Control method, system and equipment of power converter, medium and product
By sampling the primary current of the transformer, calculating the DC component and adjusting the pulse width of the switch tube, the problem of transformer bias in high-power converters is solved, and lower losses and higher data accuracy are achieved.
Patent Information
- Application Number
- CN202411448355.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2024-12-24
AI Technical Summary
In high-power converters, the area of the positive and negative half-period volts of the transformer leads to bias, which in turn increases losses and may damage the switch tube.
By obtaining the first primary current of the transformer, sampling with different sampling frequencies, calculating the DC component, and adjusting the pulse width of the switch tube according to the correction pulse width and the dead time of the switch tube to reduce the primary current of the transformer DC component, suppress bias.
Effectively reduce the DC component of the primary current of the transformer, suppress bias, reduce losses, and improve data accuracy without increasing hardware resources and processor burden.
Smart Images
Figure CN119182305A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of power control technology, and in particular, relates to a control method, system, device, medium and product of a power converter. Background Art
[0002] The 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, the high-power converter is generally connected to a transformer on the AC side.
[0003] In the actual operation of high-power converters, due to various factors, the positive and negative waveforms of the primary current of the transformer are asymmetrical, resulting in different positive and negative half-cycle volt-second areas, causing the magnetization curve of the transformer core to no longer be symmetrical about the origin when working, causing the transformer to be biased. The factors that cause the transformer to be biased are: (1) The parameters of the switch tubes in the full-bridge inverter circuit are inconsistent. In actual applications, the parameters of the upper and lower switch tubes of the same bridge arm, such as the difference in on-state voltage drop, will cause the positive and negative primary voltages of the transformer to be different, resulting in different positive and negative primary currents, which is prone to different positive and negative half-cycle volt-second areas; (2) The inconsistency of the drive circuit parameters. In actual applications, the parameters of the upper and lower switch tubes of the same bridge arm, such as the difference in on-state voltage drop, will cause the positive and negative primary voltages of the transformer to be different, resulting in different positive and negative primary currents, which is prone to different positive and negative half-cycle volt-second areas. In the application, the pulse signal drives the switch tube 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 unequal actual trigger pulse widths of each switch tube, which will cause the positive and negative primary voltages of the transformer to be unequal, resulting in unequal positive and negative primary currents, and it is easy to have unequal positive and negative half-cycle volt-second areas; (3) The influence of the control system. The control system collects electrical signals as feedback quantities for dynamic adjustment. Affected by the size of the DC voltage input on the inverter side and other quantities, it will cause unequal positive and negative primary voltages of the transformer and unequal positive and negative primary currents, and it is easy to have unequal positive and negative half-cycle volt-second areas. When the transformer is seriously biased, the core of the transformer will inevitably enter a single-direction deep saturation, causing a sharp increase in the unidirectional magnetizing current, increasing losses, and even causing damage to the switch tube in severe cases.
[0004] Therefore, how to suppress the transformer bias in the power converter is a problem that technicians in this field need to solve at present. Summary of the invention
[0005] The purpose of the present 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 the power converter provided in the present 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.
[0006] The technical solutions provided by this application are as follows: A control method for a power converter, the power converter comprising a full-bridge inverter circuit and a transformer arranged on a primary side and a full-bridge rectifier circuit arranged on a secondary side, the control method comprising: Acquire a first primary current of the transformer collected by a first current sensor, and sample the acquired first primary current using different sampling frequencies in each sampling period, and obtain a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods; obtaining a corrected pulse width according to a DC component of the first primary current; Determining a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit; Correcting the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain a corrected pulse width of each switch tube; According to the corrected pulse width of each of the switch tubes, a corresponding pulse signal is generated to drive and control each of the switch tubes.
[0007] Optionally, the acquiring the first primary current of the transformer collected by the first current sensor, and sampling the acquired first primary current using different sampling frequencies in each sampling period, and obtaining and obtaining a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods, includes: Acquire a first primary current of the transformer collected by a first current sensor; The sampling frequency of the current sampling period is obtained according to the switching frequency of the switch tube, the number of sampling periods of the current sampling period and a 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; Controlling the sampling cycle number to start accumulating until the accumulated sampling cycle number is equal to the preset sampling cycle number, thereby obtaining a plurality of groups of current sampling data whose number is the same as the preset sampling cycle number; A direct current component of the first primary current is obtained according to the multiple groups of current sampling data.
[0008] Optionally, determining a target corrected pulse width according to the corrected pulse width and a dead time of a switch tube in the full-bridge inverter circuit includes: Determining whether the modified pulse width exceeds a first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit; If yes, the corrected pulse width is limited, and the pulse width after the limit is used as the target corrected pulse width; If not, the corrected pulse width is used as the target corrected pulse width.
[0009] Optionally, the full-bridge inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, wherein the first switch tube and the fourth switch tube form a group of diagonal switch tubes, and the second switch tube and the third switch tube form another group of diagonal switch tubes, and the initial pulse width of each switch tube in the full-bridge inverter circuit is corrected according to the target corrected pulse width to obtain the corrected pulse width of each switch tube, including: Subtract the target corrected pulse width from the initial pulse width of the first switch tube and the fourth switch tube to obtain the corrected pulse width of the first switch tube and the fourth switch tube; The target corrected pulse width is added to the initial pulse widths of the second switch tube and the third switch tube to obtain the corrected pulse widths of the second switch tube and the third switch tube.
[0010] Optionally, the control method further includes: When the corrected pulse width is in a limiting state, obtaining the primary voltage of the transformer collected by the first voltage sensor, obtaining the DC current output by the power converter collected by the second current sensor, and obtaining the DC voltage output by the power converter collected by the second voltage sensor; Acquire a second primary current of the transformer collected by the first current sensor, and obtain a DC component of the second primary current according to the second primary current; Obtaining an input power of the power converter according to the second primary current and the primary voltage; Obtaining an output power of the power converter according to the DC current and the DC voltage; If the DC components of multiple second primary currents obtained within the first preset time period are all greater than the first preset DC component, or, the DC components of multiple second primary currents obtained within the second preset time period are all greater than the second preset DC component, or, the input power obtained within the third preset time period is 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, the power converter is controlled to shut down.
[0011] The present application also provides a control system for a power converter, wherein the power converter includes a full-bridge inverter circuit and a transformer arranged on a primary side and a full-bridge rectifier circuit arranged on a secondary side, and the control system includes: a first processing module, configured to obtain a first primary current of the transformer collected by a first current sensor, and sample the obtained first primary current using different sampling frequencies in each sampling period, and obtain a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods; A second processing module, configured to obtain a corrected pulse width according to a DC component of the first primary current; A determination module, used to determine a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit; A correction module, used for correcting the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain a corrected pulse width of each switch tube; The first control module is used to generate a corresponding pulse signal according to the corrected pulse width of each of the switch tubes to drive and control each of the switch tubes.
[0012] Optionally, when the first processing module executes the step of acquiring the first primary current of the transformer collected by the first current sensor, and sampling the acquired first primary current using different sampling frequencies in each sampling period, and obtaining and obtaining a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods, the first processing module is specifically used to: Acquire a first primary current of the transformer collected by a first current sensor; The sampling frequency of the current sampling period is obtained according to the switching frequency of the switch tube, the number of sampling periods of the current sampling period and a 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; Controlling the sampling cycle number to start accumulating until the accumulated sampling cycle number is equal to the preset sampling cycle number, thereby obtaining a plurality of groups of current sampling data whose number is the same as the preset sampling cycle number; A direct current component of the first primary current is obtained according to the multiple groups of current sampling data.
[0013] Optionally, when the determination module determines the target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit, it is specifically used to: Determining whether the modified pulse width exceeds a first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit; If yes, the corrected pulse width is limited, and the pulse width after the limit is used as the target corrected pulse width; If not, the corrected pulse width is used as the target corrected pulse width.
[0014] Optionally, the full-bridge inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, wherein the first switch tube and the fourth switch tube form a group of diagonal switch tubes, and the second switch tube and the third switch tube form another group of diagonal switch tubes, and when the correction module corrects the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain the corrected pulse width of each switch tube, it is specifically used to: Subtract the target corrected pulse width from the initial pulse width of the first switch tube and the fourth switch tube to obtain the corrected pulse width of the first switch tube and the fourth switch tube; The target corrected pulse width is added to the initial pulse widths of the second switch tube and the third switch tube to obtain the corrected pulse widths of the second switch tube and the third switch tube.
[0015] Optionally, the control system further includes: an acquisition module, used for acquiring the primary voltage of the transformer acquired by the first voltage sensor, acquiring the DC current output by the power converter acquired by the second current sensor, and acquiring the DC voltage output by the power converter acquired by the second voltage sensor when the modified pulse width is in a limited state; a third processing module, configured to obtain a second primary current of the transformer collected by the first current sensor, and obtain a DC component of the second primary current according to the second primary current; a fourth processing module, configured to obtain an input power of the power converter according to the second primary current and the primary voltage; a fifth processing module, configured to obtain an output power of the power converter according to the DC current and the DC voltage; The second control module is used to control the power converter to shut down if the DC components of multiple second primary currents obtained within a first preset time period are all greater than the first preset DC component, or the DC components of multiple second primary currents obtained within a second preset time period are all greater than the second preset DC component, or the input power obtained within a third preset time period is 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.
[0016] The present application also provides an electronic device, comprising: a processor, a memory, and a 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 the above items.
[0017] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are loaded and executed by a processor, the steps of the power converter control method as described in any one of the above items are implemented.
[0018] The present application also provides a computer program product, comprising computer executable instructions, which, when loaded and executed by a processor, implement the steps of the power converter control method as described in any one of the above items.
[0019] Compared with the prior art, the present application provides a control method, system, device, medium and product for a power converter, which obtains the first primary current of the transformer collected by a first current sensor, and samples the obtained first primary current at different sampling frequencies in each sampling period, and obtains and obtains the DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods, obtains a corrected pulse width according to the DC component of the first primary current, and then determines the target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit, and then corrects the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain the corrected pulse width of each switch tube, and then determines the corrected pulse width of each switch tube according to the target corrected pulse width. The corrected pulse width of each switching tube is used to generate a corresponding pulse signal, and each switching tube is driven and controlled, which 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; in addition, by sampling the acquired first primary current with different sampling frequencies in each sampling period, multiple groups of current sampling data corresponding to multiple sampling periods are obtained, so that multiple groups of current sampling data at different sampling points can be obtained through low sampling frequencies without increasing hardware resources and processor burden, so that the data accuracy of the DC component of the first primary current obtained according to the current sampling data of multiple groups of different sampling points is very high, which can further effectively suppress the transformer bias. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0021] Figure 1 A flow chart of a control method for a power converter disclosed in an embodiment of the present application; Figure 2 A circuit diagram of a power converter disclosed in an embodiment of the present application; Figure 3 A structural block diagram of a control system of a power converter disclosed in an embodiment of the present application; Figure 4 A schematic diagram of the structure of an electronic device disclosed in an embodiment of the present application. DETAILED DESCRIPTION
[0022] In order 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 are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0023] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0024] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.
[0026] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.
[0027] like Figure 1 As shown, the embodiment of the present application provides a control method for a power converter, such as Figure 2 As shown, the power converter includes a full-bridge inverter circuit 110, a transformer 120, and a full-bridge rectifier circuit 130 arranged on the primary side, and the control method includes: S11, obtaining a first primary current of the transformer collected by a first current sensor, and sampling the obtained first primary current using different sampling frequencies in each sampling period, and obtaining a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods; In this embodiment, the first primary current of the transformer collected in real time by the first current sensor can be obtained, that is, the first primary current of the transformer collected in real time by the first current sensor can be obtained. Figure 2 The current at the position marked by the red circle is sampled, and the first primary current obtained in real time is sampled at different sampling frequencies in each sampling period to obtain multiple groups of current sampling data at different sampling points corresponding to multiple sampling periods. The current sampling data at multiple groups of different sampling points are then added together to obtain the DC component of the first primary current.
[0028] S12, obtaining a corrected pulse width according to the DC component of the first primary current; In this embodiment, the DC component of the first primary current can be input into a PI controller as an error signal, and the corrected pulse width is calculated by the PI controller, wherein the PI controller (proportional integral controller) is a proportional integral controller.
[0029] S13, determining a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit; In this embodiment, the corrected pulse width may be compared with a preset percentage of the dead time of the switch tube in the full-bridge inverter circuit to determine the target corrected pulse width.
[0030] S14, correcting the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain a corrected pulse width of each switch tube; In this embodiment, the initial pulse width is the pulse width before correction.
[0031] S15. Generate corresponding pulse signals according to the corrected pulse width of each switch tube, and drive and control each switch tube.
[0032] In this embodiment, a corresponding pulse signal is generated according to the corrected pulse width of each switching tube, and the switching tube is driven after passing through the driving circuit 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.
[0033] Compared with the prior art, the present application provides a control method, system, device, medium and product for a power converter, which obtains a first primary current of a transformer collected by a first current sensor, and samples the obtained first primary current at different sampling frequencies in each sampling period, and obtains a DC component of the first primary current based on multiple groups of current sampling data corresponding to multiple sampling periods, obtains a corrected pulse width based on the DC component of the first primary current, and then determines a target corrected pulse width based on the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit, and then corrects the initial pulse width of each switch tube in the full-bridge inverter circuit based on the target corrected pulse width to obtain a corrected pulse width of each switch tube, and then determines the corrected pulse width of each switch tube based on the target corrected pulse width. The corrected pulse width of the switching tube generates a corresponding pulse signal, and drives and controls each switching tube, which 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; in addition, by sampling the acquired first primary current with different sampling frequencies in each sampling period, multiple groups of current sampling data corresponding to multiple sampling periods are obtained, so that multiple groups of current sampling data at different sampling points can be obtained through low sampling frequencies without increasing hardware resources and processor burden, so that the data accuracy of the DC component of the first primary current obtained according to the current sampling data of multiple groups of different sampling points is very high, which can further effectively suppress the transformer bias.
[0034] As an implementation manner, in the embodiment of the present application, step S11 includes: S111, obtaining a first primary current of the transformer collected by a first current sensor; S112, obtaining the sampling frequency of the current sampling period according to the switching frequency of the switch tube, the number of sampling periods of the current sampling period and a preset sampling frequency calculation formula; S113, sampling the acquired first primary current according to the sampling frequency of the current sampling period to obtain current sampling data; S114, controlling the sampling cycle number to start accumulating until the accumulated sampling cycle number is equal to the preset sampling cycle number, and obtaining a plurality of groups of current sampling data whose number is the same as the preset sampling cycle number; In this embodiment, the preset sampling frequency calculation formula is a preset sampling frequency calculation formula, and the preset sampling frequency calculation formula can be specifically: , in, is the switching frequency of the switch tube, N is the number of sampling cycles, is the sampling frequency; In this embodiment, the sampling cycle number can be initialized and set first, so that the sampling cycle number of the first sampling cycle is 1, and the first primary current of the transformer in the first time period collected by the first current sensor is obtained, and then the sampling frequency of the first sampling cycle is obtained according to the switching frequency of the switch tube, the sampling cycle number of the first sampling cycle and the preset sampling frequency calculation formula, and the first primary current of the first time period obtained is sampled according to the sampling frequency of the first sampling cycle to obtain a first group of current sampling data, and the sampling cycle number is controlled to start accumulating, that is, 1 is added to the sampling cycle number of the first sampling cycle, so that the sampling cycle number of the second sampling cycle is 2, and the first primary current of the transformer in the second time period collected by the first current sensor is continuously obtained, and then the sampling frequency of the second sampling cycle is obtained according to the switching frequency of the switch tube, the sampling cycle number of the second sampling cycle and the preset sampling frequency calculation formula, and the sampling frequency of the second sampling cycle is obtained according to the sampling frequency of the second sampling cycle. The first primary current of the Nth time period is sampled to obtain a second group of current sampling data, and the sampling period number is continued to be controlled to start accumulation. When the accumulated sampling period number N is equal to the preset sampling period number, the first primary current of the transformer of the Nth time period collected by the first current sensor is continued to be obtained, and then the sampling frequency of the Nth sampling period is obtained according to the switching frequency of the switch tube, the sampling period number of the Nth sampling period and the preset sampling frequency calculation formula. According to the sampling frequency of the Nth sampling period, the first primary current of the Nth time period obtained is sampled to obtain the Nth group of current sampling data. Since the waveforms of the first primary currents of each time period obtained are the same, the sampling frequency of the current sampling period is obtained according to the switching frequency of the switch tube, the sampling period number of the current sampling period and the preset sampling frequency calculation formula, so that the sampling frequencies of each sampling period are different, so that the N groups of current sampling data obtained by sampling in the N sampling periods are data of different sampling points on the waveform of the first primary current.
[0035] S115. Obtain a DC component of the first primary current according to the multiple sets of current sampling data.
[0036] In this embodiment, the DC component of the first primary current is obtained by adding N groups of current sampling data at different sampling points, so that the data accuracy of the DC component of the first primary current obtained according to the current sampling data of multiple groups of different sampling points is very high without increasing the sampling frequency to a very high level, that is, without increasing the hardware resources (or improving the sampling hardware conditions) and the processor burden, thereby further effectively suppressing the transformer bias.
[0037] As an implementation manner, in the embodiment of the present application, step S13 includes: S131, determining whether the corrected pulse width exceeds a first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit; In this embodiment, the first preset percentage is a pre-set percentage, and the first preset percentage may be 50%, that is, the first preset percentage of the dead time may be 50% of the dead time, and may also be specifically set as needed.
[0038] S132, if yes, then limit the corrected pulse width, and use the pulse width after limit as the target corrected pulse width; In this embodiment, if the corrected pulse width exceeds the first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit, the corrected pulse width is limited, and the first preset percentage of the dead time after limiting is used as the target corrected pulse width.
[0039] S133: If not, the corrected pulse width is used as the target corrected pulse width.
[0040] In this embodiment, if the modified pulse width does not exceed the first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit, the modified pulse width is used as the target modified pulse width.
[0041] As an implementation mode, in the embodiments of the present application, Figure 2 As shown, the full-bridge inverter circuit 110 includes a first switch tube S1, a second switch tube S2, a third switch tube S3 and a fourth switch tube S4, wherein the first switch tube S1 and the fourth switch tube S4 form a group of diagonal switch tubes, and the second switch tube S2 and the third switch tube S3 form another group of diagonal switch tubes. Step S14 includes: S141, subtracting the target corrected pulse width from the initial pulse width of the first switch tube and the fourth switch tube to obtain the corrected pulse width of the first switch tube and the fourth switch tube; S142, adding the target corrected pulse width to the initial pulse widths of the second switch tube and the third switch tube to obtain the corrected pulse widths of the second switch tube and the third switch tube.
[0042] In this embodiment, by correcting the pulse widths of the first switch tube, the fourth switch tube, the second switch tube, and the third switch tube, 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.
[0043] As an implementation manner, in the embodiment of the present application, the control method further includes: S21, when the corrected pulse width is in a limiting state, obtaining the primary voltage of the transformer collected by the first voltage sensor, obtaining the DC current output by the power converter collected by the second current sensor, and obtaining the DC voltage output by the power converter collected by the second voltage sensor; S22, obtaining a second primary current of the transformer collected by the first current sensor, and obtaining a DC component of the second primary current according to the second primary current; In this embodiment, the processing method of step S22 is similar to steps S111 to S115 and will not be described in detail herein.
[0044] S23, obtaining an input power of the power converter according to the second primary current and the primary voltage; In this embodiment, the effective value of the second primary current can be obtained based on the second primary current, and the effective value of the primary voltage can be obtained based on 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.
[0045] S24, obtaining the output power of the power converter according to the DC current and the DC voltage; In this embodiment, the DC current and the DC voltage may be multiplied to obtain the output power of the power converter.
[0046] S25. If the DC components of multiple second primary currents obtained within the first preset time period are all greater than the first preset DC component, or, the DC components of multiple second primary currents obtained within the second preset time period are all greater than the second preset DC component, or, the input power obtained within the third preset time period is 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, the power converter is controlled to shut down.
[0047] In this embodiment, the first preset time length, the second preset time length, and the third preset time length are preset time lengths, 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 time length can be 1s, the second preset time length can be 100ms, and the third preset time length can be 200ms. The first preset DC component can be 10A, the second preset DC component can be 50A, and the second preset percentage can be 80%, or it can be set specifically as needed.
[0048] In this embodiment, if the DC components of multiple second primary currents obtained in the power converter for a continuous first preset time period are all greater than the first preset DC component, or the DC components of multiple second primary currents obtained for a continuous second preset time period are all greater than the second preset DC component, or the input power obtained for a continuous third preset time period is 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, these abnormal conditions indicate that a device in the power converter has failed. By controlling the power converter to shut down, the power converter can be effectively protected.
[0049] like Figure 3 As shown, the embodiment of the present application further provides a control system of a power converter, the power converter includes a full-bridge inverter circuit and a transformer arranged on the primary side, and a full-bridge rectifier circuit arranged on the secondary side, and the control system includes: The first processing module 210 is used to obtain the first primary current of the transformer collected by the first current sensor, and sample the obtained first primary current using different sampling frequencies in each sampling period, and obtain a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods; A second processing module 220, configured to obtain a corrected pulse width according to a DC component of the first primary current; A determination module 230, configured to determine a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit; The correction module 240 is used to correct the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target correction pulse width to obtain the corrected pulse width of each switch tube; The first control module 250 is used to generate a corresponding pulse signal according to the corrected pulse width of each switch tube, and drive and control each switch tube.
[0050] As an implementation mode, in an embodiment of the present application, when the first processing module executes to obtain the first primary current of the transformer collected by the first current sensor, and samples the obtained first primary current using different sampling frequencies according to each sampling period, and obtains and obtains the DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods, it is specifically used to: Acquire a first primary current of the transformer collected by a first current sensor; The sampling frequency of the current sampling period is obtained according to the switching frequency of the switch tube, the number of sampling periods of 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; Controlling the sampling cycle number to start accumulating until the accumulated sampling cycle number is equal to the preset sampling cycle number, thereby obtaining a plurality of groups of current sampling data having the same number of groups as the preset sampling cycle number; A DC component of the first primary current is obtained according to the multiple sets of current sampling data.
[0051] As an implementation mode, in the embodiment of the present application, when the determination module determines the target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit, it is specifically used to: Determining whether the corrected pulse width exceeds a first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit; If yes, the corrected pulse width is limited, and the pulse width after the limit is used as the target corrected pulse width; If not, the corrected pulse width is used as the target corrected pulse width.
[0052] As an implementation manner, in an embodiment of the present application, the full-bridge inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, wherein the first switch tube and the fourth switch tube are a group of diagonal switch tubes, and the second switch tube and the third switch tube are another group of diagonal switch tubes. When the correction module corrects the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain the corrected pulse width of each switch tube, it is specifically used to: Subtract the target corrected pulse width from the initial pulse width of the first switch tube and the fourth switch tube to obtain the corrected pulse width of the first switch tube and the fourth switch tube; The initial pulse widths of the second switch tube and the third switch tube are added to the target corrected pulse width to obtain the corrected pulse widths of the second switch tube and the third switch tube.
[0053] As an implementation mode, in the embodiment of the present application, the control system further includes: An acquisition module, used for acquiring the primary voltage of the transformer acquired by the first voltage sensor, acquiring the DC current output by the power converter acquired by the second current sensor, and acquiring the DC voltage output by the power converter acquired by the second voltage sensor when the corrected pulse width is in a limited state; A third processing module is used to obtain the second primary current of the transformer collected by the first current sensor, and obtain a DC component of the second primary current according to the second primary current; A fourth processing module, used for obtaining the input power of the power converter according to the second primary current and the primary voltage; A fifth processing module, used for obtaining the output power of the power converter according to the DC current and the DC voltage; The second control module is used to control the power converter to shut down if the DC components of multiple second primary currents obtained within the first preset time period are all greater than the first preset DC component, or the DC components of multiple second primary currents obtained within the second preset time period are all greater than the second preset DC component, or the input power obtained within the third preset time period is 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.
[0054] like Figure 4 As shown, the embodiment of the present application further provides an electronic device, including: a processor 301, a memory 302 and a communication bus 303; The communication bus 303 is used to realize the connection and communication between the processor 301 and the memory 302; 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 above-mentioned power converter control methods.
[0055] An embodiment of the present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are loaded and executed by a processor, the steps of any of the above-mentioned power converter control methods are implemented.
[0056] An embodiment of the present 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 above-mentioned power converter control methods.
[0057] It should be understood that the use of "system", "device", "unit" and / or "module" in this application is only a method for distinguishing different components, elements, parts, parts or assemblies at different levels. However, if other words can achieve the same purpose, the word can be replaced by other expressions.
[0058] The embodiments in this specification are described in a progressive manner, and each embodiment focuses on the For the differences between other embodiments, the same or similar parts between the embodiments may be referred to each other.
[0059] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be 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 the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to 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 arranged on the primary side and a full-bridge rectifier circuit arranged on the secondary side, and the control method includes: Acquire a first primary current of the transformer collected by a first current sensor, and sample the acquired first primary current using different sampling frequencies in each sampling period, and obtain a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods; obtaining a corrected pulse width according to a DC component of the first primary current; Determining a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit; Correcting the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain a corrected pulse width of each switch tube; According to the corrected pulse width of each of the switch tubes, a corresponding pulse signal is generated to drive and control each of the switch tubes.
2. The control method according to claim 1, characterized in that: The step of acquiring the first primary current of the transformer collected by the first current sensor, sampling the acquired first primary current using different sampling frequencies in each sampling period, and obtaining a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods, includes: Acquire a first primary current of the transformer collected by a first current sensor; The sampling frequency of the current sampling period is obtained according to the switching frequency of the switch tube, the number of sampling periods of the current sampling period and a 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; Controlling the sampling cycle number to start accumulating until the accumulated sampling cycle number is equal to the preset sampling cycle number, thereby obtaining a plurality of groups of current sampling data whose number is the same as the preset sampling cycle number; A direct current component of the first primary current is obtained according to the multiple groups of current sampling data.
3. The control method according to claim 1, characterized in that: The step of determining a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit comprises: Determining whether the modified pulse width exceeds a first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit; If yes, the corrected pulse width is limited, and the pulse width after the limit is used as the target corrected pulse width; If not, the corrected pulse width is used 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 tube, a second switch tube, a third switch tube and a fourth switch tube, wherein the first switch tube and the fourth switch tube form a group of diagonal switch tubes, and the second switch tube and the third switch tube form another group of diagonal switch tubes, and the initial pulse width of each switch tube in the full-bridge inverter circuit is corrected according to the target corrected pulse width to obtain the corrected pulse width of each switch tube, including: Subtract the target corrected pulse width from the initial pulse width of the first switch tube and the fourth switch tube to obtain the corrected pulse width of the first switch tube and the fourth switch tube; The target corrected pulse width is added to the initial pulse width of the second switch tube and the third switch tube to obtain the corrected pulse width of the second switch tube and the third switch tube.
5. The control method according to claim 3, characterized in that: The control method further comprises: When the corrected pulse width is in a limiting state, obtaining the primary voltage of the transformer collected by the first voltage sensor, obtaining the DC current output by the power converter collected by the second current sensor, and obtaining the DC voltage output by the power converter collected by the second voltage sensor; Acquire a second primary current of the transformer collected by the first current sensor, and obtain a DC component of the second primary current according to the second primary current; Obtaining an input power of the power converter according to the second primary current and the primary voltage; Obtaining an output power of the power converter according to the DC current and the DC voltage; If the DC components of multiple second primary currents obtained within the first preset time period are all greater than the first preset DC component, or, the DC components of multiple second primary currents obtained within the second preset time period are all greater than the second preset DC component, or, the input power obtained within the third preset time period is 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, 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 arranged on the primary side and a full-bridge rectifier circuit arranged on the secondary side, and the control system includes: a first processing module, configured to obtain a first primary current of the transformer collected by a first current sensor, and sample the obtained first primary current using different sampling frequencies in each sampling period, and obtain a DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods; A second processing module, configured to obtain a corrected pulse width according to a DC component of the first primary current; A determination module, used to determine a target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit; A correction module, used for correcting the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain a corrected pulse width of each switch tube; The first control module is used to generate a corresponding pulse signal according to the corrected pulse width of each of the switch tubes to drive and control each of the switch tubes.
7. The control system according to claim 6, characterized in that: When the first processing module executes the step of acquiring the first primary current of the transformer collected by the first current sensor, and sampling the acquired first primary current using different sampling frequencies in each sampling period, and obtaining and obtaining the DC component of the first primary current according to multiple groups of current sampling data corresponding to multiple sampling periods, the first processing module is specifically used to: Acquire a first primary current of the transformer collected by a first current sensor; The sampling frequency of the current sampling period is obtained according to the switching frequency of the switch tube, the number of sampling periods of the current sampling period and a 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; Controlling the sampling cycle number to start accumulating until the accumulated sampling cycle number is equal to the preset sampling cycle number, thereby obtaining a plurality of groups of current sampling data whose number is the same as the preset sampling cycle number; A direct current component of the first primary current is obtained according to the multiple groups of current sampling data.
8. The control system according to claim 6, characterized in that: When the determination module determines the target corrected pulse width according to the corrected pulse width and the dead time of the switch tube in the full-bridge inverter circuit, it is specifically used to: Determining whether the modified pulse width exceeds a first preset percentage of the dead time of the switch tube in the full-bridge inverter circuit; If yes, the corrected pulse width is limited, and the pulse width after the limit is used as the target corrected pulse width; If not, the corrected pulse width is used 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 tube, a second switch tube, a third switch tube and a fourth switch tube, wherein the first switch tube and the fourth switch tube form a group of diagonal switch tubes, and the second switch tube and the third switch tube form another group of diagonal switch tubes. When the correction module corrects the initial pulse width of each switch tube in the full-bridge inverter circuit according to the target corrected pulse width to obtain the corrected pulse width of each switch tube, it is specifically used to: Subtract the target corrected pulse width from the initial pulse width of the first switch tube and the fourth switch tube to obtain the corrected pulse width of the first switch tube and the fourth switch tube; The target corrected pulse width is added to the initial pulse width of the second switch tube and the third switch tube to obtain the corrected pulse width of the second switch tube and the third switch tube.
10. The control system according to claim 8, characterized in that: The control system further comprises: an acquisition module, used for acquiring the primary voltage of the transformer acquired by the first voltage sensor, acquiring the DC current output by the power converter acquired by the second current sensor, and acquiring the DC voltage output by the power converter acquired by the second voltage sensor when the modified pulse width is in a limited state; a third processing module, configured to obtain a second primary current of the transformer collected by the first current sensor, and obtain a DC component of the second primary current according to the second primary current; a fourth processing module, configured to obtain an input power of the power converter according to the second primary current and the primary voltage; a fifth processing module, configured to obtain an output power of the power converter according to the DC current and the DC voltage; The second control module is used to control the power converter to shut down if the DC components of multiple second primary currents obtained within a first preset time period are all greater than the first preset DC component, or the DC components of multiple second primary currents obtained within a second preset time period are all greater than the second preset DC component, or the input power obtained within a third preset time period is 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.
11. An electronic device, characterized in that: include: processor, memory, and communications 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 power converter control method according to any one of claims 1 to 5.
12. A computer-readable storage medium, characterized in that: The readable storage medium stores computer executable instructions, and when the computer executable instructions are loaded and executed by the processor, the steps of the power converter control method according to any one of claims 1 to 5 are implemented.
13. A computer program product, characterized in that The method comprises computer executable instructions, which, when loaded and executed by a processor, implement the steps of the power converter control method according to any one of claims 1 to 5.