Signal synchronization method and device of converter

Abstract

The embodiment of the invention relates to the field of converters, and discloses a signal synchronization method and device of a converter. The method comprises the following steps: pre-configuring a configuration period of an internal synchronization signal; wherein the internal synchronizing signal is used for calibrating the carrier phase and frequency of the converter control unit; generating an internal synchronization signal; receiving an external synchronizing signal transmitted by the host; comparing the internal synchronization signal with the external synchronization signal to determine a synchronization state; adjusting the period of the internal synchronization signal according to the synchronization state; wherein when the synchronization state indicates that the phase of the external synchronization signal is advanced or lagged, the adjustment mode is to finely adjust the configuration period of the internal synchronization signal; when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment mode is that the internal synchronization signal is kept in the configuration period. Therefore, the large-range sudden change of the carrier period and the phase caused by direct calibration when the synchronization deviation is large is avoided.

Description

Technical Field

[0001] The present invention relates to the field of converters, and particularly to a signal synchronization method and apparatus for converters. Background Technology

[0002] In high-power converter applications, parallel operation of multiple converters is the primary method for system expansion. Converter carrier synchronization technology is the core means to ensure the stable operation of multi-converter parallel systems. Among related technologies, conventional carrier synchronization technology typically employs a master-slave approach, transmitting synchronization signals between multiple converters via communication lines such as optical fibers or cables to calibrate the carrier phase and frequency of each converter in real time.

[0003] However, this conventional synchronization method has drawbacks. On the one hand, synchronization signals (such as low-voltage level signals) are susceptible to interference pulses when transmitted on communication lines, posing a risk of missynchronization. On the other hand, when each converter uses real-time calibration, a large deviation between its own carrier signal and the synchronization signal can easily cause a wide range of abrupt changes in its carrier period and phase, thereby affecting the stability and reliability of system control. Summary of the Invention

[0004] The purpose of this invention is to provide a signal synchronization method and apparatus for a converter, thereby solving the problems in related technologies where external synchronization signals are easily interfered with, leading to missynchronization, and where the use of real-time calibration methods causes large-scale abrupt changes in carrier period and phase, affecting system stability.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a signal synchronization method for a converter, comprising: pre-configuring a configuration period for an internal synchronization signal; wherein the internal synchronization signal is used to calibrate the carrier phase and frequency of a converter control unit; generating the internal synchronization signal; receiving an external synchronization signal transmitted by a host; comparing the internal synchronization signal with the external synchronization signal to determine a synchronization state; and adjusting the period of the internal synchronization signal according to the synchronization state; wherein, when the synchronization state indicates that the phase of the external synchronization signal is leading or lagging, the adjustment is performed by fine-tuning the configuration period of the internal synchronization signal; and when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment is performed by maintaining the internal synchronization signal at the configured period.

[0006] Embodiments of the present invention also provide a signal synchronization device for a converter, comprising: a synchronization signal generation module, configured to pre-configure the configuration period of an internal synchronization signal and generate the internal synchronization signal; wherein the internal synchronization signal is used to calibrate the carrier phase and frequency of the converter control unit; a synchronization signal comparison module, configured to receive an external synchronization signal transmitted by a host; the synchronization signal comparison module is further configured to compare the internal synchronization signal with the external synchronization signal to determine a synchronization state, and output the synchronization state to the synchronization signal generation module; the synchronization signal generation module is further configured to adjust the period of the internal synchronization signal according to the synchronization state; wherein, when the synchronization state indicates that the phase of the external synchronization signal is leading or lagging, the adjustment method is to fine-tune the configuration period of the internal synchronization signal; when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment method is to maintain the internal synchronization signal at the configuration period.

[0007] In this embodiment of the invention, the synchronization state is determined by comparing the internal synchronization signal with the external synchronization signal. On one hand, when the synchronization state indicates that the period length of the external synchronization signal is abnormal (e.g., the external synchronization signal is interfered with), the adjustment method is to maintain the internal synchronization signal at the configured period, that is, no adjustment is made when the external synchronization signal is detected to be abnormal, thereby avoiding missynchronization caused by signal interference. On the other hand, when the synchronization state indicates that the phase of the external synchronization signal is leading or lagging, the adjustment method is to fine-tune the configured period of the internal synchronization signal. This smooth synchronization method using fine-tuning replaces the traditional real-time calibration, avoiding large-scale abrupt changes in carrier period and phase caused by direct calibration when the synchronization deviation is large (such as during the first synchronization), thereby enhancing the stability and reliability of control.

[0008] Furthermore, adjusting the period of the internal synchronization signal according to the synchronization state includes: when the synchronization state indicates that the phase of the external synchronization signal is lagging, setting the period of the internal synchronization signal to the configured period minus a preset fine-tuning step size; and when the synchronization state indicates that the phase of the external synchronization signal is leading, setting the period of the internal synchronization signal to the configured period plus the preset fine-tuning step size. Thus, through this periodic fine-tuning (e.g., fine-tuning only ΔT per period), the phase of the internal synchronization signal gradually approaches the phase of the external synchronization signal (i.e., the phase difference gradually decreases to 0), achieving smooth synchronization.

[0009] In addition, the method further includes: detecting whether the period length of the external synchronization signal is consistent with the period length of the configured period; if they are inconsistent, it is determined that the synchronization state indicates that the period length of the external synchronization signal is abnormal. Thus, an effective method is provided to determine whether the external synchronization signal is interfered with or abnormal, providing a basis for subsequent avoidance of missynchronization. Attached Figure Description

[0010] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0011] Figure 1 This is a schematic diagram of the device architecture used in the signal synchronization method for a converter according to an embodiment of the present invention. Figure 2 This is a schematic diagram of a module for adjusting the internal synchronization signal in a converter signal synchronization method provided according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the steps of a converter signal synchronization method provided according to an embodiment of the present invention; Figure 4 This is a comparative diagram of the internal synchronization signal and the external synchronization signal in the converter signal synchronization method provided according to an embodiment of the present invention; Figure 5 This is an execution flowchart of a converter signal synchronization method provided according to an embodiment of the present invention. Detailed Implementation

[0012] In high-power converter applications, such as large-scale wind power generation, photovoltaic power plants, or energy storage systems, parallel operation of multiple converters is the main way to achieve system expansion and improve reliability. In multi-converter parallel systems, converter carrier synchronization technology is one of the core means to ensure stable system operation. Its goal is to calibrate the carrier phase and frequency of each converter unit in real time to eliminate power oscillations and circulating current losses that may be caused by carrier phase deviation, and to ensure that the voltage and current waveforms output by each unit are highly consistent.

[0013] However, the inventors discovered that conventional carrier synchronization techniques in related technologies (e.g., using a master-slave approach to transmit a unified synchronization signal via communication lines such as optical fibers or cables) have the following fundamental problems: First, conventional solutions lack reliability. Related technologies typically rely on an externally transmitted synchronization signal (e.g., a low-voltage signal) to calibrate the carrier waves of each slave device in real time. The fundamental flaw in this approach is its over-reliance on the purity of this external synchronization signal. On one hand, when this synchronization signal is transmitted over long-distance communication lines (such as RS485 buses or cables), it is highly susceptible to strong electromagnetic interference from the field (e.g., converter switching operations), such as interference pulses superimposed on the signal. Because the slave devices use real-time calibration logic, they may misidentify these interference pulses as valid synchronization edges and immediately execute calibration actions, leading to missynchronization and causing chaos in system control.

[0014] Secondly, the stability of conventional methods is poor. Another fundamental flaw of this real-time calibration method lies in its overly rigid calibration logic. For example, after the system's initial synchronization or a unit restart, when the carrier signal of each converter unit deviates significantly from the received external synchronization signal, this real-time calibration logic attempts to forcibly level off this huge phase deviation (e.g., tens or even hundreds of microseconds) within a single cycle or instant. This calibration method inevitably leads to large-scale abrupt changes in the carrier period and phase of that unit. In a high-speed converter control system, such instantaneous phase jumps severely impact the control loop, thereby affecting the stability and reliability of system control.

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of the present invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0016] One embodiment of the present invention relates to a signal synchronization method for a converter. This method is preferably applied to the control unit of the converter, and can be optionally applied to the overall control unit of an energy storage system to which each converter belongs. The embodiment includes: pre-configuring a configuration period for an internal synchronization signal; wherein the internal synchronization signal is used to calibrate the carrier phase and frequency of the converter control unit; generating the internal synchronization signal; receiving an external synchronization signal transmitted by a host; comparing the internal synchronization signal with the external synchronization signal to determine a synchronization state; and adjusting the period of the internal synchronization signal according to the synchronization state. Wherein, when the synchronization state indicates that the phase of the external synchronization signal is leading or lagging, the adjustment method is to fine-tune the configuration period of the internal synchronization signal; when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment method is to maintain the internal synchronization signal at the configured period. In this embodiment, the synchronization state is determined by comparing the internal synchronization signal with the external synchronization signal. On the one hand, when the synchronization state indicates that the period length of the external synchronization signal is abnormal (e.g., the external synchronization signal is interfered with), the adjustment method is to maintain the internal synchronization signal at the configured period, that is, no adjustment is made when an abnormality in the external synchronization signal is detected, thereby avoiding missynchronization caused by signal interference. On the other hand, when the synchronization status indicates that the phase of the external synchronization signal is ahead or behind, the adjustment method is to fine-tune the configuration period of the internal synchronization signal. This smooth synchronization method using fine-tuning replaces the traditional real-time calibration, avoiding large-scale abrupt changes in carrier period and phase caused by direct calibration when the synchronization deviation is large (such as during the first synchronization), thereby enhancing the stability and reliability of the control.

[0017] The following is a detailed description of the implementation details of the converter signal synchronization method according to an embodiment of the present invention. The following content is only for the convenience of understanding the implementation details and is not necessary for implementing this solution.

[0018] like Figure 1 As shown, the device architecture used in this embodiment of the invention can be a system in which multiple converters operate in parallel. This system includes multiple converter modules, such as... Figure 1 The system includes converter modules 1, 2, and N. Correspondingly, the system also includes multiple converter control units, such as... Figure 1 The converter control unit consists of converter control unit 1, converter control unit 2, and converter control unit N, each of which controls a corresponding converter module. These multiple converter control units are connected in parallel via a communication line.

[0019] In a preferred embodiment, the signal synchronization method described above is specifically executed by a programmable logic device mounted in each converter control unit. For example... Figure 1As shown, each control unit includes a programmable logic device, which internally houses a "successive approximation synchronization module" for implementing the method of this invention. Furthermore, the aforementioned programmable logic device includes, but is not limited to, FPGA (Field-Programmable Gate Array) or CPLD (Complex Programmable Logic Device). FPGA or CPLD are chosen because the "successive approximation synchronization module" proposed in this invention needs to perform high-speed, real-time signal processing tasks, such as... Figure 2 As shown, the "Successive Approximation Synchronization Module" includes a "Synchronization Signal Generation Module" and a "Synchronization Signal Comparison Module." Tasks such as high-frequency counters, phase comparison logic, and state machine switching are well-suited for implementation using the parallel processing architecture and programmable logic resources of FPGAs or CPLDs.

[0020] like Figure 1 As shown, each programmable logic device receives an external synchronization signal Sync_In transmitted from the master unit via a communication line. In a specific example, the master unit can be any one of the N converter control units; for example, control unit 1 can be configured as the "master unit," and the others as "slaves." In another optional example, the "master unit" can also be a general control unit of an additional system configuration connected to the communication line, such as a higher-level energy storage system controller or BMS.

[0021] The method of applying the above system architecture to the embodiments of the present invention is as follows: Figure 3 This includes steps 110 to 150.

[0022] In step 110, the converter control unit pre-configures the configuration period of the internal synchronization signal. The internal synchronization signal is used to calibrate the carrier phase and frequency of the converter control unit.

[0023] In step 120, the synchronization signal generation module in the converter control unit generates an internal synchronization signal.

[0024] In a specific example, the execution flow of steps 110 and 120 of the present invention is as follows: First, during the initialization phase of power-on operation of each converter control unit, the period (i.e., configuration period) and duty cycle of the synchronization signal are pre-configured to their respective programmable logic devices. Subsequently, as... Figure 2 As shown, the synchronization signal generation module starts generating the internal synchronization signal Sync_Out according to the configured period and duty cycle. The Sync_Out signal, after being adjusted according to this embodiment of the invention, is the signal actually used by the converter control unit to calibrate the carrier phase and frequency of its own converter in real time.

[0025] In step 130, the synchronization signal comparison module in the converter control unit receives the external synchronization signal transmitted by the host.

[0026] In step 140, the synchronization signal comparison module in the converter control unit compares the internal synchronization signal with the external synchronization signal to determine the synchronization status.

[0027] In a specific example, the execution flow of steps 130 and 140 of the present invention is as follows: Figure 2 As shown, after step 120 is completed, the synchronization signal comparison module begins to work. It works by communicating via the communication line (see...). Figure 1 The synchronization signal comparison module receives the external synchronization signal Sync_In transmitted from the host, and the internal synchronization signal Sync_Out from the synchronization signal generation module. The core task of the synchronization signal comparison module is to compare these two signals, Sync_In and Sync_Out, to determine the current synchronization state Sync_State, and then output this state to the synchronization signal generation module.

[0028] In step 150, the synchronization signal generation module in the converter control unit adjusts the period of the internal synchronization signal according to the synchronization status. Specifically, when the synchronization status indicates that the phase of the external synchronization signal is leading or lagging, the adjustment method is to fine-tune the configuration period of the internal synchronization signal; when the synchronization status indicates that the period length of the external synchronization signal is abnormal, the adjustment method is to maintain the internal synchronization signal at the configuration period.

[0029] In a specific example, determining the synchronization state as described above includes: detecting the period length of the external synchronization signal Sync_In (e.g., Figure 4 The system checks whether the period (Tin) of the received Sync_In signal matches the configured period length; if they do not, it determines that the period length of the external synchronization signal indicating the synchronization status is abnormal. Specifically, this is the first-level priority judgment performed by the synchronization signal comparison module. It measures the period (Tin) of the received Sync_In signal using an internal counter. If this Tin value deviates from the preset configured period, such as exceeding an allowable error range, the module determines that the Sync_In signal has been interfered with and is unreliable. Therefore, if... Figure 5 As shown, the synchronization signal comparison module will immediately output "Sync_State=Abnormal".

[0030] Therefore, when the synchronization signal generation module receives "Sync_State=abnormal", it will perform an adjustment: maintaining the internal synchronization signal Sync_Out at the configured cycle. For example... Figure 5As shown, in this abnormal state, the period Tout of Sync_Out is forcibly set to the configured period, and the Sync_Fault signal is set to 1. In other words, when the system detects an abnormal external synchronization signal, it will not make any adjustments, but will choose to ignore the abnormal signal and continue to use its original configured period to generate Sync_Out. This design fundamentally avoids missynchronization caused by interference with the synchronization signal on the communication line.

[0031] In an optional example, the adjustment further includes: outputting a fault alarm signal when the synchronization status indicates an abnormal period length of the external synchronization signal. Specifically, this fault alarm signal is... Figure 2 and Figure 5 The Sync_Fault signal is shown in the diagram. When Sync_Fault is set to 1 (high level), it not only notifies the synchronization signal generation module (keeping it configured), but the Sync_Fault signal can also be routed to the main processor (such as DSP or ARM) of the converter control unit to trigger a fault alarm so that the system can record the interference event or notify maintenance personnel.

[0032] In a specific example, if the period length of the external synchronization signal is consistent with the period length of the configuration period (i.e., the Sync_In signal is considered reliable), the synchronization signal comparison module will enter the second-level judgment, namely: comparing the phase deviation between the rising edge of the internal synchronization signal and the rising edge of the external synchronization signal. For example... Figure 4 As shown, the phase deviation Δφ is the time difference between the rising edge of the Sync_In signal and the rising edge of the Sync_Out signal.

[0033] In a specific example, determining the synchronization state includes: if the phase deviation Δφ is greater than zero and less than a preset phase difference value, the synchronization state indicates that the phase deviation is lagging; if the phase deviation Δφ is greater than or equal to the preset phase difference value, the synchronization state indicates that the phase deviation is leading. Furthermore, the preset phase difference value is half the period length of the configured period. In other words, the judgment logic of the synchronization signal comparison module is: 1. If 0 < Δφ < (configuration cycle / 2), it is determined to be "lagging" (Sync_State = lag).

[0034] 2. If Δφ >= (configuration period / 2), it is determined to be "ahead" (Sync_State = ahead). This method of judgment, which uses half of the period as the dividing line, is to determine the shortest path to achieve synchronization, that is, to determine whether the phase of Sync_Out should be decelerated by increasing the period or accelerated by decreasing the period, so as to catch up with Sync_In more quickly.

[0035] In a specific example, determining the synchronization state also includes: if the phase deviation Δφ is equal to zero, the synchronization state is determined to be fully synchronized. At this time, based on the synchronization state, the period of the internal synchronization signal is adjusted, including: when the synchronization state is fully synchronized, keeping the period Tout of the internal synchronization signal constant. For example... Figure 5 As shown, when Sync_State = fully synchronized, Tout is set to the configuration period, and Sync_Fault is 0. This indicates that the frequency and phase of the internal synchronization signal and the external synchronization signal are completely consistent, and the system has reached a stable synchronization state.

[0036] In a specific example, the period of the internal synchronization signal is adjusted according to the synchronization state, including: when the synchronization state indicates that the phase of the external synchronization signal is lagging, the period of the internal synchronization signal is set to the configuration period minus the preset fine-tuning step size; when the synchronization state indicates that the phase of the external synchronization signal is leading, the period of the internal synchronization signal is set to the configuration period plus the preset fine-tuning step size.

[0037] Specifically, such as Figure 5 As shown, the core logic of the successive approximation in the above example is as follows: when Sync_State = Lead, the synchronization signal generation module will execute: Tout = Configuration period + ΔT; when Sync_State = Lag, the synchronization signal generation module will execute: Tout = Configuration period - ΔT. Here, ΔT is the preset fine-tuning step size. This fine-tuning step size ΔT is set to a relatively small length; for example, ΔT can be set to 1 clock cycle. For example, if the operating clock frequency of the programmable logic device is 100MHz, then the preset fine-tuning step size ΔT is only 10 nanoseconds.

[0038] Therefore, the synchronization process in this embodiment of the invention is a smooth, iterative process: in each cycle, the synchronization module compares the phase difference Δφ and, depending on whether it is ahead or behind, fine-tunes the period Tout of the internal synchronization signal by +ΔT or -ΔT. This fine-tuning (e.g., 10 ns) is smooth compared to the entire configuration cycle (e.g., several hundred microseconds), and therefore will not cause "large-scale abrupt changes" to the control system. However, after multiple cycles of iterative accumulation, the rising edge of the internal synchronization signal Sync_Out gradually approaches the rising edge of the external synchronization signal Sync_In, causing the phase deviation Δφ to gradually decrease and eventually shorten to zero. This approach solves both the missynchronization problem caused by interference with the external synchronization signal Sync_In (through abnormal state handling) and the carrier phase abrupt change problem caused by real-time calibration due to large phase deviations (such as during initial synchronization) (through smooth fine-tuning of ±ΔT), significantly improving the stability and reliability of the system.

[0039] In an optional embodiment, to further enhance the anti-interference capability of the external synchronization signal Sync_In, especially when the converter control units are distributed in different locations resulting in long communication lines, the synchronization signal comparison module may include a digital filtering step before receiving the external synchronization signal. For example, a median filter or a triple-modulus redundant sampling logic can be used to sample the edges of the Sync_In signal multiple times. Only when N consecutive samples are confirmed as valid edges is it considered a valid Sync_In signal and sent to the subsequent period detection (determining Tin) and phase comparison (determining Δφ) logic. This approach can effectively filter out occasional interference pulses on the communication line, adding an extra layer of protection before abnormal state detection, and further improving the reliability of synchronization.

[0040] In an optional embodiment, the preset fine-tuning step size ΔT may not be a fixed value, but rather dynamically adjustable. For example, when comparing the phase deviation Δφ, the synchronization signal comparison module can compare it with one or more thresholds. When a large phase deviation Δφ is detected (e.g., greater than the preset threshold Th_large, indicating that synchronization is in its initial stage), a larger fine-tuning step size (e.g., ΔT_large = 5 × clock) is used. When a small phase deviation Δφ is detected (e.g., less than the threshold Th_small, indicating that synchronization is imminent), a smaller fine-tuning step size is used (e.g., ΔT_small = 1 × clock). This adaptive step size approach allows for rapid approximation in the initial stage of synchronization (when the deviation is large) and fine-tuning in the later stage of synchronization (when the deviation is small), thereby shortening the overall synchronization convergence time while ensuring smooth synchronization.

[0041] In an optional embodiment, to address the potential failure of the master unit, i.e., the unit sending the Sync_In signal, the method further includes a master switching logic. Specifically, as described above, the master unit can be any one of multiple control units or a central control unit. In a master-slave configured system (e.g., unit 1 is the master, and units 2 to N are slaves), the synchronization signal comparison modules of all slave units continuously monitor the period length of the Sync_In signal for abnormal states. Based on this, if a slave unit (e.g., unit 2) detects that the duration of the abnormal state exceeds a preset master failure timeout threshold (e.g., 100 milliseconds, much longer than the duration of a single interference pulse), the slave unit can determine that the master unit has failed (e.g., crashed or the communication line is disconnected). At this time, the system can automatically perform a master switching: for example, the pre-configured backup master unit (e.g., unit 2) will automatically switch the function of its programmable logic device from receiving Sync_In to generating and sending Sync_In, thus becoming the new master unit. This design ensures that even if a single master unit fails, the synchronization signal of the entire parallel system can still be maintained, greatly improving the system's high availability and robustness.

[0042] It should be noted that the converter signal synchronization method involved in the embodiments of the present invention is applicable to scenarios requiring precise carrier synchronization of multiple converters. It is particularly suitable for the following application scenarios with stringent synchronization requirements, including but not limited to large-scale new energy power generation systems, grid-level and industrial and commercial energy storage systems, microgrid systems, high-reliability power supply systems, and residential energy storage.

[0043] Large-scale new energy power generation systems: such as large-scale photovoltaic power plants, onshore or offshore wind farms. In these scenarios, dozens or even hundreds of high-power inverters (converters) are typically required to operate in parallel to feed energy to the grid.

[0044] Grid-level and industrial / commercial energy storage systems: Whether it's a large containerized energy storage power station used for grid frequency regulation and peak shaving, or an energy storage system used for industrial and commercial peak shaving and valley filling, multiple energy storage converters need to operate in parallel to achieve megawatt-level high-power charging and discharging. The method of this invention is particularly suitable for environments where such modules are distributed in different containers and communication lines are long and susceptible to interference.

[0045] Microgrid systems: In microgrids, various distributed power sources such as photovoltaic, wind power, and energy storage units need to be connected in parallel through their respective converters to jointly support the voltage and frequency of the microgrid. The synchronization method of this invention can ensure that these different units can work stably and collaboratively in both grid-connected and islanded modes.

[0046] High-reliability power supply systems: such as uninterruptible power supply systems in data centers, emergency power supplies in hospitals or precision manufacturing. These scenarios typically employ multiple converter modules in parallel redundancy, requiring extremely high levels of speed, stability, and smooth switching.

[0047] Residential energy storage: In high-end residential systems, multiple smaller-power energy storage converters are often connected in parallel to increase capacity or achieve three-phase unbalanced output, which also requires reliable synchronization technology.

[0048] In summary, the method provided by the embodiments of the present invention can significantly improve the reliability and stability of converter carrier synchronization in the above-mentioned parallel systems, and avoid missynchronization caused by interference or sudden changes in the system due to large synchronization deviation.

[0049] In this embodiment of the invention, the synchronization state is determined by comparing the internal synchronization signal with the external synchronization signal. On one hand, when the synchronization state indicates that the period length of the external synchronization signal is abnormal (e.g., the external synchronization signal is interfered with), the adjustment method is to maintain the internal synchronization signal at its configured period, that is, no adjustment is made when an abnormality in the external synchronization signal is detected, thereby avoiding missynchronization caused by signal interference. On the other hand, when the synchronization state indicates that the phase of the external synchronization signal is leading or lagging, the adjustment method is to fine-tune the configured period of the internal synchronization signal. This smooth synchronization method using fine-tuning replaces the traditional real-time calibration, avoiding large-scale abrupt changes in carrier period and phase caused by direct calibration when the synchronization deviation is large (such as during the first synchronization), thereby enhancing the stability and reliability of control.

[0050] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0051] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0052] The steps described above are for clarity only. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the protection scope of this invention. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, without changing the core design of the algorithm and process, are also within the protection scope of this invention.

[0053] Furthermore, the examples mentioned in the above embodiments can be freely combined, and any combination can be understood as an embodiment. The terms "embodiment" or "example" appearing in various locations in the specification do not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0054] Another embodiment of the present invention relates to a signal synchronization device for a converter, comprising: a synchronization signal generation module, configured to pre-configure the configuration period of an internal synchronization signal and generate an internal synchronization signal; wherein the internal synchronization signal is used to calibrate the carrier phase and frequency of the converter control unit; a synchronization signal comparison module, configured to receive an external synchronization signal transmitted by a host; the synchronization signal comparison module is further configured to compare the internal synchronization signal with the external synchronization signal to determine the synchronization state and output the synchronization state to the synchronization signal generation module; the synchronization signal generation module is further configured to adjust the period of the internal synchronization signal according to the synchronization state; wherein, when the synchronization state indicates that the phase of the external synchronization signal is leading or lagging, the adjustment method is to fine-tune the configuration period of the internal synchronization signal; when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment method is to maintain the internal synchronization signal at the configuration period.

[0055] In some embodiments, the synchronization signal generation module is specifically used to: when the synchronization state indicates that the phase of the external synchronization signal is lagging, set the period of the internal synchronization signal to the configuration period minus the preset fine-tuning step size; when the synchronization state indicates that the phase of the external synchronization signal is leading, set the period of the internal synchronization signal to the configuration period plus the preset fine-tuning step size.

[0056] In some embodiments, the synchronization signal comparison module is specifically used to: detect whether the period length of the external synchronization signal is consistent with the period length of the configured period; if they are inconsistent, determine that the period length of the synchronization state indicates that the external synchronization signal is abnormal.

[0057] In some embodiments, the synchronization signal comparison module is further configured to: compare the phase deviation between the rising edge of the internal synchronization signal and the rising edge of the external synchronization signal when the period length of the external synchronization signal is consistent with the period length of the configured period; if the phase deviation is greater than zero and less than a preset phase difference value, determine that the synchronization state indicator phase deviation is lagging; if the phase deviation is greater than or equal to the preset phase difference value, determine that the synchronization state indicator phase deviation is leading.

[0058] In some embodiments, the synchronization signal comparison module is further configured to: determine that the synchronization state is fully synchronized if the phase deviation is equal to zero; the synchronization signal generation module is further configured to: keep the period of the internal synchronization signal unchanged when the synchronization state is fully synchronized.

[0059] In some embodiments, the preset phase difference value is half the period length of the configuration period.

[0060] In some embodiments, the synchronization signal generation module is further configured to: output a fault alarm signal when the period length of the external synchronization signal is abnormal, as indicated by the synchronization status.

[0061] In some embodiments, the signal synchronization device of the converter is configured in the control unit of the converter. There are multiple control units, which are connected in parallel via communication lines.

[0062] In some embodiments, the host is any one of a plurality of control units, or a main control unit connected to a communication line.

[0063] In some embodiments, the device is a programmable logic device in a control unit.

[0064] It is not difficult to see that this embodiment is a device embodiment corresponding to the above method embodiments, and this embodiment can be implemented in conjunction with the above method embodiments. The relevant technical details mentioned in the above method embodiments are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the above method embodiments.

[0065] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by this invention; however, this does not mean that other units are absent from this embodiment.

[0066] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A signal synchronization method for a converter, characterized in that, The method includes: The configuration period of the internal synchronization signal is pre-configured; wherein the internal synchronization signal is used to calibrate the carrier phase and frequency of the converter control unit; Generate the internal synchronization signal; Receive external synchronization signals transmitted by the host; The internal synchronization signal is compared with the external synchronization signal to determine the synchronization status; According to the synchronization state, the period of the internal synchronization signal is adjusted; wherein, when the synchronization state indicates that the phase of the external synchronization signal is ahead or behind, the adjustment method is to fine-tune the configuration period of the internal synchronization signal; when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment method is to maintain the internal synchronization signal at the configuration period.

2. The signal synchronization method for a converter according to claim 1, characterized in that, Adjusting the period of the internal synchronization signal according to the synchronization state includes: When the synchronization state indicates that the phase of the external synchronization signal is lagging, the period of the internal synchronization signal is set to the configuration period minus the preset fine-tuning step size. When the synchronization state indicates that the phase of the external synchronization signal is leading, the period of the internal synchronization signal is set to the configuration period plus the preset fine-tuning step size.

3. The signal synchronization method for a converter according to claim 1, characterized in that, The determination of the synchronization state includes: Detect whether the period length of the external synchronization signal is consistent with the period length of the configured period; If there is a discrepancy, it is determined that the synchronization status indicates an abnormal period length of the external synchronization signal.

4. The signal synchronization method for a converter according to claim 3, characterized in that, The determination of the synchronization state includes: When the period length of the external synchronization signal is consistent with the period length of the configuration period, the phase deviation between the rising edge of the internal synchronization signal and the rising edge of the external synchronization signal is compared. If the phase deviation is greater than zero and less than a preset phase difference value, the synchronization state indicates that the phase deviation is lagging. If the phase deviation is greater than or equal to the preset phase difference value, the synchronization state indicates that the phase deviation is ahead.

5. The signal synchronization method for a converter according to claim 4, characterized in that, The determination of the synchronization state includes: If the phase deviation is equal to zero, the synchronization state is determined to be fully synchronized; The step of adjusting the period of the internal synchronization signal according to the synchronization state includes: keeping the period of the internal synchronization signal unchanged when the synchronization state is fully synchronized.

6. The signal synchronization method for a converter according to claim 4, characterized in that, The preset phase difference value is half the period length of the configuration period.

7. The signal synchronization method for a converter according to claim 3, characterized in that, The adjustments also include: When the synchronization status indicates that the period length of the external synchronization signal is abnormal, a fault alarm signal is output.

8. The signal synchronization method for a converter according to any one of claims 1 to 7, characterized in that, The converter is applied to a control unit, and there are multiple control units connected in parallel via communication lines.

9. The signal synchronization method for a converter according to claim 8, characterized in that, The host is any one of the multiple control units, or the main control unit connected to the communication line.

10. The signal synchronization method for a converter according to claim 8, characterized in that, The method is executed by a programmable logic device in the control unit.

11. A signal synchronization device for a converter, characterized in that, The device includes: A synchronization signal generation module is used to pre-configure the configuration period of the internal synchronization signal and to generate the internal synchronization signal; wherein the internal synchronization signal is used to calibrate the carrier phase and frequency of the converter control unit; The synchronization signal comparison module is used to receive external synchronization signals transmitted by the host. The synchronization signal comparison module is further configured to compare the internal synchronization signal with the external synchronization signal to determine the synchronization state, and output the synchronization state to the synchronization signal generation module; The synchronization signal generation module is further configured to adjust the period of the internal synchronization signal according to the synchronization state; wherein, when the synchronization state indicates that the phase of the external synchronization signal is ahead or behind, the adjustment method is to fine-tune the configuration period of the internal synchronization signal; when the synchronization state indicates that the period length of the external synchronization signal is abnormal, the adjustment method is to maintain the internal synchronization signal at the configuration period.

12. The signal synchronization device for the converter according to claim 11, characterized in that, The synchronization signal generation module is specifically used for: When the synchronization state indicates that the phase of the external synchronization signal is lagging, the period of the internal synchronization signal is set to the configuration period minus the preset fine-tuning step size. When the synchronization state indicates that the phase of the external synchronization signal is leading, the period of the internal synchronization signal is set to the configuration period plus the preset fine-tuning step size.

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