Operation control method and apparatus for power converter, and inverter, medium and product

Abstract

The present disclosure relates to an operation control method and apparatus for a power converter, and an inverter, a medium and a product. The method comprises: when a power converter operates in a burst mode, determining whether the current direct-current voltage of a direct-current-side circuit of the power converter meets an operation control condition; and if it is determined that the operation control condition is met, controlling an operation process of the burst mode, wherein controlling the operation process comprises stopping the burst mode or adjusting the output power of the power converter. The present method can ensure the stable operation of a system where a power converter is located.

Description

Operation control methods, devices, inverters, dielectrics, and products of power converters

[0001] Related applications

[0002] This disclosure claims priority to Chinese patent application No. 2024119734528, filed on December 27, 2024, entitled "Operation Control Method, Apparatus, Inverter, Medium and Product of Power Converter", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of circuit control technology, and in particular to a method, apparatus, inverter, medium and product for operating control of a power converter. Background Technology

[0004] A power converter is a commonly used power conversion device; some power converters can convert direct current (DC) to alternating current (AC). Taking the conversion of photovoltaic DC to AC as an example, under low light conditions, the AC output of the power converter is relatively small, resulting in reduced efficiency and increased current distortion. However, by operating the power converter in burst mode, various problems caused by insufficient light intensity can be reduced.

[0005] However, when the power converter operates in burst mode, DC voltage fluctuations can easily reduce its efficiency and affect the stability of the system in which it operates. Summary of the Invention

[0006] Therefore, it is necessary to provide a power converter operation control method, device, inverter, medium, and product that can ensure the stable operation of the system in which the power converter is located, in response to the above-mentioned technical problems.

[0007] In a first aspect, this disclosure provides an operation control method for a power converter. The method includes:

[0008] When the power converter is running in burst mode, determine whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions.

[0009] If the operating control conditions are determined to be met, the operation process of the burst mode is controlled; the control of the operation process includes stopping the burst mode or adjusting the output power of the power converter.

[0010] In one embodiment, the operating control conditions include power adjustment conditions; the power adjustment conditions are determined by the voltage fluctuation range; determining whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions includes: if the current DC voltage does not belong to the voltage fluctuation range, then determining that the current DC voltage meets the power adjustment conditions; controlling the operation process of the burst mode includes: adjusting the output power of the power converter.

[0011] In one embodiment, the voltage fluctuation range is determined as follows:

[0012] Determine the average DC voltage of the DC-side circuit during its historical operation; determine the voltage fluctuation range based on the average DC voltage and the preset fluctuation voltage.

[0013] In one embodiment, adjusting the output power of the power converter includes: determining a reference control power based on the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range; and adjusting the output power of the power converter based on the reference control power.

[0014] In one embodiment, the operation control conditions include a burst mode exit condition, which is determined by a first protection threshold and a second protection threshold, wherein the first protection threshold is less than the second protection threshold; determining whether the current DC voltage of the DC side circuit of the power converter meets the operation control conditions includes: if the current DC voltage is less than the first protection threshold or greater than the second protection threshold, then determining that the current DC voltage meets the burst mode exit condition; controlling the operation process of the burst mode includes: stopping the burst mode.

[0015] In one embodiment, the operating control conditions further include power adjustment conditions, which are determined by a voltage fluctuation range; the voltage fluctuation range is between a first protection threshold and a second protection threshold.

[0016] In one embodiment, the power converter includes a DC-side circuit, a transformer, and an AC-side circuit, wherein the DC-side circuit includes an actively driven full-bridge circuit; the AC-side circuit includes an actively driven bidirectional switched half-bridge circuit; and the DC-side circuit includes a DC-side capacitor. The method further includes: when the power converter is running in burst mode, determining the current capacitance value of the DC-side capacitor in the power converter at a preset operating time; determining whether the attenuation degree of the DC-side capacitor has reached a target attenuation degree based on the current capacitance value of the DC-side capacitor; and stopping the burst mode if the target attenuation degree has been reached.

[0017] In one embodiment, determining whether the attenuation level of the DC-side capacitor has reached the target attenuation level based on the current capacitance value of the DC-side capacitor includes: determining the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor; wherein the initial capacitance value is the capacitance value of the DC-side capacitor when it is not in use; if the capacitance difference is greater than a preset capacitance difference threshold, then it is determined that the attenuation level of the DC-side capacitor has reached the target attenuation level.

[0018] In one embodiment, the method further includes: when the power converter is running in burst mode, determining the current output power of the DC-side circuit; if the current output power of the DC-side circuit is greater than a preset power threshold, then stopping the burst mode.

[0019] In one embodiment, before the power converter operates in burst mode, the method further includes: determining that the current output power of the DC-side circuit is not greater than a preset power threshold; determining whether an entry condition is met based on the current DC voltage of the DC-side circuit; and if the entry condition is met, controlling the power converter to operate in burst mode.

[0020] In one embodiment, determining whether the entry condition is met based on the current DC voltage of the DC-side circuit includes: determining that the current DC voltage of the DC-side circuit belongs to a first voltage range within a preset duration, and then determining that the entry condition is met.

[0021] Secondly, this disclosure also provides an operation control device for a power converter. The device includes:

[0022] The judgment module is used to determine whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions when the power converter is running in burst mode.

[0023] The control module is used to control the operation of the burst mode if it is determined that the operation control conditions are met; wherein controlling the operation includes stopping the burst mode or adjusting the output power of the power converter.

[0024] In one embodiment, the operating control conditions include power adjustment conditions; the power adjustment conditions are determined by the voltage fluctuation range; the judgment module is specifically used for:

[0025] If the current DC voltage does not fall within the voltage fluctuation range, then the current DC voltage is determined to meet the power adjustment conditions.

[0026] The control module is specifically used to adjust the output power of the power converter.

[0027] In one embodiment, the device further includes an interval determination module for:

[0028] Determine the average DC voltage of the DC-side circuit during its historical operation; determine the voltage fluctuation range based on the average DC voltage and the preset fluctuation voltage.

[0029] In one embodiment, the control module is specifically configured to: determine a reference control power based on the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range; and adjust the output power of the power converter based on the reference control power.

[0030] In one embodiment, the operation control conditions include a burst mode exit condition, which is determined by a first protection threshold and a second protection threshold, wherein the first protection threshold is less than the second protection threshold.

[0031] The judgment module is specifically used to: determine that the current DC voltage meets the emergency mode exit condition if the current DC voltage is less than the first protection threshold or greater than the second protection threshold;

[0032] The control module is specifically used to stop the burst mode.

[0033] In one embodiment, the operating control conditions further include power adjustment conditions, which are determined by a voltage fluctuation range; the voltage fluctuation range is between a first protection threshold and a second protection threshold.

[0034] In one embodiment, the power converter includes a DC-side circuit, a transformer, and an AC-side circuit. The DC-side circuit includes an actively driven full-bridge circuit; the AC-side circuit includes an actively driven bidirectional switched half-bridge circuit; and the DC-side circuit includes a DC-side capacitor. The device further includes a capacitor detection module for: determining the current capacitance value of the DC-side capacitor in the power converter at a preset operating time when the power converter is operating in burst mode; determining whether the attenuation level of the DC-side capacitor has reached a target attenuation level based on the current capacitance value; and stopping the burst mode if the target attenuation level has been reached.

[0035] In one embodiment, the capacitance detection module is specifically used to: determine the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor; wherein the initial capacitance value is the capacitance value of the DC-side capacitor when it is not in use; if the capacitance difference is greater than a preset capacitance difference threshold, then it is determined that the attenuation degree of the DC-side capacitor has reached the target attenuation degree.

[0036] In one embodiment, the device further includes a power detection module for: determining the current output power of the DC-side circuit when the power converter is running in burst mode; and stopping the burst mode if the current output power of the DC-side circuit is greater than a preset power threshold.

[0037] In one embodiment, the device further includes a condition determination module for: determining that the current output power of the DC-side circuit is not greater than a preset power threshold before the power converter operates in burst mode; determining whether an entry condition is met based on the current DC voltage of the DC-side circuit; and controlling the power converter to operate in burst mode if the entry condition is met.

[0038] In one embodiment, the condition determination module is specifically used to: determine that the current DC voltage of the DC side circuit belongs to the first voltage range within a preset duration, and then determine that the entry condition is met.

[0039] Thirdly, this disclosure also provides an inverter, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the method described in any of the first aspects above.

[0040] Fourthly, this disclosure also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in any one of the first aspects above.

[0041] Fifthly, this disclosure also provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the method described in any one of the first aspects.

[0042] The aforementioned power converter operation control method, device, inverter, dielectric, and product, when the power converter operates in burst mode, can determine whether the current DC voltage of the DC-side circuit of the power converter meets the operation control conditions. If it is determined that the operation control conditions are met, the operation process of burst mode is controlled. This control includes stopping the burst mode or adjusting the output power of the power converter. By setting operation control conditions, the power converter can determine that the current DC voltage output has an impact on the system if the current DC voltage of the DC-side circuit does not meet the operation control conditions. In this case, timely control of the power converter's burst mode operation ensures stable operation and prevents the system's stability from decreasing due to fluctuations in the current DC voltage affecting the power converter's efficiency. Controlling the power converter's operation process, including stopping the burst mode or adjusting the output power, not only ensures stable operation but also improves the flexibility of power converter control. It is understandable that if the burst mode is exited directly without meeting the operating control conditions, the power converter will still remain inefficient for a certain period of time, even after switching to other operating modes. The operating control method provided in this disclosure can not only stop the burst mode but also adjust the output power of the power converter. Based on this, the operating efficiency of the power converter can be improved in a timely manner, avoiding frequent switching of the power converter's operating mode and ensuring that the power converter's operating efficiency recovers to a higher value as soon as possible, effectively ensuring the stability of the power converter and its system. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments or conventional technologies of this disclosure, the accompanying drawings used in the description of the embodiments or conventional technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the disclosed drawings without creative effort.

[0044] Figure 1a is an application environment diagram of the power converter in one embodiment;

[0045] Figure 1b is a schematic diagram of the circuit structure of the power converter in one embodiment;

[0046] Figure 2 is a flowchart illustrating the operation control method of a power converter in one embodiment;

[0047] Figure 3 is a flowchart illustrating the process of determining the voltage fluctuation range in one embodiment;

[0048] Figure 4 is a schematic diagram of the process for adjusting the output power of a power converter in one embodiment;

[0049] Figure 5 is a schematic diagram showing the correspondence between DC voltage fluctuation and a preset voltage threshold in one embodiment;

[0050] Figure 6 is a flowchart illustrating the process of determining whether to stop the burst mode based on the current capacitance value in one embodiment;

[0051] Figure 7 is a schematic diagram comparing DC voltages under different scenarios in one embodiment;

[0052] Figure 8 is a flowchart illustrating the process of determining the attenuation level of the DC-side capacitor in one embodiment.

[0053] Figure 9 is a schematic diagram of the process of controlling the power converter to enter burst mode in one embodiment;

[0054] Figure 10 is a schematic diagram showing the correspondence between DC voltage fluctuation and a preset voltage threshold in another embodiment;

[0055] Figure 11 is a flowchart illustrating the operation of the power converter in one embodiment;

[0056] Figure 12 is a structural block diagram of the operation control device of the power converter in one embodiment. Detailed Implementation

[0057] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0058] To make the above-described objects, features, and advantages of this disclosure more apparent and understandable, specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that many specific details are set forth in the following description to provide a full understanding of this disclosure; however, this disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this disclosure. Therefore, this disclosure is not limited to the specific embodiments disclosed below.

[0059] 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 disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure.

[0060] It is understandable that "at least one" refers to one or more, while "multiple" refers to two or more.

[0061] 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.

[0062] Power converters are electrical conversion devices used to transform electrical energy from one form to another, enabling energy transmission and control under different power requirements. Power converters can be microinverters, energy storage converters, etc. For example, a microinverter can convert DC power to AC power. The DC input of the microinverter is connected to a DC source (such as a photovoltaic module), and the AC output of the power converter can be connected to the AC power grid and AC equipment.

[0063] Taking a microinverter that converts photovoltaic DC power to AC power as an example, under low light conditions, the AC power output of the microinverter is relatively small, resulting in reduced efficiency and increased current distortion. However, by operating in burst mode, the microinverter can reduce various problems caused by insufficient light intensity.

[0064] The burst mode is an intermittent operation mode that uses the energy accumulation of the DC-side capacitor to achieve a relatively high output current when the photovoltaic module power is low, thereby improving the working efficiency of the micro-inverter.

[0065] However, during burst mode operation, the voltage of the DC-side capacitor in the microinverter will fluctuate significantly, resulting in a series of effects such as reduced MPPT (Maximum Power Point Tracking) efficiency of the microinverter, which in turn affects the stability of the system in which the microinverter is located.

[0066] In view of this, the present disclosure provides an operation control method for a power converter, which can determine whether to exit the burst mode or adjust the output power of the power converter in a timely manner based on the current DC voltage of the DC side circuit during the operation of the power converter in burst mode. Based on these two control methods, the impact of DC voltage fluctuations caused by burst mode on the operational stability of the system where the power converter is located can be reduced, and the system can be prevented from erroneously shutting down and reducing power generation.

[0067] It should be noted that the execution subject of the method provided in this disclosure can be a power converter. Optionally, the execution subject of the method can also be the operation control device of the power converter. The operation control device of the power converter can be implemented as part or all of the power converter through software, hardware, or a combination of software and hardware; for example, the power converter includes a control component, and the operation control device of the power converter is deployed in the control component to execute the operation control method. The power converter can operate in burst mode and other modes to convert electrical energy from one form to another. In other words, the operation control method of the power converter provided in this disclosure can be used for various types of power converters that can operate in burst mode. Optionally, the power converter can be an inverter (DC / AC) for converting direct current to alternating current, such as a microinverter, which is not fully exemplified here. Optionally, in an exemplary application scenario, as shown in the application environment diagram in Figure 1a, the first end of the power converter is connected to a photovoltaic panel (PV) or other DC power source; the second end of the power converter is connected to the power grid. Exemplarily, as shown in Figure 1b, the power converter includes a DC-side circuit, a transformer, and an AC-side circuit. The DC-side circuit includes an actively driven full-bridge circuit; the AC-side circuit includes an actively driven bidirectional switching half-bridge circuit; and the DC-side circuit includes a DC-side capacitor. As shown in Figure 1b, the first bridge arm of the full-bridge circuit includes switching transistors Q1 and Q2, and the second bridge arm includes switching transistors Q3 and Q4. Points A and B are the load interfaces of the full-bridge circuit. r The transformer is used; the upper arm of the bidirectional switching half-bridge circuit is implemented based on a bidirectional switch composed of switching devices Q5 and Q6, and the lower arm is implemented based on a bidirectional switch composed of switching devices Q7 and Q8. The midpoint C of the arm is connected through the resonant inductor L. r Connected to transformer T r V dc V represents DC voltage. ac This refers to the AC side grid voltage.

[0068] The power converter includes at least the DC-side capacitor Cpv and DC / AC module shown in Figure 1a. The power converter is used to convert the DC power generated by the photovoltaic panel into AC power. In the following method embodiments, the power converter is used as the executing entity for description.

[0069] In one embodiment, as shown in Figure 2, a power converter operation control method is provided, including the following steps:

[0070] Step 201: When the power converter is running in burst mode, determine whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions.

[0071] Burst mode is an energy-saving operating mode for inverters. In this mode, the power converter does not operate continuously, but outputs power in short pulses when needed. For example, an operating cycle includes a charging cycle and a discharging cycle. During a charging cycle, the power converter acquires energy from the DC-side circuit, which accumulates on the DC-side capacitor. During the discharging cycle, the capacitor and the preceding power converter or PV module together provide energy to the subsequent circuit, outputting AC power. Therefore, when operating in burst mode, the power converter alternates between charging and discharging over multiple consecutive operating cycles.

[0072] The current DC voltage is the DC voltage output from the DC-side circuit to the power converter at the current moment. Because it is connected to the DC-side circuit, the power converter can detect the current DC voltage of the DC-side circuit. Referring to Figure 1a, the power converter includes a DC-side capacitor, and the current DC voltage can be the voltage across the DC-side capacitor.

[0073] Because the DC voltage of the DC-side circuit fluctuates during the operation of the power converter in burst mode, it is affected by the grid conditions and environmental conditions. Therefore, it is necessary to obtain the current DC voltage and determine whether the fluctuation of the current DC voltage is too large based on the current DC voltage and the operating control conditions, so as to determine whether the operation of the power converter needs to be adjusted in a timely manner.

[0074] The power converter incorporates operating control conditions. These conditions are determined based on at least one preset voltage threshold related to the DC voltage of the DC-side circuit. Therefore, it can be determined whether the operating control conditions are met based on the current DC voltage. Optionally, some preset voltage thresholds are fixed values ​​determined experimentally beforehand; others are determined during the operation of the power converter.

[0075] Step 202: If it is determined that the operation control conditions are met, then the operation process of the sudden mode is controlled.

[0076] If the operating control conditions are met, it means that the current DC voltage fluctuations will lead to lower conversion performance of the power converter, resulting in the power converter's operating efficiency being lower than the target operating efficiency. In this case, by controlling the operation of the burst mode, the DC voltage fluctuations are kept within a controllable voltage range.

[0077] The efficiency of a power converter is the ratio of output power to input power, representing the converter's energy conversion efficiency. For example, when a power converter operates based on the MPPT algorithm, it needs to adjust its operating point according to the output characteristics of the PV module to achieve maximum power output. However, when the DC voltage fluctuates excessively, the MPPT algorithm struggles to accurately determine the actual operating state of the PV module, leading to algorithm failure or reduced efficiency. For instance, when the PV module is stably operating at its maximum power point, the input power of the power converter is constant, while the output power is transient, resulting in a momentary power imbalance between the input and output. This imbalance manifests as a disturbance component in the output voltage of the PV module. If the DC voltage fluctuation is too large, this disturbance becomes more pronounced, affecting the effectiveness of the power decoupling stage and thus reducing the efficiency of the MPPT algorithm.

[0078] Therefore, when the PV module is operating stably at its maximum power point, it is necessary to ensure that the DC voltage fluctuation is within a controllable voltage range. At this time, the MPPT algorithm can accurately determine the actual operating state of the PV module and make accurate adjustments, thereby ensuring that the MPPT efficiency of the power converter is high.

[0079] Based on this, in the embodiments of this disclosure, the operation of the power converter in burst mode can be precisely controlled in a timely manner based on the operation control conditions, so as to ensure that the DC voltage fluctuation is within the controllable voltage range, thereby ensuring that the power converter has high operating efficiency.

[0080] In this embodiment of the disclosure, controlling the operation process includes stopping the burst mode or adjusting the output power of the power converter.

[0081] In other words, in one possible implementation, when it is determined that the operating control conditions are met and the current DC voltage fluctuation causes the power converter's operating efficiency to drop below the minimum operating efficiency, it is determined that it is no longer suitable to continue operating in the burst mode. Therefore, the power converter is controlled to stop operating in the burst mode, thereby alleviating the current DC voltage fluctuation range. This can reduce the risk of overvoltage and undervoltage faults in the DC side circuit in a timely manner, and avoid situations such as reduced power generation caused by the shutdown of the system where the power converter is located due to excessive voltage fluctuations.

[0082] Optionally, when burst mode is stopped, i.e., the power converter exits burst mode, the power converter can switch to normal mode operation. In normal mode, the power converter continuously performs the process of receiving DC power, converting DC power to AC power, and outputting AC power to the subsequent circuitry. That is, in normal mode, the power converter can continuously output AC power.

[0083] In another optional implementation, when it is determined that the operating control conditions are met, and the fluctuation level of the current DC voltage causes the power converter's operating efficiency to be lower than the second operating efficiency, the second operating efficiency can be higher than the first operating efficiency. That is, in this case, the burst mode can remain in effect, but the power converter's operating efficiency is still low. To bring the current DC voltage fluctuation back within a controllable voltage range and ensure higher power converter operating efficiency, the output power of the power converter can be adjusted.

[0084] For example, adjusting the output power can reduce the current output power of the power converter. When the output power of the power converter decreases, the energy drawn by the power converter from the capacitor decreases, and correspondingly, the voltage fluctuation range on the DC side capacitor will decrease, thus falling back to the controllable voltage range.

[0085] Optionally, the fluctuation of the current DC voltage when determining to perform the step of regulating the output power of the power converter is less than the fluctuation of the current DC voltage when determining to perform the step of stopping the burst mode.

[0086] In the above-mentioned power converter operation control method, DC voltage is used as a parameter to determine whether the operation control conditions are met. This is because DC voltage best reflects the magnitude and changes in the output energy of the power converter. The power converter contains multiple devices and operates under complex conditions, resulting in many variables affecting the output energy. The influence of these variables on the output energy is ultimately reflected in the DC voltage. Using DC voltage as a parameter to determine whether the operation control conditions are met covers the most variables affecting the entry and exit of burst modes and is compatible with almost all operating conditions. Therefore, the adjustment of the power converter's operation process will be more precise.

[0087] When the power converter operates in burst mode, it can determine whether the current DC voltage of the DC-side circuit meets the operating control conditions. If the operating control conditions are met, the burst mode operation is controlled. This control includes stopping the burst mode or adjusting the output power of the power converter. By setting operating control conditions, the power converter can determine if the current DC voltage output affects the system when the current DC voltage does not meet the operating control conditions. In this case, timely control of the power converter's burst mode operation ensures stable operation and prevents the system's stability from being reduced due to fluctuations in DC voltage affecting the power converter's efficiency. Controlling the power converter's operation, including stopping the burst mode or adjusting the output power, not only ensures stable operation but also improves the flexibility of power converter control. Furthermore, it is understandable that if the burst mode is exited directly without meeting the operating control conditions, the power converter will still have low operating efficiency for a certain period of time, even if it switches to other operating modes. This disclosure not only provides a control method to stop the burst mode, but also a control method to adjust the output power of the power converter. Based on this, the operating efficiency of the power converter can be improved in a timely manner, which not only avoids frequent switching of the operating mode of the power converter, but also ensures that the operating efficiency of the power converter recovers to a higher value as soon as possible.

[0088] In one embodiment, since stopping the burst mode and adjusting the output power of the power converter are two different control processes, different operating control conditions are set for different control processes. This allows the power converter to accurately determine which control process to execute based on the operating control conditions currently met by the DC voltage, ensuring the precise operation of the power converter.

[0089] The following describes the process of adjusting the output power of the power converter and the judgment process of the corresponding operating control conditions.

[0090] In one embodiment, determining whether the current DC voltage of the DC-side circuit of the power converter meets the operating control conditions includes: if the current DC voltage does not fall within the voltage fluctuation range, then determining that the current DC voltage meets the power adjustment conditions. Controlling the operation process in burst mode includes: adjusting the output power of the power converter.

[0091] The operating control conditions include power adjustment conditions. These power adjustment conditions are determined by the voltage fluctuation range. The power converter can determine whether the current DC voltage of the DC-side circuit does not fall within the voltage fluctuation range. If it is determined that it does not fall within the voltage fluctuation range, then the power adjustment conditions are met. If the power adjustment conditions are met, the output power of the power converter is adjusted.

[0092] Optionally, the voltage fluctuation range is determined during the operation of the power converter. For example, it could be the voltage fluctuation range determined while the power converter is operating in burst mode.

[0093] Optionally, the voltage fluctuation range is determined before the current DC voltage is determined. In other words, the current DC voltage is the DC voltage of the DC-side circuit at the current operating moment, while the voltage fluctuation range can be determined based on the DC voltage of historical operating phases prior to the current operating moment.

[0094] This disclosure provides a dynamic output power adjustment mechanism that determines in real time whether the current DC voltage meets the power adjustment conditions. If the conditions are met, the output power of the power converter is dynamically adjusted promptly. This ensures that even when the DC-side circuit provides different current DC voltages, the current DC voltage can fall back to a controllable range without exiting burst mode, allowing the power converter to continue operating normally in burst mode. Furthermore, the mechanism determines whether the power adjustment conditions are met based on the relationship between the current DC voltage and the voltage fluctuation range, improving the efficiency of determining whether output power adjustment is needed with low complexity.

[0095] In one embodiment, Figure 3 illustrates a flowchart for determining a voltage fluctuation range. The voltage fluctuation range is determined as follows:

[0096] Step 301: Determine the average DC voltage of the DC-side circuit during the historical operation phase.

[0097] Optionally, the historical operation phase includes multiple historical operation cycles prior to the current operation moment.

[0098] Optionally, the power converter samples the DC voltage of the DC-side circuit at different operating times. After each acquisition of the DC voltage, it stores that voltage. It can be understood that the DC voltage acquired before the current operating time is the DC voltage sampled during historical operating phases.

[0099] In one optional implementation, the power converter acquires the historical DC voltages sampled in the n historical operating cycles prior to the current operating moment, calculates the average value of each historical DC voltage, and obtains the average DC voltage of the historical operating phase.

[0100] In another optional implementation, the power converter acquires the historical DC voltages sampled in the n historical operating cycles prior to the current operating time. For each historical operating cycle, the historical average DC voltage corresponding to that historical operating cycle is calculated based on the historical DC voltages sampled within that historical operating cycle. Thus, the historical average DC voltage corresponding to each historical operating cycle can be obtained. The average value of each historical average DC voltage is calculated to obtain the average DC voltage of the aforementioned historical operating phase.

[0101] Optional, n≥1.

[0102] Optionally, the n historical running cycles are the n historical running cycles that are closest to the current running time.

[0103] Optionally, the number of historical DC voltages sampled in the historical operating cycle is the same. That is, the power converter samples the current DC voltage at fixed time intervals, stores the current DC voltage, and determines whether the operating control conditions are met based on the current DC voltage, and then determines whether to control the operation process.

[0104] Step 302: Determine the voltage fluctuation range based on the average DC voltage and the preset fluctuation voltage.

[0105] A preset fluctuation voltage is pre-installed in the power converter. This preset fluctuation voltage can be determined in advance through experiments.

[0106] For example, in an experimental environment, an experimental power converter is set up for testing. The preset fluctuation voltage is determined based on the DC-side capacitor of the experimental power converter, the output power and output voltage of the experimental power converter, and the operating mode of the experimental power converter.

[0107] For example, the preset fluctuation voltage can be 5V. It is understood that different power converters may have different preset fluctuation voltages set according to requirements, and this is not an exhaustive example.

[0108] In one optional implementation, determining the voltage fluctuation range based on the average DC voltage and a preset fluctuation voltage includes: using the difference between the average DC voltage and the preset fluctuation voltage as the left interval endpoint voltage; and using the sum of the average DC voltage and the preset fluctuation voltage as the right interval endpoint voltage. The left and right interval endpoint voltages constitute the voltage fluctuation range. For example, the average DC voltage is U... dc_avg If the preset fluctuation voltage is ΔU, then the voltage at the left interval endpoint U pro_min =U dc_avg -ΔU; Voltage at the right interval endpoint U pro_max =U dc_avg +ΔU. The voltage fluctuation range is a closed interval: [U pro_min Upro_max ].

[0109] It is understandable that as the power converter continues to operate, the historical operating phases are constantly updated over time, and therefore the average DC voltage and voltage fluctuation range of the historical operating phases are constantly updated.

[0110] In this embodiment, the voltage fluctuation range is dynamically determined in real time based on the average DC voltage during historical operation, thus obtaining the power adjustment conditions. This allows for real-time judgment of whether the current DC voltage meets the power adjustment conditions. Based on this judgment, the output power of the power converter is adjusted to match the operation of the DC-side circuit, enabling the DC voltage fluctuation to quickly return to a controllable range while ensuring the accuracy and precision of the entire adjustment process. Furthermore, since the voltage fluctuation range can be determined based on the average DC voltage during historical operation and the preset fluctuation voltage, this method can accurately determine the voltage fluctuation range with low complexity, thereby ensuring the efficiency of voltage fluctuation range updates.

[0111] In one embodiment, Figure 4 illustrates a flowchart for adjusting the output power of a power converter. Adjusting the output power of the power converter includes:

[0112] Step 401: Determine the reference control power based on the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range.

[0113] Here, the interval endpoint voltage includes the left and right interval endpoint voltages of the voltage fluctuation intervals mentioned above.

[0114] In one optional implementation, if the current DC voltage does not belong to the voltage fluctuation range and the current DC voltage is less than the voltage at the left end of the range, then the reference control power is determined based on the difference between the voltage at the left end of the voltage fluctuation range and the current DC voltage.

[0115] In another optional implementation, if the current DC voltage does not belong to the voltage fluctuation range and the current DC voltage is greater than the right interval endpoint voltage, then the reference control power is determined based on the difference between the current DC voltage and the right interval endpoint voltage of the voltage fluctuation range.

[0116] Optionally, a power relationship mapping table is pre-deployed in the power converter; this table includes multiple sets of voltage difference values ​​and candidate control powers. After determining the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range, the power relationship mapping table is consulted based on this difference, and the candidate control power corresponding to this difference is used as the reference control power.

[0117] Step 402: Adjust the output power of the power converter according to the reference control power.

[0118] For example, if the determined reference control power is less than the current output power of the power converter, the output power of the power converter can be adjusted to the value of the reference control power.

[0119] In this embodiment, based on the current DC voltage and voltage fluctuation range, the required reference control power is determined. The current output power of the power converter is adaptively adjusted based on the reference control power to ensure that the current output power adjustment matches the degree of DC voltage fluctuation, thus guaranteeing the accuracy of the adjustment. Therefore, by taking this protective measure of adjusting the output power, the power converter continues to operate stably in burst mode, maintaining high MPPT efficiency and reducing current distortion rate by intermittently supplying power to the grid.

[0120] The following describes the control process for stopping the sudden mode and the judgment process for the corresponding operation control conditions.

[0121] In one embodiment, determining whether the current DC voltage of the DC-side circuit of the power converter meets the operating control conditions includes: if the current DC voltage is less than a first protection threshold or greater than a second protection threshold, then determining that the current DC voltage meets the burst mode exit condition. Controlling the operation of the burst mode includes: stopping the burst mode.

[0122] The operational control conditions also include emergency mode exit conditions. These emergency mode exit conditions are determined by a first protection threshold and a second protection threshold, where the first protection threshold is less than the second protection threshold.

[0123] Optionally, the first protection threshold and the second protection threshold are fixed values ​​determined in advance through experiments. They can be pre-deployed in the power converter. For example, in an experimental environment, multiple scenarios are provided where the experimental power converter detects excessively high or low DC voltages, requiring the experimental power converter to exit burst mode. The first protection threshold and the second protection threshold are determined based on the DC voltage detected in the DC-side circuit when exiting burst mode in these scenarios.

[0124] It is understandable that if the current DC voltage is less than the first protection threshold, it indicates that the current DC voltage is too low; if the current DC voltage is greater than the second protection threshold, it indicates that the current DC voltage is too high. Both excessively low and excessively high DC voltages pose a risk of power converter shutdown. Therefore, it is necessary to exit the emergency mode promptly.

[0125] In this embodiment, when the current DC voltage is less than the first protection threshold or greater than the second protection threshold, the system promptly exits the burst mode and switches to normal mode. In normal mode, the power converter needs to continuously output AC power, and the DC-side capacitor does not continuously accumulate energy as in burst mode. Therefore, the energy accumulated in the DC-side capacitor is lower than in burst mode. As energy continues to be converted, the voltage across the DC-side capacitor decreases, thus reducing the risk of power converter failure and shutdown due to overvoltage and undervoltage, preventing power converter shutdown. In this way, the power converter can operate normally and output AC power throughout the entire process of switching from burst mode to normal mode, without reducing the power generation of the system containing the power converter.

[0126] In one embodiment, as mentioned above, the operating control conditions further include power adjustment conditions, which are determined by a voltage fluctuation range. Furthermore, the voltage fluctuation range is between a first protection threshold and a second protection threshold.

[0127] Optionally, Figure 5 shows a schematic diagram illustrating the correspondence between DC voltage fluctuations and a preset voltage threshold. Here, the first protection threshold U... exit_min The voltage U at the left end of the voltage fluctuation range is less than the voltage of the range. pro_min Second protection threshold U exit_max The voltage U at the right end of the voltage fluctuation range is greater than the voltage at the right end of the range. pro_max .

[0128] It is understandable that if the current DC voltage is within the voltage fluctuation range, the power converter will operate normally in burst mode. Therefore, as shown in Figure 5, the first protection threshold U... exit_min and the voltage U at the left interval endpoint pro_min The voltage protection range is defined by the two voltage thresholds; the second protection threshold U exit_max and the right interval endpoint voltage U pro_max This forms another voltage protection range. The first protection threshold U... exit_min Second protection threshold U exit_max Outside of these ranges, the exit range for burst mode needs to be exited. Correspondingly, if the current DC voltage is within the voltage protection range, the output power of the power converter is adjusted to achieve undervoltage protection; if the current DC voltage is within the exit range, burst mode is stopped to achieve overvoltage exit.

[0129] Optionally, the values ​​of the first protection threshold and the voltage at the left interval endpoint can be negative, depending on the operation of the power converter, and no specific limitation is made here.

[0130] Since the voltage fluctuation range is between the first protection threshold and the second protection threshold, if it is determined that the power adjustment condition is not met, that is, the current DC voltage is within the voltage fluctuation range, then the current DC voltage must also be between the first protection threshold and the second protection threshold, which does not meet the emergency mode exit condition.

[0131] Therefore, optionally, it can first be determined whether the current DC voltage meets the power adjustment conditions based on the voltage fluctuation range. If the power adjustment conditions are met, then it can be determined whether the current DC voltage meets the burst mode exit conditions. If it is determined that the current DC voltage does not meet the power adjustment conditions, i.e., the current DC voltage is within the voltage fluctuation range, then the process of determining whether the current DC voltage meets the burst mode exit conditions can be skipped, thereby reducing the computing power of the power converter.

[0132] As mentioned above, power converters include DC-side capacitors, which will age or become damaged during use. Since the degree of DC voltage fluctuation is inversely proportional to the capacitance value of the DC-side capacitor, if the DC-side capacitor ages or becomes damaged, it will also cause excessive DC voltage fluctuations when the power converter operates in burst mode.

[0133] Therefore, embodiments of this disclosure can also determine whether it is necessary to exit the burst mode in a timely manner based on the DC-side capacitor, ensuring the normal operation of the power converter. Optionally, the DC-side capacitor in the power converter is a capacitor bank composed of multiple capacitors, and the capacitance value of the DC-side capacitor is the equivalent capacitance value of the multiple capacitors.

[0134] In one embodiment, the power converter of this disclosure includes a DC-side circuit, a transformer, and an AC-side circuit, wherein the DC-side circuit includes an actively driven full-bridge circuit; the AC-side circuit includes an actively driven bidirectional switching half-bridge circuit; and the DC-side circuit includes a DC-side capacitor C. DC It should be noted that Cpv in Figure 1a and C in Figure 2 are different. DC It can be the same capacitor.

[0135] Figure 6 illustrates a flowchart of a method for determining whether to stop burst mode based on the current capacitance value. This method further includes:

[0136] Step 601: When the power converter is running in burst mode, determine the current capacitance value of the DC-side capacitor in the power converter at a preset running time.

[0137] Optionally, the preset operating time is the end time of the first operating cycle of the power converter in burst mode. That is, the current capacitor value is determined at the end of the first operating cycle.

[0138] Optionally, the preset running time can also be the end time of any running cycle.

[0139] Among them, the maximum DC voltage U of the DC-side circuit detected by the power converter during the first operating cycle can be used as a reference. H Minimum DC voltage U L Total operating cycle duration T, DC current I of DC-side circuit at preset operating time. pv and the DC voltage U at the preset operating time PV Determine the current capacitance value of the DC-side capacitor.

[0140] For example, based on the circuit configuration of the power converter, it can be seen that:

[0141] Therefore, the estimated value C of the DC-side capacitor is... DC for:

[0142] Therefore, the current capacitance value C can be estimated using the above formula. DC .

[0143] Step 602: Determine whether the attenuation level of the DC-side capacitor has reached the target attenuation level based on the current capacitance value of the DC-side capacitor.

[0144] As the DC-side capacitor is used continuously, its capacitance value decreases, meaning it continuously degrades. Therefore, the current capacitance value can be used to determine whether the capacitor has degraded to the target level. For example, Figure 7 shows a comparison of DC voltage under different scenarios. It can be seen that when the DC-side capacitor in the power converter is a normal capacitor that has not yet reached the target degrade level, the DC voltage fluctuation amplitude of the DC-side circuit is small. However, when the DC-side capacitor in the power converter is an aged capacitor that has reached the target degrade level, the DC voltage fluctuation amplitude of the DC-side circuit is large.

[0145] Optionally, the target attenuation level is characterized by a preset capacitance value or a preset capacitance value range.

[0146] Step 603: If the target attenuation level is reached, stop the burst mode.

[0147] If the target attenuation level is reached, it indicates that the current capacitance value has attenuated excessively, which will have a significant impact on the DC voltage of the DC side circuit. Therefore, it is necessary to stop the burst mode in order to avoid these effects in time.

[0148] In this embodiment, the current capacitance value of the DC-side capacitor is determined to determine whether the DC-side capacitor has excessively degraded, and the burst mode is exited in a timely manner. This avoids excessive DC voltage fluctuations caused by reduced capacitance, which could lead to overvoltage or undervoltage, and also reduces the impact on the MPPT tracking efficiency of the power converter, ensuring its performance. It can be understood that by combining the setting of operating control conditions with the degree of DC-side capacitor degradation to determine whether to stop the burst mode, the control process of the power converter is more comprehensive, and the stability of the power converter during burst mode operation is guaranteed.

[0149] In one embodiment, Figure 8 illustrates a flowchart for determining the attenuation level of the DC-side capacitor. Determining whether the attenuation level of the DC-side capacitor has reached the target attenuation level based on its current capacitance value includes:

[0150] Step 801: Determine the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor.

[0151] The initial capacitance value is the value of the DC-side capacitor when it is not in use. The power converter has an initial capacitance value pre-installed.

[0152] Step 802: If the capacitance difference is greater than the preset capacitance difference threshold, then it is determined that the attenuation of the DC side capacitor has reached the target attenuation level.

[0153] The power converter has a preset capacitance difference threshold. The calculated capacitance difference is compared with the preset capacitance difference threshold. If it is greater than the preset capacitance difference threshold, it means that the DC-side capacitor has degraded excessively and reached the target degradation level.

[0154] In this embodiment of the disclosure, based on the initial capacitance value and the preset capacitance difference threshold, the power converter can accurately and efficiently determine whether the DC-side capacitor has reached the target attenuation level, and improve the flexibility of the power converter operation control.

[0155] In one embodiment, the method further includes: when the power converter is running in burst mode, determining the current output power of the DC-side circuit; if the current output power of the DC-side circuit is greater than a preset power threshold, then stopping the burst mode.

[0156] The current output power of the DC-side circuit can refer to the output power of the DC-side circuit at the current operating moment.

[0157] The current output power of the DC-side circuit is compared with the preset power threshold. When it is determined that the current output power of the DC-side circuit is greater than the preset power threshold, it means that the current power is large enough and there is no need to operate in the burst mode to ensure the output power. Therefore, it is necessary to exit the burst mode. At this time, the power converter can switch to normal mode to ensure normal power generation.

[0158] Optionally, if it is determined that the current output power of the DC-side circuit is greater than a preset power threshold, then the current output power is continuously monitored to see if it is greater than the preset power threshold. If the current output power of the DC-side circuit is greater than the preset power threshold throughout the first duration, then the burst mode is stopped. It is understood that at a certain moment, the DC voltage may suddenly change significantly, causing the output power of the DC-side circuit to exceed the preset power threshold. If the DC voltage drops in the next moment, the output power will also drop below the preset power threshold. Considering this situation, in this embodiment, the burst mode is stopped only when it is determined that the current output power of the DC-side circuit is greater than the preset power threshold throughout the first duration. This avoids the possibility of incorrect switching of the power converter's operating mode due to a sudden increase in the output power of the DC-side circuit, ensuring the stability of the power converter's operating mode.

[0159] The control process of the power converter during burst mode operation has been described above. Furthermore, to ensure stable operation of the power converter in burst mode and avoid switching back and forth between burst mode and normal mode, entry conditions are set to ensure that the power converter enters burst mode under stable conditions.

[0160] In one embodiment, Figure 9 illustrates a flowchart of controlling a power converter to enter burst mode. The method further includes:

[0161] Step 901: Determine that the current output power of the DC side circuit is not greater than the preset power threshold.

[0162] Before the power converter operates in burst mode, during the operation of the power converter, the current output power of the DC side circuit is determined and compared with a preset power threshold.

[0163] Optionally, before operating in burst mode, the power converter can operate in normal mode, that is, it is determined that the current output power of the DC side circuit of the power converter does not exceed the preset power threshold when operating in normal mode.

[0164] If it is determined that the current output power of the DC-side circuit is not greater than the preset power threshold, then prepare to enter the burst mode.

[0165] Step 902: Determine whether the entry conditions are met based on the current DC voltage of the DC side circuit.

[0166] Entry conditions are pre-determined in the power converter. Optionally, these entry conditions are determined by a pre-defined first voltage range.

[0167] For example, if the current DC voltage of the DC-side circuit belongs to the first voltage range, then the entry condition is determined to be met.

[0168] Step 903: If the entry conditions are met, control the power converter to operate in burst mode.

[0169] In other words, when it is determined that the current output power of the DC-side circuit is not greater than the preset power threshold, preparations are made to enter the burst mode. At this point, if it is determined that the entry conditions are still met, the burst mode is officially entered, and the power converter is controlled to operate in burst mode.

[0170] It is understandable that if the power converter is controlled to operate in burst mode only when the current output power of the DC side circuit is not greater than the preset power threshold, then, combined with the above-mentioned handling of stopping burst mode when the current output power of the DC side circuit is greater than the preset power threshold, it can be seen that if the current output power of the DC side circuit fluctuates around the preset power threshold, the power converter will cause the power converter to constantly switch between entering and exiting burst mode, resulting in unstable operation of the power converter, which may lead to power converter failure, reduced power generation, and affect the overall operational stability of the system in which the power converter is located.

[0171] In this embodiment, before entering burst mode, it is first determined whether the current output power of the DC-side circuit is lower than a preset power threshold and whether the current DC voltage is within a first voltage range. Based on this, the decision to activate burst mode is made by considering both output power and DC voltage. Compared to determining whether to enter burst mode solely based on output power, this approach allows for more precise and effective control of the power converter to enter burst mode under appropriate conditions, avoiding frequent switching of the power converter's operating mode and improving the stability of the power converter's operation.

[0172] In one embodiment, determining whether the entry condition is met based on the current DC voltage of the DC-side circuit includes: determining that the current DC voltage of the DC-side circuit belongs to a first voltage range within a preset duration, and then determining that the entry condition is met.

[0173] In other words, when it is determined that the current output power of the DC-side circuit is not greater than a preset power threshold, and the current DC voltage of the DC-side circuit is determined to be in the first voltage range, then the system continues to detect whether the current DC voltage of the DC-side circuit remains within the first voltage range for a preset duration. If so, then the entry condition is satisfied.

[0174] Optionally, within a preset duration, the current output power of the DC-side circuit shall not exceed a preset power threshold.

[0175] Optionally, before the power converter operates in burst mode, it can determine at fixed intervals whether the current output power of the DC-side circuit is not greater than a preset power threshold.

[0176] Optionally, the first voltage range lies within the voltage fluctuation range. That is, as shown in Figure 10, the voltage U at the left endpoint of the voltage fluctuation range... pro_min The voltage U at the left end of the first voltage range is less than the voltage at the left end of the first voltage range. in_min Voltage U at the right endpoint of the voltage fluctuation range pro_max The voltage U at the right end of the first voltage range is greater than the voltage at the right end of the first voltage range. in_max .

[0177] Therefore, if the DC voltage remains within the first voltage range for the preset duration, it indicates that the current DC voltage is relatively stable. Entering burst mode when both the current DC voltage and output power of the DC-side circuit are relatively stable can prevent the power converter from frequently switching operating modes due to instantaneous DC voltage or output power fluctuations, ensuring the effectiveness of the power converter switching to burst mode. In this way, while improving the efficiency of the power converter operating in burst mode, DC voltage fluctuations are kept within a controllable range. By setting the first voltage range, overvoltage or undervoltage problems can be prevented immediately upon entering burst mode, ensuring stable operation.

[0178] For ease of understanding, the following describes the operation control method of a power converter using a complete embodiment. Please refer to Figure 11, which shows a flowchart of the operation process of a power converter.

[0179] When the power converter is operating in normal mode, it determines whether the current output power of the DC-side circuit is not greater than a preset power threshold. If it is determined that the current output power of the DC-side circuit is not greater than the preset power threshold, it then determines whether the current DC voltage of the DC-side circuit belongs to the first voltage range [U] within a preset duration. in_min U in_max If so, the entry condition is met, and the power converter is controlled to operate in burst mode. When the power converter is operating in burst mode, it is determined whether the current DC voltage of the DC side circuit of the power converter does not belong to the range determined by the first protection threshold and the second protection threshold. exit_min U exit_maxIf the current value of the DC-side capacitor in the power converter is greater than the initial value, then exit the burst mode. Also, at a preset operating time, determine the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor. If the capacitance difference is greater than a preset capacitance difference threshold, then exit the burst mode. Furthermore, determine whether the current output power of the DC-side circuit is greater than a preset power threshold. If so, then exit the burst mode. Finally, determine whether the current DC voltage does not belong to the voltage fluctuation range [U]. pro_min U pro_max Within this range, the output power of the power converter is adjusted. Specifically, a reference control power is determined based on the difference between the current DC voltage and the voltage at the endpoints of the voltage fluctuation range; the output power of the power converter is then adjusted based on this reference control power.

[0180] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0181] Based on the same inventive concept, this disclosure also provides an operation control device for a power converter to implement the operation control method of the power converter described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more embodiments of the operation control device for a power converter provided below can be found in the limitations of the operation control method for the power converter described above, and will not be repeated here.

[0182] In one embodiment, as shown in FIG12, an operation control device for a power converter is provided. The operation control device 1200 for the power converter includes: a judgment module 1201 and a control module 1202, wherein:

[0183] The judgment module 1201 is used to determine whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions when the power converter is running in burst mode.

[0184] The control module 1202 is used to control the operation process of the burst mode if it is determined that the operation control conditions are met; wherein, controlling the operation process includes stopping the burst mode or adjusting the output power of the power converter.

[0185] In one embodiment, the operating control conditions include power adjustment conditions; the power adjustment conditions are determined by the voltage fluctuation range; the judgment module 1201 is specifically used for:

[0186] If the current DC voltage does not fall within the voltage fluctuation range, then the current DC voltage is determined to meet the power adjustment conditions.

[0187] The control module 1202 is specifically used to adjust the output power of the power converter.

[0188] In one embodiment, the device further includes an interval determination module, configured to:

[0189] Determine the average DC voltage of the DC-side circuit during its historical operation; determine the voltage fluctuation range based on the average DC voltage and the preset fluctuation voltage.

[0190] In one embodiment, the control module 1202 is specifically configured to: determine a reference control power based on the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range; and adjust the output power of the power converter based on the reference control power.

[0191] In one embodiment, the operating control conditions include a burst mode exit condition, which is determined by a first protection threshold and a second protection threshold, wherein the first protection threshold is less than the second protection threshold.

[0192] The judgment module 1201 is specifically used to: determine that the current DC voltage meets the emergency mode exit condition if the current DC voltage is less than the first protection threshold or greater than the second protection threshold;

[0193] Control module 1202 is specifically used to: stop the burst mode.

[0194] In one embodiment, the operating control conditions further include power adjustment conditions, which are determined by a voltage fluctuation range; the voltage fluctuation range is between a first protection threshold and a second protection threshold.

[0195] In one embodiment, the power converter includes a DC-side circuit, a transformer, and an AC-side circuit. The DC-side circuit includes an actively driven full-bridge circuit; the AC-side circuit includes an actively driven bidirectional switching half-bridge circuit; and the DC-side circuit includes a DC-side capacitor. The device further includes a capacitor detection module for: determining the current capacitance value of the DC-side capacitor in the power converter at a preset operating time when the power converter is operating in burst mode; determining whether the attenuation level of the DC-side capacitor has reached a target attenuation level based on the current capacitance value of the DC-side capacitor; and stopping the burst mode if the target attenuation level has been reached.

[0196] In one embodiment, the capacitance detection module is specifically used to: determine the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor; wherein the initial capacitance value is the capacitance value of the DC-side capacitor when it is not in use; if the capacitance difference is greater than a preset capacitance difference threshold, then it is determined that the attenuation degree of the DC-side capacitor has reached the target attenuation degree.

[0197] In one embodiment, the device further includes a power detection module, configured to: determine the current output power of the DC-side circuit when the power converter is operating in burst mode; and stop the burst mode if the current output power of the DC-side circuit is greater than a preset power threshold.

[0198] In one embodiment, the device further includes a condition determination module, configured to: determine that the current output power of the DC-side circuit is not greater than a preset power threshold before the power converter operates in burst mode; determine whether an entry condition is met based on the current DC voltage of the DC-side circuit; and control the power converter to operate in burst mode if the entry condition is met.

[0199] In one embodiment, the condition determination module is specifically used to: determine that the current DC voltage of the DC-side circuit belongs to the first voltage range within a preset duration, and then determine that the entry condition is met.

[0200] Each module in the operation control device of the aforementioned power converter can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the power converter in hardware form or independent of it, or they can be stored in the memory of the power converter in software form, so that the processor can call and execute the operations corresponding to each module.

[0201] In one embodiment, an inverter is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0202] When the power converter is running in burst mode, it is determined whether the current DC voltage of the DC side circuit of the power converter meets the operation control conditions. If it is determined that the operation control conditions are met, the operation process of burst mode is controlled. The operation process control includes stopping burst mode or adjusting the output power of the power converter.

[0203] In one embodiment, the operating control conditions include power adjustment conditions; the power adjustment conditions are determined by the voltage fluctuation range; when the processor executes the computer program, it also performs the following steps: if the current DC voltage does not belong to the voltage fluctuation range, it determines that the current DC voltage meets the power adjustment conditions; and adjusts the output power of the power converter.

[0204] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0205] Determine the average DC voltage of the DC-side circuit during its historical operation; determine the voltage fluctuation range based on the average DC voltage and the preset fluctuation voltage.

[0206] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0207] The reference control power is determined based on the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range; the output power of the power converter is adjusted based on the reference control power.

[0208] In one embodiment, the operating control conditions include a burst mode exit condition, which is determined by a first protection threshold and a second protection threshold, wherein the first protection threshold is less than the second protection threshold; the processor also performs the following steps when executing the computer program:

[0209] If the current DC voltage is less than the first protection threshold or greater than the second protection threshold, then the current DC voltage is determined to meet the exit condition for the burst mode; the burst mode is stopped.

[0210] In one embodiment, the operating control conditions further include power adjustment conditions, which are determined by a voltage fluctuation range; the voltage fluctuation range is between a first protection threshold and a second protection threshold.

[0211] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0212] When the power converter is running in burst mode, at a preset running time, the current capacitance value of the DC-side capacitor in the power converter is determined; based on the current capacitance value of the DC-side capacitor, it is determined whether the attenuation degree of the DC-side capacitor has reached the target attenuation degree; if the target attenuation degree has been reached, the burst mode is stopped.

[0213] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0214] Determine the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor; where the initial capacitance value is the capacitance value when the DC-side capacitor is not in use; if the capacitance difference is greater than a preset capacitance difference threshold, then determine that the attenuation degree of the DC-side capacitor has reached the target attenuation degree.

[0215] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0216] When the power converter is running in burst mode, the current output power of the DC side circuit is determined; if the current output power of the DC side circuit is greater than the preset power threshold, the burst mode is stopped.

[0217] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0218] Determine that the current output power of the DC-side circuit is not greater than the preset power threshold; determine whether the entry condition is met based on the current DC voltage of the DC-side circuit; if the entry condition is met, control the power converter to operate in burst mode.

[0219] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0220] If the current DC voltage of the DC-side circuit is determined to be within the first voltage range within a preset duration, then the entry condition is determined to be met.

[0221] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0222] 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.

[0223] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, databases, or other media used in the embodiments provided in this disclosure can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this disclosure may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this disclosure may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0224] 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.

[0225] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the 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 disclosure, and these all fall within the scope of protection of this disclosure. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for controlling the operation of a power converter, characterized in that, The method includes: When the power converter is running in burst mode, it is determined whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions. If the operation control conditions are determined to be met, the operation process of the burst mode is controlled; wherein, controlling the operation process includes stopping the burst mode or adjusting the output power of the power converter.

2. The method according to claim 1, characterized in that, The operating control conditions include power adjustment conditions; the power adjustment conditions are determined by the voltage fluctuation range. Determining whether the current DC voltage of the DC-side circuit of the power converter meets the operating control conditions includes: if the current DC voltage does not belong to the voltage fluctuation range, then determining that the current DC voltage meets the power adjustment conditions; Controlling the operation of the burst mode includes adjusting the output power of the power converter.

3. The method according to claim 2, characterized in that, The voltage fluctuation range is determined as follows: Determine the average DC voltage of the DC-side circuit during its historical operation. The voltage fluctuation range is determined based on the average DC voltage and the preset fluctuation voltage.

4. The method according to any one of claims 2-3, characterized in that, The adjustment of the output power of the power converter includes: The reference control power is determined based on the difference between the current DC voltage and the voltage at the endpoint of the voltage fluctuation range. The output power of the power converter is adjusted according to the reference control power.

5. The method according to any one of claims 1-4, characterized in that, The operation control conditions include the emergency mode exit conditions, which are determined by a first protection threshold and a second protection threshold, wherein the first protection threshold is less than the second protection threshold. Determining whether the current DC voltage of the DC-side circuit of the power converter meets the operating control conditions includes: if the current DC voltage is less than the first protection threshold or greater than the second protection threshold, then determining that the current DC voltage meets the burst mode exit condition; Controlling the operation of the sudden mode includes stopping the sudden mode.

6. The method according to claim 5, characterized in that, The operating control conditions also include power adjustment conditions, which are determined by the voltage fluctuation range; The voltage fluctuation range is between the first protection threshold and the second protection threshold.

7. The method according to any one of claims 1 to 6, characterized in that, The power converter includes a DC-side circuit, a transformer, and an AC-side circuit, wherein... The DC-side circuit includes an actively driven full-bridge circuit; The AC side circuit includes an actively driven bidirectional switching half-bridge circuit. The DC-side circuit includes a DC-side capacitor; The method further includes: When the power converter is running in burst mode, at a preset running time, the current capacitance value of the DC-side capacitor in the power converter is determined; Based on the current capacitance value of the DC-side capacitor, determine whether the attenuation level of the DC-side capacitor has reached the target attenuation level. If the target attenuation level is reached, the burst mode is stopped.

8. The method according to claim 7, characterized in that, The step of determining whether the attenuation level of the DC-side capacitor has reached the target attenuation level based on the current capacitance value of the DC-side capacitor includes: Determine the capacitance difference between the current capacitance value and the initial capacitance value of the DC-side capacitor; wherein the initial capacitance value is the capacitance value of the DC-side capacitor when it is not in use; If the capacitance difference is greater than the preset capacitance difference threshold, then it is determined that the attenuation degree of the DC-side capacitor has reached the target attenuation degree.

9. The method according to any one of claims 1 to 6, characterized in that, The method further includes: When the power converter is running in burst mode, determine the current output power of the DC-side circuit; If the current output power of the DC-side circuit is greater than a preset power threshold, the burst mode is stopped.

10. The method according to any one of claims 1 to 6, characterized in that, Before the power converter operates in burst mode, the method further includes: Determine that the current output power of the DC-side circuit is not greater than a preset power threshold; Determine whether the entry conditions are met based on the current DC voltage of the DC-side circuit; If the entry condition is met, the power converter is controlled to operate in the burst mode.

11. The method according to claim 10, characterized in that, The step of determining whether the entry condition is met based on the current DC voltage of the DC-side circuit includes: If the current DC voltage of the DC-side circuit is determined to be within the first voltage range for a preset duration, then the entry condition is determined to be met.

12. An operation control device for a power converter, characterized in that, The device includes: The judgment module is used to determine whether the current DC voltage of the DC side circuit of the power converter meets the operating control conditions when the power converter is running in burst mode. The control module is used to control the operation of the burst mode if it is determined that the operation control conditions are met; wherein controlling the operation includes stopping the burst mode or adjusting the output power of the power converter.

13. An inverter, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 11.

14. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 11.

15. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 11.

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