Control method and system for power converter, device, medium, and product

Abstract

A control method and system for a power converter, a device, a medium, and a product. An acquired first primary current is sampled at different sampling frequencies according to each sampling period to obtain multiple sets of current sampling data corresponding to multiple sampling periods, such that multiple sets of current sampling data of different sampling points can be obtained at a low sampling frequency without increasing hardware resources and processor load, thereby ensuring high data accuracy of a direct current component of the first primary current obtained on the basis of the multiple sets of current sampling data of the different sampling points; and then, on the basis of the direct current component of the first primary current and the dead time of switching transistors, an initial pulse width of each switching transistor is corrected to obtain a corrected pulse width of each switching transistor, and on the basis of said corrected pulse width, a corresponding pulse signal is generated so as to drive each switching transistor. A direct current component of a primary current of a transformer in a power converter can be reduced, thereby suppressing the magnetic biasing of the transformer in the power converter.

Description

A control method, system, device, medium, and product for a power converter. Technical Field

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

[0002] Full-bridge inverter circuit topology is widely used in high-power converters with high-voltage input. In order to achieve electrical isolation between input and output and obtain a suitable output voltage amplitude, high-power converters generally have a transformer connected on the AC side.

[0003] In the actual operation of high-power converters, due to various factors, the positive and negative waveforms of the transformer primary current are asymmetrical, resulting in unequal positive and negative half-cycle volt-second areas. This causes the magnetization curve of the transformer core to no longer be symmetrical about the origin, resulting in the transformer generating bias magnetism. The factors causing the transformer to generate bias magnetism include: (1) Inconsistent parameters of the switching transistors in the full-bridge inverter circuit. In actual applications, the parameters of the two switching transistors on the same bridge arm, such as the difference in on-state voltage drop, will cause unequal positive and negative primary voltages of the transformer, resulting in unequal positive and negative primary currents, which easily leads to unequal positive and negative half-cycle volt-second areas; (2) Inconsistent parameters of the drive circuit. In the application, the pulse signal drives the switching transistor after passing through the driving circuit. Due to the inconsistency of the parameters of the driving circuit components, the dead time will be unequal, resulting in the unequal actual trigger pulse width of each switching transistor. This will cause the positive and negative primary voltages of the transformer to be unequal, resulting in the positive and negative primary currents to be unequal, and it is easy to have the positive and negative half-cycle volt-second area unequal; (3) The influence of the control system: The control system collects electrical signals as feedback quantities for dynamic adjustment. It is affected by the magnitude of the DC input voltage on the inverter side and other quantities, which will cause the positive and negative primary voltages of the transformer to be unequal, resulting in the positive and negative primary currents to be unequal, and it is easy to have the positive and negative half-cycle volt-second area unequal. When the transformer is severely biased, the transformer core will inevitably enter a unidirectional deep saturation, causing a surge in unidirectional magnetization current, increasing losses, and in severe cases, even damaging the switching transistor.

[0004] Therefore, how to suppress transformer bias in power converters is a problem that those skilled in the art need to solve.

[0005] Summary of the Invention

[0006] The purpose of this application is to provide a control method, system, device, medium, and product for a power converter. The control method, system, device, medium, and product for a power converter provided by this application can effectively reduce the DC component of the primary current of the transformer in the power converter, thereby effectively suppressing the transformer bias in the power converter.

[0007] The technical solution provided in this application is as follows:

[0008] A control method for a power converter, the power converter including a full-bridge inverter circuit and a transformer on the primary side, and a full-bridge rectifier circuit on the secondary side, the control method comprising:

[0009] The first primary current of the transformer is acquired by the first current sensor, and the acquired first primary current is sampled at a different sampling frequency according to each sampling period. Based on the multiple sets of current sampling data corresponding to multiple sampling periods, the DC component of the first primary current is obtained.

[0010] The corrected pulse width is obtained based on the DC component of the first primary current;

[0011] The target corrected pulse width is determined based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit;

[0012] The initial pulse width of each switch in the full-bridge inverter circuit is corrected according to the target correction pulse width to obtain the corrected pulse width of each switch.

[0013] Based on the corrected pulse width of each of the switching transistors, a corresponding pulse signal is generated to drive and control each of the switching transistors.

[0014] Optionally, the step of acquiring the first primary current of the transformer collected by the first current sensor, and sampling the acquired first primary current at different sampling frequencies according to each sampling period, to obtain and obtain the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods, includes:

[0015] Acquire the first primary current of the transformer collected by the first current sensor;

[0016] The sampling frequency of the current sampling period is obtained based on the switching frequency of the switching transistor, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula.

[0017] The first primary current is sampled according to the sampling frequency of the current sampling period to obtain current sampling data;

[0018] The number of control sampling periods is incremented until the number of accumulated sampling periods equals the preset number of sampling periods, resulting in multiple sets of current sampling data with the same number of sets as the preset number of sampling periods.

[0019] Based on multiple sets of current sampling data, the DC component of the first primary current is obtained.

[0020] Optionally, determining the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit includes:

[0021] Determine whether the width of the correction pulse exceeds a first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit;

[0022] If so, the corrected pulse width is limited, and the limited pulse width is used as the target corrected pulse width;

[0023] If not, then the corrected pulse width is taken as the target corrected pulse width.

[0024] Optionally, the full-bridge inverter circuit includes a first switch, a second switch, a third switch, and a fourth switch, wherein the first switch and the fourth switch form a diagonal pair of switches, and the second switch and the third switch form another diagonal pair of switches. The step of correcting the initial pulse width of each switch in the full-bridge inverter circuit according to the target corrected pulse width to obtain the corrected pulse width of each switch includes:

[0025] Subtract the target corrected pulse width from the initial pulse width of the first switch and the fourth switch to obtain the corrected pulse width of the first switch and the fourth switch.

[0026] The target corrected pulse width is added to the initial pulse width of the second and third switches to obtain the corrected pulse width of the second and third switches.

[0027] Optionally, the control method further includes:

[0028] When the corrected pulse width is in a limited state, the primary voltage of the transformer collected by the first voltage sensor is obtained, the DC current output by the power converter collected by the second current sensor is obtained, and the DC voltage output by the power converter collected by the second voltage sensor is obtained.

[0029] The second primary current of the transformer is acquired by the first current sensor, and the DC component of the second primary current is obtained based on the second primary current.

[0030] The input power of the power converter is obtained based on the second primary current and the primary voltage.

[0031] The output power of the power converter is obtained based on the DC current and the DC voltage.

[0032] If the DC components of multiple second primary currents obtained within a first preset duration are all greater than the first preset DC component, or if the DC components of multiple second primary currents obtained within a second preset duration are all greater than the second preset DC component, or if the input power obtained within a third preset duration is all less than the second preset percentage of the output power, or if the instantaneous value of the second primary current is greater than the rated current of the transformer, then the power converter is controlled to shut down.

[0033] This application also provides a control system for a power converter, the power converter including a full-bridge inverter circuit and a transformer disposed on the primary side, and a full-bridge rectifier circuit disposed on the secondary side, the control system including:

[0034] The first processing module is used to acquire the first primary current of the transformer collected by the first current sensor, and to sample the acquired first primary current at different sampling frequencies according to each sampling period, and to obtain the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods.

[0035] The second processing module is used to obtain the corrected pulse width based on the DC component of the first primary current;

[0036] The determining module is used to determine the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit;

[0037] The correction module is used to correct the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width, so as to obtain the corrected pulse width of each switch.

[0038] The first control module is used to generate a corresponding pulse signal based on the corrected pulse width of each of the switching transistors, and to drive and control each of the switching transistors.

[0039] Optionally, when the first processing module performs the process of acquiring the first primary current of the transformer collected by the first current sensor, and sampling the acquired first primary current at a different sampling frequency according to each sampling period, and obtaining the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods, the specific processing module is used to:

[0040] Acquire the first primary current of the transformer collected by the first current sensor;

[0041] The sampling frequency of the current sampling period is obtained based on the switching frequency of the switching transistor, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula.

[0042] The first primary current is sampled according to the sampling frequency of the current sampling period to obtain current sampling data;

[0043] The number of control sampling periods is incremented until the number of accumulated sampling periods equals the preset number of sampling periods, resulting in multiple sets of current sampling data with the same number of sets as the preset number of sampling periods.

[0044] Based on multiple sets of current sampling data, the DC component of the first primary current is obtained.

[0045] Optionally, when the determining module performs the step of determining the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit, it is specifically used for:

[0046] Determine whether the width of the correction pulse exceeds a first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit;

[0047] If so, the corrected pulse width is limited, and the limited pulse width is used as the target corrected pulse width;

[0048] If not, then the corrected pulse width is taken as the target corrected pulse width.

[0049] Optionally, the full-bridge inverter circuit includes a first switch, a second switch, a third switch, and a fourth switch, wherein the first switch and the fourth switch form a diagonal pair of switches, and the second switch and the third switch form another diagonal pair of switches. When the correction module performs the step of correcting the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width to obtain the corrected pulse width of each switch, it is specifically used for:

[0050] Subtract the target corrected pulse width from the initial pulse width of the first switch and the fourth switch to obtain the corrected pulse width of the first switch and the fourth switch.

[0051] The target corrected pulse width is added to the initial pulse width of the second and third switches to obtain the corrected pulse width of the second and third switches.

[0052] Optionally, the control system further includes:

[0053] The acquisition module is used to acquire the primary voltage of the transformer collected by the first voltage sensor, the DC current output by the power converter collected by the second current sensor, and the DC voltage output by the power converter collected by the second voltage sensor when the correction pulse width is in the limiting state.

[0054] The third processing module is used to acquire the second primary current of the transformer collected by the first current sensor, and to obtain the DC component of the second primary current based on the second primary current.

[0055] The fourth processing module is used to obtain the input power of the power converter based on the second primary current and the primary voltage;

[0056] The fifth processing module is used to obtain the output power of the power converter based on the DC current and the DC voltage;

[0057] The second control module is configured to control the power converter to shut down if the DC components of multiple second primary currents obtained within a first preset duration are all greater than a first preset DC component, or the DC components of multiple second primary currents obtained within a second preset duration are all greater than a second preset DC component, or the input power obtained within a third preset duration is all less than a second preset percentage of the output power, or the instantaneous value of the second primary current is greater than the rated current of the transformer.

[0058] This application also provides an electronic device, including: a processor, a memory, and a communication bus;

[0059] The communication bus is used to realize the connection and communication between the processor and the memory;

[0060] The processor is used to execute the control processing program of the power converter stored in the memory to implement the steps of the power converter control method as described in any of the above.

[0061] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when loaded and executed by a processor, implement the steps of the control method for the power converter as described in any of the preceding claims.

[0062] This application also provides a computer program product, including computer-executable instructions, which, when loaded and executed by a processor, implement the steps of the control method for the power converter as described in any of the preceding claims.

[0063] Compared with existing technologies, the control method, system, device, medium, and product of a power converter provided in this application acquires the first primary current of the transformer collected by a first current sensor, and samples the acquired first primary current at different sampling frequencies according to each sampling period. Based on multiple sets of current sampling data corresponding to multiple sampling periods, the DC component of the first primary current is obtained. Based on the DC component of the first primary current, a corrected pulse width is obtained. Then, based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit, a target corrected pulse width is determined. The initial pulse width of each switching transistor in the full-bridge inverter circuit is then corrected based on the target corrected pulse width to obtain the corrected pulse width of each switching transistor. Finally, based on the corrected pulse width of each switching transistor... The corrected pulse width of each switching transistor generates a corresponding pulse signal to drive and control each switching transistor. This effectively reduces the DC component of the primary current of the transformer in the power converter, thereby effectively suppressing transformer bias. In addition, by sampling the first primary current at different sampling frequencies for each sampling period, multiple sets of current sampling data corresponding to multiple sampling periods are obtained. This allows for the acquisition of multiple sets of current sampling data at different sampling points at a low sampling frequency without increasing hardware resources and processor burden. This results in very high accuracy of the DC component of the first primary current obtained from multiple sets of current sampling data at different sampling points, which further effectively suppresses transformer bias. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0065] Figure 1 is a flowchart of a control method for a power converter disclosed in an embodiment of this application;

[0066] Figure 2 is a circuit diagram of a power converter disclosed in an embodiment of this application;

[0067] Figure 3 is a structural block diagram of a power converter control system disclosed in an embodiment of this application;

[0068] Figure 4 is a schematic diagram of the structure of an electronic device disclosed in an embodiment of this application. Detailed Implementation

[0069] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0071] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0073] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0074] As shown in Figure 1, this application embodiment provides a control method for a power converter. As shown in Figure 2, the power converter includes a full-bridge inverter circuit 110 and a transformer 120 disposed on the primary side, and a full-bridge rectifier circuit 130 disposed on the secondary side. The control method includes:

[0075] S11. Obtain the first primary current of the transformer collected by the first current sensor, and sample the first primary current with a different sampling frequency according to each sampling period, and obtain the DC component of the first primary current based on the multiple sets of current sampling data corresponding to multiple sampling periods.

[0076] In this embodiment, the first primary current of the transformer can be acquired in real time by the first current sensor, that is, the current at the position marked by the red circle in Figure 2 can be acquired in real time by the first current sensor. Then, the first primary current acquired in real time is sampled at a different sampling frequency according to each sampling period to obtain multiple sets of current sampling data at different sampling points corresponding to multiple sampling periods. Then, the current sampling data at multiple different sampling points are added together to obtain the DC component of the first primary current.

[0077] S12. Obtain the corrected pulse width based on the DC component of the first primary current;

[0078] In this embodiment, the DC component of the first primary current can be used as an error signal input to the PI controller, and the correction pulse width can be calculated by the PI controller. The PI controller is a proportional integral controller.

[0079] S13. Determine the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit;

[0080] In this embodiment, the target corrected pulse width can be determined by comparing the corrected pulse width with a preset percentage of the dead time of the switching transistors in the full-bridge inverter circuit.

[0081] S14. Correct the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width to obtain the corrected pulse width of each switch.

[0082] In this embodiment, the initial pulse width is the pulse width before correction.

[0083] S15. Generate corresponding pulse signals based on the corrected pulse width of each switching transistor to drive and control each switching transistor.

[0084] In this embodiment, a corresponding pulse signal is generated based on the corrected pulse width of each switching transistor. After passing through the driving circuit, the switching transistor is driven to reduce the DC component of the primary current of the transformer in the power converter, so that the positive and negative primary currents of the transformer are equal or substantially equal.

[0085] Compared with existing technologies, this application provides a control method, system, device, medium, and product for a power converter. It acquires the first primary current of the transformer from a first current sensor, and samples the acquired first primary current at different sampling frequencies for each sampling period. Based on multiple sets of current sampling data corresponding to multiple sampling periods, it obtains the DC component of the first primary current. Based on the DC component of the first primary current, it obtains a corrected pulse width. Then, based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit, it determines a target corrected pulse width. Finally, it corrects the initial pulse width of each switching transistor in the full-bridge inverter circuit based on the target corrected pulse width, obtaining the corrected pulse width of each switching transistor. Finally, it determines the corrected pulse width of each switching transistor based on the target corrected pulse width. The corrected pulse width of the switching transistor generates a corresponding pulse signal to drive and control each switching transistor. This effectively reduces the DC component of the primary current of the transformer in the power converter, thereby effectively suppressing transformer bias. In addition, by sampling the first primary current at different sampling frequencies for each sampling period, multiple sets of current sampling data corresponding to multiple sampling periods are obtained. This allows for the acquisition of multiple sets of current sampling data at different sampling points at a low sampling frequency without increasing hardware resources and processor burden. This results in very high accuracy of the DC component of the first primary current obtained from multiple sets of current sampling data at different sampling points, further effectively suppressing transformer bias.

[0086] As one implementation method, in this embodiment of the application, step S11 includes:

[0087] S111. Obtain the first primary current of the transformer collected by the first current sensor;

[0088] 10

[0089] S112. Based on the switching frequency of the switching transistor, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula, obtain the sampling frequency of the current sampling period.

[0090] S113. Sample the first primary current according to the sampling frequency of the current sampling period to obtain current sampling data;

[0091] S114. Control the number of sampling cycles to start accumulating until the number of accumulated sampling cycles is equal to the preset number of sampling cycles, and obtain multiple sets of current sampling data with the same number of sets as the preset number of sampling cycles.

[0092] In this embodiment, the preset sampling frequency calculation formula is a pre-set sampling frequency calculation formula, which can be specifically as follows:

[0093] Where f1 is the switching frequency of the switching transistor, N is the number of sampling periods, and f2 is the sampling frequency;

[0094] In this embodiment, the number of sampling periods can be initialized first, so that the number of sampling periods in the first sampling period is 1. The first primary current of the transformer in the first time period is acquired from the first current sensor. Then, based on the switching frequency of the switching transistor, the number of sampling periods in the first sampling period, and the preset sampling frequency calculation formula, the sampling frequency of the first sampling period is obtained. The first primary current of the first time period is sampled according to the sampling frequency of the first sampling period to obtain the first set of current sampling data. The number of sampling periods is then incremented, i.e., 1 is added to the number of sampling periods in the first sampling period, making the number of sampling periods in the second sampling period 2. The first primary current of the transformer in the second time period is acquired from the first current sensor. Then, based on the switching frequency of the switching transistor, the number of sampling periods in the second sampling period, and the preset sampling frequency calculation formula, the sampling frequency of the second sampling period is obtained. The first primary current of the transformer in the second time period is sampled according to the sampling frequency of the second sampling period. The primary current of the first time period is sampled to obtain the second set of current sampling data. The number of sampling periods continues to accumulate. When the accumulated number of sampling periods N equals the preset number of sampling periods, the first primary current of the transformer in the Nth time period collected by the first current sensor is acquired. Then, according to the switching frequency of the switch, the number of sampling periods in the Nth sampling period, and the preset sampling frequency calculation formula, the sampling frequency of the Nth sampling period is obtained. The first primary current of the Nth time period is sampled according to the sampling frequency of the Nth sampling period to obtain the Nth set of current sampling data. Since the waveform of the first primary current in each time period is the same, the sampling frequency of the current sampling period is obtained by calculating the current sampling frequency according to the switching frequency of the switch, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula. This makes the sampling frequency of each sampling period different, so that the N sets of current sampling data obtained by sampling in N sampling periods are data from different sampling points on the waveform of the first primary current.

[0095] S115. Based on multiple sets of current sampling data, obtain the DC component of the first primary current.

[0096] In this embodiment, by adding N sets of current sampling data from different sampling points, the DC component of the first primary current is obtained. This makes the accuracy of the DC component of the first primary current obtained from multiple sets of current sampling data from different sampling points very high without increasing the sampling frequency to a very high level, i.e. without increasing hardware resources (or improving sampling hardware conditions) and processor burden. This further enables effective suppression of transformer bias.

[0097] As one implementation method, in this embodiment of the application, step S13 includes:

[0098] S131. Determine whether the correction pulse width exceeds the first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit;

[0099] In this embodiment, the first preset percentage is a pre-set percentage, which can be 50%, that is, the first preset percentage of dead time can be 50% of dead time, or it can be set specifically as needed.

[0100] S132. If so, then the corrected pulse width is limited, and the limited pulse width is used as the target corrected pulse width.

[0101] In this embodiment, if the corrected pulse width exceeds a first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit, the corrected pulse width is limited, and the first preset percentage of the limited dead time is used as the target corrected pulse width.

[0102] S133. If not, then the corrected pulse width will be used as the target corrected pulse width.

[0103] In this embodiment, if the corrected pulse width does not exceed the first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit, the corrected pulse width is taken as the target corrected pulse width.

[0104] As one implementation method, in this embodiment of the application, as shown in FIG2, the full-bridge inverter circuit 110 includes a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4, wherein the first switch S1 and the fourth switch S4 form a pair of diagonal switches, and the second switch S2 and the third switch S3 form another pair of diagonal switches. Step S14 includes:

[0105] S141. Subtract the target corrected pulse width from the initial pulse width of the first switch and the fourth switch to obtain the corrected pulse width of the first switch and the fourth switch.

[0106] S142. Add the target corrected pulse width to the initial pulse width of the second and third switching transistors to obtain the corrected pulse width of the second and third switching transistors.

[0107] In this embodiment, by modifying the pulse widths of the first and fourth switching transistors, as well as the second and third switching transistors, the DC component of the primary current of the high-frequency transformer can be effectively reduced, and the transformer bias in the power converter can be effectively suppressed.

[0108] As one implementation method, in this embodiment of the application, the control method further includes:

[0109] S21. When the correction pulse width is in the limiting state, acquire the primary voltage of the transformer collected by the first voltage sensor, acquire the DC current output of the power converter collected by the second current sensor, and acquire the DC voltage output of the power converter collected by the second voltage sensor.

[0110] S22. Obtain the second primary current of the transformer collected by the first current sensor, and obtain the DC component of the second primary current based on the second primary current.

[0111] In this embodiment, the processing method of step S22 is similar to that of steps S111 to S115, and will not be described again here.

[0112] S23. Obtain the input power of the power converter based on the second primary current and primary voltage;

[0113] In this embodiment, the effective value of the second primary current can be obtained from the second primary current, and the effective value of the primary voltage can be obtained from the primary voltage. The effective value of the second primary current and the effective value of the primary voltage can be multiplied to obtain the input power of the power converter.

[0114] S24. Obtain the output power of the power converter based on the DC current and DC voltage;

[0115] In this embodiment, the DC current and DC voltage can be multiplied to obtain the output power of the power converter.

[0116] S25. If the DC components of multiple second primary currents obtained within a first preset duration are all greater than the first preset DC component, or if the DC components of multiple second primary currents obtained within a second preset duration are all greater than the second preset DC component, or if the input power obtained within a third preset duration is all less than the second preset percentage of the output power, or if the instantaneous value of the second primary current is greater than the rated current of the transformer, then the power converter is controlled to shut down.

[0117] In this embodiment, the first preset duration, the second preset duration, and the third preset duration are preset durations, the first preset DC component and the second preset DC component are preset DC components, and the second preset percentage is a preset percentage. The first preset duration can be 1 second, the second preset duration can be 100 ms, the third preset duration can be 200 ms, the first preset DC component can be 10 A, the second preset DC component can be 50 A, and the second preset percentage can be 80%, or can be specifically set as needed.

[0118] In this embodiment, if the DC components of multiple second primary currents obtained in the power converter within a first preset duration are all greater than the first preset DC component, or the DC components of multiple second primary currents obtained within a second preset duration are all greater than the second preset DC component, or the input power obtained within a third preset duration is all less than the second preset percentage of the output power, or the instantaneous value of the second primary current is greater than the rated current of the transformer, it indicates that a device in the power converter has malfunctioned. By controlling the power converter to shut down, the power converter can be effectively protected.

[0119] As shown in Figure 3, this application embodiment also provides a control system for a power converter. The power converter includes a full-bridge inverter circuit and a transformer disposed on the primary side, and a full-bridge rectifier circuit disposed on the secondary side. The control system includes:

[0120] The first processing module 210 is used to acquire the first primary current of the transformer collected by the first current sensor, and to sample the acquired first primary current using a different sampling frequency according to each sampling period, and to obtain the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods.

[0121] The second processing module 220 is used to obtain the corrected pulse width based on the DC component of the first primary current;

[0122] The determination module 230 is used to determine the target correction pulse width based on the correction pulse width and the dead time of the switching transistors in the full-bridge inverter circuit;

[0123] The correction module 240 is used to correct the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width, so as to obtain the corrected pulse width of each switch.

[0124] The first control module 250 is used to generate corresponding pulse signals based on the corrected pulse width of each switching transistor, and to drive and control each switching transistor.

[0125] As one implementation method, in this embodiment of the application, when the first processing module acquires the first primary current of the transformer collected by the first current sensor, and samples the acquired first primary current at a different sampling frequency according to each sampling period, and obtains and obtains the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods, the module is specifically used for:

[0126] Obtain the first primary current of the transformer collected by the first current sensor;

[0127] The sampling frequency of the current sampling period is obtained based on the switching frequency of the switching transistor, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula.

[0128] The first primary current is sampled according to the sampling frequency of the current sampling period to obtain current sampling data;

[0129] The number of control sampling periods starts to accumulate until the number of accumulated sampling periods equals the preset number of sampling periods, thus obtaining multiple sets of current sampling data with the same number of sets as the preset number of sampling periods.

[0130] The DC component of the first primary current is obtained based on multiple sets of current sampling data.

[0131] As one implementation method, in this embodiment of the application, when the determining module determines the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit, it is specifically used for:

[0132] Determine whether the correction pulse width exceeds a first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit;

[0133] If so, the correction pulse width is limited, and the limited pulse width is used as the target correction pulse width;

[0134] If not, then the corrected pulse width will be used as the target corrected pulse width.

[0135] In one implementation embodiment of this application, the full-bridge inverter circuit includes a first switch, a second switch, a third switch, and a fourth switch, wherein the first and fourth switches form a diagonal pair, and the second and third switches form another diagonal pair. When the correction module corrects the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width to obtain the corrected pulse width of each switch, it is specifically used for:

[0136] Subtract the target corrected pulse width from the initial pulse width of the first and fourth switching transistors to obtain the corrected pulse width of the first and fourth switching transistors.

[0137] The initial pulse widths of the second and third switching transistors are added to the target corrected pulse widths to obtain the corrected pulse widths of the second and third switching transistors.

[0138] As one implementation method, in this embodiment of the application, the control system further includes:

[0139] The acquisition module is used to acquire the primary voltage of the transformer collected by the first voltage sensor, the DC current output by the power converter collected by the second current sensor, and the DC voltage output by the power converter collected by the second voltage sensor when the correction pulse width is in the limiting state.

[0140] The third processing module is used to acquire the second primary current of the transformer collected by the first current sensor, and to obtain the DC component of the second primary current based on the second primary current.

[0141] The fourth processing module is used to obtain the input power of the power converter based on the second primary current and primary voltage;

[0142] The fifth processing module is used to obtain the output power of the power converter based on the DC current and DC voltage;

[0143] The second control module is configured to control the power converter to shut down if the DC components of multiple second primary currents obtained within a first preset duration are all greater than the first preset DC component, or if the DC components of multiple second primary currents obtained within a second preset duration are all greater than the second preset DC component, or if the input power obtained within a third preset duration is all less than the second preset percentage of the output power, or if the instantaneous value of the second primary current is greater than the rated current of the transformer.

[0144] As shown in Figure 4, this application embodiment also provides an electronic device, including: a processor 301, a memory 302, and a communication bus 303;

[0145] Communication bus 303 is used to realize the connection and communication between processor 301 and memory 302;

[0146] The processor 301 is used to execute the control processing program of the power converter stored in the memory 302 to implement the steps of any of the power converter control methods described above.

[0147] This application also provides a computer-readable storage medium storing computer-executable instructions. When the computer-executable instructions are loaded and executed by a processor, they implement the steps of any of the power converter control methods described above.

[0148] This application also provides a computer program product, including computer-executable instructions, which, when loaded and executed by a processor, implement the steps of any of the power converter control methods described above.

[0149] It should be understood that the use of terms such as "system," "device," "unit," and / or "module" in this application is merely one method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0150] The embodiments in this specification are described in a progressive manner, with each embodiment focusing on the related aspects.

[0151] For any differences between the embodiments, or for the same or similar parts between the embodiments, please refer to each other.

[0152] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a power converter, characterized in that, The power converter includes a full-bridge inverter circuit and a transformer on the primary side, and a full-bridge rectifier circuit on the secondary side. The control method includes: The first primary current of the transformer is acquired by the first current sensor, and the acquired first primary current is sampled at a different sampling frequency according to each sampling period. Based on the multiple sets of current sampling data corresponding to multiple sampling periods, the DC component of the first primary current is obtained. The corrected pulse width is obtained based on the DC component of the first primary current; The target corrected pulse width is determined based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit; The initial pulse width of each switch in the full-bridge inverter circuit is corrected according to the target correction pulse width to obtain the corrected pulse width of each switch. Based on the corrected pulse width of each of the switching transistors, a corresponding pulse signal is generated to drive and control each of the switching transistors.

2. The control method according to claim 1, characterized in that, The first primary current of the transformer is acquired by the first current sensor, and the acquired first primary current is sampled at different sampling frequencies according to each sampling period. Based on multiple sets of current sampling data corresponding to multiple sampling periods, the DC component of the first primary current is obtained, including: Acquire the first primary current of the transformer collected by the first current sensor; The sampling frequency of the current sampling period is obtained based on the switching frequency of the switching transistor, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula. The first primary current is sampled according to the sampling frequency of the current sampling period to obtain current sampling data; The number of control sampling periods is incremented until the number of accumulated sampling periods equals the preset number of sampling periods, resulting in multiple sets of current sampling data with the same number of sets as the preset number of sampling periods. Based on multiple sets of current sampling data, the DC component of the first primary current is obtained.

3. The control method according to claim 1, characterized in that, Determining the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit includes: Determine whether the width of the correction pulse exceeds a first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit; If so, the corrected pulse width is limited, and the limited pulse width is used as the target corrected pulse width; If not, then the corrected pulse width is taken as the target corrected pulse width.

4. The control method according to claim 3, characterized in that, The full-bridge inverter circuit includes a first switch, a second switch, a third switch, and a fourth switch, wherein the first switch and the fourth switch form a diagonal pair of switches, and the second switch and the third switch form another diagonal pair of switches. The step of correcting the initial pulse width of each switch in the full-bridge inverter circuit according to the target corrected pulse width to obtain the corrected pulse width of each switch includes: Subtract the target corrected pulse width from the initial pulse width of the first switch and the fourth switch to obtain the corrected pulse width of the first switch and the fourth switch. The target corrected pulse width is added to the initial pulse width of the second and third switches to obtain the corrected pulse width of the second and third switches.

5. The control method according to claim 3, characterized in that, The control method further includes: When the corrected pulse width is in a limited state, the primary voltage of the transformer collected by the first voltage sensor is obtained, the DC current output by the power converter collected by the second current sensor is obtained, and the DC voltage output by the power converter collected by the second voltage sensor is obtained. The second primary current of the transformer is acquired by the first current sensor, and the DC component of the second primary current is obtained based on the second primary current. The input power of the power converter is obtained based on the second primary current and the primary voltage. The output power of the power converter is obtained based on the DC current and the DC voltage. If the DC components of the multiple second primary currents obtained within a first preset duration are all greater than the first preset DC component, or if the multiple second primary currents obtained within a second preset duration are all greater than the first preset DC component, then... If the DC components of both primary currents are greater than the second preset DC component, or if the input power obtained within a third preset duration is less than the second preset percentage of the output power, or if the instantaneous value of the second primary current is greater than the rated current of the transformer, then the power converter is controlled to shut down.

6. A control system for a power converter, characterized in that, The power converter includes a full-bridge inverter circuit and a transformer on the primary side, and a full-bridge rectifier circuit on the secondary side. The control system includes: The first processing module is used to acquire the first primary current of the transformer collected by the first current sensor, and to sample the acquired first primary current at different sampling frequencies according to each sampling period, and to obtain the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods. The second processing module is used to obtain the corrected pulse width based on the DC component of the first primary current; The determining module is used to determine the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit; The correction module is used to correct the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width, so as to obtain the corrected pulse width of each switch. The first control module is used to generate a corresponding pulse signal based on the corrected pulse width of each of the switching transistors, and to drive and control each of the switching transistors.

7. The control system according to claim 6, characterized in that, When the first processing module performs the process of acquiring the first primary current of the transformer collected by the first current sensor, and sampling the acquired first primary current at a different sampling frequency according to each sampling period, and obtaining the DC component of the first primary current based on multiple sets of current sampling data corresponding to multiple sampling periods, the specific functions are as follows: Acquire the first primary current of the transformer collected by the first current sensor; The sampling frequency of the current sampling period is obtained based on the switching frequency of the switching transistor, the number of sampling periods in the current sampling period, and the preset sampling frequency calculation formula. The first primary current is sampled according to the sampling frequency of the current sampling period. Obtain current sampling data; The number of control sampling periods is incremented until the number of accumulated sampling periods equals the preset number of sampling periods, resulting in multiple sets of current sampling data with the same number of sets as the preset number of sampling periods. Based on multiple sets of current sampling data, the DC component of the first primary current is obtained.

8. The control system according to claim 6, characterized in that, When the determining module performs the step of determining the target corrected pulse width based on the corrected pulse width and the dead time of the switching transistors in the full-bridge inverter circuit, it is specifically used for: Determine whether the width of the correction pulse exceeds a first preset percentage of the dead time of the switching transistor in the full-bridge inverter circuit; If so, the corrected pulse width is limited, and the limited pulse width is used as the target corrected pulse width; If not, then the corrected pulse width is taken as the target corrected pulse width.

9. The control system according to claim 8, characterized in that, The full-bridge inverter circuit includes a first switch, a second switch, a third switch, and a fourth switch. The first and fourth switches form a diagonal pair, and the second and third switches form another diagonal pair. When the correction module corrects the initial pulse width of each switch in the full-bridge inverter circuit according to the target correction pulse width to obtain the corrected pulse width of each switch, it is specifically used for: Subtract the target corrected pulse width from the initial pulse width of the first switch and the fourth switch to obtain the corrected pulse width of the first switch and the fourth switch. The target corrected pulse width is added to the initial pulse width of the second and third switches to obtain the corrected pulse width of the second and third switches.

10. The control system according to claim 8, characterized in that, The control system further includes: The acquisition module is used to acquire the primary voltage of the transformer collected by the first voltage sensor, the DC current output by the power converter collected by the second current sensor, and the DC voltage output by the power converter collected by the second voltage sensor when the correction pulse width is in the limiting state. The third processing module is used to acquire the current collected by the first current sensor from the transformer. The two primary currents are used to obtain the DC component of the second primary current. The fourth processing module is used to obtain the input power of the power converter based on the second primary current and the primary voltage; The fifth processing module is used to obtain the output power of the power converter based on the DC current and the DC voltage; The second control module is configured to control the power converter to shut down if the DC components of multiple second primary currents obtained within a first preset duration are all greater than a first preset DC component, or the DC components of multiple second primary currents obtained within a second preset duration are all greater than a second preset DC component, or the input power obtained within a third preset duration is all less than a second preset percentage of the output power, or the instantaneous value of the second primary current is greater than the rated current of the transformer.

11. An electronic device, characterized in that, include: Processor, memory, and communication bus; The communication bus is used to realize the connection and communication between the processor and the memory; The processor is used to execute the control processing program of the power converter stored in the memory to implement the steps of the control method of the power converter as described in any one of claims 1-5.

12. A computer-readable storage medium, characterized in that, The readable storage medium stores computer-executable instructions, which, when loaded and executed by a processor, implement the steps of the control method for the power converter as described in any one of claims 1 to 5.

13. A computer program product, characterized in that, It includes computer-executable instructions, which, when loaded and executed by a processor, implement the steps of the control method for the power converter as described in any one of claims 1 to 5.

Images