Method, device, equipment, storage medium and product for synchronizing ac and dc voltages

Abstract

The application relates to a synchronous method and device of AC-DC voltage, equipment, a storage medium and a product. The method comprises the following steps: performing synchronous system conversion processing on a current AC voltage to be synchronized to obtain a direct-axis voltage and a quadrature-axis voltage of the AC voltage; updating a previous candidate filter bandwidth according to the direct-axis voltage to obtain a target candidate filter bandwidth of a current AC voltage synchronization process; wherein the previous candidate filter bandwidth is a target candidate filter bandwidth of a previous AC-DC voltage synchronization process; and performing AC-DC voltage synchronization processing on the quadrature-axis voltage according to the target candidate filter bandwidth of the current AC voltage synchronization process. The method can simultaneously ensure the transient response speed and the steady-state anti-disturbance capability of a phase-locked loop.

Description

Technical Field

[0001] This application relates to the field of power grid technology, and in particular to a method, apparatus, device, storage medium and product for synchronizing AC and DC voltages. Background Technology

[0002] AC / DC emergency power distribution systems play a crucial role in the power supply of nuclear power plants, and the power electronic converters within these systems are key to AC / DC voltage synchronization. Since AC voltage contains not only the fundamental frequency component but also harmonics that can affect AC / DC voltage synchronization, it is necessary to extract and filter these harmonics during the synchronization process.

[0003] Currently, phase-locked loops (PLLs) are commonly used for harmonic extraction and filtering. Specifically, this is achieved by setting filters with different bandwidths within the PLL. For example, a lower bandwidth filter ensures the PLL's steady-state noise immunity, while a higher bandwidth filter ensures its transient response speed. Since the transient response speed and steady-state noise immunity of a PLL have different bandwidth requirements, simultaneously ensuring both transient response speed and steady-state noise immunity is a pressing problem that needs to be solved. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, device, storage medium, and product for synchronizing AC and DC voltages that can simultaneously guarantee the transient response speed and steady-state disturbance rejection capability of the phase-locked loop, addressing the aforementioned technical problems.

[0005] In one aspect, this application provides a method for synchronizing AC and DC voltages. The method includes:

[0006] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0007] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0008] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0009] In one embodiment, the previous candidate filter bandwidth is updated based on the direct-axis voltage to obtain the target candidate filter bandwidth for the current AC voltage synchronization process, including:

[0010] Based on the previous candidate filter bandwidth and direct-axis voltage, calculate the direct-axis component evaluation index of the previous candidate filter bandwidth;

[0011] Based on the evaluation index of the direct-axis component of the previous candidate filter bandwidth, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0012] In one embodiment, the direct-axis component evaluation index of the previous candidate filter bandwidth is calculated based on the previous candidate filter bandwidth and the direct-axis voltage, including:

[0013] Based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth;

[0014] The evaluation index of the direct-axis component of each candidate filter bandwidth is determined based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter.

[0015] In one embodiment, the previous candidate filter bandwidth is updated based on the direct-axis component evaluation index of the previous candidate filter bandwidth to obtain the target candidate filter bandwidth for the current AC voltage synchronization process, including:

[0016] The target evaluation index is determined from the evaluation index of the direct axis component of the previous candidate filter bandwidth;

[0017] Based on the previous candidate filter bandwidth corresponding to the target evaluation index, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0018] In one embodiment, the previous candidate filter bandwidth is updated based on the previous candidate filter bandwidth corresponding to the target evaluation index to obtain the target candidate filter bandwidth for the current AC voltage synchronization process, including:

[0019] The previous candidate filter bandwidth corresponding to the target evaluation index is used as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0020] Using a binary search method, other target candidate filter bandwidths for the current AC voltage synchronization process are generated based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0021] In one embodiment, the quadrature-axis voltage is subjected to AC / DC voltage synchronization processing based on the target candidate filter bandwidth of the current AC voltage synchronization process, including:

[0022] The target filter bandwidth is determined from the target candidate filter bandwidths of the current AC voltage synchronization process;

[0023] Based on the target filtering bandwidth, the quadrature axis voltage is processed to synchronize AC and DC voltages.

[0024] Secondly, this application also provides a synchronization device for AC / DC voltage. The device includes:

[0025] The voltage processing module is used to perform synchronization system transformation on the current AC voltage to be synchronized, to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0026] The bandwidth determination module is used to update the previous candidate filter bandwidth based on the direct-axis voltage to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; wherein, the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0027] The voltage synchronization module is used to perform AC / DC voltage synchronization processing on the quadrature axis voltage based on the target candidate filter bandwidth of the current AC voltage synchronization process.

[0028] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to perform the following steps:

[0029] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0030] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0031] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0032] Fourthly, this application also provides a computer-readable storage medium. This computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the following steps:

[0033] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0034] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0035] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0036] Fifthly, this application also provides a computer program product. This computer program product includes a computer program that, when executed by a processor, performs the following steps:

[0037] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0038] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0039] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0040] The aforementioned AC / DC voltage synchronization method, apparatus, equipment, storage medium, and product update the previous candidate filter bandwidth based on the direct-axis voltage obtained after performing a synchronization system transformation on the current AC voltage to be synchronized. The updated filter bandwidth is then used as the target candidate filter bandwidth for the current AC voltage synchronization process. AC / DC voltage synchronization processing is then performed on the quadrature-axis voltage of the current AC voltage to be synchronized based on this target candidate filter bandwidth. Since the target candidate filter bandwidth for the current AC voltage synchronization process is updated based on the direct-axis voltage, meaning that the determination of the target candidate filter bandwidth takes into account the direct-axis voltage of the current AC voltage rather than being manually determined, the target candidate filter bandwidth will be more closely matched to the current AC voltage to be synchronized, without being too large or too small. In other words, the target candidate filter bandwidth can retain the necessary harmonics and filter out unnecessary harmonics when filtering the quadrature-axis voltage. Therefore, using the target candidate filter bandwidth to filter the quadrature-axis voltage can simultaneously ensure the transient response speed and steady-state disturbance rejection capability of the phase-locked loop (PLL). In other words, the aforementioned AC / DC voltage synchronization method can guarantee both the transient response speed and steady-state disturbance rejection capability of the PLL. Attached Figure Description

[0041] Figure 1 This diagram illustrates the application environment of an AC / DC voltage synchronization method provided in this embodiment.

[0042] Figure 2 This is a flowchart illustrating the first AC / DC voltage synchronization method provided in this embodiment;

[0043] Figure 3 This embodiment provides a flowchart illustrating how to update the previous candidate filter bandwidth to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0044] Figure 4This is a flowchart illustrating a method for generating other target candidate filter bandwidths for the current AC voltage synchronization process, as provided in this embodiment.

[0045] Figure 5 This is a flowchart illustrating the second AC / DC voltage synchronization method provided in this embodiment;

[0046] Figure 6 This is a schematic flowchart of the third AC / DC voltage synchronization method provided in this embodiment;

[0047] Figure 7 This is a structural block diagram of the first AC / DC voltage synchronization device provided in this embodiment;

[0048] Figure 8 This is a structural block diagram of the second type of AC / DC voltage synchronization device provided in this embodiment;

[0049] Figure 9 This is a structural block diagram of the third type of AC / DC voltage synchronization device provided in this embodiment;

[0050] Figure 10 This is an internal structural diagram of a computer device provided in this embodiment. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0052] Currently, the design of synchronous control loops is of great significance for the safe operation of power electronic equipment in AC / DC emergency power distribution systems. Phase-locked loops (PLLs), due to their ability to acquire the frequency and phase of AC voltage and synchronize with it in subsequent control, are widely used in power electronic equipment in AC / DC power distribution systems. Among them, synchronous coordinate system PLLs (i.e., synchronous PLLs) account for a large proportion of PLL applications because their steady-state results for positive-sequence power frequency inputs only contain DC voltage, making controller design easier. Synchronous PLLs can extract and filter harmonics from AC voltages by setting the filter bandwidth. Generally, to ensure high transient response speed, high-frequency signals must be allowed to be retained to ensure the closed-loop response to sudden changes in external input, while high-frequency signals cannot be filtered out. In other words, to ensure transient response speed, a large filter bandwidth is required. However, to ensure high steady-state disturbance rejection capability, only low-frequency signals, or even only signals at a single frequency point, must be retained, while all other high-frequency signals must be filtered out. In other words, to ensure steady-state disturbance rejection capability, a sufficiently small filter bandwidth is required. Existing technical solutions can only guarantee one of the transient impact rate and steady-state disturbance rejection capability, but cannot simultaneously achieve both.

[0053] The AC / DC voltage synchronization method provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, in one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows. Figure 1 As shown, the computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database stores data related to AC / DC voltage synchronization. The network interface communicates with external terminals via a network connection. When executed by the processor, the computer program implements an AC / DC voltage synchronization method.

[0054] In one embodiment, such as Figure 2 As shown, a method for synchronizing AC and DC voltages is provided, which can be applied to... Figure 1 Taking a computer as an example, the explanation includes the following steps:

[0055] S201 performs a synchronization system transformation on the AC voltage to be synchronized, obtaining the direct-axis voltage and quadrature-axis voltage of the AC voltage.

[0056] The AC voltage to be synchronized can be the AC voltage requiring AC / DC voltage synchronization in an AC / DC emergency power distribution system. This means the AC voltage to be synchronized must meet the voltage range requirements of the corresponding AC / DC emergency power distribution system. Synchronization system transformation processing can be the process of synchronizing AC and DC voltages. Specifically, it can involve generating a DC voltage of equal magnitude to the measured AC voltage value, and then performing AC / DC voltage synchronization based on this DC voltage. The quadrature-axis voltage and direct-axis voltage can be the two component voltages obtained after the AC voltage undergoes synchronization system transformation.

[0057] Optionally, the synchronization system transformation of the AC voltage to be synchronized can be performed by transforming the AC voltage to be synchronized based on the three-phase AC voltages contained in the AC voltage to be synchronized and the phase output feedback corresponding to the AC / DC voltage synchronization at the previous moment, to obtain the quadrature-axis voltage and direct-axis voltage corresponding to the AC voltage to be synchronized. Specifically, the synchronization system transformation can be performed according to the following formula (1).

[0058]

[0059] In the formula, v a vb and v c These represent the three-phase AC voltages included in the AC voltage; θ represents the phase output feedback corresponding to the AC / DC voltage synchronization at the previous moment; v d It is the direct-axis voltage obtained after the AC voltage has been transformed by the synchronization system; v q It is the quadrature-axis voltage obtained after the AC voltage has been transformed by the synchronization system.

[0060] S202 updates the previous candidate filter bandwidth based on the direct-axis voltage to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0061] The previous candidate filter bandwidth is the target candidate filter bandwidth of the previous AC / DC voltage synchronization process. The target candidate filter bandwidth can be any filter bandwidth that can be selected during AC / DC voltage synchronization. It is understood that there are usually multiple target candidate filter bandwidths, and there is no limitation on them.

[0062] Optionally, there are many ways to update the previous candidate filter bandwidth based on the direct-axis voltage, and no limitation is imposed on this. One possible approach is to obtain the direct-axis voltage of the AC voltage to be synchronized and the previous candidate filter bandwidth, and update the previous candidate filter bandwidth according to the current direct-axis voltage and a preset candidate filter bandwidth update strategy to obtain the target candidate filter bandwidth corresponding to the current AC voltage synchronization process. Another possible approach is to input the direct-axis voltage of the AC voltage to be synchronized and the previous candidate filter bandwidth into a pre-trained candidate filter bandwidth update model. The candidate filter bandwidth update model processes the input direct-axis voltage and the previous candidate filter bandwidth and outputs the target candidate filter bandwidth corresponding to the current AC voltage synchronization process.

[0063] It should be noted that the target candidate filter bandwidth determined this time can be used as the "previous candidate filter bandwidth" for the next AC / DC voltage synchronization.

[0064] S203 performs AC / DC voltage synchronization processing on the quadrature axis voltage based on the target candidate filter bandwidth of the current AC voltage synchronization process.

[0065] Optionally, in this embodiment, the quadrature-axis voltage of the AC voltage to be synchronized can be subjected to AC / DC voltage synchronization processing based on the determined target candidate filter bandwidth of the current AC voltage synchronization process. Alternatively, one of the target candidate filter bandwidths of the current AC voltage synchronization process can be selected as the target filter bandwidth, and the quadrature-axis voltage of the AC voltage to be synchronized can be subjected to AC / DC voltage synchronization processing based on the target filter bandwidth. A preferred embodiment may involve determining a target filter bandwidth from the target candidate filter bandwidths of the current AC voltage synchronization process; and performing AC / DC voltage synchronization processing on the quadrature-axis voltage based on the target filter bandwidth. The target filter bandwidth can be the filter bandwidth used when filtering the current AC voltage to be synchronized. According to a predetermined target candidate filter bandwidth determination strategy, one is selected from the target candidate filter bandwidths as the target filter bandwidth, and the quadrature-axis voltage is then subjected to AC / DC voltage synchronization processing based on the target filter bandwidth. For example, all target candidate filter bandwidths can be sorted by size, and the middle one is selected as the target filter bandwidth based on the sorting result. Of course, if the number of target candidate filter bandwidths is even (e.g., 4), the average of the two middle target candidate filter bandwidths (e.g., the second and third ranked) can be selected as the target filter bandwidth. Since the target candidate filter bandwidth is updated based on the direct-axis voltage of the current AC voltage to be synchronized, it ensures a good match between the target candidate filter bandwidth and the current AC voltage to be synchronized. That is, it can basically guarantee the transient response speed and steady-state disturbance rejection capability of the phase-locked loop. In this embodiment, a filter bandwidth in the middle is selected from the target candidate filter bandwidths as the target filter bandwidth to filter the quadrature-axis voltage, avoiding situations where the target filter bandwidth is too large or too small, while also ensuring the transient response speed and steady-state disturbance rejection capability of the phase-locked loop to a certain extent.

[0066] Optionally, the AC / DC voltage synchronization processing of the quadrature-axis voltage of the AC voltage to be synchronized can be performed by filtering the quadrature-axis voltage of the AC voltage to be synchronized according to the determined target candidate filtering bandwidth of the current AC voltage synchronization process. The filtered quadrature-axis voltage can be used as an error quantity and input to the proportional-integral controller. The proportional-integral controller processes the filtered quadrature-axis voltage and outputs the phase corresponding to the quadrature-axis voltage, which is the phase corresponding to the AC voltage to be synchronized. This phase is then used as a synchronization signal and input to other control links of the power electronic converter in the AC / DC emergency power distribution system, thereby completing the AC / DC voltage synchronization processing.

[0067] In the aforementioned AC / DC voltage synchronization method, the previous candidate filter bandwidth is updated based on the direct-axis voltage obtained after performing a synchronization system transformation on the current AC voltage to be synchronized. This updated filter bandwidth is then used as the target candidate filter bandwidth for the current AC voltage synchronization process. AC / DC voltage synchronization is then performed on the quadrature-axis voltage of the current AC voltage to be synchronized based on this target candidate filter bandwidth. Since the target candidate filter bandwidth for the current AC voltage synchronization process is updated based on the direct-axis voltage, meaning that the determination of the target candidate filter bandwidth takes into account the direct-axis voltage of the current AC voltage rather than being manually determined, the target candidate filter bandwidth will be more closely matched to the current AC voltage to be synchronized, avoiding being too large or too small. In other words, the target candidate filter bandwidth can retain the necessary harmonics and filter out unnecessary harmonics when filtering the quadrature-axis voltage. Therefore, using the target candidate filter bandwidth to filter the quadrature-axis voltage can simultaneously ensure the transient response speed and steady-state disturbance rejection capability of the phase-locked loop (PLL). In other words, the aforementioned AC / DC voltage synchronization method can guarantee both the transient response speed and steady-state disturbance rejection capability of the PLL.

[0068] Furthermore, to enrich and complete the methods for determining the target candidate filter bandwidth, and to further ensure that the target candidate filter bandwidth of the current AC voltage synchronization process can better match the AC voltage to be synchronized, in one embodiment, such as... Figure 3 As shown, based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process, including:

[0069] S301, based on the previous candidate filter bandwidth and direct-axis voltage, calculate the direct-axis component evaluation index of the previous candidate filter bandwidth.

[0070] Among them, the direct-axis component evaluation index can be determined based on the previous candidate filter bandwidth and direct-axis voltage, according to a pre-determined direct-axis component evaluation strategy, and is used to evaluate the previous candidate filter bandwidth.

[0071] Optionally, the method for calculating the direct-axis component evaluation index of the previous candidate filter bandwidth can be as follows: based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth; based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter, determine the direct-axis component evaluation index of each previous candidate filter bandwidth. Specifically, for each previous candidate filter bandwidth, determine its corresponding discrete frequency domain transfer function of the low-pass filter, and the preset discrete frequency domain transfer function of the sliding filter, and based on the predetermined direct-axis component evaluation index calculation strategy, determine the direct-axis component evaluation index of each previous candidate filter bandwidth. Optionally, the predetermined direct-axis component evaluation index calculation strategy can be a calculation formula, for example, as shown in the following formula (2):

[0072]

[0073] In the formula, r represents the calculation formula for the evaluation index of the direct axis component; G LPF (z) represents the transfer function of the low-pass filter in the continuous frequency domain; v d G represents the direct-axis component of AC voltage. SG (z) represents the discrete frequency domain transfer function of the sliding filter.

[0074] Formula (2) above can be understood as: v of the molecular part d First, it is filtered by a low-pass filter controller, and then processed by a separately configured sliding filter; the denominator v d First, the square value is taken, then processed by a separately configured sliding filter, and finally the square root is taken. Here, the "separately configured sliding filter" is just one example of a low-pass filter used to calculate the index; other types of low-pass filters can also be used instead.

[0075] Furthermore, the discrete frequency domain transfer function of the low-pass filter for each candidate filter bandwidth can be determined based on a pre-set formula for determining the discrete frequency domain transfer function of the low-pass filter according to the filter bandwidth of the low-pass filter. For example, it can be determined by the following formula (3). The discrete frequency domain transfer function of the sliding filter can be shown by the following formula (4).

[0076]

[0077] In the formula, G LPF(z) represents the transfer function of the low-pass filter in the continuous frequency domain; z represents the unit input in the discrete frequency domain model, which has no specific physical meaning here and is only used to indicate that the transfer function is expressed in the discrete frequency domain; where T is the unit time length corresponding to the discrete frequency domain; and e is a natural constant.

[0078]

[0079] In the formula, N SG is the multiple of the maximum period of harmonics to be filtered out relative to the sampling period; z represents the unit input in the discrete frequency domain model, which has no specific physical meaning here, but is only used to indicate that the transfer function is expressed in the discrete frequency domain.

[0080] S302, based on the direct-axis component evaluation index of the previous candidate filter bandwidth, update the previous candidate filter bandwidth to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0081] Optionally, in this embodiment, based on the direct-axis component evaluation index of each previous candidate filter bandwidth and combined with a predetermined candidate filter bandwidth update strategy, each previous candidate filter bandwidth is updated, and the updated previous candidate filter bandwidth is used as the target candidate filter bandwidth for the current AC voltage synchronization process.

[0082] A preferred implementation may involve determining a target evaluation index from the direct-axis component evaluation indices of the previous candidate filter bandwidth; updating the previous candidate filter bandwidth according to the target evaluation index to obtain the target candidate filter bandwidth for the current AC voltage synchronization process. Optionally, the target evaluation index may be determined based on the calculated direct-axis component evaluation indices of each previous candidate filter bandwidth, combined with a pre-determined target evaluation index determination rule. For example, the largest or smallest direct-axis component evaluation index may be selected as the target evaluation index, and the previous candidate filter bandwidth may be updated according to the pre-determined filter bandwidth update rule based on the target evaluation index.

[0083] It should be noted that, based on the determined target evaluation index, and in conjunction with the pre-determined filter bandwidth update rule, the previous candidate filter bandwidth corresponding to the target evaluation index can be updated first; then, based on the updated previous candidate filter bandwidth corresponding to the target evaluation index and the filter bandwidth update rule, the remaining previous candidate filter bandwidths can be updated. It is understood that the strategy for updating the previous candidate filter bandwidth corresponding to the target evaluation index can be the same as or different from the strategy for updating the remaining previous candidate filter bandwidths; this is not limited.

[0084] In this embodiment, a target evaluation index is selected from each direct-axis component evaluation index. The previous candidate filter bandwidth is updated according to the target evaluation index. Since the direct-axis component evaluation index is the index for evaluating the filter bandwidth, the previous candidate filter bandwidth corresponding to the target evaluation index can be understood as the optimal one among all previous candidate filter bandwidths. Therefore, updating the previous candidate filter bandwidth according to the optimal filter bandwidth can make the updated filter bandwidth better.

[0085] In the above embodiments, the evaluation index of the direct-axis component of each candidate filter bandwidth determined based on the previous candidate filter bandwidth and the direct-axis voltage can be used to characterize the quality of each candidate filter bandwidth. Updating the previous candidate filter bandwidth based on the evaluation index can make the process of updating the previous candidate filter bandwidth more purposeful, so that the target candidate filter bandwidth can be better matched with the current AC voltage, thus providing a guarantee for ensuring the transient response speed and steady-state anti-disturbance capability of the phase-locked loop.

[0086] Furthermore, such as Figure 4 The above process of first updating the previous candidate filter bandwidth corresponding to the target evaluation index, and then updating the remaining previous candidate filter bandwidths, can be explained in detail and may include the following steps:

[0087] S401, the previous candidate filter bandwidth corresponding to the target evaluation index is used as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0088] In this embodiment, the previous candidate filter bandwidth corresponding to the target evaluation index can be directly used as a target candidate filter bandwidth for the current AC voltage synchronization process. For example, the number of previous candidate filter bandwidths is three, such as ω... LPF(1) ω LPF(2) and ω LPF(0) Correspondingly, the number of evaluation metrics for the direct-axis components is also three, for example, f(ω) LPF(1) f(ω) LPF(2) ) and f(ω LPF(0) Based on the evaluation index of the direct-axis component and the predetermined target evaluation index determination strategy, one of the above three target evaluation indices is selected as the target evaluation index. For example, the evaluation indices of each direct-axis component can be sorted by size, and the one ranked highest (i.e., the largest or smallest) is taken as the target evaluation index. The previous candidate filter bandwidth corresponding to this target evaluation index is then used as a target candidate filter bandwidth for the current AC voltage synchronization process. For example, if f(ω) LPF(0) If f(ω) ranks highest in the evaluation index ranking results for each direct axis component, then f(ω) can be ranked as the highest. LPF(0) ) corresponding to ω LPF(0)This serves as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0089] S402 uses a binary search method to generate other target candidate filter bandwidths for the current AC voltage synchronization process based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0090] Among them, the bisection method can be a method for obtaining an approximate value of the zero point by continuously dividing the interval containing the zero point of the function y = f(x) on the interval [a, b] into two, so that the two endpoints of the interval gradually approach the zero point.

[0091] Optionally, the other target candidate filter bandwidths for the current AC voltage synchronization process can be generated by inputting the previous candidate filter bandwidth corresponding to the target evaluation index into a pre-trained target candidate filter bandwidth determination model. The target candidate filter bandwidth determination model processes the previous candidate filter bandwidth corresponding to the target evaluation index and outputs other target candidate filter bandwidths as the other target candidate filter bandwidths for the current AC voltage synchronization process. Alternatively, other target candidate filter bandwidths can be calculated based on the previous candidate filter bandwidth corresponding to the target evaluation index, combined with a pre-determined formula for determining other target candidate filter bandwidths. For example, other target candidate filter bandwidths can be updated using the following formula (5).

[0092]

[0093] In the formula, ω LPF(1) (k+1) represents the updated ω LPF(1) ;ω LPF(0) (k+1) represents a target candidate filter bandwidth for the current AC voltage synchronization process; ω LPF(2) (k+1) represents the updated ω LPF(2) ;ω MIN ω represents the preset lower limit of the settable range of the target candidate filter bandwidth; MAX This indicates the preset upper limit of the target candidate filter bandwidth range.

[0094] It should be noted that the previous candidate filter bandwidth corresponding to the target evaluation index can be used as one of the previous candidate filter bandwidths corresponding to the next time step. Then, the other previous candidate filter bandwidths can be determined by combining the above formula (5) to determine the previous candidate filter bandwidth corresponding to the next time step.

[0095] In the above embodiments, based on the binary search method, the previous candidate filter bandwidth corresponding to the target evaluation index is processed to determine other target candidate filter bandwidths in the current AC voltage synchronization process, instead of updating in one step. This makes the determination of the target candidate filter bandwidth more accurate and stable, thereby ensuring that the target candidate filter bandwidth matches the current AC voltage update to be synchronized, and further ensuring the transient response speed and steady-state anti-disturbance capability of the phase-locked loop.

[0096] To facilitate understanding by those skilled in the art, the above-mentioned AC / DC voltage synchronization method will be described in detail, such as... Figure 5 As shown, the method may include:

[0097] S501 performs synchronization system transformation on the AC voltage to be synchronized, obtaining the direct-axis voltage and quadrature-axis voltage of the AC voltage.

[0098] S502, based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth.

[0099] S503, based on each previous candidate filter bandwidth, and the discrete frequency domain transfer function of the low-pass filter of that candidate filter bandwidth and the preset discrete frequency domain transfer function of the sliding filter, determine the direct-axis component evaluation index of each previous candidate filter bandwidth.

[0100] S504. Determine the target evaluation index from the direct-axis component evaluation index of the previous candidate filter bandwidth.

[0101] S505 uses the previous candidate filter bandwidth corresponding to the target evaluation index as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0102] S506 uses a binary search method to generate other target candidate filter bandwidths for the current AC voltage synchronization process based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0103] S507 determines the target filter bandwidth from the target candidate filter bandwidths of the current AC voltage synchronization process.

[0104] S508 performs AC / DC voltage synchronization processing on the quadrature axis voltage according to the target filter bandwidth.

[0105] For example, the flowchart of the above AC / DC voltage synchronization method can be as follows: Figure 6 As shown in the figure, A1 represents the bandwidth of the previous candidate filter {ω}. LPF(k)}, including ω LPF(1)(k) ω LPF(2)(k) and ω LPF(0)(k) A2 represents the target candidate filter bandwidth {ω} LPF(k+1)}, including ωLPF(1)(k+1) ω LPF(2)(k+1) and ω LPF(0)(k+1) B represents the evaluation metric corresponding to the bandwidth of each previous candidate filter, including f(ω). LPF(1)(k) f(ω) LPF(2)(k) ) and f(ω LPF(0)(k) First, after obtaining the current AC voltage to be synchronized, a synchronization system transformation is performed on the current AC voltage to be synchronized to obtain the direct-axis voltage v of the current AC voltage to be synchronized. d and quadrature axis voltage v q For the direct-axis voltage v of the AC voltage to be synchronized d Combined with the previous candidate filter bandwidth A1 (i.e., ω) LPF(1)(k) ω LPF(2)(k) and ω LPF(0)(k) ), and a predetermined formula for calculating the evaluation index of the direct axis component, to calculate the evaluation index (i.e., f(ω)) corresponding to each candidate filter bandwidth. LPF(1)(k) f(ω) LPF(2)(k) ) and f(ω LPF(0)(k) Furthermore, based on the evaluation index corresponding to each previous candidate filter bandwidth, and according to the predetermined target candidate filter bandwidth determination strategy, ω is... LPF(0) Update to get ω LPF(0) (k+1). Then determine f(ω). LPF(1)(k) Is it greater than f(ω)? LPF(0)(k) If so, then use f(ω). LPF(1)(k) ) corresponding to ω LPF(1)(k) Replace ω LPF(0)(k) If not, then determine f(ω) LPF(2)(k) Is it greater than f(ω)? LPF(0)(k) If so, then use f(ω). LPF(2)(k) ) corresponding to ω LPF(2)(k) Replace ω LPF(0)(k) Additionally, if f(ω) LPF(1)(k) ) and f(ω) LPF(2)(k) All are less than f(ω) LPF(0)(k) If ω is not correct, then it is incorrect. LPF(0)(k) Perform a replacement operation, that is, replace ω LPF(0)(k) As the updated ω LPF(0)(k) The updated ω LPF(0)(k) As a target candidate filter bandwidth (i.e., ω) corresponding to the current AC voltage to be synchronized LPF(0)(k+1) And based on the binary search method, the bandwidth ω of other target candidate filters is calculated. LPF(1) (k+1) and ω LPF(2) (k+1), then, the target candidate filter bandwidth A2 (i.e., ω) LPF(1)(k+1) ω LPF(2)(k+1) and ω LPF(0)(k+1)The output is sent to the quadrature axis voltage side. Among the target candidate filter bandwidths A2, one of the filter bandwidths is selected as the target filter bandwidth. The quadrature axis voltage is filtered based on the target filter bandwidth, and the output phase is processed for AC / DC voltage synchronization.

[0106] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0107] Based on the same inventive concept, this application also provides an AC / DC voltage synchronization device for implementing the AC / DC voltage synchronization method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more AC / DC voltage synchronization device embodiments provided below can be found in the limitations of the AC / DC voltage synchronization method described above, and will not be repeated here.

[0108] In one embodiment, such as Figure 7 As shown, an AC / DC voltage synchronization device 1 is provided, comprising: a voltage processing module 10, a bandwidth determination module 11, and a voltage synchronization module 12, wherein:

[0109] The voltage processing module 10 is used to perform synchronization system transformation processing on the AC voltage to be synchronized, so as to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage.

[0110] The bandwidth determination module 11 is used to update the previous candidate filter bandwidth based on the direct axis voltage to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0111] Among them, the previous candidate filter bandwidth is the target candidate filter bandwidth of the previous AC / DC voltage synchronization process.

[0112] The voltage synchronization module 12 is used to perform AC / DC voltage synchronization processing on the quadrature axis voltage according to the target candidate filter bandwidth of the current AC voltage synchronization process.

[0113] In one embodiment, such as Figure 8As shown, the bandwidth determination module 11 includes an index calculation unit 110 and a bandwidth determination unit 111. Wherein:

[0114] The index calculation unit 110 is used to calculate the direct-axis component evaluation index of the previous candidate filter bandwidth based on the previous candidate filter bandwidth and direct-axis voltage.

[0115] The bandwidth determination unit 111 is used to update the previous candidate filter bandwidth according to the evaluation index of the direct axis component of the previous candidate filter bandwidth, so as to obtain the target candidate filter bandwidth of the current AC voltage synchronization process.

[0116] In one embodiment, the index calculation unit 110 includes a first determining subunit and a second determining subunit, wherein:

[0117] The first determining subunit is used to determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth based on each previous candidate filter bandwidth.

[0118] The second determining subunit is used to determine the direct-axis component evaluation index of each candidate filter bandwidth based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter.

[0119] In one embodiment, the bandwidth determination unit 111 includes a third determination subunit and a fourth determination subunit, wherein:

[0120] The third determining subunit is used to determine the target evaluation index from the direct-axis component evaluation index of the previous candidate filter bandwidth.

[0121] The fourth determination subunit is used to update the previous candidate filter bandwidth according to the previous candidate filter bandwidth corresponding to the target evaluation index, so as to obtain the target candidate filter bandwidth of the current AC voltage synchronization process.

[0122] In one embodiment, the fourth determining subunit is specifically used to take the previous candidate filter bandwidth corresponding to the target evaluation index as a target candidate filter bandwidth for the current AC voltage synchronization process; and to generate other target candidate filter bandwidths for the current AC voltage synchronization process using a binary search method based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0123] In one embodiment, such as Figure 9 As shown, the voltage synchronization module 12 includes a target filter bandwidth determination unit 120 and a voltage synchronization unit 121. Wherein:

[0124] The target filter bandwidth determination unit 120 is used to determine the target filter bandwidth from the target candidate filter bandwidths of the current AC voltage synchronization process.

[0125] The voltage synchronization unit 121 is used to perform AC / DC voltage synchronization processing on the quadrature axis voltage according to the target filtering bandwidth.

[0126] Each module in the aforementioned AC / DC voltage synchronization device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0127] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 10 As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for synchronizing AC and DC voltages. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0128] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0129] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0130] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0131] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0132] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0133] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0134] Based on the previous candidate filter bandwidth and direct-axis voltage, calculate the direct-axis component evaluation index of the previous candidate filter bandwidth;

[0135] Based on the evaluation index of the direct-axis component of the previous candidate filter bandwidth, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0136] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0137] Based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth;

[0138] The evaluation index of the direct-axis component of each candidate filter bandwidth is determined based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter.

[0139] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0140] The target evaluation index is determined from the evaluation index of the direct axis component of the previous candidate filter bandwidth;

[0141] Based on the previous candidate filter bandwidth corresponding to the target evaluation index, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0142] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0143] The previous candidate filter bandwidth corresponding to the target evaluation index is used as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0144] Using a binary search method, other target candidate filter bandwidths for the current AC voltage synchronization process are generated based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0145] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0146] The target filter bandwidth is determined from the target candidate filter bandwidths of the current AC voltage synchronization process;

[0147] Based on the target filtering bandwidth, the quadrature axis voltage is processed to synchronize AC and DC voltages.

[0148] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0149] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0150] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0151] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0152] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0153] Based on the previous candidate filter bandwidth and direct-axis voltage, calculate the direct-axis component evaluation index of the previous candidate filter bandwidth;

[0154] Based on the evaluation index of the direct-axis component of the previous candidate filter bandwidth, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0155] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0156] Based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth;

[0157] The evaluation index of the direct-axis component of each candidate filter bandwidth is determined based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter.

[0158] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0159] The target evaluation index is determined from the evaluation index of the direct axis component of the previous candidate filter bandwidth;

[0160] Based on the previous candidate filter bandwidth corresponding to the target evaluation index, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0161] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0162] The previous candidate filter bandwidth corresponding to the target evaluation index is used as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0163] Using a binary search method, other target candidate filter bandwidths for the current AC voltage synchronization process are generated based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0164] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0165] The target filter bandwidth is determined from the target candidate filter bandwidths of the current AC voltage synchronization process;

[0166] Based on the target filtering bandwidth, the quadrature axis voltage is processed to synchronize AC and DC voltages.

[0167] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0168] The AC voltage to be synchronized is subjected to synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage;

[0169] Based on the direct-axis voltage, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process; where the previous candidate filter bandwidth is the target candidate filter bandwidth for the previous AC / DC voltage synchronization process.

[0170] Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature axis voltage is processed for AC / DC voltage synchronization.

[0171] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0172] Based on the previous candidate filter bandwidth and direct-axis voltage, calculate the direct-axis component evaluation index of the previous candidate filter bandwidth;

[0173] Based on the evaluation index of the direct-axis component of the previous candidate filter bandwidth, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0174] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0175] Based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth;

[0176] The evaluation index of the direct-axis component of each candidate filter bandwidth is determined based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter.

[0177] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0178] The target evaluation index is determined from the evaluation index of the direct axis component of the previous candidate filter bandwidth;

[0179] Based on the previous candidate filter bandwidth corresponding to the target evaluation index, the previous candidate filter bandwidth is updated to obtain the target candidate filter bandwidth for the current AC voltage synchronization process.

[0180] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0181] The previous candidate filter bandwidth corresponding to the target evaluation index is used as a target candidate filter bandwidth for the current AC voltage synchronization process.

[0182] Using a binary search method, other target candidate filter bandwidths for the current AC voltage synchronization process are generated based on the previous candidate filter bandwidth corresponding to the target evaluation index.

[0183] In one embodiment, when the computer program is executed by a processor, it also performs the following steps:

[0184] The target filter bandwidth is determined from the target candidate filter bandwidths of the current AC voltage synchronization process;

[0185] Based on the target filtering bandwidth, the quadrature axis voltage is processed to synchronize AC and DC voltages.

[0186] It should be noted that the user information (including but not limited to AC voltage information, direct-axis voltage information and quadrature-axis voltage information to be synchronized) and data (including but not limited to the discrete frequency domain transfer function of the low-pass filter and the discrete frequency domain transfer function of the sliding filter) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0187] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0188] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0189] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for synchronizing AC and DC voltages, characterized in that, The method includes: The AC voltage to be synchronized is subjected to a synchronization system transformation to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage; Based on the previous candidate filter bandwidth and the direct-axis voltage, calculate the direct-axis component evaluation index of the previous candidate filter bandwidth; determine the target evaluation index from the direct-axis component evaluation index of the previous candidate filter bandwidth; take the previous candidate filter bandwidth corresponding to the target evaluation index as a target candidate filter bandwidth for the current AC voltage synchronization process; using a binary search method, generate other target candidate filter bandwidths for the current AC voltage synchronization process based on the previous candidate filter bandwidth corresponding to the target evaluation index; wherein, the previous candidate filter bandwidth is the target candidate filter bandwidth of the previous AC / DC voltage synchronization process; Based on the target candidate filter bandwidth of the current AC voltage synchronization process, the quadrature-axis voltage is subjected to AC / DC voltage synchronization processing.

2. The method according to claim 1, wherein calculating the direct-axis component evaluation index of the previous candidate filter bandwidth based on the previous candidate filter bandwidth and the direct-axis voltage includes: Based on each previous candidate filter bandwidth, determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth; Based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter, the evaluation index of the direct-axis component for each previous candidate filter bandwidth is determined.

3. The method according to claim 1, characterized in that, The step of performing AC / DC voltage synchronization processing on the quadrature-axis voltage based on the target candidate filter bandwidth of the current AC voltage synchronization process includes: The target filter bandwidth is determined from the target candidate filter bandwidths of the current AC voltage synchronization process; Based on the target filtering bandwidth, the quadrature-axis voltage is subjected to AC / DC voltage synchronization processing.

4. The method according to any one of claims 1-3, characterized in that, The step of determining the target evaluation index from the direct-axis component evaluation indexes of the previous candidate filter bandwidth includes: The evaluation metrics of each direct axis component of the previous candidate filter bandwidth are sorted by size. The evaluation index of the highest-ranked direct axis component is used as the target evaluation index.

5. A synchronization device for AC / DC voltage, characterized in that, The device includes: The voltage processing module is used to perform synchronization system transformation processing on the current AC voltage to be synchronized, to obtain the direct-axis voltage and quadrature-axis voltage of the AC voltage; The bandwidth determination module is used to calculate the direct-axis component evaluation index of the previous candidate filter bandwidth based on the previous candidate filter bandwidth and the direct-axis voltage; determine the target evaluation index from the direct-axis component evaluation index of the previous candidate filter bandwidth; take the previous candidate filter bandwidth corresponding to the target evaluation index as a target candidate filter bandwidth for the current AC voltage synchronization process; and generate other target candidate filter bandwidths for the current AC voltage synchronization process using a binary search method based on the previous candidate filter bandwidth corresponding to the target evaluation index; wherein, the previous candidate filter bandwidth is the target candidate filter bandwidth of the previous AC / DC voltage synchronization process. The voltage synchronization module is used to perform AC / DC voltage synchronization processing on the quadrature-axis voltage according to the target candidate filter bandwidth of the current AC voltage synchronization process.

6. The AC / DC voltage synchronization device according to claim 5, characterized in that, The bandwidth determination module includes: The first determining subunit is used to determine the discrete frequency domain transfer function of the low-pass filter for each previous candidate filter bandwidth based on each previous candidate filter bandwidth. The second determining subunit is used to determine the direct-axis component evaluation index of each candidate filter bandwidth based on the direct-axis voltage, the discrete frequency domain transfer function of the low-pass filter for each candidate filter bandwidth, and the preset discrete frequency domain transfer function of the sliding filter.

7. The AC / DC voltage synchronization device according to claim 5, characterized in that, The voltage synchronization module includes: The target filter bandwidth determination unit is used to determine the target filter bandwidth from the target candidate filter bandwidths of the current AC voltage synchronization process; A voltage synchronization unit is used to perform AC / DC voltage synchronization processing on the quadrature axis voltage according to the target filtering bandwidth.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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