Control method and control system of power converter, power converter and chip

Abstract

The invention relates to a control method and a control system of a power converter, the power converter and a chip, and relates to the technical field of circuit control. The control method comprises the following steps: periodically acquiring real-time voltage of a power grid according to a first preset duration; if the acquired real-time voltage of the first power grid is not within the preset voltage threshold range, controlling the power converter to enter a wave sealing standby state from a normal power generation state; when the power converter is in the wave sealing standby state, acquiring the duration of the real-time voltage of the power grid within the voltage threshold range; and when the duration is not less than a second preset duration, controlling the power converter to enter the normal power generation state. By adopting the control method of the power converter, when the voltage of the power grid suddenly changes, the wave sealing protection of the power converter can be quickly responded and triggered, and the working efficiency of the power converter under the condition of small fluctuation of the power grid can be ensured.

Description

Technical Field

[0001] This application relates to the field of circuit control technology, and in particular to a control method, control system, power converter, and chip for a power converter. Background Technology

[0002] With the development of renewable energy technologies, photovoltaic power generation systems and other power systems have been widely applied. In these systems, power converters, as important devices, can convert different forms of electrical energy (such as direct current) into alternating current or direct current that meets the requirements of the target system and connect it to the grid or other loads. Precise control of power converters is crucial to ensuring the efficient and stable delivery of electrical energy to the grid.

[0003] However, during power grid operation, fluctuations or sudden changes in grid voltage and frequency, especially during sudden grid disconnections or brief fluctuations, can severely impact the operation of power converters. In such situations, traditional grid protection mechanisms (such as undervoltage and underfrequency protection) struggle to react within such a short timeframe, preventing power converters from adjusting their control strategies in a timely manner. This can lead to risks such as phase-locked loop failure, control malfunctions, and even equipment overcurrent damage.

[0004] Therefore, how to effectively protect the power converter when the power grid experiences abnormal fluctuations has become an urgent problem to be solved in the field of circuit control technology. Summary of the Invention

[0005] Therefore, it is necessary to provide a control method, control system, power converter, and chip for the power converter to address the above-mentioned technical problems.

[0006] Firstly, this application provides a control method for a power converter. The control method includes:

[0007] The real-time voltage of the power grid is acquired periodically according to the first preset duration.

[0008] If the first real-time grid voltage is not within the preset voltage threshold range, the power converter is controlled to enter the wave blocking standby state from the normal power generation state.

[0009] When the power converter is in the standby state, the duration for which the real-time voltage of the power grid is within the voltage threshold range is obtained;

[0010] When the duration is not less than the second preset duration, the power converter is controlled to enter the normal power generation state.

[0011] In one embodiment, the control method is applied to the control system of a power converter, the control system including at least a main controller and a CPLD;

[0012] The control method is implemented by the main controller;

[0013] The CPLD is used to respond to the control commands of the main controller to enter the waveform generation state or the waveform blocking state, so that the power converter enters the normal power generation state or the waveform blocking standby state.

[0014] In one embodiment, the first preset duration is determined by the maximum interrupt frequency of the main controller.

[0015] In one embodiment, the second preset duration is determined by the power grid frequency.

[0016] In one embodiment, the second preset duration is greater than twice the AC cycle duration of the power grid, but less than twice the AC cycle duration.

[0017] In one embodiment, the control method further includes:

[0018] If the power converter remains in standby mode for a duration longer than a third preset duration, the power converter will enter a shutdown state.

[0019] In one embodiment, after periodically acquiring the real-time grid voltage according to a first preset duration, the method further includes:

[0020] The voltage threshold range corresponding to the current AC cycle of the power grid is determined based on the real-time voltage of the power grid obtained during the historical AC cycle of the power grid.

[0021] In one embodiment, the voltage threshold range corresponding to the current AC cycle of the power grid includes the voltage threshold range corresponding to each moment within the current AC cycle of the power grid;

[0022] The voltage threshold range corresponding to each moment is as follows: the median value is obtained from the real-time voltage of the power grid within N AC cycles in the history of the power grid, and the span is a voltage range with a preset voltage difference.

[0023] Secondly, this application also provides a control system for a power converter. The control system includes a main controller and a CPLD, the main controller being used for:

[0024] The real-time voltage of the power grid is periodically acquired according to the first interval duration;

[0025] If the first real-time voltage of the power grid is not within the preset voltage threshold range, the CPLD is controlled to enter the blocking state from the wave generation state.

[0026] When the CPLD is in the wave blocking state, the duration for which the real-time voltage of the power grid is within the voltage threshold range is obtained;

[0027] When the duration is not less than the second preset duration, the CPLD is controlled to enter the waveform transmission state.

[0028] Thirdly, this application also provides a power converter, which includes the control system described in the second aspect.

[0029] Fourthly, this application also provides a chip including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method provided in the first aspect.

[0030] The control method for the power converter disclosed in this application periodically samples the real-time grid voltage. When the real-time grid voltage is abnormal, the power converter is controlled to enter a standby state with voltage suppression. After the real-time grid voltage returns to normal and remains so for a period of time, the power converter is controlled to enter normal power generation. In this way, by periodically sampling the grid voltage, real-time monitoring of grid voltage changes is achieved, allowing the power converter to switch to standby mode promptly in case of grid anomalies. This avoids abnormal impacts and reduces the risk of component damage. Furthermore, through continuous monitoring and timing mechanisms, the power converter can promptly resume power generation after the grid returns to normal, improving energy utilization efficiency. It also avoids frequent switching of the power converter's operating state due to short-term grid fluctuations, helping to extend the equipment's service life. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the control method for a power converter in one embodiment;

[0033] Figure 2 This is a schematic diagram of the control system of the power converter in one embodiment;

[0034] Figure 3 This is a schematic diagram of the control method for a power converter in another embodiment. Detailed Implementation

[0035] 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.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0037] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0038] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0039] It is understood that the term "based on" as used in this application is used to describe one or more factors that influence the determination, but does not exclude other factors that may influence the determination. For example, the phrase "determine A based on B" means that the determination of A can be based entirely or at least partially on factor B. That is, B is a factor that influences the determination of A, but does not exclude the fact that the determination of A is also based on C.

[0040] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0041] During power grid operation, voltage and frequency fluctuate due to load changes, generator fluctuations, and faults. Specifically, grid voltage may rise or fall due to load changes or faults, causing voltage fluctuations. Imbalances between generation and load can lead to grid frequency fluctuations. Short circuits and switching operations can also cause voltage drops or interruptions, resulting in transient grid voltage fluctuations. The power converter's control system relies on a phase-locked loop (PLL) to synchronize the grid voltage frequency and phase. When grid frequency fluctuations are significant or voltage interruptions occur, the PLL may lose lock, leading to asynchronous output voltage and frequency, and causing control system malfunctions. Furthermore, when grid voltage changes suddenly, the power converter's current control loop may fail to adjust in time, causing current surges or overcurrents, potentially damaging the equipment. In addition, when grid fluctuations occur, the power converter will struggle to maintain stable output voltage and frequency, potentially leading to increased harmonics, voltage distortion, and other problems, affecting power quality.

[0042] Traditional power grid protection mechanisms primarily rely on long-term changes in grid parameters to determine whether to activate protection. However, voltage and frequency fluctuations can occur within a very short timeframe. Traditional protection mechanisms have slow response times and lag, which may result in the power converter entering an unstable state before protection mechanisms are triggered during brief grid fluctuations. Therefore, in the event of instantaneous grid fluctuations, the power converter may be damaged before the protection mechanism takes effect.

[0043] To address the aforementioned issues, this application provides a control method for a power converter, wherein the execution entity of this method can be the control system of the power converter. A power converter can be used to convert one form of electrical energy into another, and can be an inverter, rectifier, AC / DC converter, etc. In a photovoltaic power generation system or microgrid, the power converter can be an inverter used to convert DC power into AC power for grid connection or to supply power to loads. This application uses a micro-inverter in a photovoltaic power generation system as an example for illustration; other cases are similar, and will be explained where necessary. The control system can be used to control the power switching elements (such as MOSFETs or IGBTs) of the power converter, generate PWM (pulse width modulation) signals to adjust the operating state of the power converter, and also monitor the state of the photovoltaic power generation system or microgrid, identify abnormal states, and take countermeasures. Furthermore, depending on the system design and application requirements, the control system of the power converter can be either part of the power converter (i.e., directly integrated inside the power converter) or an external system independent of the power converter.

[0044] In one embodiment, such as Figure 1As shown, a control method for a power converter is provided, including the following steps:

[0045] Step 101: Periodically acquire the real-time voltage of the power grid according to the first preset time period.

[0046] In implementation, the power converter's control system can be equipped with a data acquisition module. This module can include various sensors (current sensors, voltage sensors, temperature sensors, etc.) to acquire real-time status signals of the power converter and / or the power grid. The control system can periodically sample the real-time voltage of the power grid through the data acquisition module. The sampling interval can be a first preset duration, which can be a sampling interval duration pre-set according to control requirements.

[0047] Step 102: If the first real-time grid voltage is not within the preset voltage threshold range, the control power converter is switched from normal power generation state to standby state.

[0048] The voltage threshold range can be a pre-set voltage value range based on grid parameters. This voltage value range can be used to determine whether there is a disturbance or power outage in the grid. The first real-time grid voltage can be the real-time grid voltage sampled at any given time.

[0049] In implementation, the power converter's control system can be pre-configured with the aforementioned voltage threshold range to assess whether the periodically sampled real-time grid voltage is normal. If the first sampled real-time grid voltage at a certain moment is not within the preset voltage threshold range (either higher than the upper limit or lower than the lower limit), the grid voltage can be determined to be abnormal, thus controlling the power converter to enter a standby state from normal power generation. Here, normal power generation refers to the normal operation of the power converter. For microinverters, this means the microinverter will convert the DC power output from the photovoltaic panel into AC power according to the PWM control signal and transmit it to the grid. The standby state is a protection mode for the power converter, used to prevent damage to the equipment due to abnormal voltage. For microinverters, this means the microinverter suspends power output to the grid and is in standby or current-limiting protection mode, i.e., in a standby state, and decides whether to resume power generation or shut down based on subsequent control commands.

[0050] Step 103: When the power converter is in the standby state, obtain the duration for which the real-time grid voltage is within the voltage threshold range.

[0051] In implementation, after the power converter enters the voltage-blocking standby state in response to the control command, the control system can continue to periodically collect the real-time grid voltage and determine whether the real-time grid voltage is within the preset voltage threshold range, i.e., monitor whether the grid voltage has returned to normal. Simultaneously, the control system can record the duration for which the real-time grid voltage remains within the voltage threshold range using a timer. Essentially, when the power converter enters the voltage-blocking standby state, timing begins the first time the real-time grid voltage is detected to be within the voltage threshold range. If the real-time grid voltage is detected again and is still within the voltage threshold range, timing continues, accumulating the duration. If the real-time grid voltage is detected again but is not within the voltage threshold range, timing restarts, and the accumulated duration is reset to zero.

[0052] Step 104: When the duration is not less than the second preset duration, control the power converter to enter the normal power generation state.

[0053] The second preset duration can be a preset interval time set according to actual operating needs, which is the interval time for the power converter to resume operation from standby after the power grid returns to normal.

[0054] In practice, after detecting that the real-time grid voltage has remained stable (i.e., continuously within the voltage threshold range) for more than a second preset time, the control system can control the power converter to switch from the standby state back to the normal power generation state. For microinverters, at this time, the microinverter can resume normal operation, converting the DC power output from the photovoltaic panels back into AC power and transmitting it to the grid.

[0055] The control method for the power converter disclosed in this application periodically samples the real-time grid voltage. When the real-time grid voltage is abnormal, the power converter is controlled to enter a standby state with voltage suppression. After the real-time grid voltage returns to normal and remains so for a period of time, the power converter is controlled to enter normal power generation. In this way, by periodically sampling the grid voltage, real-time monitoring of grid voltage changes is achieved, allowing the power converter to switch to standby mode promptly in case of grid anomalies. This avoids abnormal impacts and reduces the risk of component damage. Furthermore, through continuous monitoring and timing mechanisms, the power converter can promptly resume power generation after the grid returns to normal, improving energy utilization efficiency. It also avoids frequent switching of the power converter's operating state due to short-term grid fluctuations, helping to extend the equipment's service life.

[0056] In one embodiment, such as Figure 2As shown, the control system of a power converter can include at least a main controller and a CPLD (Complex Programmable Logic Device). The main controller can be an MCU, DSP, FPGA, etc., and is used to manage the entire power converter's workflow, execute control algorithms, and coordinate various modules in the control system. In this embodiment, an MCU is selected as the main controller; other cases are similar and will not be described in detail. During the operation of the control system, the main controller can generate PWM control parameters based on the collected current, voltage, power, and other signals, and then send the PWM control parameters to the CPLD through a communication link. The CPLD can receive the PWM control parameters transmitted by the main controller and quickly generate PWM signals to control the on and off of power switching devices, thereby affecting the output voltage and current of the power converter. Since the CPLD is a hardware logic device, its processing speed is very fast, capable of responding in nanoseconds, and can generate high-precision control signals in a shorter time. It can be seen that the main controller is mainly responsible for high-level control decisions and parameter calculations, while the CPLD is responsible for executing real-time control logic. This architecture can effectively improve the response speed of the control system, thereby enabling the power converter to achieve high-efficiency and stable power conversion. Furthermore, the state switching processing of the power converter in steps 102 and 104 can essentially be implemented by the MCU sending control commands to the CPLD. That is, after the MCU sends a waveform blocking command to the CPLD, the CPLD can enter a waveform blocking and current limiting state, pausing the transmission of PWM control signals to the power converter, thereby causing the power converter to enter a waveform blocking standby state; after the MCU sends a waveform transmission command to the CPLD, the CPLD can enter a normal waveform transmission state, continuously sending PWM control signals to the power converter, thereby causing the power converter to enter a normal power generation state.

[0057] In one embodiment, the sampling interval (first preset duration) of the real-time grid voltage can be determined by the maximum interrupt frequency of the main controller. The interrupt frequency of the main controller refers to the maximum frequency of interrupt signals that the main controller can process, i.e., the number of times the main controller can respond to interrupt requests per unit time. The maximum interrupt frequency of the main controller is affected by its clock frequency and interrupt handling capability. The clock frequency is the speed at which the main controller executes instructions, and the interrupt handling time is the time taken for the main controller to perform interrupt handling each time it responds to an interrupt. Interrupt handling may include saving the current state, executing interrupt tasks, restoring the state, etc. The higher the complexity of the processing, the longer the time consumed. Specifically, if the maximum interrupt frequency of the main controller is 40kHz, then the sampling frequency of the real-time grid voltage can be 40kHz, and the first preset duration can be 25 microseconds. Thus, by setting the sampling frequency of the grid voltage according to the maximum interrupt frequency of the main controller, the main controller can process grid voltage changes in a timely manner and perform control as needed, thereby ensuring the real-time response capability of the control system, especially in the event of grid anomalies, to protect the power converter. For example, when the power grid is disconnected, the grid voltage changes abruptly within tens of microseconds. Existing grid-related protection response times are all over tens of milliseconds, which cannot protect the power converter in time. The power converter will operate and generate waves under abnormal grid voltage conditions, which can easily lead to internal control disorder, power transistor shoot-through, and subsequent failure or overcurrent. The control method of this embodiment can provide timely wave blocking protection for the power converter in this situation to reduce the risk of failure or overcurrent.

[0058] In one embodiment, the second preset duration can be determined by the power grid frequency. The power grid frequency is the fluctuation frequency of alternating current in the power grid, representing the number of periodic changes in the power grid voltage per unit time. The power grid frequency can be 50Hz, with the power grid voltage alternating positive and negative 50 times per second, and each AC cycle of the power grid lasting 20ms. The second preset duration is used to detect whether the power grid voltage has returned to stability. Correlating the second preset duration with the power grid frequency allows for a more accurate and effective determination of when the power grid has returned to stability.

[0059] Specifically, considering that grid voltage may fluctuate in the short term, choosing a shorter duration might lead to misjudgment, assuming the grid is stable when the actual grid frequency is still changing. This could cause the power converter to frequently switch between generation and standby states, increasing the burden on the control system and potentially negatively impacting the power converter's lifespan. Therefore, a second preset duration can be set to be at least twice the AC cycle length of the grid. This ensures that at least one complete AC cycle is covered to detect grid voltage changes, avoiding misjudgments of grid stability due to short-term voltage fluctuations. On the other hand, if the second preset duration is too long, while it provides a more reliable assessment of grid stability, it might cause unnecessary delays in the control system after the grid stabilizes. The power converter would need to wait a longer time to resume generation, affecting energy utilization efficiency and the dynamic response capability of the control system. Therefore, a second preset duration can be set to be less than twice the AC cycle length of the grid to ensure accurate judgment while reducing unnecessary waiting time.

[0060] Furthermore, when the AC cycle duration of the power grid is 20ms, a second preset duration can preferably be set to 30ms. In the prior art, when the power grid experiences minor fluctuations due to the connection of household appliances, the power converter is triggered to shut down due to wave blocking, resulting in extremely low efficiency. The control method of this embodiment avoids direct wave blocking and shutdown of the power converter under minor fluctuation conditions, thus improving the efficiency of the power converter under conditions of a small number of minor fluctuations and providing wave blocking protection even under severe conditions of numerous minor fluctuations in the power grid.

[0061] In one embodiment, after a relatively long period of standby with wave blocking, the power converter can enter a shutdown state, i.e., as shown below. Figure 3 As shown, after step 103, there can be step 105: if the power converter remains in the standby state for a longer period than the third preset duration, the power converter will enter the shutdown state.

[0062] The third preset duration can be a preset safety time limit, used to indicate the maximum time the power converter can remain in the standby state. If the power converter continues to operate in the standby state for more than the third preset duration, it indicates that the power grid may have long-term instability or serious anomalies and cannot be restored to normal power generation state in a short time. Specifically, when the AC cycle duration of the power grid is 20ms, the third preset duration can preferably be 10 seconds.

[0063] In implementation, after the power converter enters the waveform-sealed standby state, it can start timing to record the duration of this state. If the duration exceeds a third preset duration, the power converter can then transition from waveform-sealed standby to shutdown. It's understandable that the control system will still maintain basic circuit operation in waveform-sealed standby, resulting in some energy consumption. Especially when the power grid cannot be restored for an extended period, continuing to maintain waveform-sealed standby is meaningless; therefore, it can enter shutdown mode.

[0064] The power supply is completely cut off to save energy and extend the lifespan of the equipment. It's worth noting that if the control system is integrated inside the power converter, the entire device (including the control system) will stop working in the shutdown state. Therefore, the monitoring function for real-time grid voltage will also be disabled, and the power converter can only restart when the grid returns to normal and is reactivated by an external signal or through manual intervention by technicians. However, if the control system is external, the monitoring function for real-time grid voltage can continue even when the power converter is in the shutdown state. The control system can continue to monitor the grid status to determine whether to restart the power converter, thus automatically resuming operation of the power converter after the grid returns to normal, without manual intervention.

[0065] In one embodiment, the voltage threshold range can be determined by the real-time voltage of the power grid within a historical period. Accordingly, the following processing can be performed: determine the voltage threshold range corresponding to the current AC cycle of the power grid based on the real-time voltage of the power grid obtained within the historical AC cycle of the power grid.

[0066] The AC cycle in the power grid history refers to one or more AC cycles experienced within a past period, with a total duration that can be a few seconds, a few minutes, etc. Preferably, 50 AC cycles can be selected, that is, when the AC cycle is 20ms, the total duration can be selected as 1s.

[0067] In implementation, the control system samples the real-time voltage of the power grid within each AC cycle and stores the real-time voltage along with the sampling time. When determining the voltage threshold range, the voltage threshold range for each AC cycle can be set. Furthermore, the control system can analyze historical voltage data of the power grid to derive the voltage threshold range for the current AC cycle, i.e., analyze the changing trends (such as fluctuation amplitude and frequency) of the real-time voltage of the power grid over multiple historical AC cycles, and dynamically adjust the voltage threshold range. Of course, the selected historical AC cycles can be multiple consecutive AC cycles adjacent to the current AC cycle, multiple AC cycles with intervals, or AC cycles excluding specific AC cycles, etc., depending on the actual needs of the power grid scenario. In this way, through statistical analysis of past voltage fluctuations, possible future voltage changes can be predicted, making the voltage threshold range more adaptable to the dynamic changes of the power grid. This reduces unnecessary misjudgments of power grid anomalies and the state switching of power converters, improving the stability and reliability of the power system.

[0068] Specifically, the voltage threshold range corresponding to the current AC cycle of the power grid includes the voltage threshold range corresponding to each moment within the current AC cycle of the power grid; the voltage threshold range corresponding to each moment is: the median value is obtained from the real-time voltage of the power grid within N AC cycles in the history of the power grid, and the span is a voltage range with a preset voltage difference.

[0069] In implementation, taking a 20ms AC cycle as an example, the real-time voltage of the power grid fluctuates within one AC cycle in the form of a trigonometric function. At different times within the AC cycle, the real-time voltage will exhibit different values. Correspondingly, a voltage threshold range should be set for each moment within one AC cycle. For example, when the real-time voltage is rising, the overall value of the voltage threshold range at a certain moment may be higher; conversely, when the voltage is falling, the overall value of the voltage threshold range at another moment may be lower. Furthermore, the voltage threshold range can be in the form of voltage intervals, defined based on a median value and voltage difference. Here, the median value can be the center value of the voltage interval or a reference voltage for voltage fluctuations. The median value can be calculated based on the real-time voltage of the power grid over N historical AC cycles. If the voltage is typically higher at certain moments in historical AC cycles, the median value at that moment in the current AC cycle will be correspondingly higher; conversely, it will be lower. The preset voltage difference is the span of the voltage threshold range, that is, the allowable voltage fluctuation range. As long as the real-time voltage fluctuation of the power grid does not exceed this range, it will not affect the normal operation of the power converter. Otherwise, it will trigger the voltage blocking protection for the power converter. The specific value of the preset voltage difference can be set according to the voltage fluctuation of the power system, the effective value of the grid voltage, and the equipment performance of the power converter. In this way, by referring to the voltage fluctuation of historical AC cycles, the voltage threshold at each moment in the current AC cycle is dynamically adjusted, and historical data is used to set the intermediate value, with the preset voltage difference added to tolerate a certain degree of voltage fluctuation without easily triggering the protection mechanism. This not only improves the adaptability to grid fluctuations but also avoids frequent entry into standby or shutdown states, thereby improving the operating efficiency of the power converter.

[0070] It should be understood that although the steps in the flowcharts of the above embodiments 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 above embodiments 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.

[0071] Based on the same inventive concept, this application also provides a control system for a power converter, the control system including a main controller and a CPLD, the main controller being used for:

[0072] The real-time voltage of the power grid is periodically acquired according to the first interval duration;

[0073] If the first real-time voltage of the power grid is not within the preset voltage threshold range, the CPLD is controlled to enter the blocking state from the wave generation state.

[0074] When the CPLD is in the wave blocking state, the duration for which the real-time voltage of the power grid is within the voltage threshold range is obtained;

[0075] When the duration is not less than the second preset duration, the CPLD is controlled to enter the waveform transmission state.

[0076] In one embodiment, the first preset duration is determined by the maximum interrupt frequency of the main controller.

[0077] In one embodiment, the second preset duration is determined by the power grid frequency.

[0078] In one embodiment, the second preset duration is greater than twice the AC cycle duration of the power grid, but less than twice the AC cycle duration.

[0079] In one embodiment, if the power converter remains in the standby state for a duration longer than a third preset duration, the power converter will enter a shutdown state.

[0080] In one embodiment, the main controller is further configured to:

[0081] The voltage threshold range corresponding to the current AC cycle of the power grid is determined based on the real-time voltage of the power grid obtained during the historical AC cycle of the power grid.

[0082] In one embodiment, the voltage threshold range corresponding to the current AC cycle of the power grid includes the voltage threshold range corresponding to each moment within the current AC cycle of the power grid;

[0083] The voltage threshold range corresponding to each moment is as follows: the median value is obtained from the real-time voltage of the power grid within N AC cycles in the history of the power grid, and the span is a voltage range with a preset voltage difference.

[0084] This application also provides a power converter that includes the control system described above.

[0085] This application also provides a chip, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0086] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0087] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0088] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0089] Those skilled in the art will understand that all or part of the processes in 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. When executed, the computer program can include the processes of the embodiments described above. 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 processors involved in the embodiments provided in this application can 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 thereto.

[0090] 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.

[0091] 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 control method for a power converter, characterized in that, The control method includes: The real-time voltage of the power grid is acquired periodically according to the first preset duration. If the first real-time grid voltage is not within the preset voltage threshold range, the power converter is controlled to enter the wave blocking standby state from the normal power generation state. When the power converter is in the standby state, the duration for which the real-time voltage of the power grid is within the voltage threshold range is obtained; When the duration is not less than the second preset duration, the power converter is controlled to enter the normal power generation state.

2. The control method according to claim 1, characterized in that, The control method is applied to the control system of a power converter, which includes at least a main controller and a CPLD. The control method is implemented by the main controller; The CPLD is used to respond to the control commands of the main controller to enter the waveform generation state or the waveform blocking state, so that the power converter enters the normal power generation state or the waveform blocking standby state.

3. The control method according to claim 2, characterized in that, The first preset duration is determined by the maximum interrupt frequency of the main controller.

4. The control method according to claim 1, characterized in that, The second preset duration is determined by the power grid frequency.

5. The control method according to claim 4, characterized in that, The second preset duration is greater than twice the AC cycle duration of the power grid, but less than twice the AC cycle duration.

6. The control method according to claim 1, characterized in that, The control method further includes: If the power converter remains in standby mode for a duration longer than a third preset duration, the power converter will enter a shutdown state.

7. The control method according to claim 1, characterized in that, After periodically acquiring the real-time voltage of the power grid according to the first preset time period, the method further includes: The voltage threshold range corresponding to the current AC cycle of the power grid is determined based on the real-time voltage of the power grid obtained during the historical AC cycle of the power grid.

8. The control method according to claim 7, characterized in that, The voltage threshold range corresponding to the current AC cycle of the power grid includes the voltage threshold range corresponding to each moment within the current AC cycle of the power grid. The voltage threshold range corresponding to each moment is as follows: the median value is obtained from the real-time voltage of the power grid within N AC cycles in the history of the power grid, and the span is a voltage range with a preset voltage difference.

9. A control system for a power converter, characterized in that, The control system includes a main controller and a CPLD, the main controller being used for: The real-time voltage of the power grid is periodically acquired according to the first interval duration; If the first real-time voltage of the power grid is not within the preset voltage threshold range, the CPLD is controlled to enter the blocking state from the wave generation state. When the CPLD is in the wave blocking state, the duration for which the real-time voltage of the power grid is within the voltage threshold range is obtained; When the duration is not less than the second preset duration, the CPLD is controlled to enter the waveform transmission state.

10. A power converter, characterized in that, The power converter includes the control system described in claim 9.

11. A chip comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the control method for the power converter according to any one of claims 1 to 8.

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