Use a prediction algorithm to perform time-series extrapolation on the calculated characteristic parameters of the IGBT to obtain prediction results of the characteristic parameters of the IGBT, perform threshold determination on the prediction results, and implement early warning of potential faults of the IGBT.

2. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter according to claim 1, characterized in that: The specific process of S100 is: the voltage sensor collects the voltage data output by the inverter according to the sampling frequency f1, and saves the data collected by the voltage sensor in chronological order: IN t =[in t1 ,in t2 ,…,in ti ,…,in tn ]。 3. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter as claimed in claim 2, characterized in that: In S200, the data of the switch tube S1 corresponding to the positive half cycle is: Where T is the sampling period.

4. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter as claimed in claim 2, characterized in that: In S200, the data of the switch tube S2 corresponding to the negative half cycle is: Where T is the sampling period.

5. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter as claimed in claim 3, characterized in that: In S300, the characteristic parameter of the IGBT is the phase difference between the output voltage waveform and the modulation wave, and its calculation method includes: When calculating the characteristic parameters of the switch tube S1 corresponding to the positive half cycle, the data sampling points closest to both sides of the zero crossing point are determined as follows: and The voltage values ​​corresponding to the two sampling points have opposite signs; Calculate the time coordinate corresponding to the zero-crossing point: The zero-crossing point coordinates corresponding to the calculated positive half-cycle reconstructed data are saved in chronological order and recorded as: Get the corresponding modulation wave zero-crossing point coordinates, recorded as: Calculate the corresponding phase offset:

6. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter as claimed in claim 4, characterized in that: In S300, the characteristic parameter of the IGBT is the phase difference between the output voltage waveform and the modulation wave, and the calculation method thereof further includes: When calculating the characteristic parameters of the switch tube S2 corresponding to the negative half cycle, the data sampling points closest to both sides of the zero crossing point are determined as follows: and The voltage values ​​corresponding to the two sampling points have opposite signs; Calculate the time coordinate corresponding to the zero-crossing point: The zero-crossing point coordinates corresponding to the calculated positive half-cycle reconstructed data are saved in chronological order and recorded as: Get the corresponding modulation wave zero-crossing point coordinates, recorded as: Calculate the corresponding phase offset:

7. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter according to claim 1, characterized in that: In S400, the calculation formula of the aging degree p of IGBT is: Among them, θ p is the currently measured phase offset, θ b is the phase shift in the initial state, θ e is the IGBT failure threshold.

8. The IGBT state monitoring and fault prediction method applicable to a single-phase half-bridge inverter according to claim 1, characterized in that: The calculation formula for the change rate k of the phase offset θ is: Among them, θ i and θ j Respectively represent t i and t j The phase offset obtained at the moment.

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