A method and system for combustion fault warning of a gas turbine

Abstract

The application discloses a combustion fault alarm method of a gas turbine, and belongs to the technical field of gas turbine fault detection. The method comprises the following steps: obtaining combustion pressure data of the gas turbine; inputting the combustion pressure data of the gas turbine into a pre-constructed pressure feature monitoring model to output a pressure feature monitoring result; inputting the pressure feature monitoring result into a pre-constructed combustion state prediction model, comparing the pressure feature monitoring result with a pre-set health threshold, and outputting a combustion fault result; and generating a fault alarm result according to the combustion fault result; wherein the construction of the pressure feature monitoring model comprises the following steps: obtaining a comb filter; adding an adaptive notch filter after a band-pass filter in the comb filter to obtain the pressure feature monitoring model; and the band-pass filter is an empirical guide multi-band band-pass filter. The application can improve the feature monitoring precision and reliability of the combustion process of the gas turbine, and ensure the stable operation of the combustion system.

Description

Technical Field

[0001] This invention relates to the field of gas turbine fault monitoring technology, and in particular to a combustion fault alarm method and system for gas turbines. Background Technology

[0002] With the growth of global energy demand and increasing environmental awareness, gas turbines, as a highly efficient and clean power source, have been widely used in power generation, ship propulsion, and aerospace. However, the combustion process in gas turbines is extremely complex, and combustion instability can lead to a series of problems, potentially even causing safety accidents in severe cases. Therefore, effective monitoring of the stability and safety of the gas turbine combustion process is crucial.

[0003] Combustion pulsation pressure is an important indicator of combustion stability, often exhibiting non-stationary characteristics during combustion. Traditional combustion monitoring technologies mainly rely on various types of sensors, such as pressure and temperature sensors. However, due to the performance limitations of these sensors, they cannot accurately capture high-frequency combustion pulsation signals. Furthermore, under high temperature, high pressure, and strong electromagnetic interference environments, sensors are easily affected by external factors, causing data distortion. With the development of digital signal processing technology, by converting time-domain signals into frequency-domain signals and identifying the main frequency components of combustion pulsations, it can be used for combustion state monitoring and evaluation tasks. However, the non-stationary signals generated by combustion make commonly used time-frequency analysis methods ineffective and computationally intensive. Existing filtering techniques are also insufficient to effectively handle the multiple frequency components typically contained in combustion pulsations simultaneously. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fault alarm method for gas turbines. This method can solve the problem that the existing real-time monitoring capability of combustion pressure is limited and cannot accurately capture the multi-feature of rapidly changing pulsating pressure signals during combustion, thereby achieving a high-accuracy fault alarm.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] On one hand, the present invention provides a combustion fault alarm method for a gas turbine, comprising:

[0007] Obtain combustion pressure data from the gas turbine;

[0008] The combustion pressure data of the gas turbine is input into a pre-built pressure characteristic monitoring model, and the pressure characteristic monitoring results are output.

[0009] The pressure characteristic monitoring results are input into a pre-built combustion state prediction model, compared with a preset health threshold, and the combustion fault results are output; based on the combustion fault results, a fault alarm result is generated.

[0010] The construction of the pressure characteristic monitoring model includes:

[0011] Obtain the comb filter;

[0012] An adaptive notch filter is added after the bandpass filter in the comb filter to obtain the pressure characteristic monitoring model; the bandpass filter is an empirically guided multi-band bandpass filter.

[0013] Optionally, the combustion pressure data of the gas turbine can be acquired using sensors.

[0014] Optionally, before inputting the combustion pressure data of the gas turbine into the pre-built pressure characteristic monitoring model, the method further includes:

[0015] The combustion pressure data is cleaned using a filtering algorithm;

[0016] The construction of the combustion state prediction model includes:

[0017] The combustion state prediction model is trained using a time-series prediction algorithm to obtain the constructed combustion state prediction model.

[0018] Optionally, the bandpass filter is represented as:

[0019] ;

[0020] In the formula, Indicates the first The transfer function of a bandpass filter; This indicates the typical frequency range of combustion pulsation pressure; Indicates the first The quality factor of a bandpass filter; Indicates the first The center frequency of a bandpass filter.

[0021] Optionally, the processing steps of the pressure monitoring model include:

[0022] The combustion pressure data of the gas turbine is input into a bandpass filter, and a pressure filter signal is output.

[0023] The pressure-filtered signal is input into an adaptive notch filter to obtain the frequency characteristic values ​​of the pressure-filtered signal and its corresponding amplitude.

[0024] Optionally, the pressure filter signal is represented as:

[0025] ;

[0026] In the formula, Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; This indicates that the input at time point n is the first... Combustion pressure data of a gas turbine with a bandpass filter; Indicates the first The impulse response of a bandpass filter at time point n.

[0027] Optionally, the frequency characteristic values ​​of the pressure-filtered signal are expressed as:

[0028] ;

[0029] ;

[0030] ;

[0031] ;

[0032] In the formula, Indicates the first Frequency characteristic values ​​of the pressure-filtered signal at time point n for an adaptive notch filter; Indicates the sampling frequency; Indicates the first Frequency estimation coefficients of an adaptive notch filter at time point n; Indicates the first The frequency estimation coefficients of an adaptive notch filter at time point n+1; Indicates the step size parameter; Indicates the first The residual signal output by an adaptive notch filter at time point n; Indicates the first The gradient signal output by an adaptive notch filter at time point n; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-1; Indicates the notch width; Indicates the first The residual signal output by an adaptive notch filter at time point n-1; Indicates the first The residual signal output by an adaptive notch filter at time point n-2; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-2.

[0033] Optionally, the amplitude corresponding to the frequency characteristic value of the pressure filtered signal is expressed as:

[0034] ;

[0035] ;

[0036] ;

[0037] In the formula, Indicates the first The amplitude corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the smoothing factor; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n-1 of an adaptive notch filter; Indicates the first An adaptive notch filter contains only a harmonic signal with a single characteristic frequency at time point n; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; Indicates the first The residual signal output by an adaptive notch filter at time point n.

[0038] Optionally, the pressure characteristic monitoring results are input into a pre-built combustion state prediction model, compared with a preset health threshold, and the combustion failure results are output, including:

[0039] If the pressure characteristic monitoring result is greater than the preset health threshold, a combustion fault is output.

[0040] If the pressure characteristic monitoring result is not greater than the preset health threshold, then a no-combustion fault is output.

[0041] On the other hand, the present invention also provides a combustion fault alarm system for a gas turbine, comprising:

[0042] The data acquisition module is used to acquire combustion pressure data of the gas turbine.

[0043] The pressure detection module is used to: input the combustion pressure data of the gas turbine into a pre-built pressure characteristic monitoring model and output the pressure characteristic monitoring results;

[0044] The fault alarm module is used to: input the pressure characteristic monitoring results into a pre-built combustion state prediction model, compare it with a preset health threshold, and output a combustion fault result; and generate a fault alarm result based on the combustion fault result.

[0045] The construction of the pressure characteristic monitoring model includes:

[0046] Obtain the comb filter;

[0047] An adaptive notch filter is added after the bandpass filter in the comb filter to obtain the pressure characteristic monitoring model; the bandpass filter is an empirically guided multi-band bandpass filter.

[0048] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0049] This invention improves the monitoring accuracy and reliability of the combustion process in gas turbines, ensuring the stable operation of the combustion system. By introducing a pressure characteristic monitoring technology that combines multi-band bandpass filters and adaptive notch filters, it achieves accurate extraction of the characteristic frequencies and amplitudes of the typical frequency range of combustion pulsating pressure. This allows for timely and effective detection of potential safety hazards in gas turbines operating at high temperatures, enabling timely fault alerts and troubleshooting measures. It significantly improves the operating efficiency of gas turbines, reduces the failure rate, and extends equipment lifespan, demonstrating significant practical importance and broad application prospects. Attached Figure Description

[0050] Figure 1 The diagram shown is a flowchart of one embodiment of the combustion fault alarm method for gas turbines of the present invention.

[0051] Figure 2 The diagram shown is a structural schematic of the combustion fault alarm system for a gas turbine according to one embodiment of the present invention;

[0052] In the diagram: 1-Data acquisition module; 2-Signal conditioning module; 3-Data processing module; 4-Pressure detection module; 5-Fault alarm module. Detailed Implementation

[0053] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0054] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0055] Example 1

[0056] like Figure 1 As shown in the figure, this embodiment introduces a combustion fault alarm method for a gas turbine, which specifically includes the following steps:

[0057] Step 1: Acquire combustion pressure data of the gas turbine. In this embodiment, a high-sensitivity, high-temperature resistant pressure sensor is used. The pressure sensor is placed at key locations in the combustion chamber, such as the combustion chamber inlet, center, wall, or outlet, to ensure that the sensor can work stably and collect the required monitoring data periodically or continuously. It is equipped with a charge amplifier and signal conditioning module, or a dynamic pressure probe of the same technical specifications can be used directly to realize the parallel acquisition and conditioning of analog signals, ensuring that the rapidly changing pulsating pressure signals during combustion can be accurately captured.

[0058] Step 2: Clean the combustion pressure data using a filtering algorithm, which mainly includes preprocessing operations such as noise reduction, outlier removal, filtering, or signal enhancement.

[0059] Step 3: Input the combustion pressure data of the gas turbine into the pre-constructed pressure characteristic monitoring model, and output the pressure characteristic monitoring results. The construction of the pressure characteristic monitoring model includes:

[0060] Obtain the comb filter;

[0061] An adaptive notch filter is added after the bandpass filter in the comb filter to obtain the pressure characteristic monitoring model. The bandpass filter is an empirically guided multi-band bandpass filter. Multiple bandpass filters are designed based on the typical frequency range of combustion pulsating pressure, with each bandpass filter covering a specific frequency band. It is assumed that the frequency range of combustion pulsating pressure is... to Then design There are 3 bandpass filters, each with a center frequency of 1 / 2. , , ..., Its transfer function can be expressed as:

[0062] ;

[0063] In the formula, Indicates the first The transfer function of a bandpass filter; This indicates the typical frequency range of combustion pulsation pressure; Indicates the first The quality factor of a bandpass filter; Indicates the first The center frequency of a bandpass filter.

[0064] The processing steps of the pressure characteristic monitoring model include:

[0065] The combustion pressure data of the gas turbine The input is a bandpass filter, and the output is a pressure-filtered signal, which is expressed as:

[0066] ;

[0067] In the formula, Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; Indicates the first The impulse response of a bandpass filter at time point n.

[0068] The filtered signals of each frequency band are input into an adaptive notch filter to extract and identify the dominant frequency and amplitude in each band in real time, ultimately obtaining the frequency characteristic values ​​of the pressure-filtered signal and its corresponding amplitude. The frequency characteristic values ​​of the pressure-filtered signal are expressed as follows:

[0069] ;

[0070] ;

[0071] ;

[0072] ;

[0073] The amplitude corresponding to the frequency characteristic value of the pressure filtered signal is expressed as follows:

[0074] ;

[0075] ;

[0076] ;

[0077] In the formula, Indicates the first Frequency characteristic values ​​of the pressure-filtered signal at time point n for an adaptive notch filter; Indicates the sampling frequency; Indicates the first Frequency estimation coefficients of an adaptive notch filter at time point n; Indicates the first The frequency estimation coefficients of an adaptive notch filter at time point n+1; Indicates the step size parameter; Indicates the first The residual signal output by an adaptive notch filter at time point n; Indicates the first The gradient signal output by an adaptive notch filter at time point n is recursively represented here using the naive gradient descent method. Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-1; Indicates the notch width; Indicates the first The residual signal output by an adaptive notch filter at time point n-1; Indicates the first The residual signal output by an adaptive notch filter at time point n-2; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-2; Indicates the first The amplitude corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the smoothing factor; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n-1 of an adaptive notch filter; Indicates the first An adaptive notch filter contains only a harmonic signal with a single characteristic frequency at time point n.

[0078] Finally, by passing the constructed comb filter, the target characteristic frequencies within each frequency band can be obtained. and corresponding amplitude This is to enable further fault prediction and feedback control.

[0079] In this embodiment, the bandpass filter and the adaptive notch filter have a one-to-one correspondence. The signal first passes through the bandpass filter and then through the adaptive notch filter to obtain the frequency characteristic value of the signal and its corresponding amplitude.

[0080] Step 4: Input the pressure characteristic monitoring results into the pre-built combustion state prediction model, compare it with the preset health threshold, and output the combustion fault results; generate fault alarm results based on the combustion fault results.

[0081] By using time-series prediction algorithms to train on historical data, a well-constructed combustion state prediction model is obtained, and the prediction results are visualized. Once the system predicts potential fault signs, it immediately generates a fault warning, which includes possible fault sources and an assessment of the urgency level.

[0082] If the pressure characteristic monitoring result is greater than the preset health threshold, a combustion fault is output.

[0083] If the pressure characteristic monitoring result is not greater than the preset health threshold, then a no-combustion fault is output.

[0084] Example 2

[0085] like Figure 2 As shown in the figure, this embodiment introduces a combustion fault alarm system for a gas turbine, specifically including:

[0086] Data acquisition module 1 is used to acquire combustion pressure data of the gas turbine. It employs a high-sensitivity, high-temperature-resistant pressure sensor installed in the gas turbine combustion chamber, along with a charge amplifier and signal conditioning module, to achieve parallel acquisition and conditioning of analog signals, ensuring accurate capture of rapidly changing pulsating pressure signals during combustion. The acquired signals are transmitted to the central processing unit in real time via a LAN bus interface.

[0087] Signal conditioning module 2 is used for: preliminary calibration, filtering, and conversion of collected sensor signals.

[0088] Data processing module 3 is used to: realize data preprocessing of monitoring signals and analysis functions in time domain, frequency domain, and time-frequency domain. It mainly includes time domain statistical index calculation, frequency domain characteristic frequency and amplitude estimation, and storage and recording of monitoring data and processed characteristic data based on domestic storage devices. It also configures certain filtering algorithms to perform data cleaning on the signals collected by the sensors, mainly including preprocessing operations such as noise reduction, outlier removal, filtering or signal enhancement.

[0089] The pressure detection module 4 is used to: input the combustion pressure data of the gas turbine into a pre-built pressure characteristic monitoring model and output the pressure characteristic monitoring results; transmit the calculated time-domain indicators, frequency-domain characteristic values, etc. to the central processing unit in real time, and provide a reminder when the indicators exceed the limit according to the status threshold.

[0090] The fault alarm module 5 is used to: input the pressure characteristic monitoring results into a pre-built combustion state prediction model, compare it with a preset health threshold, and output a combustion fault result; generate a fault alarm result based on the combustion fault result; and store monitoring data for a long time to form a rich historical database. Based on a time-series prediction method, it predicts the evolution trend of combustion pressure characteristics and compares it with a preset health threshold. The prediction results are displayed to the user in chart form to help the user make decisions. According to a preset alarm mechanism, when an abnormal situation is detected or a known fault is predicted, the system automatically issues an alarm to remind operators to troubleshoot or take preventive measures in a timely manner.

[0091] The construction of the pressure characteristic monitoring model includes:

[0092] Obtain the comb filter;

[0093] An adaptive notch filter is added after the bandpass filter in the comb filter to obtain the pressure characteristic monitoring model; the bandpass filter is an empirically guided multi-band bandpass filter.

[0094] In this embodiment, the pressure sensor, data acquisition card, signal conditioning circuit, storage module and processing unit are integrated into a compact system to ensure the stability and reliability of the system.

[0095] Develop a user-friendly software platform that supports real-time data display, storage, and analysis, and provides a graphical user interface.

[0096] The system was thoroughly tested under laboratory conditions to verify the correctness and reliability of each function.

[0097] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied 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.

[0098] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0099] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0100] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0101] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A combustion fault alarm method for a gas turbine, characterized in that, include: Obtain combustion pressure data from the gas turbine; The combustion pressure data of the gas turbine is input into a pre-built pressure characteristic monitoring model, and the pressure characteristic monitoring results are output. The pressure characteristic monitoring results are input into a pre-built combustion state prediction model, compared with a preset health threshold, and the combustion failure results are output. Based on the combustion fault results, generate a fault alarm result; The construction of the pressure characteristic monitoring model includes: Obtain the comb filter; An adaptive notch filter is added after the bandpass filter in the comb filter to obtain the pressure characteristic monitoring model; the bandpass filter is an empirically guided multi-band bandpass filter. The processing steps of the pressure characteristic monitoring model include: The combustion pressure data of the gas turbine is input into a bandpass filter, and a pressure filter signal is output. The pressure-filtered signal is input into an adaptive notch filter to obtain the frequency characteristic values ​​of the pressure-filtered signal and its corresponding amplitude. The pressure-filtered signal is represented as follows: ； In the formula, Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; This indicates that the input at time point n is the first... Combustion pressure data of a gas turbine with a bandpass filter; Indicates the first The impulse response of a bandpass filter at time point n; The frequency characteristic value of the pressure-filtered signal is expressed as: ； ； ； ； In the formula, Indicates the first Frequency characteristic values ​​of the pressure-filtered signal at time point n for an adaptive notch filter; Indicates the sampling frequency; Indicates the first Frequency estimation coefficients of an adaptive notch filter at time point n; Indicates the first The frequency estimation coefficients of an adaptive notch filter at time point n+1; Indicates the step size parameter; Indicates the first The residual signal output by an adaptive notch filter at time point n; Indicates the first The gradient signal output by an adaptive notch filter at time point n; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-1; Indicates the notch width; Indicates the first The residual signal output by an adaptive notch filter at time point n-1; Indicates the first The residual signal output by an adaptive notch filter at time point n-2; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-2; The amplitude corresponding to the frequency characteristic value of the pressure filtered signal is expressed as follows: ； ； ； In the formula, Indicates the first The amplitude corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the smoothing factor; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n-1 of an adaptive notch filter; Indicates the first An adaptive notch filter contains only a harmonic signal with a single characteristic frequency at time point n.

2. The combustion fault alarm method for a gas turbine according to claim 1, characterized in that, The combustion pressure data of the gas turbine is obtained using sensors.

3. The combustion fault alarm method for a gas turbine according to claim 1, characterized in that, Before inputting the combustion pressure data of the gas turbine into the pre-built pressure characteristic monitoring model, the method further includes: The combustion pressure data is cleaned using a filtering algorithm; The construction of the combustion state prediction model includes: The combustion state prediction model is trained using a time-series prediction algorithm to obtain the constructed combustion state prediction model.

4. The combustion fault alarm method for a gas turbine according to claim 1, characterized in that, The bandpass filter is represented as follows: ； In the formula, Indicates the first The transfer function of a bandpass filter; This indicates the typical frequency range of combustion pulsation pressure; Indicates the first The quality factor of a bandpass filter; Indicates the first The center frequency of a bandpass filter.

5. The combustion fault alarm method for a gas turbine according to claim 1, characterized in that, The pressure characteristic monitoring results are input into a pre-built combustion state prediction model, compared with a preset health threshold, and the combustion fault results are output, including: If the pressure characteristic monitoring result is greater than the preset health threshold, a combustion fault is output. If the pressure characteristic monitoring result is not greater than the preset health threshold, then a no-combustion fault is output.

6. A combustion fault alarm system for a gas turbine, characterized in that, include: The data acquisition module is used to acquire combustion pressure data of the gas turbine. The pressure detection module is used to: input the combustion pressure data of the gas turbine into a pre-built pressure characteristic monitoring model and output the pressure characteristic monitoring results; The fault alarm module is used to: input the pressure characteristic monitoring results into a pre-built combustion state prediction model, compare them with a preset health threshold, and output combustion fault results; Based on the combustion fault results, generate a fault alarm result; The construction of the pressure characteristic monitoring model includes: Obtain the comb filter; An adaptive notch filter is added after the bandpass filter in the comb filter to obtain the pressure characteristic monitoring model; the bandpass filter is an empirically guided multi-band bandpass filter. The processing steps of the pressure characteristic monitoring model include: The combustion pressure data of the gas turbine is input into a bandpass filter, and a pressure filter signal is output. The pressure-filtered signal is input into an adaptive notch filter to obtain the frequency characteristic values ​​of the pressure-filtered signal and its corresponding amplitude. The pressure-filtered signal is represented as follows: ； In the formula, Indicates the first The pressure-filtered signal output by a bandpass filter at time point n; This indicates that the input at time point n is the first... Combustion pressure data of a gas turbine with a bandpass filter; Indicates the first The impulse response of a bandpass filter at time point n; The frequency characteristic value of the pressure-filtered signal is expressed as: ； ； ； ； In the formula, Indicates the first Frequency characteristic values ​​of the pressure-filtered signal at time point n for an adaptive notch filter; Indicates the sampling frequency; Indicates the first Frequency estimation coefficients of an adaptive notch filter at time point n; Indicates the first The frequency estimation coefficients of an adaptive notch filter at time point n+1; Indicates the step size parameter; Indicates the first The residual signal output by an adaptive notch filter at time point n; Indicates the first The gradient signal output by an adaptive notch filter at time point n; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-1; Indicates the notch width; Indicates the first The residual signal output by an adaptive notch filter at time point n-1; Indicates the first The residual signal output by an adaptive notch filter at time point n-2; Indicates the first The pressure-filtered signal output by a bandpass filter at time point n-2; The amplitude corresponding to the frequency characteristic value of the pressure filtered signal is expressed as follows: ； ； ； In the formula, Indicates the first The amplitude corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n of an adaptive notch filter; Indicates the smoothing factor; Indicates the first The energy value corresponding to the frequency characteristic value of the pressure filtered signal at time point n-1 of an adaptive notch filter; Indicates the first An adaptive notch filter contains only a harmonic signal with a single characteristic frequency at time point n.

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