Gate blocking control method for converter, and converter and chip

Abstract

The present disclosure relates to a gate blocking control method for a converter, and a converter and a chip. The converter comprises an alternating-current side half-bridge circuit, a filter capacitor and a controller, wherein the filter capacitor is connected in parallel to an output end of the alternating-current side half-bridge circuit. The gate blocking control method for a converter is applied to a controller. The gate blocking control method for a converter comprises: in response to a gate blocking signal corresponding to a converter, acquiring the current polarity of an alternating-current side grid voltage, and controlling an alternating-current side half-bridge circuit to operate according to a target freewheeling path corresponding to the current polarity, so as to transfer leakage inductance energy to a filter capacitor. By using the gate blocking control method for a converter, the problem of voltage stress of an alternating-current side half-bridge circuit during gate blocking can be solved, thereby preventing an alternating-current side switch device from being damaged.

Description

Converter wave envelope control method, converter and chip

[0001] Related applications

[0002] This disclosure claims priority to Chinese patent application number 2024104743878, filed on April 19, 2024, entitled “Converter Envelope Control Method, Converter and Chip,” which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates to the technical field of converter control, and in particular to a converter envelope control method, a converter, and a chip. Background Art

[0004] When blocking the AC side of a converter using a half-bridge circuit, if all the switches on the AC side are directly turned off, the energy stored in the transformer leakage inductance has no discharge path, which can easily cause problems such as overvoltage stress in the AC side half-bridge circuit connecting the converter to the grid, leading to damage to the AC side switching devices.

[0005] Therefore, a method for controlling the blocking of the converter is urgently needed to solve the voltage stress problem of the AC side half-bridge circuit during blocking and avoid damage to the AC side switching devices.

[0006] Summary of the Invention

[0007] Based on this, it is necessary to provide a converter blocking control method, converter and chip that can solve the voltage stress risk of the AC side half-bridge circuit during blocking, in order to address the above technical problems.

[0008] In a first aspect, the present disclosure provides a method for controlling a wave envelope of a converter, wherein the converter includes an AC side half-bridge circuit, a filter capacitor, and a controller, wherein the filter capacitor is connected in parallel to the output end of the AC side half-bridge circuit. The method is used in the controller, and the method includes:

[0009] In response to the corresponding blocking signal of the converter, the current polarity of the AC side grid voltage is obtained, and the AC side half-bridge circuit is controlled to operate according to the target freewheeling path corresponding to the current polarity to transfer the leakage inductance energy to the filter capacitor.

[0010] In one embodiment, controlling the AC side half-bridge circuit to operate according to a target freewheeling path corresponding to the current polarity includes:

[0011] When the current polarity is positive, the first switching device group is controlled to be turned on, and the second switching device group is controlled to be turned off;

[0012] When the current polarity is negative, the second switching device group is controlled to be turned on, and the first switching device group is controlled to be turned off;

[0013] The first switch device group includes two switch devices in the AC side half-bridge circuit, and the second switch device group includes other two switch devices in the AC side half-bridge circuit.

[0014] In one of the embodiments, the upper bridge arm circuit of the AC side half-bridge circuit includes the first switch device and the second switch device, and the lower bridge arm circuit of the AC side half-bridge circuit includes the third switch device and the fourth switch device, and the second switch device and the third switch device are connected with the bridge arm midpoint of the AC side half-bridge circuit respectively.

[0015] The method further includes:

[0016] When the current polarity is positive, the second switch device and the fourth switch device are controlled to be turned on, and the first switch device and the third switch device are controlled to be turned off.

[0017] When the current polarity is negative, the first switch device and the third switch device are controlled to be turned on, and the second switch device and the fourth switch device are controlled to be turned off.

[0018] In one of the embodiments, the current polarity of the AC side grid voltage is obtained by:

[0019] The current phase of the AC side grid voltage is obtained.

[0020] The current polarity is determined according to the current phase.

[0021] In one of the embodiments, the method further includes:

[0022] The current polarity of the AC side grid voltage is obtained by:

[0023] The current instantaneous voltage of the AC side grid voltage is obtained.

[0024] The current polarity is determined according to the instantaneous voltage.

[0025] In one of the embodiments, the method further includes:

[0026] The current power value of the AC side half-bridge circuit is obtained in response to the clamping signal corresponding to the converter.

[0027] The preset time length is obtained based on the current power value and the capacitance value of the filter capacitor.

[0028] In one of the embodiments, the preset time length ranges from 1 microsecond to 100 microseconds.

[0029] In a second aspect, the disclosure further provides a converter including an AC side half-bridge circuit, a filter capacitor, and a controller.

[0030] The filter capacitor is connected in parallel with the output end of the AC side half-bridge circuit.

[0031] The controller is configured to obtain a current polarity of the AC side grid voltage in response to the corresponding clamping signal of the converter, and control the AC side half-bridge circuit to work in a target freewheeling path corresponding to the current polarity, so as to transfer the leakage energy to the filter capacitor.

[0032] In a third aspect, the disclosure also provides a chip including a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the method provided in the first aspect when executing the computer program.

[0033] The above-mentioned converter clamping control method, converter and chip, wherein the converter includes an AC side half-bridge circuit, a filter capacitor and a controller, the filter capacitor is connected in parallel with the output end of the AC side half-bridge circuit, the method is used in the controller, and the method includes: obtaining a current polarity of the AC side grid voltage in response to the corresponding clamping signal of the converter, and controlling the AC side half-bridge circuit to work in a target freewheeling path corresponding to the current polarity, so as to transfer the leakage energy to the filter capacitor; in this way, the leakage energy is stored in the filter capacitor with a large capacitance, the leakage energy can be quickly transferred, the risk of voltage stress of the AC side switching device in the clamping process is reduced, and the reliability of the operation of the converter is improved; at the same time, the current polarity of the AC side grid voltage is considered when the target freewheeling path is selected, the AC side grid is prevented from being short-circuited, and the safety of the converter clamping control is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the disclosed drawings.

[0035] FIG. 1 is a circuit topology structure of a single-stage isolated grid-connected inverter in an embodiment;

[0036] FIG. 2 is a circuit topology structure of a single-stage isolated grid-connected inverter in another embodiment;

[0037] FIG. 3 is a control timing diagram of switching devices in the AC side half-bridge circuit when the current polarity is positive in an embodiment;

[0038] FIG. 4 is a control timing diagram of switching devices in the AC side half-bridge circuit when the current polarity is negative in an embodiment;

[0039] FIG. 5 is a current flow direction diagram of the target freewheeling path when the current polarity is positive in an embodiment;

[0040] FIG. 6 is a schematic diagram of current flow in a target freewheeling path when the current polarity is negative in one embodiment;

[0041] FIG. 7 is a flowchart of a converter clamping control method in one embodiment. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present disclosure.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure.

[0044] It can be understood that the terms "first", "second" and the like used in the present disclosure are used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. For example, without departing from the scope of the present disclosure, the first resistor can be referred to as the second resistor, and similarly, the second resistor can be referred to as the first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0045] It can be understood that "connection" in the following embodiments, if the circuits, modules, units and the like connected to each other have transmission of electrical signals or data, should be understood as "electrical connection", "communication connection" and the like.

[0046] It can be understood that the term "based on" used in the present disclosure is used to describe one or more factors that affect the determination, and does not exclude other factors that can affect the determination. For example, the phrase "determining A based on B" means that the determination of A can be based entirely or at least partially on factor B, that is, B is one factor that affects the determination of A, but does not exclude that the determination of A is also based on C.

[0047] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Furthermore, the term "and / or" as used in this specification includes any and all combinations of the relevant listed items.

[0048] The converter wave-sealing control method provided in the embodiments of the present disclosure can be used in a controller in a converter using a half-bridge circuit structure on the AC side, wherein the upper and lower arms of the half-bridge circuit are both implemented by bidirectional switches, and the controller is connected to at least each switching device in the converter to control the on-off frequency, duty cycle, and phase shift of each switching device. The converter can be a direct current alternating current (DC-AC) converter, such as a single-stage isolated grid-connected inverter, or an alternating current direct current (AC-DC) converter, such as a single-stage isolated rectifier.

[0049] Please refer to Figure 1 and Figure 2, which are the circuit topology of a single-stage isolated grid-connected inverter. dc Indicates the DC side power supply voltage, V ac is the AC side grid voltage; the AC side half-bridge circuit includes the upper bridge arm circuit, the lower bridge arm circuit, and the resonant capacitor C p and resonant capacitor C n The upper arm circuit is realized based on a bidirectional switch composed of switching devices Q5 and Q6, and the lower arm circuit is realized based on a bidirectional switch composed of switching devices Q7 and Q8. The midpoint C of the bridge arm is connected to the leakage inductance L of the converter. r , the upper arm circuit and the resonant capacitor C p Correspondingly, the lower bridge arm circuit and the resonant capacitor C n Correspondingly, the capacitor C p and capacitor C n Series, resonant capacitor C p and resonant capacitor C n The middle connection point D is connected to the transformer in the converter; the filter capacitor C o Connected in parallel at the output end of the AC side half-bridge circuit, the filter capacitor C o and filter resistor Z g In this technical field, if the converter is an inverter, the AC side is the output end, and the filter capacitor C o Also called output capacitance.

[0050] The controller is not shown in FIGS. 1 and 2, and can be implemented by an MCU (Microcontroller Unit) chip, or based on a DSP (Digital Signal Processor) chip, an FPGA (Field-Programmable Gate Array), or a self-customized controller chip. The specific implementation hardware of the controller is not limited in the embodiments of the present disclosure.

[0051] Referring to FIG. 2, the DC side of the transformer for which the transformer clamping control method provided by the embodiments of the present disclosure is used can be implemented by an H-bridge circuit. The first bridge arm circuit of the DC side H-bridge circuit includes a switching device Q1 and a switching device Q2, and the second bridge arm circuit includes a switching device Q3 and a switching device Q4. A point and B point are load interfaces of the DC side H-bridge circuit, and T point and S point are output terminals of the DC side H-bridge circuit. r The transformer.

[0052] It should be noted that the specific circuit structure adopted by the DC side is not limited in the embodiments of the present disclosure, and FIG. 2 is only an exemplary schematic.

[0053] In the embodiments of the present disclosure, the switching device can also be referred to as a power switch tube. For example, the switching device can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or an IGBT (Insulated Gate Bipolar Transistor). The specific type and model of the switching device are not limited in the present disclosure.

[0054] In an exemplary embodiment, the transformer includes an AC side half-bridge circuit, a filter capacitor, and a controller. The filter capacitor is connected in parallel to the output terminal of the AC side half-bridge circuit. The transformer clamping control method provided by the present embodiment is used in the controller, and the method includes: in response to a clamping signal corresponding to the transformer, acquiring the current polarity of the AC side grid voltage, and controlling the AC side half-bridge circuit to work in a target freewheeling path corresponding to the current polarity, so as to transfer the leakage energy to the filter capacitor.

[0055] The clamping signal can be based on an external input shutdown instruction, or the controller can generate the clamping signal by itself when the running condition of the transformer meets a preset shutdown condition, so as to shut down the transformer. Referring to FIGS. 3 and 4, time t1 represents the time when the controller starts to respond to the clamping signal for clamping control after receiving the clamping signal.

[0056] The target freewheeling path refers to a freewheeling path that can transfer leakage energy to the filter capacitor; the target freewheeling path is constructed according to the current polarity of the AC side power grid voltage, so that the leakage energy can be quickly transferred to the filter capacitor, and at the same time, short circuit of the AC side power grid is avoided.

[0057] In a possible implementation, the process of obtaining the current polarity of the AC side power grid voltage includes: obtaining a current phase of the AC side power grid voltage, and determining the current polarity according to the current phase.

[0058] The phase corresponding to the positive polarity is 0° to 180°, and the phase corresponding to the negative polarity is 180° to 360°. At the interval boundary phase of 0°, 180° or 360°, that is, the zero-crossing phase of the AC side power grid voltage, the positive polarity can be determined or the negative polarity can be determined.

[0059] In a possible implementation, the process of obtaining the current polarity of the AC side power grid voltage includes: obtaining a current instantaneous voltage of the AC side power grid voltage, and determining the current polarity according to the instantaneous voltage.

[0060] When the instantaneous voltage is positive, the current polarity is positive; when the instantaneous voltage is negative, the current polarity is negative. When the current instantaneous voltage is 0, the positive polarity can be determined or the negative polarity can be determined.

[0061] The filter capacitor generally uses a capacitor with a large capacitance, about 100 nF (nanofarad) or uF (microfarad), and the resonance capacitor generally uses a capacitor with a small capacitance, about 10 nF. The target of constructing the target freewheeling path in the embodiment is to transfer leakage energy to the filter capacitor. Compared with the related art in which leakage energy is released through the resonance capacitor, the energy of the resonance capacitor is small, so that the leakage energy is transmitted back and forth between the leakage inductance and the resonance capacitor, the energy release speed is slow, and the voltage stress risk of the AC side switching device still exists during the clamping process. In the embodiment, the leakage energy is transferred to the filter capacitor, and because the filter capacitor has a large capacitance, the leakage energy can be quickly absorbed, and the voltage stress risk of the AC side switching device during the clamping process is reduced.

[0062] The converter control method provided in the embodiment responds to the clamping signal corresponding to the converter, obtains the current polarity of the AC side power grid voltage, controls the AC side half-bridge circuit to work according to the target freewheeling path corresponding to the current polarity, and transfers the leakage energy to the filter capacitor. In this way, the leakage energy is stored in the filter capacitor with a large capacitance, the leakage energy can be quickly transferred, the voltage stress risk of the AC side switching device during the clamping process is reduced, and the reliability of the converter is improved. At the same time, the current polarity of the AC side power grid voltage is considered when the target freewheeling path is selected, so that short circuit of the AC side power grid is avoided, and the safety of the clamping control of the converter is ensured.

[0063] Through a large number of experiments, the applicant summarizes that the transformer clamping control method provided in the embodiments of the present disclosure can transfer the leakage energy to the filter capacitor within a time of a microsecond (μs) level, complete the leakage energy discharge, and improve the reliability of the clamping control. For example, the leakage energy transfer time is less than 100 μs. In the related art, the time required for discharging the leakage energy through the resonant capacitor is generally in the millisecond (ms) level, which is much larger than the time required for the transformer clamping control method provided in the embodiments of the present disclosure.

[0064] In one example embodiment, the control of the alternating current side half-bridge circuit to work according to the target freewheeling path corresponding to the current polarity includes: when the current polarity is positive, controlling the first switch device group to be turned on and the second switch device group to be turned off; and when the current polarity is negative, controlling the second switch device group to be turned on and the first switch device group to be turned off.

[0065] The first switch device group includes two switch devices in the alternating current side half-bridge circuit, and the second switch device group includes the other two switch devices in the alternating current side half-bridge circuit.

[0066] In one possible implementation of the present embodiment, the upper bridge arm circuit of the alternating current side half-bridge circuit includes a first switch device and a second switch device, the lower bridge arm circuit of the alternating current side half-bridge circuit includes a third switch device and a fourth switch device, and the second switch device and the third switch device are respectively connected to the bridge arm midpoint of the alternating current side half-bridge circuit. In combination with the circuit topologies of FIGS. 1 and 2, the first switch device in the present embodiment is the switch device Q5 in FIGS. 1 and 2, the second switch device is the switch device Q6 in FIGS. 1 and 2, the third switch device is the switch device Q7 in FIGS. 1 and 2, and the fourth switch device is the switch device Q8 in FIGS. 1 and 2.

[0067] In the present embodiment, the first switch device group includes the second switch device and the fourth switch device, and the third switch device includes the first switch device and the fourth switch device. The control of the alternating current side half-bridge circuit to work according to the target freewheeling path corresponding to the current polarity includes: when the current polarity is positive, controlling the second switch device and the fourth switch device to be turned on and the first switch device and the third switch device to be turned off; and when the current polarity is negative, controlling the first switch device and the third switch device to be turned on and the second switch device and the fourth switch device to be turned off.

[0068] Please refer to Figures 3 and 5, wherein Figure 3 is a schematic diagram of the control timing of the switching devices of the AC side half-bridge circuit when the current polarity is positive, and Figure 5 is a schematic diagram of the current flow direction of the leakage inductance energy transferred according to the target freewheeling path when the current polarity is positive. As shown in Figure 3, before time t1, the AC side grid voltage is in the positive half-cycle. Regardless of whether it is outside the zero-crossing interval at this time, the control mode of the AC side half-bridge circuit is the first mode, that is, the switching devices Q6 and the switching device Q8 are constantly on, and the switching devices Q5 and the switching device Q7 are high-frequency complementary conductive, or whether it is within the zero-crossing interval, the control mode of the AC side half-bridge circuit is the second mode (this second mode is not specifically limited in this disclosure), and at time t1, the switching devices Q5 and the switching device Q7 are controlled to be turned off, and the switching devices Q6 and the switching device Q8 are controlled to be conductive.

[0069] Please refer to (a) in Figure 5. At time t1, the leakage inductance L r The current direction is from the leakage inductance L r Flows to point C, at this time, the leakage inductance energy through the target freewheeling path is transferred to the resonant capacitor C through the anti-parallel diode in the turned-on switch device Q6 and the turned-off switch device Q5 p and filter capacitor C o ; Due to the filter capacitor C o The capacitance is large, which can quickly absorb the leakage inductance energy, making the AC side half-bridge circuit safely blocked.

[0070] Please refer to (b) in Figure 5. At time t1, the leakage inductance L r The direction of the current at is from point C to the leakage inductance L r At this time, through the target freewheeling path, the leakage inductance energy is transferred to the resonant capacitor C through the anti-parallel diode in the turned-on switching device Q8 and the turned-off switching device Q7. n and filter capacitor C o ; Due to the filter capacitor C o The capacitance is large, which can quickly absorb the leakage inductance energy, making the AC side half-bridge circuit safely blocked.

[0071] Please refer to Figures 4 and 6, where Figure 4 is a schematic diagram of the control timing of the switching devices of the AC-side half-bridge circuit when the current polarity is negative, and Figure 6 is a schematic diagram of the current flow of leakage inductance energy transferred along the target freewheeling path when the current polarity is negative. As shown in Figure 4, before time t1, the AC-side grid voltage is in the negative half-cycle. At this time, whether it is outside the zero-crossing interval, the control mode of the AC-side half-bridge circuit is the first mode, that is, switching devices Q5 and Q7 are constantly on, and switching devices Q6 and Q8 are complementary and conducting at high frequency, or within the zero-crossing interval, the control mode of the AC-side half-bridge circuit is the second mode, at time t1, switching devices Q6 and Q8 are controlled to be off, and switching devices Q5 and Q7 are controlled to be on.

[0072] Please refer to (a) in FIG. 6, at time t1, the current direction at the leakage inductance L r flows from the leakage inductance L r to point C, at this time, the leakage energy is transferred to the resonant capacitor C n and the filter capacitor C o through the anti-parallel diode in the turned-on switch Q7 and the turned-off switch Q8 in the target freewheeling path. o Because the capacitance of the filter capacitor C r is large, the leakage energy can be quickly absorbed, so that the half-bridge circuit on the AC side is safely clamped.

[0073] Please refer to (b) in FIG. 6, at time t1, the current direction at the leakage inductance L r flows from point C to the leakage inductance L p , at this time, the leakage energy is transferred to the resonant capacitor C o and the filter capacitor C o through the anti-parallel diode in the turned-on switch Q5 and the turned-off switch Q6 in the target freewheeling path.

[0074] As can be seen from FIG. 5, when the grid voltage on the AC side is positive, no matter whether the current direction at the leakage inductance L r flows from the leakage inductance L r to point C or from point C to the leakage inductance L r , the target freewheeling path provided in this embodiment can enable the filter capacitor C o to be continuously charged in the first direction; similarly, as can be seen from FIG. 6, when the grid voltage on the AC side is negative, no matter whether the current direction at the leakage inductance L r flows from the leakage inductance L r to point C or from point C to the leakage inductance L r , the target freewheeling path provided in this embodiment can enable the filter capacitor C o to be continuously charged in the second direction; in this way, the clamping control method for the converter provided in this embodiment can enable the filter capacitor C o to be continuously charged in one charging direction, achieve the effect of quickly transferring the leakage energy to the filter capacitor for storage, reduce the voltage stress risk of the switch on the AC side when clamping, and improve the reliability of the operation of the converter; at the same time, in the clamping control method for the converter provided in this embodiment, there is no need to judge the current direction at the leakage inductance L r at the clamping time, thereby avoiding the voltage stress risk of the switch on the AC side caused by the possible misjudgment of the current direction when selecting the freewheeling path according to the current direction at the leakage inductance L r in the related art.

[0075] Further, even if the polarity of the AC side grid voltage near the zero crossing point is not accurate, the short-time through generally does not cause stress risk to the switching device due to the small value of the AC side voltage near the zero crossing point and the small leakage energy. Meanwhile, the target freewheeling path provided in the embodiment can still ensure that the leakage energy is in the leakage inductance L r and the resonant capacitor C p or the resonant capacitor C n flows bidirectionally, further avoiding causing stress risk to the device.

[0076] In an exemplary embodiment, when the current value at the leakage inductance L r all the switching devices of the AC side half-bridge circuit are controlled.

[0077] In an exemplary embodiment, a preset time length for freewheeling operation according to the target freewheeling path is preconfigured; after the AC side half-bridge circuit is controlled to work according to the target freewheeling path for the preset time length, all the switching devices of the AC side half-bridge circuit are controlled to be turned off. For example, referring to FIG. 3 and FIG. 4, all the switching devices of the AC side half-bridge circuit are controlled to be turned off at time t2, and ΔT in FIG. 3 and FIG. 4 is the preset time length.

[0078] In a possible implementation, the transformer clamping control method further includes: in response to the clamping signal corresponding to the transformer, obtaining a current power value corresponding to the AC side half-bridge circuit; and based on the current power value and the capacitance value of the filter capacitor, obtaining the preset time length.

[0079] In the embodiment, the preset time length obtained based on the current duty cycle value of the AC side half-bridge circuit when the clamping signal is received and the capacitance value of the filter capacitor improves the accuracy of the freewheeling operation time length in the clamping process.

[0080] In another possible implementation, in the transformer clamping control method, the preset time length for working according to the target freewheeling path is preconfigured according to a large number of experiments.

[0081] The applicant finds through a large number of experiments that the time length for transferring the leakage energy in the clamping process to the filter capacitor through the target freewheeling path is in the order of μs (microsecond), generally less than 100 μs. Optionally, the preset time length is in the range of 1 μs to 100 μs; optionally, the preset time length is in the range of 1 μs to 10 μs. In the embodiment, the freewheeling operation preset time length is preconfigured according to the empirical value, which can save the real-time power value acquisition of the AC side half-bridge circuit and the calculation process of the preset time length in the clamping process, and improve the clamping control efficiency.

[0082] In the embodiment, the working time length of the freewheeling path is controlled according to the determined preset time length, which is compared with the real-time acquisition of the leakage inductance L rThe method for determining the off of all switch devices of the AC side half-bridge circuit by the current value of the current in the inductor, without additional current sampling circuit, saves hardware resources and improves control efficiency.

[0083] In an exemplary embodiment, the converter comprises an AC side half-bridge circuit, a filter capacitor connected in parallel with the output of the AC side half-bridge circuit, and a controller, the upper bridge arm circuit of the AC side half-bridge circuit comprises a first switch device and a second switch device, the lower bridge arm circuit of the AC side half-bridge circuit comprises a third switch device and a fourth switch device, and the second switch device and the third switch device are connected with the bridge arm midpoint of the AC side half-bridge circuit respectively; the converter for the controller provided by the converter clamp control method of the embodiment, please refer to Fig. 7, the method comprises steps 702 to 708, wherein:

[0084] Step 702, in response to the corresponding clamp signal of the converter, the current polarity of the AC side grid voltage and the current power value corresponding to the AC side half-bridge circuit are obtained.

[0085] Optionally, the current phase of the AC side grid voltage is obtained, and the current polarity is determined according to the current phase.

[0086] Optionally, the current instantaneous voltage of the AC side grid voltage is obtained, and the current polarity is determined according to the instantaneous voltage.

[0087] Step 704, based on the current power value and the capacitance value of the filter capacitor, a preset time length is obtained.

[0088] Step 706, it is judged whether the current polarity is positive or not.

[0089] Step 708, if the current polarity is positive, the first switch device and the third switch device are directly turned off, and the second switch device and the fourth switch device are turned on for a preset time length and then turned off.

[0090] Step 710, if the current polarity is negative, the second switch device and the fourth switch device are directly turned off, and the first switch device and the fourth switch device are turned on for a preset time length and then turned off.

[0091] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the arrows, the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, the execution of the steps is not strictly limited in sequence, and the steps can be executed in other sequences or simultaneously. Moreover, at least some of the steps in the flowcharts involved in the above embodiments can include multiple steps or stages, which are not necessarily executed at the same time but can be executed at different times, and the execution sequence of the steps or stages is not necessarily sequential but can be executed alternately or alternately with at least some of the other steps or steps or stages in the other steps.

[0092] The embodiments of the present disclosure also provide a converter, comprising an AC side half-bridge circuit, a filter capacitor and a controller; the filter capacitor is connected in parallel to the output end of the AC side half-bridge circuit; the controller is configured to, in response to a corresponding blocking signal of the converter, obtain a current polarity of an AC side grid voltage, and control the AC side half-bridge circuit to operate according to a target freewheeling path corresponding to the current polarity, so as to transfer leakage energy to the filter capacitor.

[0093] In an exemplary embodiment, the controller is configured to, when the current polarity is positive, control the first group of switching devices to be turned on while controlling the second group of switching devices to be turned off; and when the current polarity is negative, control the second group of switching devices to be turned on while controlling the first group of switching devices to be turned off; wherein the first group of switching devices comprises two switching devices in the AC side half-bridge circuit, and the second group of switching devices comprises the other two switching devices in the AC side half-bridge circuit.

[0094] In an exemplary embodiment, the upper bridge arm circuit of the AC side half-bridge circuit comprises a first switching device and a second switching device, the lower bridge arm circuit of the AC side half-bridge circuit comprises a third switching device and a fourth switching device, and the second switching device and the third switching device are connected to the bridge arm midpoint of the AC side half-bridge circuit respectively; the controller is configured to, when the current polarity is positive, control the second switching device and the fourth switching device to be turned on while controlling the first switching device and the third switching device to be turned off; and when the current polarity is negative, control the first switching device and the third switching device to be turned on while controlling the second switching device and the fourth switching device to be turned off.

[0095] In an exemplary embodiment, the controller is further configured to obtain a current phase of the AC side grid voltage; and determine the current polarity according to the current phase.

[0096] In an exemplary embodiment, the controller is further configured to obtain a current instantaneous voltage of the AC side grid voltage; and determine the current polarity according to the instantaneous voltage.

[0097] In an example embodiment, the controller controls all switching devices of the AC side half-bridge circuit to be turned off after a preset time length for operating the AC side half-bridge circuit according to the target freewheeling path.

[0098] In an example embodiment, the controller obtains a current power value of the AC side half-bridge circuit in response to a corresponding clamping signal of the converter; and obtains the preset time length based on the current power value and a capacitance value of the filter capacitor.

[0099] In an example embodiment, the preset time length ranges from 1 microsecond to 100 microseconds.

[0100] The embodiments of the present disclosure further provide a chip including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above-mentioned method embodiments when executing the computer program.

[0101] In an example embodiment, a computer device is also provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above-mentioned method embodiments when executing the computer program.

[0102] In an example embodiment, a computer readable storage medium is provided, storing a computer program, and the computer program implementing the steps in the above-mentioned method embodiments when executed by a processor.

[0103] In an example embodiment, a computer program product is provided, including a computer program, and the computer program implementing the steps in the above-mentioned method embodiments when executed by a processor.

[0104] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present disclosure are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of the related data need to comply with relevant regulations.

[0105] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of each method can be included. Any reference to memory, database or other medium used in each embodiment provided by the present disclosure can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in each embodiment provided by the present disclosure can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in each embodiment provided by the present disclosure can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0106] Each technical feature of the above-mentioned embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of each technical feature in the above-mentioned embodiments are not described, however, as long as the combination of these technical features does not exist contradictory, it should be considered as the scope of the present disclosure.

[0107] The above-mentioned embodiments only express several implementation manners of the present disclosure, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent application. It should be noted that for those skilled in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made, which are within the scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure should be subject to the appended claims.

Claims

1. A method of inverter hysteresis control, wherein, The converter comprises an alternating current side half-bridge circuit, a filter capacitor connected in parallel to an output end of the alternating current side half-bridge circuit, and a controller, the method is used in the controller, and the method comprises the following steps: In response to a corresponding clamping signal of the converter, a current polarity of an alternating current side grid voltage is obtained, and the alternating current side half-bridge circuit is controlled to work according to a target freewheeling path corresponding to the current polarity, so as to transfer leakage energy into the filter capacitor.

2. The method of claim 1, wherein, The control of the alternating current side half-bridge circuit to work according to the target freewheeling path corresponding to the current polarity comprises the following steps: When the current polarity is positive, a first switch device group is controlled to be turned on, and a second switch device group is controlled to be turned off; When the current polarity is negative, the second switch device group is controlled to be turned on, and the first switch device group is controlled to be turned off; The first switch device group comprises two switch devices in the alternating current side half-bridge circuit, and the second switch device group comprises the other two switch devices in the alternating current side half-bridge circuit.

3. The method of claim 2, wherein, The upper bridge arm circuit of the alternating current side half-bridge circuit comprises a first switch device and a second switch device, and the lower bridge arm circuit of the alternating current side half-bridge circuit comprises a third switch device and a fourth switch device, and the second switch device and the third switch device are connected to the bridge arm midpoint of the alternating current side half-bridge circuit respectively; The control of the alternating current side half-bridge circuit to work according to the target freewheeling path corresponding to the current polarity comprises the following steps: When the current polarity is positive, the second switch device and the fourth switch device are controlled to be turned on, and the first switch device and the third switch device are controlled to be turned off; When the current polarity is negative, the first switch device and the third switch device are controlled to be turned on, and the second switch device and the fourth switch device are controlled to be turned off.

4. The method of claim 1, wherein, The obtaining of the current polarity of the alternating current side grid voltage comprises the following steps: A current phase of the alternating current side grid voltage is obtained; The current polarity is determined according to the current phase.

5. The method of claim 1, wherein, The obtaining of the current polarity of the alternating current side grid voltage comprises the following steps: A current instantaneous voltage of the alternating current side grid voltage is obtained; The current polarity is determined according to the instantaneous voltage.

6. The method of claim 1, wherein, The method further comprises the following steps: After the alternating current side half-bridge circuit is controlled to work according to the target freewheeling path for a preset time length, all switch devices of the alternating current side half-bridge circuit are controlled to be turned off.

7. The method of claim 6, wherein, The method further comprises the following steps: In response to the corresponding clamping signal of the converter, a current power value corresponding to the alternating current side half-bridge circuit is obtained; Based on the current power value and the capacitance value of the filter capacitor, the preset time length is obtained.

8. The method of claim 6, wherein, The preset time length ranges from 1 microsecond to 100 microseconds.

9. An inverter wherein, The converter comprises an alternating current side half-bridge circuit, a filter capacitor, and a controller; The filter capacitor is connected in parallel to an output end of the alternating current side half-bridge circuit; The controller is used to obtain a current polarity of an alternating current side grid voltage in response to a corresponding clamping signal of the converter, and control the alternating current side half-bridge circuit to work according to a target freewheeling path corresponding to the current polarity, so as to transfer leakage energy into the filter capacitor.

10. A chip comprising a memory and a processor, the memory storing a computer program, wherein, The processor, when executing the computer program, implements the steps of the method according to any one of claims 1 to 8.

Images