Power conversion circuit state monitoring method and system for multi-phase half-bridge stacking

Abstract

The invention provides a power conversion circuit state monitoring method and system for multiphase half-bridge stacking, and relates to the technical field of half-bridge circuit state monitoring. After real-time electrical data and environment data of a conversion circuit are collected and preprocessed, frequency domain characteristics of the electrical data are extracted through fast Fourier transform; the anti-interference capability is calculated by calculating output interference signals, equipment aging interference noise and environment interference data, the comprehensive stability is calculated according to the stability of input and output voltages and the load adaptability, and the comprehensive coordination of the circuit is calculated according to the synchronism, ripple balance and dynamic response consistency of control signals. And calculating a current state index according to the anti-interference capability, the comprehensive stability and the comprehensive coordination, performing linear fitting according to changes of the anti-interference capability, the comprehensive stability and the comprehensive coordination in each adjacent time window, and judging a circuit state change trend according to a linear relationship of the three fits.

Description

Technical Field

[0001] The present invention relates to the technical field of half - bridge circuit state monitoring, and specifically to a method and system for monitoring the state of a power conversion circuit for multi - phase half - bridge stacking. Background Art

[0002] In modern industrial applications, power conversion circuits with multi - phase half - bridge stacking are widely used due to their high efficiency and high power density. However, during the operation of such circuits, they face complex and variable environmental interferences and equipment aging problems, which seriously affect the accuracy and real - time performance of circuit state monitoring. Traditional monitoring methods often struggle to effectively separate and suppress various interference signals, resulting in an incomplete and inaccurate assessment of the circuit's health status. In addition, existing technologies have deficiencies in evaluating the stability, dynamic response consistency, etc. of the circuit, and it is difficult to comprehensively reflect the actual working state of the circuit. Therefore, there is an urgent need for a monitoring method that can comprehensively consider various factors and accurately evaluate the state of the power conversion circuit.

[0003] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure, and thus it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for monitoring the state of a power conversion circuit for multi - phase half - bridge stacking to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A method and system for monitoring the state of a power conversion circuit for multi - phase half - bridge stacking, the specific steps including:

[0007] Step 1: Collect real - time electrical data and environmental data of the conversion circuit and perform pre - processing. Divide the processed electrical data into time windows at the same time interval, and extract the frequency - domain characteristics of the electrical data through fast Fourier transform.

[0008] Step 2: After denoising the input voltage according to the frequency - domain characteristics, obtain the output interference signal by calculating the theoretical output voltage through control parameters, judge the equipment aging interference noise according to the frequency - domain characteristics, calculate the environmental interference noise according to the environmental interference data, and calculate the anti - interference ability according to the output interference signal, equipment aging interference noise, and environmental interference data.

[0009] Step 3: Calculate the stability of the input voltage according to the voltage input data, calculate the stability of the output voltage according to the output voltage and the load step recovery time, calculate the load adaptability of the circuit according to the load data, and calculate the comprehensive stability according to the stability of the input and output voltages and the load adaptability.

[0010] Step 4: Calculate the synchronization of the control signal according to the circuit control phase angle, calculate the ripple balance of the output current according to the output current of each phase, calculate the dynamic response consistency of the circuit according to the load step recovery time, and calculate the comprehensive coordination of the circuit according to the synchronization, ripple balance and dynamic response consistency of the control signal;

[0011] Step 5: Calculate the current state index according to the anti-interference ability, comprehensive stability and comprehensive coordination, perform linear fitting according to the changes of the anti-interference ability, comprehensive stability and comprehensive coordination in each adjacent time window, and judge the change trend of the circuit state based on the three fitted linear relationships.

[0012] Further, the electrical data includes the input voltage and the output voltage;

[0013] The method of preprocessing is normalization, and the calculation formula is:

[0014]

[0015] Among them, Xg is the data after normalization of each data, Xmax is the largest number in each data type collected, Xmin is the smallest number in each data type collected, and xi ig is the igth data in each data type collected, and nx is the number of data in each data type collected.

[0016] The specific formula for extracting the frequency domain characteristics of the electrical data through fast Fourier transform is;

[0017]

[0018] Among them, VS(m) is the mth component in the frequency domain signal of the electrical data, Xq(in) is the inth sample in the electrical data, N is the total number of samples, m represents the mth frequency component in the frequency domain, 0 ≤ m ≤ N - 1, and j is the imaginary unit.

[0019] Further, the environmental data is the electromagnetic field intensity signal;

[0020] The control parameters include the PWM duty cycle of the half-bridge circuit and the number of parallel phases;

[0021] The calculation formula for the theoretical output voltage is:

[0022]

[0023] Among them, Vout is the theoretical output voltage, and Vin kj is the denoised input voltage of the kjth phase half-bridge circuit, and D kjis the PWM duty cycle of the kj-phase half-bridge circuit, and NJ is the number of parallel phases;

[0024] The calculation formula for the output interference signal is:

[0025] Pgr = Vout - Voul

[0026] where Pgr is the output interference signal, Vout is the circuit output voltage, and Voul is the theoretical output voltage;

[0027] The method for judging the aging interference noise of the device according to the frequency domain characteristics is: by analyzing the frequency domain characteristics, extracting the amplitudes of odd and even harmonics, and calculating according to the amplitudes of odd and even harmonics. The specific calculation formula is:

[0028]

[0029] where Elh is the aging interference noise of the device, A 2kb is the amplitude of the even harmonic, A 2kb-1 is the amplitude of the odd harmonic, and mb and nb are the harmonic orders analyzed respectively;

[0030] The calculation formula for the environmental interference noise is:

[0031]

[0032] where Ehj is the environmental interference noise, Vout(t) is the output voltage signal at time t, Emi(t + τ) is the electromagnetic field intensity signal after a time delay of τ, T is the time window, and τ is the time delay parameter;

[0033] The calculation formula for the anti-interference ability index is:

[0034]

[0035] where Qgr is the anti-interference ability index and Evi is the noise removed from the input voltage.

[0036] Furthermore, the voltage input data includes the input rated voltage and the number of times the voltage deviates from the rated voltage;

[0037] The load data includes the load step recovery time, the load step recovery time standard, the voltage at the load point, the current at the load point, and the number of load points;

[0038] The calculation formula for the stability of the input voltage is:

[0039]

[0040] Among them, Wvin is the stability of the input voltage, Vinbz is the rated input voltage, Vinmax and Vinmin are respectively the maximum and minimum values of the input voltage of the circuit, T is the time window, and Nbp is the number of times the input voltage deviates from the rated voltage;

[0041] The technical formula for the stability of the output voltage is:

[0042]

[0043] Among them, Wvou is the stability of the output voltage, σVout is the standard deviation of the output voltage, t re is the standard of the load step recovery time, t rise is the load step recovery time;

[0044] The calculation formula for the load adaptability analysis is:

[0045]

[0046] Among them, Wfz is the load adaptability of the circuit, Vout ka is the voltage at the ka-th load point, Voute is the rated output voltage, Ma is the number of load points, ωa ka is the load weight at the ka-th load point, and ΔIlod is the load change current

[0047] The technical formula for the comprehensive stability is:

[0048]

[0049] Among them, Qzw is the comprehensive stability, and α1 and α2 are respectively the penalty coefficients for the stability of the input voltage and the stability of the output voltage.

[0050] Furthermore, the calculation formula for the synchronization of the control signal is:

[0051]

[0052] Among them, Sct is the synchronization of the control signal, γ is the attenuation coefficient, are respectively the phase angles of the PWM signals of the ia-th and ja-th phases;

[0053] The calculation formula for the ripple balance of the output current is:

[0054]

[0055] Among them, Sbw is the ripple balance of the output current, μΔI is the mean value of the current ripple per phase, and σΔI is the standard deviation of the current ripple per phase;

[0056] The calculation formula for the dynamic response consistency of the circuit is as follows:

[0057]

[0058] Sdt is the dynamic response consistency of each phase half-bridge circuit, and σt rise is the standard deviation of the load step recovery time, and μt rise is the mean value of the load step recovery time.

[0059] Furthermore, the calculation formula for the comprehensive coordination of the circuit is as follows:

[0060]

[0061] Among them, Qzh is the comprehensive coordination of the circuit, and α3 is the coordination contradiction weight coefficient, amplifying the conflict effect between the ripple and the control.

[0062] Furthermore, the calculation method for the current state index is as follows:

[0063]

[0064] Among them, Pzt is the current state index, Qgr is the anti-interference ability index, Qzw is the comprehensive stability, and Qzh is the comprehensive coordination of the circuit.

[0065] Furthermore, the calculation method for the linear fitting is as follows:

[0066]

[0067] Among them, Kxl xi is the linear fitting value of the data type xi fitting, Nt is the number of time windows, tc is the tc-th window, and xl tc is the value of xl in the data of the tc-th window, where xi ∈ {Qgr, Qzw, Qzh};

[0068] When it is determined that the circuit state is good;

[0069] Among them, is the circuit state judgment threshold;

[0070] The calculation formula for the circuit state change trend is as follows:

[0071] Pqs = μ1 * Kxl1 + μ2 * Kxl2 + μ3 * Kxl3

[0072] Among them, Pqs is the trend of circuit state change, μ1, μ2, and μ3 are the weights of the anti-interference ability index, comprehensive stability, and comprehensive coordination of the circuit respectively, and Kxl1, Kxl2, and Kxl3 are the linear fitting values of the anti-interference ability index, comprehensive stability, and comprehensive coordination of the circuit respectively;

[0073] When it is determined that the circuit state is gradually stable;

[0074] When it is determined that the circuit state is stable;

[0075] When it is determined that the circuit state is gradually deteriorating.

[0076] The present invention also provides a power conversion circuit state monitoring system for a multiphase half-bridge stack. The circuit state monitoring system is used to execute the above-mentioned power conversion circuit state monitoring method for a multiphase half-bridge stack, including:

[0077] A data acquisition and processing module, which is used to acquire real-time electrical data and environmental data of the conversion circuit and perform preprocessing, divide the processed electrical data into time windows at the same time interval, and extract the frequency domain characteristics of the electrical data through fast Fourier transform;

[0078] An interference evaluation module, which is used to denoise the input voltage according to the frequency domain characteristics, obtain the output interference signal by calculating the theoretical output voltage through control parameters, judge the equipment aging interference noise according to the frequency domain characteristics, calculate the environmental interference noise according to the environmental interference data, and calculate the anti-interference ability according to the output interference signal, equipment aging interference noise and environmental interference data;

[0079] A stability evaluation module, which is used to calculate the stability of the input voltage according to the voltage input data, calculate the stability of the output voltage according to the output voltage and the load step recovery time, calculate the load adaptability of the circuit according to the load data, and calculate the comprehensive stability according to the stability of the input and output voltages and the load adaptability;

[0080] A coordination evaluation module, which is used to calculate the synchronization of the control signal according to the circuit control phase angle, calculate the ripple balance of the output current according to the output current of each phase, calculate the dynamic response consistency of the circuit according to the load step recovery time, and calculate the comprehensive coordination of the circuit according to the synchronization of the control signal, ripple balance and dynamic response consistency;

[0081] Comprehensive evaluation module, which is used to calculate the current state index according to the anti-interference ability, comprehensive stability, and comprehensive coordination, perform linear fitting based on the changes of the anti-interference ability, comprehensive stability, and comprehensive coordination in each adjacent time window, and judge the changing trend of the circuit state based on the three fitted linear relationships.

[0082] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0083] After collecting and preprocessing the real-time electrical data and environmental data of the conversion circuit, the present invention extracts the frequency-domain characteristics of the electrical data through fast Fourier transform, calculates the anti-interference ability by calculating the output interference signal, equipment aging interference noise, and environmental interference data, calculates the comprehensive stability according to the stability of the input and output voltages and the load adaptability, calculates the comprehensive coordination of the circuit according to the synchronization, ripple balance, and dynamic response consistency of the control signal, calculates the current state index according to the anti-interference ability, comprehensive stability, and comprehensive coordination, performs linear fitting based on the changes of the anti-interference ability, comprehensive stability, and comprehensive coordination in each adjacent time window, and judges the changing trend of the circuit state based on the three fitted linear relationships;

[0084] Based on the multi-dimensional data analysis and feature extraction, the present invention significantly improves the accuracy and comprehensiveness of the state monitoring of the power conversion circuit. The fast Fourier transform is used to effectively remove the noise in the input voltage, and the anti-interference ability of the circuit is accurately calculated. By comprehensively evaluating the stability of the input and output voltages, the load adaptability, and the synchronization, ripple balance, and dynamic response consistency of the control signal, the comprehensive stability and comprehensive coordination of the circuit are comprehensively reflected. Through the linear fitting of the anti-interference ability, comprehensive stability, and comprehensive coordination, the changing trend of the circuit state can be accurately judged, and potential problems can be predicted in advance. This method not only improves the real-time performance and reliability of the monitoring, but also provides strong support for the maintenance and optimization of the power conversion circuit, and has important engineering application value. Description of the Drawings

[0085] Figure 1 It is a schematic diagram of the overall method flow of the present invention;

[0086] Figure 2 It is a schematic diagram of the overall system flow of the present invention. Detailed Embodiments

[0087] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in conjunction with specific embodiments.

[0088] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention pertains. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0089] Embodiment:

[0090] Please refer to Figure 1 , the present invention provides a technical solution:

[0091] A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack, the specific steps including:

[0092] Step 1: Collect real-time electrical data and environmental data of the conversion circuit and perform preprocessing. Divide the processed electrical data into time windows at the same time interval, and extract the frequency-domain features of the electrical data through fast Fourier transform.

[0093] By collecting electrical data (such as input voltage, output voltage) and environmental data (such as electromagnetic field intensity signal), the operating state of the power conversion circuit and the external environmental conditions can be grasped in real time. The preprocessing adopts maximum normalization, which is a commonly used feature scaling method. Its core idea is to scale the original data to a specific range according to a ratio, usually between 0 and 1. In this way, the influence caused by the difference in dimension or value range between different features can be eliminated, so that the data can be compared and analyzed on a unified scale. Data preprocessing can eliminate sensor noise or other interference signals, improve the accuracy and reliability of the data. Only high-quality data after preprocessing can provide effective support for subsequent analysis.

[0094] The processed electrical data is divided into time windows at the same time interval, which can analyze the operating state of the circuit in different time periods. This division method helps to capture the dynamic changes of the circuit (such as load mutations, voltage fluctuations, etc.), so as to better evaluate the stability, response characteristics and coordination of the circuit. By using the Fast Fourier Transform (FFT) to extract the frequency-domain characteristics of the electrical data, periodic interference signals in the circuit, noise caused by equipment aging, and environmental interference signals can be separated. Frequency-domain analysis can help identify harmonic distortion, noise sources and potential fault characteristics in the circuit, providing key information for subsequent condition assessment.

[0095] The stability of the input voltage directly affects the operating efficiency and output quality of the power conversion circuit. Excessive voltage fluctuations may cause circuit damage or unstable output. The change of the output voltage reflects the circuit's response ability to load changes. By analyzing the stability of the output voltage (such as load step recovery time), the dynamic response characteristics of the circuit can be evaluated. Stability of input and output voltages: Voltage stability is an important indicator to measure the health status of the circuit. Unstable voltage may lead to a decrease in circuit efficiency, damage to load equipment, or unsafe system operation.

[0096] In this embodiment, the electrical data includes input voltage and output voltage;

[0097] The preprocessing method is normalization, and the calculation formula is:

[0098]

[0099] where Xg is the data after normalization of each data, Xmax is the largest number in each data type collected, Xmin is the smallest number in each data type collected, and xi ig is the ig-th data in each data type collected, and nx is the number of data in each data type collected.

[0100] The specific formula for extracting the frequency-domain characteristics of electrical data by using the Fast Fourier Transform is;

[0101]

[0102] where VS(m) is the m-th component in the frequency-domain signal of the electrical data, Xq(in) is the in-th sample in the electrical data, N is the total number of samples, m represents the m-th frequency component in the frequency domain, 0 ≤ m ≤ N - 1, and j is the imaginary unit.

[0103] Step 2: After denoising the input voltage according to the frequency-domain characteristics, obtain the output interference signal by calculating the theoretical output voltage through control parameters, judge the device aging interference noise according to the frequency-domain characteristics, calculate the environmental interference noise according to the environmental interference data, and calculate the anti-interference ability according to the output interference signal, device aging interference noise and environmental interference data.

[0104] Input interference signals usually refer to the noise or irregular fluctuations existing in the input power supply or signals in the power system. These interference signals may originate from the external power system, the operation of other devices, or the instability of the power supply. The characteristic of input interference signals is that they directly affect the starting point of the circuit operation and the stability of the input terminal. For example, in a half-bridge circuit, if the input voltage has large fluctuations or high-frequency noise, this will directly affect the efficiency of the circuit and the stability of the output. By analyzing the frequency-domain characteristics of the input interference signals, the quality and stability of the input signals can be judged, so as to determine the performance of the circuit when facing such signals. By analyzing the input interference signals, designers can take appropriate filtering measures to reduce the noise influence at the input terminal and improve the adaptability of the circuit to input signal interference.

[0105] Device aging interference noise refers to the performance degradation of circuit components caused by long-term use, thermal stress, mechanical fatigue, etc. over time. This kind of degradation usually manifests as the aging of components such as capacitors, inductors, and transformers. The parameter changes of these components will cause noise or interference in the circuit. For example, the capacitance value of a capacitor will decrease over time, resulting in a decline in the filtering performance of the circuit, thus generating stronger noise. The increase in device aging interference noise means that the anti-interference ability of the circuit decreases, which may lead to instability when the circuit operates in a harsh environment. By performing frequency-domain analysis on the device aging interference noise, the aging trend of circuit components can be detected in advance, and targeted maintenance or component replacement can be carried out. This kind of analysis can help designers evaluate the long-term stability of the circuit, avoid failures caused by device aging, and improve the service life of the circuit.

[0106] In this embodiment, the environmental data is the electromagnetic field intensity signal;

[0107] The control parameters include the PWM duty cycle and the number of parallel phases of the half-bridge circuit;

[0108] The calculation formula for the theoretical output voltage is:

[0109]

[0110] where Vout is the theoretical output voltage, Vin kj is the denoised input voltage of the kj-phase half-bridge circuit, D kj is the PWM duty cycle of the kj-phase half-bridge circuit, and NJ is the number of parallel phases;

[0111] The calculation formula for the output interference signal is as follows:

[0112] Pgr = Vout - Voul

[0113] Where Pgr is the output interference signal, Vout is the circuit output voltage, and Voul is the theoretical output voltage;

[0114] The method for judging the equipment aging interference noise according to the frequency domain characteristics is as follows: by analyzing the frequency domain characteristics, extracting the amplitudes of odd and even harmonics, and calculating according to the amplitudes of odd and even harmonics. The specific calculation formula is as follows:

[0115]

[0116] Where Elh is the equipment aging interference noise, A 2kb is the amplitude of the even harmonic, A 2kb-1 is the amplitude of the odd harmonic, and mb and nb are the harmonic orders analyzed respectively.

[0117] The output interference signal refers to the noise or interference that appears at the output end of the circuit caused by the internal circuit characteristics or external influences. This kind of interference is usually closely related to the working mode of the circuit, such as factors like switching actions, load changes, or instability of control strategies. Specifically, the waveform of PWM modulation, the switching frequency, and the response time of the switching components may all cause certain interference signals at the output end. The output interference signal may manifest as voltage fluctuations, current fluctuations, or noise, and these signals will affect the stability and accuracy of the circuit. Especially in high-precision applications, it may lead to system misoperations or mismeasurements. By analyzing the output interference signal, potential design defects in the circuit, such as insufficient filtering, improper PWM frequency setting, etc., can be identified, thus providing guidance for further optimizing the circuit. By performing frequency domain analysis on the output signal, the stability of the circuit under different working conditions can be judged to ensure the reliability of the equipment in actual use.

[0118] The calculation formula for the environmental interference noise is as follows:

[0119]

[0120] Where Ehj is the environmental interference noise, Vout(t) is the output voltage signal at time t, Emi(t + τ) is the electromagnetic field intensity signal after a time delay of τ, T is the time window, and τ is the time delay parameter.

[0121] Environmental interference data refers to the interference generated by the electromagnetic field intensity signals existing in the external environment on the circuit. The electromagnetic field intensity signals originate from various electronic devices, communication devices, etc. around the circuit. The electromagnetic waves emitted by these devices are conducted to the power conversion circuit through air or power lines, etc., affecting its normal operation. Environmental interference data reflects the electromagnetic field intensity and its influence intensity on the circuit. Especially in a high electromagnetic interference environment, the circuit may be subject to stronger external interference. These interference signals may cause the control system of the circuit to fail, generate voltage fluctuations, and even affect the safety of the system. By monitoring and analyzing the electromagnetic field intensity signals, the environmental conditions of the circuit can be effectively identified, and the influence of external interference on the circuit can be evaluated. Based on this data, designers can optimize the electromagnetic compatibility design of the circuit and take measures such as increasing electromagnetic shielding, reasonable wiring, and grounding to improve the anti-interference ability of the circuit.

[0122] The calculation formula for the anti-interference ability index is as follows:

[0123]

[0124] Where Qgr is the anti-interference ability index, and Evi is the noise removed from the input voltage.

[0125] The anti-interference ability refers to the ability of a system to maintain its normal operation and functions in the face of external and internal interferences. For a power conversion circuit with a multi-phase half-bridge stack, the strength of the anti-interference ability is directly related to the stability, efficiency, and reliability of the circuit. The interference signals in the circuit mainly come from factors such as input voltage fluctuations, equipment aging, environmental interference, and internal noise. Through effective anti-interference ability evaluation, it can be ensured that the circuit can still maintain the desired output performance under various complex conditions without being affected by excessive disturbances.

[0126] In a power conversion circuit with a multi-phase half-bridge stack, the monitoring and evaluation of these anti-interference abilities can help designers make real-time adjustments during the operation of the device and take necessary maintenance measures according to the state of the circuit. By continuously optimizing the anti-interference ability, the system can adapt to various complex electromagnetic environments, ensuring the long-term stable operation of the power electronic system and avoiding system failures or efficiency drops caused by environmental interference or equipment problems.

[0127] Step 3: Calculate the stability of the input voltage based on the voltage input data, calculate the stability of the output voltage based on the output voltage and the load step recovery time, calculate the load adaptability of the circuit based on the load data, and calculate the comprehensive stability based on the stabilities of the input and output voltages and the load adaptability.

[0128] In this embodiment, the voltage input data includes the input rated voltage and the number of times the voltage deviates from the rated voltage;

[0129] The load data includes the load step recovery time, the load step recovery time standard, the voltage at the load point, the current at the load point, and the number of load points;

[0130] The calculation formula for the stability of the input voltage is:

[0131]

[0132] where Wvin is the stability of the input voltage, Vinbz is the rated input voltage, Vinmax and Vinmin are respectively the maximum and minimum values of the input voltage of the circuit, T is the time window, and Nbp is the number of times the input voltage deviates from the rated voltage;

[0133] The technical formula for the stability of the output voltage is:

[0134]

[0135] where Wvou is the stability of the output voltage, σVout is the standard deviation of the output voltage, t re is the load step recovery time standard, and t rise is the load step recovery time.

[0136] The stability of the input voltage and the stability of the output voltage are key indicators for describing the voltage performance of the power conversion circuit under different working conditions. The stability of the input voltage refers to the ability of the input voltage to remain constant or fluctuate within a certain range when the circuit receives the input voltage signal. If the input voltage is unstable, it may cause the operating point of the circuit to change, thereby affecting the performance of the circuit and even causing failures. Therefore, monitoring and calculating the stability of the input voltage is an important step to ensure the smooth operation of the circuit and avoid system abnormalities caused by voltage fluctuations.

[0137] The stability of the output voltage refers to the ability of the circuit to maintain a stable output voltage under conditions such as load changes, environmental changes, and circuit component aging. Therefore, the stability of the output voltage is usually evaluated through the load step recovery time. If the recovery time is too long, it means that the circuit's response to sudden load changes is not timely, which may lead to unstable system operation.

[0138] The calculation formula for the load adaptability analysis is:

[0139]

[0140] where wfz is the load adaptability of the circuit, Vout ka is the voltage at the ka-th load point, Voute is the rated output voltage, Ma is the number of load points, and ωa kais the load weight at the ka-th load point, and ΔIlod is the load change current.

[0141] Load adaptability describes the operation performance of the power conversion circuit under different load conditions. The load change may be gradual or sudden, which requires the circuit to quickly adapt to the load change and maintain a stable output voltage. Therefore, the evaluation of load adaptability is usually carried out by the situation of load change. If the circuit can quickly respond to the load change and maintain a stable output voltage, it indicates that its load adaptability is better.

[0142] The technical formula for the comprehensive stability is as follows:

[0143]

[0144] Among them, Qzw is the comprehensive stability, and α1 and α2 are the penalty coefficients for the stability of the input voltage and the stability of the output voltage respectively.

[0145] Comprehensive stability is a comprehensive index of the ability of a power electronic circuit to maintain stable operation under various operating conditions. In a power conversion circuit with a multiphase half-bridge stack, the comprehensive stability can reflect the overall response and adaptation ability of the circuit when facing input voltage fluctuations, output voltage changes, and load changes. It is evaluated by combining the three important factors of the stability of the input voltage, the stability of the output voltage, and the load adaptability. Therefore, it has strong comprehensiveness and representativeness to comprehensively evaluate the response ability of the circuit to different voltage fluctuations and load changes in practical applications.

[0146] Step 4: Calculate the synchronism of the control signal according to the circuit control phase angle, calculate the ripple balance of the output current according to the output current of each phase, calculate the dynamic response consistency of the circuit according to the load step recovery time, and calculate the comprehensive coordination of the circuit according to the synchronism, ripple balance, and dynamic response consistency of the control signal.

[0147] The synchronism of the control signal refers to whether the phase control signals in the circuit are synchronously controlled according to the predetermined phase relationship. In a multiphase power conversion circuit, usually multiple phases work in parallel, and the switching signals of each phase should be controlled in a strict time sequence to ensure the smooth output of the current and the complementary effect between each phase. Poor synchronism of the control signal may lead to interference between phases, inconsistent switching frequencies, and then cause an increase in the fluctuations of the output voltage and current, and even lead to overheating, reduced efficiency, or equipment damage. Therefore, good synchronism of the control signal can ensure the coordinated operation between phases and improve the overall performance and stability of the system.

[0148] Ripple balance refers to the balance degree of the output current ripple of each phase when the circuit outputs current. In a multi-phase circuit, the output current ripple of each phase (i.e., the pulsating part of the current) is normal, but the ripples between different phases may vary in frequency and amplitude. If the ripple is unbalanced, it will lead to uneven harmonic distribution in the current, increase power loss, and affect the circuit efficiency. Good ripple balance means that the current ripple of each phase is basically equal, and the system can effectively disperse the pulsation of the load current, thereby reducing the harmonics in the current, reducing the electromagnetic interference of the equipment, and improving the overall stability and performance of the circuit.

[0149] Dynamic response consistency refers to whether the dynamic responses of each phase are consistent when the load of the circuit changes. A sudden change in the load will cause fluctuations in the output voltage and current of the circuit, and the response ability of the circuit determines whether it can quickly adjust and return to a stable state. There may be certain differences in the dynamic responses of different phases. If a certain phase reacts slowly or overreacts, it may lead to inconsistent responses of the overall circuit and affect the stability of the system.

[0150] In this embodiment, the calculation formula for the synchronization of the control signal is as follows:

[0151]

[0152] where Sct is the synchronization of the control signal, γ is the attenuation coefficient, are the phase angles of the PWM signals of the ia-th and ja-th phases respectively;

[0153] The calculation formula for the ripple balance of the output current is as follows:

[0154]

[0155] where Sbw is the ripple balance of the output current, μΔI is the mean value of the current ripple of each phase, and σΔI is the standard deviation of the current ripple of each phase;

[0156] The calculation formula for the dynamic response consistency of the circuit is as follows:

[0157]

[0158] Sdt is the dynamic response consistency of each half-bridge circuit of each phase, σt rise is the standard deviation of the load step recovery time, μt rise is the mean value of the load step recovery time.

[0159] In this embodiment, the calculation formula for the comprehensive coordination of the circuit is as follows:

[0160]

[0161] Among them, Qzh is the comprehensive coordination of the circuit, α3 is the coordination contradiction weight coefficient, amplifying the conflict effect between the ripple and the control.

[0162] The comprehensive coordination is an important index for measuring the coordinated operation among various parts of the multiphase half-bridge stacked power conversion circuit (such as control signals, output current waveforms, and dynamic responses, etc.). It comprehensively considers the synchronization of control signals of each phase in the circuit, the balance of output current ripples, and the consistency of dynamic responses when the circuit has a load step change, reflecting the overall performance and coordination degree of the circuit under different working conditions.

[0163] Step 5: Calculate the current state index according to the anti-interference ability, comprehensive stability, and comprehensive coordination. Perform linear fitting based on the changes of the anti-interference ability, comprehensive stability, and comprehensive coordination in each adjacent time window, and judge the change trend of the circuit state according to the three fitted linear relationships.

[0164] In this embodiment, the calculation method of the current state index is as follows:

[0165]

[0166] Among them, Pzt is the current state index, Qgr is the anti-interference ability index, Qzw is the comprehensive stability, and Qzh is the comprehensive coordination of the circuit;

[0167] When it is judged that the circuit state is good;

[0168] Among them, is the circuit state judgment threshold.

[0169] In this embodiment, the calculation method for performing linear fitting is as follows:

[0170]

[0171] Among them, Kxl xi is the linear fitting value of the data type xi fitting, Nt is the number of time windows, tc is the tc-th window, and xl tc is the value of xl in the data of the tc-th window, where xi ∈ {Qgr, Qzw, Qzh};

[0172] The calculation formula for the change trend of the circuit state is:

[0173] Pqs = μ1 * Kxl1 + μ2 * Kxl2 + μ3 * Kxl3

[0174] Among them, Pqs is the circuit state change trend, μ1, μ2, and μ3 are the weights of the anti-interference ability index, comprehensive stability, and comprehensive coordination of the circuit respectively, and Kxl1, Kxl2, and Kxl3 are the linear fitting values of the anti-interference ability index, comprehensive stability, and comprehensive coordination of the circuit respectively;

[0175] When it is determined that the circuit state is gradually stabilizing;

[0176] When it is determined that the circuit state is stable;

[0177] When it is determined that the circuit state is gradually deteriorating;

[0178] Among them, is the threshold for judging the circuit state change trend.

[0179] The role of the current state index in circuit state monitoring is to comprehensively evaluate the operating state of the circuit at a certain moment, reflecting the overall performance of the circuit's anti-interference ability, comprehensive stability, and comprehensive coordination. By calculating these indexes, the performance of the circuit can be quantitatively evaluated to ensure that the circuit operates within the normal working range.

[0180] The judgment of the circuit state change trend is obtained by linearly fitting the changes of the three indexes of anti-interference ability, comprehensive stability, and comprehensive coordination in each adjacent time window. The core of this process is to track the performance of these three indexes in different time periods, use the linear fitting method to predict the change trend of the circuit, and then judge whether the operating state of the circuit is in an improved, stable, or deteriorating state. The advantage of linear fitting is that it is simple and effective, and can quickly judge the direction and amplitude of the changes of each index. When the fitting curves of these indexes show an obvious upward trend, it usually means that the circuit is developing towards a more stable and coordinated direction; on the contrary, if the fitting curve shows a downward trend, it may mean that some performances of the circuit are declining and need further analysis and optimization.

[0181] By analyzing these trends, the circuit state monitoring system can continuously evaluate the comprehensive coordination of the circuit during operation, so as to ensure the stable and efficient operation of the circuit under various working conditions. Especially in complex situations such as load changes and environmental fluctuations, potential problems can be identified in advance and measures can be taken in time, thereby improving the reliability and performance of the circuit system.

[0182] Please refer to Figure 2 In addition, the present invention also provides a circuit state monitoring system for a multiphase half-bridge stack. The circuit state monitoring system is used to execute the above-mentioned circuit state monitoring method for a multiphase half-bridge stack, including:

[0183] A data acquisition and processing module, which is used to collect real-time electrical data and environmental data of the conversion circuit, perform preprocessing, divide the processed electrical data into time windows at the same time interval, and extract the frequency-domain characteristics of the electrical data through fast Fourier transform;

[0184] An interference evaluation module, which is used to denoise the input voltage according to the frequency-domain characteristics, obtain the output interference signal by calculating the theoretical output voltage through control parameters, judge the equipment aging interference noise according to the frequency-domain characteristics, calculate the environmental interference noise according to the environmental interference data, and calculate the anti-interference ability according to the output interference signal, equipment aging interference noise and environmental interference data;

[0185] A stability evaluation module, which is used to calculate the stability of the input voltage according to the voltage input data, calculate the stability of the output voltage according to the output voltage and the load step recovery time, calculate the load adaptability of the circuit according to the load data, and calculate the comprehensive stability according to the stability of the input and output voltages and the load adaptability;

[0186] A coordination evaluation module, which is used to calculate the synchronization of the control signal according to the circuit control phase angle, calculate the ripple balance of the output current according to the output current of each phase, calculate the dynamic response consistency of the circuit according to the load step recovery time, and calculate the comprehensive coordination of the circuit according to the synchronization, ripple balance and dynamic response consistency of the control signal;

[0187] A comprehensive evaluation module, which is used to calculate the current state index according to the anti-interference ability, comprehensive stability and comprehensive coordination, perform linear fitting according to the changes of the anti-interference ability, comprehensive stability and comprehensive coordination in each adjacent time window, and judge the change trend of the circuit state according to the three fitted linear relationships.

[0188] The above formulas are all calculated by taking the numerical value after dimensionless, and the formula is a formula obtained by software simulation of collecting a large amount of data to approximate the real situation. The preset parameters in the formula are set by those skilled in the art according to the actual situation.

[0189] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0190] The unit described as a separation component may or may not be physically separated. The component displayed as a unit may or may not be a physical unit, and it may be located in one place or distributed across multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0191] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application.

Claims

1. A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack, characterized in that, The specific steps include: Step 1: Collect real-time electrical data and environmental data of the conversion circuit and perform preprocessing. Divide the processed electrical data into time windows at the same time interval, and extract the frequency-domain features of the electrical data through fast Fourier transform. Step 2: After denoising the input voltage according to the frequency-domain features, obtain the output interference signal by calculating the theoretical output voltage through control parameters. Judge the equipment aging interference noise according to the frequency-domain features, calculate the environmental interference noise according to the environmental interference data, and calculate the anti-interference ability according to the output interference signal, equipment aging interference noise and environmental interference data. Step 3: Calculate the stability of the input voltage according to the voltage input data, calculate the stability of the output voltage according to the output voltage and the load step recovery time, calculate the load adaptability of the circuit according to the load data, and calculate the comprehensive stability according to the stability of the input and output voltages and the load adaptability. Step 4: Calculate the synchronization of the control signal according to the circuit control phase angle, calculate the ripple balance of the output current according to the output current of each phase, calculate the dynamic response consistency of the circuit according to the load step recovery time, and calculate the comprehensive coordination of the circuit according to the synchronization, ripple balance and dynamic response consistency of the control signal. Step 5: Calculate the current state index according to the anti-interference ability, comprehensive stability and comprehensive coordination. Perform linear fitting according to the changes of the anti-interference ability, comprehensive stability and comprehensive coordination in each adjacent time window, and judge the change trend of the circuit state based on the three fitted linear relationships.

2. A method for monitoring the state of a power conversion circuit for multiphase half-bridge stacking according to claim 1, characterized in that: The electrical data includes input voltage and output voltage. The method of the preprocessing is normalization, and the calculation formula is: Among them, Xg is the data after normalization of each data, Xmax is the largest number in each data type collected, Xmin is the smallest number in each data type collected, and xi ig is the ig-th data in each data type collected, and nx is the number of data in each data type collected. The specific formula for extracting the frequency-domain features of the electrical data through fast Fourier transform is; Among them, VS(m) is the m-th component in the frequency-domain signal of the electrical data, Xq(in) is the in-th sample in the electrical data, N is the total number of samples, m represents the m-th frequency component in the frequency domain, 0 ≤ m ≤ N - 1, and j is the imaginary unit.

3. A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack according to claim 1, characterized in that: The environmental data is the electromagnetic field intensity signal. The control parameters include the PWM duty cycle of the half-bridge circuit and the number of parallel phases. The calculation formula for the theoretical output voltage is: Among them, Vout is the theoretical output voltage, and Vin kj is the input voltage after noise reduction of the kj-phase half-bridge circuit, D kj is the PWM duty cycle of the kj-phase half-bridge circuit, and NJ is the number of parallel phases; The calculation formula for the output interference signal is: Pgr = Vout - Voul Among them, Pgr is the output interference signal, Vout is the circuit output voltage, and Voul is the theoretical output voltage. The method for judging the equipment aging interference noise according to the frequency-domain features is: by analyzing the frequency-domain features, extract the amplitudes of odd and even harmonics, and calculate according to the amplitudes of odd and even harmonics. The specific calculation formula is: Among them, Elh is the device aging interference noise, A 2kb is the even harmonic amplitude, A 2kb-1 is the odd harmonic amplitude, mb and nb are the harmonic orders of analysis respectively; The calculation formula for the environmental interference noise is: Among them, Ehj is the environmental interference noise, Vout(t) is the output voltage signal at time t, Emi(t + τ) is the electromagnetic field intensity signal after a time delay τ, T is the time window, and τ is the time delay parameter. The calculation formula for the anti-interference ability index is: Among them, Qgr is the anti-interference ability index, and Evi is the noise removed from the input voltage.

4. A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack according to claim 1, characterized in that: The voltage input data includes the input rated voltage and the number of times the voltage deviates from the rated voltage. The load data includes the load step recovery time, the standard of the load step recovery time, the voltage at the load point, the current at the load point, and the number of load points; The calculation formula for the stability of the input voltage is: where Wvin is the stability of the input voltage, Vinbz is the rated input voltage, Vinmax and Vinmin are respectively the maximum and minimum values of the input voltage of the circuit, T is the time window, and Nbp is the number of times the input voltage deviates from the rated voltage; The technical formula for the stability of the output voltage is: Among them, Wvou is the stability of the output voltage, σVout is the standard deviation of the output voltage, and t re is the standard of the load step recovery time, and t rise is the load step recovery time; The calculation formula for the load adaptability analysis is: Among them, Wfz is the load adaptability of the circuit, Vout ka is the voltage at the ka-th load point, Voute is the rated output voltage, Ma is the number of load points, ωa ka is the load weight at the ka-th load point, and ΔIlod is the load change current The technical formula for the comprehensive stability is: where Qzw is the comprehensive stability, and α1 and α2 are respectively the penalty coefficients for the stability of the input voltage and the stability of the output voltage.

5. A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack according to claim 1, characterized in that: The calculation formula for the synchronization of the control signal is: where Sct is the synchronization of the control signal, γ is the attenuation coefficient, are the phase angles of the ia-th and ja-th phase PWM signals respectively; The calculation formula for the ripple balance of the output current is: where Sbw is the ripple balance of the output current, μΔI is the mean value of the current ripple per phase, and σΔI is the standard deviation of the current ripple per phase; The calculation formula for the dynamic response consistency of the circuit is: Sdt is the dynamic response consistency of each phase half-bridge circuit, and σt rise is the standard deviation of the load step recovery time, and μt rise is the mean value of the load step recovery time.

6. A method for monitoring the state of a power conversion circuit for multiphase half-bridge stacking according to claim 5, characterized in that: The calculation formula for the comprehensive coordination of the circuit is: where Qzh is the comprehensive coordination of the circuit, and α3 is the coordination contradiction weight coefficient, which amplifies the conflict effect between the amplified ripple and the control.

7. A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack according to claim 1, characterized in that: The calculation method for the current state index is: where Pzt is the current state index, Qgr is the anti-interference ability index, Qzw is the comprehensive stability, and Qzh is the comprehensive coordination of the circuit.

8. A method for monitoring the state of a power conversion circuit for a multiphase half-bridge stack according to claim 1, characterized in that: The calculation method for performing linear fitting is: Among them, Kxl xi is the linear fitting value fitted for the data type xi, Nt is the number of time windows, tc is the tc-th window, and xl tc is the value of xl in the data of the tc-th window, where xi ∈ {Qgr, Qzw, Qzh}; When the circuit state is judged to be good; Among them, is the circuit state judgment threshold value; The calculation formula for the change trend of the circuit state is: Pqs = μ1 * Kxl1 + μ2 * Kxl2 + μ3 * Kxl3 where Pqs is the change trend of the circuit state, μ1, μ2, and μ3 are respectively the weights of the anti-interference ability index, the comprehensive stability, and the comprehensive coordination of the circuit, and Kxl1, Kxl2, and Kxl3 are respectively the linear fitting values of the anti-interference ability index, the comprehensive stability, and the comprehensive coordination of the circuit; When the circuit state gradually stabilizes When the circuit state is determined to be stable; When the circuit state gradually deteriorates.

9. A power conversion circuit state monitoring system for a multiphase half-bridge stack, characterized in that: The circuit state monitoring system is used to execute the power conversion circuit state monitoring method for multi-phase half-bridge stacking according to any one of claims 1-8, including; A data acquisition and processing module, which is used to collect real-time electrical data and environmental data of the conversion circuit, perform preprocessing, divide the processed electrical data into time windows at the same time interval, and extract the frequency domain characteristics of the electrical data through fast Fourier transform; An interference evaluation module, which is used to denoise the input voltage according to the frequency domain characteristics, obtain the output interference signal by calculating the theoretical output voltage through control parameters, judge the equipment aging interference noise according to the frequency domain characteristics, calculate the environmental interference noise according to the environmental interference data, and calculate the anti-interference ability according to the output interference signal, the equipment aging interference noise, and the environmental interference data; A stability evaluation module, which is used to calculate the stability of the input voltage according to the voltage input data, calculate the stability of the output voltage according to the output voltage and the load step recovery time, calculate the load adaptability of the circuit according to the load data, and calculate the comprehensive stability according to the stability of the input and output voltages and the load adaptability; A coordination evaluation module, which is used to calculate the synchronization of control signals according to the circuit control phase angle, calculate the ripple balance of output current according to the output current of each phase, calculate the dynamic response consistency of the circuit according to the load step recovery time, and calculate the comprehensive coordination of the circuit according to the synchronization, ripple balance and dynamic response consistency of the control signals; A comprehensive evaluation module, which is used to calculate the current state index according to the anti-interference ability, comprehensive stability and comprehensive coordination, perform linear fitting according to the changes of the anti-interference ability, comprehensive stability and comprehensive coordination in each adjacent time window, and judge the change trend of the circuit state based on the three fitted linear relationships.

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