A protection method and device for a bidirectional DC / DC converter

Abstract

The present application provides a protection method and device for a novel bidirectional DC / DC converter, which relates to the field of power equipment maintenance and includes: performing waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter to obtain the corresponding frequency-domain distribution characteristics; inputting the frequency-domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault types, where the fault types include external faults of the converter and internal faults of the converter; and if the fault type is an external fault of the converter, controlling the converter to perform short-time blocking. The present application can, when a fault occurs in the insulated gate bipolar transistor in the converter, distinguish whether the fault belongs to an external fault of the converter or an internal fault of the converter, and avoid automatic tripping of the novel bidirectional DC / DC converter connecting two voltage levels caused by short-time external fault impacts.

Description

Technical Field

[0001] The present application relates to the field of power equipment maintenance, and specifically to a protection method and device for a novel bidirectional DC / DC converter. Background Art

[0002] In order to meet the transmission requirements of high voltage and high power in transmission lines, the prior art mostly adopts an input series output parallel type (abbreviated as ISOP type) topology to construct a high voltage-low voltage DC converter. This topology is composed of multiple isolated power modules. The modules on the input side are connected in series to ensure that they can withstand medium and high voltages. The output side is connected in parallel to the low voltage bus to output a large current. The topology of the ISOP type is shown in Figure 1 as shown.

[0003] Among them, the isolated dual active bridge converter (abbreviated as isolated DAB converter) is a typical one based on the ISOP type topology, and it is widely adopted due to its many excellent characteristics. The topology of the isolated DAB converter is relatively simple, consisting of a high-frequency inverter on the input side, a high-frequency transformer in the middle, and a high-frequency rectifier on the output side. The structure is shown in Figure 2 as shown. A series-parallel combination of multiple isolated DAB converters can obtain an ISOP-DAB DC transformer, and the structure is shown in Figure 3 as shown. Figure 3 All DAB modules in expect to have exactly the same parameters. However, limited by the actual manufacturing process, each module contains many components, and there will inevitably be differences in parameters.

[0004] The prior art protection strategy for the ISOP-DAB DC transformer is generally that when encountering an external fault, the ISOP-DAB DC transformer will not cut itself out of the circuit; when encountering an internal fault, the ISOP-DAB DC transformer will act to cut itself out of the circuit. However, when the external fault is a short-term large fault impact, the protection strategy of the ISOP-DAB DC transformer may misjudge and mistake itself for an internal fault, thus cutting out a certain group of converters.

[0005] Once a certain group of converters is cut out by protection, this group of converters will immediately stop running. In fact, this group of converters should not be stopped. This will cause jitter and glitches in the entire ISOP-DAB voltage conversion. In addition to this group of converters, other converters will also have short-term unbalanced currents, and the locally excessive unbalanced current may even cause the switching tubes of the local converters to overheat and be damaged, or even explode. Once a certain group of converters is wrongly cut out, it may operate for a short time, but long-term operation will cause irreversible damage to other converters except this group of converters. Summary of the Invention

[0006] In view of the problems in the prior art, the present application provides a protection method and device for a novel bidirectional DC / DC converter, which can distinguish whether a fault in the insulated gate bipolar transistor in the converter belongs to an external fault of the converter or an internal fault of the converter when a fault occurs, and avoid automatic tripping of the novel bidirectional DC / DC converter connecting two voltage levels caused by short-term fault impacts from the outside.

[0007] To solve the above technical problems, the present application provides the following technical solutions:

[0008] In a first aspect, the present application provides a protection method for a novel bidirectional DC / DC converter, including:

[0009] Performing waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the collected converter to obtain the corresponding frequency-domain distribution characteristics;

[0010] Inputting the frequency-domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes an external fault of the converter and an internal fault of the converter;

[0011] If the fault type is an external fault of the converter, controlling the converter to perform short-term blocking.

[0012] Further, the steps of training the converter fault classification model include:

[0013] When a fault occurs in the converter, collecting the historical high-frequency current waveform of the resistor-capacitor absorption circuit;

[0014] Performing fault type marking on the historical high-frequency current waveform;

[0015] Training according to the fault type marking result, the historical high-frequency current waveform and a predefined training function until the corresponding loss function converges to obtain the converter fault classification model.

[0016] Further, the performing fault type marking on the historical high-frequency current waveform includes:

[0017] Performing Fourier transform on the historical high-frequency current waveform to obtain each historical frequency component;

[0018] Determining the historical frequency-domain distribution characteristics of the historical high-frequency current waveform according to each historical frequency component;

[0019] Comparing the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an external fault occurs in the converter and comparing the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an internal fault occurs in the converter;

[0020] If the historical high-frequency current waveform corresponds to an external fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as the external fault of the converter;

[0021] If the historical high-frequency current waveform corresponds to an internal fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as the internal fault of the converter.

[0022] Further, the frequency domain distribution feature includes the total harmonic distortion rate of the current; the waveform feature analysis of the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter is performed to obtain the corresponding frequency domain distribution feature, including:

[0023] Perform Fourier transform on the high-frequency current waveform to obtain each frequency component;

[0024] Determine the total harmonic distortion rate of the high-frequency current waveform according to each frequency component.

[0025] In a second aspect, the present application provides a protection device for a novel bidirectional DC / DC converter, including:

[0026] A waveform feature analysis unit for performing waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter to obtain the corresponding frequency domain distribution feature;

[0027] A fault type determination unit for inputting the frequency domain distribution feature into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes an external fault of the converter and an internal fault of the converter;

[0028] A fault processing unit for controlling the converter to perform short-time blocking when the fault type is the external fault of the converter.

[0029] Further, the protection device for the novel bidirectional DC / DC converter further includes:

[0030] A historical waveform acquisition unit for acquiring the historical high-frequency current waveform of the resistor-capacitor absorption circuit when the converter fails;

[0031] A fault type marking unit for marking the fault type of the historical high-frequency current waveform;

[0032] A function training unit for training according to the fault type marking result, the historical high-frequency current waveform and a predefined training function until the corresponding loss function converges to obtain the converter fault classification model.

[0033] Further, the fault type marking unit includes:

[0034] A frequency component extraction module, configured to perform Fourier transform on the historical high-frequency current waveform to obtain each historical frequency component;

[0035] A historical frequency domain feature determination module, configured to determine the historical frequency domain distribution feature of the historical high-frequency current waveform according to each historical frequency component;

[0036] A fault comparison module, configured to compare the historical frequency domain distribution feature with the frequency domain distribution feature of the resistor-capacitor absorption circuit when an external fault occurs in the converter, and compare the historical frequency domain distribution feature with the frequency domain distribution feature of the resistor-capacitor absorption circuit when an internal fault occurs in the converter;

[0037] An external fault determination module, configured to, if the historical high-frequency current waveform corresponds to an external fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as the external fault of the converter;

[0038] An internal fault determination module, configured to, if the historical high-frequency current waveform corresponds to an internal fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as the internal fault of the converter.

[0039] Further, the frequency domain distribution feature includes the total harmonic distortion rate of the current; the waveform feature analysis unit includes:

[0040] A frequency component determination module, configured to perform Fourier transform on the high-frequency current waveform to obtain each frequency component;

[0041] A total distortion rate determination module, configured to determine the total harmonic distortion rate of the high-frequency current waveform according to each frequency component.

[0042] In a third aspect, the present application provides an electronic device including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the protection method for the novel bidirectional DC / DC converter are implemented.

[0043] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the protection method for the novel bidirectional DC / DC converter are implemented.

[0044] In view of the problems in the prior art, the protection method and device for the novel bidirectional DC / DC converter provided by this application can, when a failure occurs in the insulated gate bipolar transistor in the converter, distinguish whether the failure belongs to an external failure of the converter or an internal failure of the converter, avoid automatic tripping of the novel bidirectional DC / DC converter that connects two voltage levels caused by short-term external fault impacts, enable the novel bidirectional DC / DC converter to perform short-term locking relying on its own protection strategy, avoid short-term fault impacts, and thus guide the normal and stable operation of the novel bidirectional DC / DC converter. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] Figure 1 Schematic diagram of the ISOP structure in the prior art;

[0047] Figure 2 Schematic diagram of the structure of the isolated DAB converter in the prior art;

[0048] Figure 3 Schematic diagram of the structure of the ISOP-DAB DC transformer in the prior art;

[0049] Figure 4 Schematic diagram of the topology structure of the bidirectional DC / DC converter in the embodiment of this application;

[0050] Figure 5 Flowchart of the protection method for the novel bidirectional DC / DC converter in the embodiment of this application;

[0051] Figure 6 Flowchart of training the converter fault classification model in the embodiment of this application;

[0052] Figure 7 Flowchart of marking the fault types for the historical high-frequency current waveforms in the embodiment of this application;

[0053] Figure 8 Flowchart of obtaining the corresponding frequency domain distribution characteristics in the embodiment of this application;

[0054] Figure 9 Schematic diagram of the structure of a single full-bridge converter (FBC) in the embodiment of this application;

[0055] Figure 10One of the structural diagrams of the protection device for the novel bidirectional DC / DC converter in the embodiments of the present application;

[0056] Figure 11 Another structural diagram of the protection device for the novel bidirectional DC / DC converter in the embodiments of the present application;

[0057] Figure 12 The structural diagram of the fault type marking unit in the embodiments of the present application;

[0058] Figure 13 The structural diagram of the waveform feature analysis unit in the embodiments of the present application;

[0059] Figure 14 The simplified structural schematic diagram of the full-bridge converter (FBC) in the embodiments of the present application;

[0060] Figure 15 The structural schematic diagram of the electronic device in the embodiments of the present application;

[0061] Figure 16 The general waveform schematic diagram of the high-frequency current in the embodiments of the present application;

[0062] Figure 17 The schematic diagram of the decline curve of the loss value during the training process of the training set data in the embodiments of the present application;

[0063] Figure 18 The schematic diagram of the decline curve of the loss value during the training process of the validation set data in the embodiments of the present application;

[0064] Figure 19 The schematic diagram of the overall validation accuracy rate of the validation set in the embodiments of the present application. Detailed implementation manners

[0065] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0066] In the technical solutions of the present application, the acquisition, storage, use, and processing of data all comply with the relevant regulations of national laws and regulations.

[0067] In one embodiment, the embodiments of the present application provide a protection method for a novel bidirectional DC / DC converter, which can be applied to a novel bidirectional DC / DC converter. For clarity, the topological structure of this novel bidirectional DC / DC converter is described herein first.

[0068] In one embodiment, refer toFigure 4 This new bidirectional DC / DC converter topology includes a converter input terminal and a converter output terminal.

[0069] Among them, the converter input terminal includes multiple input full-bridge converters connected in series; the number of stages of the input full-bridge converter is 2N; the first-stage input full-bridge converter to the 2Nth-stage input full-bridge converter are connected in series in sequence; the DC positive pole of the first-stage input full-bridge converter is connected to the positive pole of the high-voltage bus (UdcL+), and the DC negative pole of the 2Nth-stage input full-bridge converter is connected to the negative pole of the high-voltage bus (UdcL-); the DC terminals of the Nth-stage input full-bridge converter and the (N + 1)th-stage input full-bridge converter are both grounded; N is a positive integer greater than 2.

[0070] The converter output terminal includes multiple output full-bridge converters connected in parallel; the DC positive poles of each stage of the output full-bridge converter are all connected to the positive pole of the low-voltage bus (UdcL+), and the DC negative poles of each stage of the output full-bridge converter are all connected to the negative pole of the low-voltage bus (UdcL-).

[0071] It should be noted that the schematic diagram of the topology structure of a single full-bridge converter can be seen in Figure 9 as shown. Among them, C is a capacitor, and Q1 to Q4 are all Insulated Gate Bipolar Transistors (IGBT for short). Udc+ and Udc- are respectively the positive and negative poles of the DC terminal (also known as the DC side), Udc represents the voltage difference between the positive and negative poles of the DC side, Uac+ and Uac- respectively represent the positive and negative poles of the AC side, and Uac represents the voltage difference between the positive and negative poles of the AC side. In a large-scale power electronics schematic diagram, Figure 9 can be replaced by Figure 14 for simplicity and clarity. Figure 4 in which is the use of Figure 14 the simplified symbol in to represent FBC.

[0072] In one embodiment, referring to Figure 5 , in order to be able to distinguish whether the fault belongs to an external fault of the converter or an internal fault of the converter when an Insulated Gate Bipolar Transistor in the converter fails, and to avoid the new bidirectional DC / DC converter connecting two voltage levels from tripping automatically due to external short-term fault impacts, the present application provides a protection method for a new bidirectional DC / DC converter, including:

[0073] S101: Analyze the waveform characteristics of the high-frequency current waveform of the resistor-capacitor absorption circuit of the Insulated Gate Bipolar Transistor in the converter to obtain the corresponding frequency-domain distribution characteristics.

[0074] S102: Input the frequency domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type. Among them, the fault type includes external faults of the converter and internal faults of the converter.

[0075] S103: If the fault type is an external fault of the converter, control the converter to perform a short-term lockout.

[0076] It can be understood that for the insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, abbreviated as IGBT) of the converter, the faults that occur may be external faults (also known as external faults of the converter) or internal faults (also known as internal faults of the converter). Among them, an external fault of the converter means that the fault occurs outside the bidirectional DCDC converter. An internal fault means that it occurs inside the converter. It mainly depends on the location where the fault occurs.

[0077] The core of the embodiments of this application lies in distinguishing between external faults and internal faults. If it is determined by using the method provided in this application that the occurring fault belongs to an external fault, the converter should be controlled to perform a short-term lockout, so as to avoid automatic tripping of the DC / DC converter connecting two voltage levels caused by short-term external fault impacts. In other words, it enables the DC / DC converter connecting two voltage levels to rely on its own protection strategy to achieve short-term lockout, so as to avoid short-term external fault impacts and not cut itself out of the power grid through automatic tripping.

[0078] Specifically, it is realized by using the high-frequency current on the IGBT snubber circuit. When an external fault occurs, the high-frequency current waveforms of the snubber circuits of all IGBTs that are in the same phase and at the same position in Figure 4 should be similar, that is, they have similar frequency domain distribution characteristics. When an internal fault occurs, the high-frequency current waveforms of the snubber circuits of all IGBTs that are in the same phase and at the same position in Figure 4 should be similar, that is, they have similar frequency domain distribution characteristics. And the high-frequency current waveform when an external fault occurs should be different from the high-frequency current waveform when an internal fault occurs, that is, they have significantly different frequency domain distribution characteristics.

[0079] Based on the above principle, the embodiments of this application can use a deep learning algorithm to compare and analyze the high-frequency current waveforms of the snubber circuits of all IGBTs that are in the same phase and at the same position in Figure 4 , see Figure 16 , and then identify and classify the frequency domain distribution characteristics of this waveform, so as to determine whether the occurring fault is an internal fault or an external fault. If the fault type is an external fault of the converter, control the converter to perform a short-term lockout.

[0080] From the above description, it can be seen that the protection method of the new bidirectional DC / DC converter provided by the present application can distinguish whether the fault is an external fault of the converter or an internal fault of the converter when a fault occurs in the insulated gate bipolar transistor in the converter, thereby avoiding the automatic tripping of the new bidirectional DC / DC converter connecting two voltage levels caused by an external short-term fault shock, so that the new bidirectional DC / DC converter can rely on its own protection strategy to perform short-term locking, avoid short-term fault shocks, and then guide the normal and stable operation of the new bidirectional DC / DC converter.

[0081] Steps S101 to S103 are described in detail below.

[0082] Step S101: performing waveform characteristic analysis on the collected high-frequency current waveform of the insulated gate bipolar transistor resistance-capacitance absorption loop in the converter to obtain corresponding frequency domain distribution characteristics.

[0083] It is understandable that, considering that the high-frequency current waveform when an external fault occurs should be different from the high-frequency current waveform when an internal fault occurs, that is, it has significantly different frequency domain distribution characteristics, therefore, in order to subsequently determine the fault type, in this step, the corresponding frequency domain distribution characteristics can be obtained based on the collected high-frequency current waveform. The so-called frequency domain distribution characteristics include but are not limited to the total harmonic distortion rate of the current.

[0084] Figure 8 The present invention is a specific embodiment of a novel bidirectional DC / DC converter protection method implemented in the embodiment of the present application.

[0085] In one embodiment, see Figure 8 , the frequency domain distribution characteristics include the total harmonic distortion rate of the current; the waveform characteristic analysis of the high-frequency current waveform of the insulated gate bipolar transistor resistor-capacitor absorption loop in the converter is performed to obtain the corresponding frequency domain distribution characteristics, including:

[0086] S401: Perform Fourier transform on the high-frequency current waveform to obtain various frequency components;

[0087] S402: Determine the total current harmonic distortion rate of the high-frequency current waveform according to the frequency components.

[0088] It can be understood that by performing Fourier transform on the high-frequency current waveform, the frequency components of the high-frequency current waveform can be obtained; the so-called frequency components include but are not limited to the fundamental component, the second harmonic component, ... and the Nth harmonic component.

[0089] Generally, before Fourier transforming the high-frequency current waveform to obtain each frequency component, the collected high-frequency current waveform can also be cleaned to remove obvious abnormal data points. The data cleaning method can be described below.

[0090] Further, according to each frequency component, the total harmonic distortion (THD) of the current harmonic wave pattern of the high-frequency current can be calculated.

[0091] The specific calculation method / formula is as follows:

[0092] The square root of the sum of the squares of the ratios of the effective values Gn of all harmonic components not greater than a specific order H to the effective value G1 of the fundamental wave component. Where the symbol G represents the effective value of the harmonic component.

[0093]

[0094] As can be seen from the above description, the protection method of the novel bidirectional DC / DC converter provided by this application can perform waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit in the converter, and obtain the corresponding frequency domain distribution characteristics.

[0095] Step S102: Input the frequency domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes external faults and internal faults of the converter.

[0096] It can be understood that the key point of this step is how to train the converter fault classification model. After training the converter fault classification model, the fault type can be judged by using this model.

[0097] Figure 6 This is a specific embodiment for implementing the protection method of the novel bidirectional DC / DC converter in the embodiments of this application.

[0098] In one embodiment, referring to Figure 6 , the steps of training the converter fault classification model include:

[0099] S201: When a fault occurs in the converter, collect the historical high-frequency current waveform of the resistor-capacitor absorption circuit;

[0100] S202: Mark the fault type for the historical high-frequency current waveform;

[0101] S203: Train according to the fault type marking result, the historical high-frequency current waveform and a predefined training function until the corresponding loss function converges to obtain the converter fault classification model. Specifically, the fault type marking result and the historical frequency domain distribution characteristics corresponding to the historical high-frequency current waveform are input into the training function. The extraction method of the historical frequency domain distribution characteristics can be referred to the description of steps S301 to S302.

[0102] It can be understood that the prerequisite for training the converter fault classification model is to collect the historical high-frequency current waveforms of the resistor-capacitor absorption circuit when the converter fails. Then, these historical high-frequency current waveforms are marked with fault types. That is to say, it is pre-marked whether these historical high-frequency current waveforms correspond to internal faults or external faults. The embodiments of the present application can be implemented by two methods. The first is to mark manually, that is, the technician knows what kind of fault has occurred in the converter in the historical actual project, then collects the historical high-frequency current waveform, and marks it as the corresponding fault type.

[0103] The second is to refer to the descriptions in steps S301 to S304.

[0104] Figure 7 This is a specific embodiment for implementing the protection method of the novel bidirectional DC / DC converter in the embodiments of the present application.

[0105] In one embodiment, referring to Figure 7 , step S202 specifically includes:

[0106] S301: Perform Fourier transform on the historical high-frequency current waveforms to obtain each historical frequency component;

[0107] S302: Determine the historical frequency domain distribution characteristics of the historical high-frequency current waveforms according to the historical frequency components;

[0108] S303: Compare the historical frequency domain distribution characteristics with the frequency domain distribution characteristics of the resistor-capacitor absorption circuit when the converter has an external fault and compare the historical frequency domain distribution characteristics with the frequency domain distribution characteristics of the resistor-capacitor absorption circuit when the converter has an internal fault;

[0109] S304: If the historical high-frequency current waveform corresponds to an external fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as the external fault of the converter;

[0110] S305: If the historical high-frequency current waveform corresponds to an internal fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as the internal fault of the converter.

[0111] During specific implementation, perform Fourier transform on the historical high-frequency current waveform to obtain each historical frequency component; determine the historical frequency-domain distribution characteristics of the historical high-frequency current waveform according to each historical frequency component; compare the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an external fault occurs in the converter, and determine whether the historical high-frequency current waveform corresponds to an external fault of the converter. If it corresponds to an external fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as an external fault of the converter; otherwise, compare the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an internal fault occurs in the converter, and determine whether the historical high-frequency current waveform corresponds to an internal fault of the converter. If it corresponds to an internal fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as an internal fault of the converter. That is to say, through automatic execution of the program, marking is achieved.

[0112] Further, the historical frequency-domain distribution characteristics can be obtained from historical oscillograms during fault occurrence and normal operation. Performing Fourier transform on the historical oscillograms can obtain their respective frequency-domain distribution characteristics.

[0113] It should be noted that the method for obtaining each historical frequency component in step S301 can refer to the description of step S401. The only difference is that step S301 processes the historical high-frequency current waveform (i.e., the high-frequency current waveform collected in historical engineering practice), while step S401 processes the high-frequency current waveform (i.e., the high-frequency current waveform to be analyzed this time).

[0114] And the method for determining the historical frequency-domain distribution characteristics of the historical high-frequency current waveform in step S302 can refer to the description of step S402. The only difference is that step S302 processes the historical high-frequency current waveform (i.e., the high-frequency current waveform collected in historical engineering practice), while step S402 processes the high-frequency current waveform (i.e., the high-frequency current waveform to be analyzed this time).

[0115] Further, through the method of artificial intelligence, establish a training model for high-frequency current waveforms and train the above data. It is found through multiple experiments in the embodiments of the present application that using the VGG network (full name Visual Geometry Group Network) as the original model for training can obtain better model training effects.

[0116] The following elaborates on the process of model establishment, including several steps such as data acquisition, data cleaning, and model training.

[0117] (1) Data acquisition. That is, how to obtain the high-frequency current waveform of the snubber circuit of the IGBT. When a fault occurs in the IGBT, the high-frequency current waveform of its snubber circuit is collected and marked. The waveform record can be in the form of time + data points or presented as a picture, including the horizontal axis (time) and the vertical axis (value).

[0118] Example:

[0119]

[0120]

[0121]

[0122] (2) Data cleaning. Based on the data obtained in the previous step, abnormal data points and bad points are removed. Abnormal data points include, but are not limited to, unreasonable sudden increases and decreases. Common data bad points include: suddenly becoming 0, Nan, Null, etc. In this step, a special data outlier detection function is set up to detect and remove data outliers.

[0123] (3) Model training. Define the training function and start training, including model training, validation, and printing the loss value. Generally, it is written as the following code segment and implemented in a loop.

[0124] for eval_x,eval_y in eval_loader:

[0125] outs=model(eval_x)

[0126] loss=loss_func(outs,eval_y)

[0127] eval_loss+=loss

[0128] The model training includes several epochs. In this example, it is set to 20 epochs.

[0129] The process of the overall model training is printed as follows:

[0130] ---------epoch:0,train_loss:0.729,eval_loss:0.773,eval_acc:0.734-------

[0131] ---------epoch:1,train_loss:0.408,eval_loss:0.367,eval_acc:0.859-------

[0132] ---------epoch:2,train_loss:0.307,eval_loss:0.431,eval_acc:0.828-------

[0133] ---------epoch:3,train_loss:0.256,eval_loss:0.541,eval_acc:0.828-------

[0134] ---------epoch:4,train_loss:0.270,eval_loss:0.404,eval_acc:0.922-------

[0135] ---------epoch:5,train_loss:0.271,eval_loss:0.535,eval_acc:0.906-------

[0136] ---------epoch:6,train_loss:0.245,eval_loss:0.584,eval_acc:0.906-------

[0137] ---------epoch:7,train_loss:0.158,eval_loss:0.394,eval_acc:0.922-------

[0138] ---------epoch:8,train_loss:0.100,eval_loss:0.446,eval_acc:0.938-------

[0139] ---------epoch:9,train_loss:0.096,eval_loss:0.438,eval_acc:0.938-------

[0140] ---------epoch:10,train_loss:0.094,eval_loss:0.414,eval_acc:0.938-------

[0141] ---------epoch:11,train_loss:0.081,eval_loss:0.436,eval_acc:0.938-------

[0142] ---------epoch:12,train_loss:0.057,eval_loss:0.444,eval_acc:0.938-------

[0143] ---------epoch:13,train_loss:0.068,eval_loss:0.580,eval_acc:0.922-------

[0144] ---------epoch:14,train_loss:0.073,eval_loss:0.479,eval_acc:0.938-------

[0145] ---------epoch:15,train_loss:0.053,eval_loss:0.507,eval_acc:0.938-------

[0146] ---------epoch:16,train_loss:0.031,eval_loss:0.545,eval_acc:0.938-------

[0147] ---------epoch:17,train_loss:0.031,eval_loss:0.511,eval_acc:0.953-------

[0148] ---------epoch:18,train_loss:0.039,eval_loss:0.436,eval_acc:0.938-------

[0149] ---------epoch:19,train_loss:0.049,eval_loss:0.508,eval_acc:0.906-------

[0150] Plot the loss function curve, where the vertical axis includes: the descending curve of the loss value during the training process of the training set data, i.e., train_loss (see Figure 17 ); the descending curve of the loss value during the training process of the validation set data, i.e., eval_loss (see Figure 18 ); and the overall validation accuracy of the validation set, eval_acc (see Figure 19) It can be seen that the accuracy rate is the highest in the 17th round. Therefore, in this calculation example, the model obtained from the 17th round of training can be selected as the converter fault classification model. After the training is completed, the obtained model parameters are saved.

[0151] During the training process, the judgment effect of the model can be improved. The improvement methods include but are not limited to: setting training hyperparameters, selecting optimization methods and loss functions; then calling the training function for training. During this process, the loss function value loss will continuously decrease, corresponding to the continuous improvement of the model training effect. Finally, draw the loss function decline curve and save the final network parameters, that is, the network parameter weights obtained through several trainings. Save the model obtained in the above step (3). This model can distinguish whether the current fault is an external fault or an internal fault. After the training is completed, the input of the model is the frequency domain distribution characteristics corresponding to the high-frequency current waveform of the resistor-capacitor absorption circuit of the IGBT, and the output is the fault type (external fault or internal fault).

[0152] As can be seen from the above description, the novel bidirectional DC / DC converter protection method provided by this application can train a converter fault classification model.

[0153] Figure 9 This is a specific embodiment for implementing the novel bidirectional DC / DC converter protection method in the embodiments of this application.

[0154] Step S103: If the fault type is an external fault of the converter, control the converter to perform short-time blocking.

[0155] It can be understood that if it is determined by the method provided by this application that the occurring fault belongs to an external fault, the converter should be controlled to perform short-time blocking, so as to avoid the automatic tripping of the DC / DC converter connecting two voltage levels caused by the short-time external fault impact.

[0156] In one embodiment, if the fault type is an external fault of the converter, controlling the converter to perform short-time blocking can be specifically implemented as follows.

[0157] It can be understood that in the embodiments of this application, this protection method is applied to a novel bidirectional DC / DC converter. Considering that the novel bidirectional DC / DC converter is different from the traditional converter in structure, therefore, there are unique ways to control its short-time blocking, which are mainly reflected in the following two aspects: First, when different IGBTs perform blocking, the time coordination problem needs to be considered. Specifically, it is necessary to make targeted adjustments according to the specific layout of the IGBTs in the topology of the novel bidirectional DC / DC converter; Second, the blocking delay adopts a delay step design method, which needs to be designed specifically according to the layout of the IGBTs and different models.

[0158] If the fault type is an internal fault of the converter, the converter in this group will trip automatically, that is, cut itself out of the power grid.

[0159] As can be seen from the above description, the protection method of the novel bidirectional DC / DC converter provided by this application can control the converter to perform short-term blocking when the fault type is an external fault of the converter.

[0160] Based on the same inventive concept, the embodiment of this application also provides a protection device for a novel bidirectional DC / DC converter, which can be used to implement the method described in the above embodiment, as described in the following embodiment. Since the principle of the protection device of the novel bidirectional DC / DC converter to solve problems is similar to that of the protection method of the novel bidirectional DC / DC converter, the implementation of the protection device of the novel bidirectional DC / DC converter can refer to the implementation of the method for determining software performance benchmarks, and the repeated parts will not be described again. As used hereinafter, the term "unit" or "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0161] In one embodiment, referring to Figure 10 , in order to be able to distinguish whether the fault belongs to an external fault of the converter or an internal fault of the converter when an insulated gate bipolar transistor in the converter fails, and to avoid the automatic tripping of the novel bidirectional DC / DC converter connecting two voltage levels caused by external short-term fault impacts, this application provides a protection device for a novel bidirectional DC / DC converter, including: a waveform feature analysis unit 1001, a fault type determination unit 1002, and a fault processing unit 1003.

[0162] The waveform feature analysis unit 1001 is configured to perform waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter to obtain the corresponding frequency domain distribution characteristics;

[0163] The fault type determination unit 1002 is configured to input the frequency domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes an external fault of the converter and an internal fault of the converter;

[0164] The fault processing unit 1003 is configured to control the converter to perform short-term blocking when the fault type is an external fault of the converter.

[0165] In one embodiment, referring to Figure 11, the protection device of the novel bidirectional DC / DC converter further includes: a historical waveform acquisition unit 1101, a fault type marking unit 1102, and a function training unit 1103.

[0166] The historical waveform acquisition unit 1101 is configured to acquire the historical high-frequency current waveform of the resistor-capacitor absorption circuit when a fault occurs in the converter.

[0167] The fault type marking unit 1102 is configured to mark the fault type of the historical high-frequency current waveform.

[0168] The function training unit 1103 is configured to train according to the fault type marking result, the historical high-frequency current waveform, and a predefined training function until the corresponding loss function converges, so as to obtain the converter fault classification model.

[0169] In one embodiment, refer to Figure 12 , the fault type marking unit 1102 includes: a frequency component extraction module 1201, a historical frequency domain feature determination module 1202, a fault comparison module 1203, an external fault judgment module 1204, and an internal fault judgment module 1205.

[0170] The frequency component extraction module 1201 is configured to perform Fourier transform on the historical high-frequency current waveform to obtain each historical frequency component.

[0171] The historical frequency domain feature determination module 1202 is configured to determine the historical frequency domain distribution feature of the historical high-frequency current waveform according to each historical frequency component.

[0172] The fault comparison module 1203 is configured to compare the historical frequency domain distribution feature with the frequency domain distribution feature of the resistor-capacitor absorption circuit when an external fault occurs in the converter and compare the historical frequency domain distribution feature with the frequency domain distribution feature of the resistor-capacitor absorption circuit when an internal fault occurs in the converter.

[0173] The external fault judgment module 1204 is configured to, if the historical high-frequency current waveform corresponds to an external fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as an external fault of the converter.

[0174] The internal fault judgment module 1205 is configured to, if the historical high-frequency current waveform corresponds to an internal fault of the converter, mark the fault type corresponding to the historical high-frequency current waveform as an internal fault of the converter.

[0175] In one embodiment, refer to Figure 13 , the frequency domain distribution feature includes the total harmonic distortion rate of the current; the waveform feature analysis unit 1001 includes: a frequency component determination module 1301 and a total distortion rate determination module 1302.

[0176] A frequency component determination module 1301 is configured to perform a Fourier transform on the high-frequency current waveform to obtain each frequency component;

[0177] A total distortion rate determination module 1302 is configured to determine the total current harmonic distortion rate of the high-frequency current waveform according to the respective frequency components.

[0178] From a hardware perspective, in order to be able to distinguish whether a fault of an insulated gate bipolar transistor in a converter is an external fault of the converter or an internal fault of the converter when a fault occurs, and to avoid automatic tripping of a new type of bidirectional DC / DC converter connecting two voltage levels caused by a short-term external fault impact, the present application provides an embodiment of an electronic device for implementing all or part of the content in the protection method of the new type of bidirectional DC / DC converter. The electronic device specifically includes the following content:

[0179] A processor, a memory, a communication interface, and a bus; wherein, the processor, the memory, and the communication interface complete communication with each other through the bus; the communication interface is used to implement information transmission between the protection device of the new type of bidirectional DC / DC converter and related devices such as a core business system, a user terminal, and a related database, etc. The logic controller can be a desktop computer, a tablet computer, a mobile terminal, etc., and this embodiment is not limited thereto. In this embodiment, the logic controller can be implemented with reference to the embodiments of the protection method of the new type of bidirectional DC / DC converter and the embodiments of the protection device of the new type of bidirectional DC / DC converter, and the content is incorporated herein, and the repeated parts will not be described again.

[0180] It can be understood that the user terminal may include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, a smart wearable device, etc. Among them, the smart wearable device may include smart glasses, a smart watch, a smart bracelet, etc.

[0181] In practical applications, part of the protection method of the new type of bidirectional DC / DC converter can be executed on the electronic device side as described above, or all operations can be completed in the client device. Specifically, it can be selected according to the processing capacity of the client device and the limitations of the user usage scenario, etc. The present application does not make any limitations in this regard. If all operations are completed in the client device, the client device may further include a processor.

[0182] The above-mentioned client device may have a communication module (i.e., a communication unit), which can communicate with a remote server to achieve data transmission with the server. The server may include a server on the task scheduling center side, and in other implementation scenarios, it may also include a server of an intermediate platform, such as a server of a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, or a server cluster composed of multiple servers, or a server structure of a distributed device.

[0183] Figure 15 FIG. is a schematic block diagram of the system composition of the electronic device 9600 according to an embodiment of the present application. As Figure 15 shown, the electronic device 9600 may include a central processing unit 9100 and a memory 9140; the memory 9140 is coupled to the central processing unit 9100. It should be noted that this Figure 15 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0184] In one embodiment, the protection method function of the novel bidirectional DC / DC converter may be integrated into the central processing unit 9100. Among them, the central processing unit 9100 may be configured to perform the following controls:

[0185] S101: Analyze the waveform characteristics of the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter collected to obtain the corresponding frequency-domain distribution characteristics;

[0186] S102: Input the frequency-domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes external faults of the converter and internal faults of the converter;

[0187] S103: If the fault type is an external fault of the converter, control the converter to perform a short-term lockout.

[0188] As can be seen from the above description, the protection method of the novel bidirectional DC / DC converter provided by the present application can, when a fault occurs in the insulated gate bipolar transistor in the converter, distinguish whether the fault belongs to an external fault of the converter or an internal fault of the converter, avoid automatic tripping of the novel bidirectional DC / DC converter that connects two voltage levels caused by short-term external fault impacts, enable the novel bidirectional DC / DC converter to perform short-term lockout relying on its own protection strategy to avoid short-term fault impacts, and thus guide the normal and stable operation of the novel bidirectional DC / DC converter.

[0189] In another embodiment, the protection device of the novel bidirectional DC / DC converter can be separately configured from the central processor 9100. For example, the protection device of the novel bidirectional DC / DC converter can be configured as a chip connected to the central processor 9100, and the functions of the protection method of the novel bidirectional DC / DC converter can be realized through the control of the central processor.

[0190] As Figure 15 shown, the electronic device 9600 may further include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It should be noted that the electronic device 9600 does not necessarily have to include Figure 15 all the components shown in Figure 15 ; in addition, the electronic device 9600 may further include

[0191] As Figure 15 shown, the central processor 9100, sometimes also referred to as a controller or operation control, may include a microprocessor or other processor device and / or logic device. The central processor 9100 receives inputs and controls the operations of the various components of the electronic device 9600.

[0192] Among them, the memory 9140, for example, may be one or more of a buffer, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory, or other suitable devices. The above information related to failures can be stored, and in addition, programs for executing relevant information can also be stored. And the central processor 9100 can execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0193] The input unit 9120 provides inputs to the central processor 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to supply power to the electronic device 9600. The display 9160 is used for displaying display objects such as images and texts. The display may be, for example, an LCD display, but is not limited thereto.

[0194] The memory 9140 can be a solid-state memory, such as, for example, a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It can also be a memory that stores information even when power is off, can be selectively erased and is provided with more data. Examples of such a memory are sometimes referred to as EPROMs, etc. The memory 9140 can also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 can include an application / function storage unit 9142 that is used to store application programs and function programs or the processes for operating the electronic device 9600 by the central processing unit 9100.

[0195] The memory 9140 can also include a data storage unit 9143 that is used to store data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 can include various drivers of the electronic device for communication functions and / or for performing other functions of the electronic device (such as a messaging application, an address book application, etc.).

[0196] The communication module 9110 is a transmitter / receiver 9110 that transmits and receives signals via the antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which can be the same as in the case of a conventional mobile communication terminal.

[0197] Based on different communication technologies, multiple communication modules 9110 can be provided in the same electronic device, such as a cellular network module, a Bluetooth module, and / or a wireless local area network module, etc. The communication module (transmitter / receiver) 9110 is also coupled to the speaker 9131 and the microphone 9132 via the audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby implementing normal telecommunication functions. The audio processor 9130 can include any suitable buffer, decoder, amplifier, etc. Additionally, the audio processor 9130 is also coupled to the central processing unit 9100, so that recording can be performed on the local device via the microphone 9132 and the sound stored on the local device can be played via the speaker 9131.

[0198] An embodiment of the present application also provides a computer-readable storage medium capable of implementing all steps of the protection method of the novel bidirectional DC / DC converter whose execution subject in the above embodiment is a server or a client. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, all steps of the protection method of the novel bidirectional DC / DC converter whose execution subject in the above embodiment is a server or a client are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0199] S101: Analyze the waveform characteristics of the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter collected, and obtain the corresponding frequency-domain distribution characteristics;

[0200] S102: Input the frequency-domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes external faults of the converter and internal faults of the converter;

[0201] S103: If the fault type is an external fault of the converter, control the converter to perform short-time blocking.

[0202] As can be seen from the above description, the protection method of the novel bidirectional DC / DC converter provided by the present application can distinguish whether the fault belongs to an external fault of the converter or an internal fault of the converter when a fault occurs in the insulated gate bipolar transistor in the converter, avoid automatic tripping of the novel bidirectional DC / DC converter connecting two voltage levels caused by short-time external fault impacts, enable the novel bidirectional DC / DC converter to perform short-time blocking relying on its own protection strategy to avoid short-time fault impacts, and further guide the normal and stable operation of the novel bidirectional DC / DC converter.

[0203] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a device, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0204] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (devices), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing device generate means for implementing the functions specified in one or more flows and / or one or more blocks in the flow Figure 1 one or more flows and / or blocks Figure 1 or means for implementing the functions specified in one or more blocks.

[0205] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means for implementing the functions specified in one or more flows and / or one or more blocks in the flow Figure 1 one or more flows and / or blocks Figure 1 or means for implementing the functions specified in one or more blocks.

[0206] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows and / or one or more blocks in the flow Figure 1 one or more flows and / or blocks Figure 1 or means for implementing the functions specified in one or more blocks.

[0207] Specific embodiments are applied in the present invention to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A protection method for a bidirectional DC / DC converter, characterized in that, Including: Performing waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter collected, to obtain the corresponding frequency-domain distribution characteristics; wherein, the frequency-domain distribution characteristics include the total harmonic distortion rate of the current; the performing waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter collected, to obtain the corresponding frequency-domain distribution characteristics, includes: performing Fourier transform on the high-frequency current waveform to obtain each frequency component; determining the total harmonic distortion rate of the high-frequency current waveform according to each frequency component; specifically, performing comparative analysis on the high-frequency current waveforms of the resistor-capacitor absorption circuits of insulated gate bipolar transistors in the same phase and at the same position. Inputting the frequency-domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes external faults of the converter and internal faults of the converter; when the high-frequency current waveforms are similar, determining that the fault type is an internal fault of the converter; when the high-frequency current waveforms are different, determining that the fault type is an external fault of the converter. If the fault type is an external fault of the converter, controlling the converter to perform short-time blocking.

2. The protection method of the bidirectional DC / DC converter according to claim 1, characterized in that The steps of training the converter fault classification model include: When a fault occurs in the converter, collecting the historical high-frequency current waveforms of the resistor-capacitor absorption circuit. Performing fault type marking on the historical high-frequency current waveforms. Training according to the fault type marking result, the historical high-frequency current waveforms and a predefined training function until the corresponding loss function converges, to obtain the converter fault classification model.

3. The protection method of the bidirectional DC / DC converter according to claim 2, characterized in that, The performing fault type marking on the historical high-frequency current waveforms includes: Performing Fourier transform on the historical high-frequency current waveforms to obtain each historical frequency component. Determining the historical frequency-domain distribution characteristics of the historical high-frequency current waveforms according to each historical frequency component. Comparing the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an external fault occurs in the converter and comparing the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an internal fault occurs in the converter. If the historical high-frequency current waveforms correspond to an external fault of the converter, marking the fault type corresponding to the historical high-frequency current waveforms as an external fault of the converter. If the historical high-frequency current waveforms correspond to an internal fault of the converter, marking the fault type corresponding to the historical high-frequency current waveforms as an internal fault of the converter.

4. A protection device for a bidirectional DC / DC converter, characterized in that, Including: A waveform feature analysis unit is used to perform waveform feature analysis on the high-frequency current waveform of the resistor-capacitor absorption circuit of the insulated gate bipolar transistor in the converter collected, and obtain the corresponding frequency-domain distribution characteristics; wherein, the frequency-domain distribution characteristics include the total harmonic distortion rate of the current; the waveform feature analysis unit includes: a frequency component determination module, which is used to perform Fourier transform on the high-frequency current waveform to obtain each frequency component; a total distortion rate determination module, which is used to determine the total harmonic distortion rate of the high-frequency current waveform according to each frequency component; specifically, perform comparative analysis on the high-frequency current waveforms of the resistor-capacitor absorption circuits of insulated gate bipolar transistors with the same phase and the same position. A fault type determination unit is used to input the frequency-domain distribution characteristics into a pre-trained converter fault classification model to obtain the corresponding fault type; wherein, the fault type includes external faults of the converter and internal faults of the converter; when the high-frequency current waveforms are similar, determine that the fault type is an internal fault of the converter; when the high-frequency current waveforms are different, determine that the fault type is an external fault of the converter. A fault handling unit is used to control the converter to perform short-term blocking when the fault type is an external fault of the converter.

5. The protection device of the bidirectional DC / DC converter according to claim 4, characterized in that, It further includes: A historical waveform acquisition unit is used to acquire the historical high-frequency current waveform of the resistor-capacitor absorption circuit when a fault occurs in the converter. A fault type marking unit is used to mark the fault type of the historical high-frequency current waveform. A function training unit is used to perform training according to the fault type marking result, the historical high-frequency current waveform and a predefined training function until the corresponding loss function converges, and obtain the converter fault classification model.

6. The protection device of the bidirectional DC / DC converter according to claim 5, characterized in that, The fault type marking unit includes: A frequency component extraction module is used to perform Fourier transform on the historical high-frequency current waveform to obtain each historical frequency component. A historical frequency-domain feature determination module is used to determine the historical frequency-domain distribution characteristics of the historical high-frequency current waveform according to each historical frequency component. A fault comparison module is used to compare the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an external fault occurs in the converter and the historical frequency-domain distribution characteristics with the frequency-domain distribution characteristics of the resistor-capacitor absorption circuit when an internal fault occurs in the converter. An external fault judgment module is used to mark the fault type corresponding to the historical high-frequency current waveform as an external fault of the converter if the historical high-frequency current waveform corresponds to an external fault of the converter. An internal fault judgment module is used to mark the fault type corresponding to the historical high-frequency current waveform as an internal fault of the converter if the historical high-frequency current waveform corresponds to an internal fault of the converter.

7. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the protection method of the bidirectional DC / DC converter according to any one of claims 1 to 3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the protection method of the bidirectional DC / DC converter according to any one of claims 1 to 3.

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