Output current detection method and device, electronic equipment and storage medium

Abstract

The invention discloses an output current detection method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining a primary side current of a DC power supply, and determining a target current based on a topological structure of the DC power supply and the primary side current, the topological structure comprising a dual-active bridge topological structure and a series resonance topological structure; processing the target current to obtain a processed target current; and determining a secondary side current according to the processed target current, and further determining an output current of the direct current power supply according to the secondary side current. According to the invention, the sampling element loss and the detection cost of DC power supply output current detection can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of current detection technology, and in particular to an output current detection method, device, electronic equipment and storage medium. Background Art

[0002] Traditional DC power supply output current detection mostly uses shunts + amplifiers or Hall sensors, etc. These detection methods are often very costly when collecting large DC currents. Specifically, when sampling large DC currents, the current will flow directly through the shunt and Hall sensor, and the loss of the sampling element is proportional to the square of the current. Large DC currents are often large, resulting in large losses in the sampling element and high detection costs. The prior art requires a DC power supply output current detection solution with low sampling element losses and low detection costs. Summary of the invention

[0003] In order to solve at least one technical problem in the above-mentioned background technology, the present invention proposes an output current detection method, device, electronic device and storage medium.

[0004] In order to achieve the above object, according to one aspect of the present invention, an output current detection method is provided, the method comprising:

[0005] Acquire a primary current of a DC power supply, and determine a target current based on a topology of the DC power supply and the primary current, wherein the topology includes a dual active bridge topology and a series resonant topology;

[0006] Processing the target current to obtain a processed target current;

[0007] A secondary current is determined according to the processed target current, and then an output current of the DC power supply is determined according to the secondary current.

[0008] Optionally, determining the target current based on the topology of the DC power supply and the primary current includes:

[0009] If the DC power supply is a series resonant topology structure, the target current is determined according to a driving signal of a primary switch tube and the primary current, wherein the primary switch tube is a switch tube arranged in a primary circuit;

[0010] If the DC power supply is a dual active bridge topology structure, the target current is determined according to a driving signal of a secondary switch tube and the primary current, wherein the secondary switch tube is a switch tube arranged in a secondary circuit.

[0011] Optionally, the primary switch tube includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube;

[0012] If the DC power supply is a series resonant topology structure, determining the target current according to the driving signal of the primary switch tube and the primary current includes:

[0013] If the DC power supply is a series resonant topology structure, the target current is determined according to the driving signals of the first switch tube and the third switch tube, or the target current is determined according to the driving signals of the second switch tube and the fourth switch tube.

[0014] Optionally, the secondary side switch tube includes a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube;

[0015] If the DC power supply is a dual active bridge topology structure, determining the target current according to the drive signal of the secondary switch tube and the primary current includes:

[0016] If the DC power supply is a dual active bridge topology structure, the target current is determined according to the drive signals of the fifth switch tube and the seventh switch tube, or the target current is determined according to the drive signals of the sixth switch tube and the eighth switch tube.

[0017] Optionally, the processing the target current to obtain a processed target current includes:

[0018] Obtaining a target amplifier circuit based on the driving signal, wherein the target amplifier circuit is a non-inverting amplifier circuit or an inverting amplifier circuit;

[0019] The target current is amplified according to the target amplification circuit to obtain an amplified target current.

[0020] Optionally, the primary current includes a primary excitation current and a current transmitted to a secondary side;

[0021] The step of determining the secondary current according to the processed target current, and further determining the output current of the DC power supply according to the secondary current, comprises:

[0022] Subtracting the primary side excitation current from the processed target current to obtain the current transmitted to the secondary side;

[0023] The secondary side current is determined according to the current transmitted to the secondary side, and the output current of the DC power supply is determined according to the secondary side current and a preset calculation formula.

[0024] Optionally, the step of removing the primary excitation current from the processed target current to obtain the current transmitted to the secondary side includes:

[0025] Setting the filtering frequency of the filtering circuit according to the frequency characteristics of the primary excitation current;

[0026] The current transmitted to the secondary side is obtained by removing the primary side excitation current in the processed target current through the filtering circuit based on the filtering frequency.

[0027] In order to achieve the above object, according to another aspect of the present invention, an output current detection device is provided, the device comprising:

[0028] a target current determination unit, configured to obtain a primary current of a DC power supply, and determine a target current based on a topology of the DC power supply and the primary current, wherein the topology includes a dual active bridge topology and a series resonant topology;

[0029] a current processing unit, used for processing the target current to obtain a processed target current;

[0030] The output current determining unit is used to determine the secondary current according to the processed target current, and further determine the output current of the DC power supply according to the secondary current.

[0031] In order to achieve the above-mentioned purpose, according to another aspect of the present invention, an electronic device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned output current detection method when executing the computer program.

[0032] In order to achieve the above object, according to another aspect of the present invention, a computer-readable storage medium is provided, on which a computer program / instruction is stored, and when the computer program / instruction is executed by a processor, the steps of the output current detection method are implemented.

[0033] The beneficial effects of the present invention are:

[0034] The present invention determines the output current of the DC power supply based on the primary current of the transformer in the DC power supply. Since the primary current is smaller than the output current of the DC power supply, the loss of collecting the primary current is smaller than the loss of directly collecting the output current of the DC power supply. Therefore, the present invention reduces the loss of the sampling element when detecting the output current of the DC power supply, thereby reducing the detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0036] Figure 1 is a flow chart of an output current detection method according to an embodiment of the present invention;

[0037] Figure 2 is a flow chart of processing the target current according to an embodiment of the present invention;

[0038] Figure 3 is a flow chart of determining output current according to an embodiment of the present invention;

[0039] Figure 4 is a flow chart of removing the primary excitation current according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of collecting primary current according to an embodiment of the present invention;

[0041] Figure 6 is a schematic diagram of primary current processing in an embodiment of the present invention;

[0042] Figure 7 is a schematic diagram of a primary current processing circuit according to an embodiment of the present invention;

[0043] Figure 8 is a schematic diagram of a dual active bridge circuit according to an embodiment of the present invention;

[0044] Fig. 9 It is a signal schematic diagram of a dual active bridge circuit according to an embodiment of the present invention;

[0045] Fig.10 is a schematic diagram of a series resonant circuit according to an embodiment of the present invention;

[0046] Fig.11 is a schematic diagram of signals of a series resonant circuit according to an embodiment of the present invention;

[0047] Fig.12 is a structural block diagram of an output current detection device according to an embodiment of the present invention;

[0048] Fig.13 Schematic diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0051] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0052] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0053] Figure 1 is a flow chart of the output current detection method according to an embodiment of the present invention. Figure 1 As shown, in one embodiment of the present invention, the output current detection method of the present invention includes steps S101 to S103.

[0054] Step S101, obtaining a primary current of a DC power supply, and determining a target current based on a topology structure of the DC power supply and the primary current, wherein the topology structure includes a dual active bridge topology structure and a series resonant topology structure.

[0055] In one embodiment of the present invention, this step specifically obtains the primary current of the transformer in the DC power supply. The primary current of the transformer is the current flowing through the primary winding of the transformer. The secondary current of the transformer is the current output from the secondary winding of the transformer and provided to the load for use.

[0056] Figure 5 The schematic diagram of collecting the primary current of the transformer of the present invention. In one embodiment of the present invention, the present invention can use a current transformer (CT), a Hall effect sensor or a shunt to collect the primary current. Generally, the current transformer is widely used in high-frequency switching power supplies, and can effectively provide a current signal, and the current sampling will not generate an excessive load on the circuit.

[0057] The primary current of the transformer includes the excitation current part and the current part transmitted to the secondary side, among which the current part transmitted to the secondary side is the basis for the subsequent calculation of the secondary current.

[0058] Among the primary currents of the transformer, the excitation current is the current necessary to maintain the magnetic field of the transformer. The source of the excitation current is directly related to the magnetization process of the iron core. The excitation current is a periodic alternating current, and its magnitude is related to the rated capacity of the transformer, the material properties of the iron core, and the operating frequency of the transformer.

[0059] In the present invention, the present invention performs a pass-selection process on the primary current based on the topological structure of the DC power supply, and extracts a target current from the primary current, and the target current meets the excitation current ampere-second balance condition.

[0060] The ampere-second balance condition of the excitation current means that the total current time integral of the excitation current should be zero in a cycle or a period of time. That is, in a cycle, the time integral of the positive and reverse parts of the excitation current is equal, and the positive and negative ampere-second values ​​(the product of current and time) cancel each other out.

[0061] like Fig. 9 In the illustrated embodiment, the primary excitation current is symmetrical in positive and negative directions in the time period t0 to t2, meeting the excitation current ampere-second balance condition. At this time, the signal in the time period t0 to t2 can be selected as the target current.

[0062] like Fig.11 In the illustrated embodiment, the excitation current ampere-second balance condition is met during the time period t0 to t2, and the signal during the time period t0 to t2 can be selected as the target current.

[0063] During the operation of the transformer, the excitation current is periodic. The present invention can ensure that the positive and negative symmetrical parts of the excitation current are effectively offset during a specific time period by selecting the specific time period, thereby eliminating the influence of the excitation current.

[0064] In one embodiment of the present invention, when determining the target current, the present invention can first obtain the primary excitation current, and then determine the specific time period that meets the excitation current ampere-second balance condition from the primary excitation current signal, thereby determining the target current from the primary current.

[0065] In one embodiment of the present invention, the present invention can obtain the primary excitation current from the primary current through a low-pass filter. Since the primary excitation current is a periodic signal, it usually has a low frequency and a stable amplitude characteristic. Therefore, a low-pass filter can be used to extract the primary excitation current. Specifically, first determine the frequency range of the primary excitation current (usually the same as the operating frequency of the transformer, such as 50Hz or 60Hz); then design a low-pass filter and set its cut-off frequency slightly higher than the operating frequency of the primary excitation current, which will allow the frequency components of the primary excitation current to pass through while filtering out the higher frequency load current and other noise; the primary current passes through the low-pass filter, and the primary excitation current portion is extracted therefrom. Since the frequency of the load current is usually high, the low-pass filter can effectively remove the load current and other high-frequency noise, retaining only the low-frequency primary excitation current.

[0066] In another embodiment of the present invention, the present invention can perform a fast Fourier transform (FFT) on the primary current to convert the signal from the time domain to the frequency domain. Then, through spectrum analysis, the low-frequency components in the signal (usually a fundamental wave of 50Hz or 60Hz, representing the primary excitation current) are identified. Since the frequency of the primary excitation current is near the operating frequency of the transformer, these frequency components usually have obvious peaks. Finally, by extracting the fundamental wave part (i.e., the most important low-frequency component) in the spectrum, the primary excitation current can be obtained. Usually, the frequency of the fundamental wave corresponds to the operating frequency of the transformer, and the load current usually contains higher-frequency components.

[0067] Step S102, processing the target current to obtain a processed target current.

[0068] The characteristics of the excitation current are that it is periodic and has nothing to do with the secondary current. Since the excitation current is positive and negative symmetrical within half a cycle, the average value within a certain period of time is close to zero. Therefore, the present invention can use this characteristic to remove the primary excitation current portion of the target current during the processing process, and the processed target current obtained contains only the current portion transmitted to the secondary side, but not the excitation current portion. This signal is the basis for further calculating the secondary current.

[0069] In one embodiment of the present invention, the present invention can first obtain the primary excitation current, and then remove the primary excitation current in the target current to obtain the processed target current.

[0070] Step S103, determining a secondary current according to the processed target current, and further determining an output current of the DC power supply according to the secondary current.

[0071] In the present invention, the present invention can first determine the current transmitted to the secondary side according to the processed target current, and then calculate the secondary current according to the current transmitted to the secondary side and the turns ratio n of the transformer (the ratio of the primary turns to the secondary turns).

[0072] In a DC power supply, the secondary current is rectified, filtered, and other processes to eventually form a DC output current. Since the output current is rectified and filtered, the fluctuation of the secondary current will be smoothed, and the final output DC current can be equivalent to the secondary current.

[0073] The present invention can accurately infer the output current of the DC power supply through the calculated secondary current. This process reduces the dependence on traditional high current sampling, especially in the application of DC high current, avoiding the high loss problem of directly measuring the secondary high current.

[0074] When sampling large DC current, the current will flow directly through the shunt and the Hall, and the loss of the sampling element is I 2 R. The present invention directly collects the primary current, which is 1 / n of the DC current. n is the turns ratio of the transformer (the ratio of the primary turns to the secondary turns). The loss of the sampling element is Since n is usually much larger than 1, the loss of the solution of the present invention is much smaller than that of the traditional method. Therefore, the present invention reduces the loss of the sampling element when detecting the output current of the DC power supply and reduces the detection cost.

[0075] In one embodiment of the present invention, when determining the target current from the primary current, the present invention needs to determine the signal in the topology structure of the DC power supply that can reflect the ampere-second balance characteristics of the transformer excitation current as the driving signal of the gating circuit, and then input the primary current into the gating circuit to obtain the target current extracted from the primary current by the gating circuit.

[0076] In one embodiment of the present invention, the step S101 of determining the target current based on the topological structure of the DC power supply and the primary current specifically includes:

[0077] If the DC power supply is a series resonant topology structure, the target current is determined according to a driving signal of a primary switch tube and the primary current, wherein the primary switch tube is a switch tube arranged in a primary circuit;

[0078] If the DC power supply is a dual active bridge topology structure, the target current is determined according to a driving signal of a secondary switch tube and the primary current, wherein the secondary switch tube is a switch tube arranged in a secondary circuit.

[0079] In the present invention, if the DC power supply adopts a dual active bridge topology, the secondary drive signal of the transformer is determined as the drive signal of the gating circuit, and the target current is extracted from the primary current through the gating circuit; if the DC power supply adopts a series resonant topology, the primary drive signal of the transformer is determined as the drive signal of the gating circuit, and the target current is extracted from the primary current through the gating circuit.

[0080] The gating circuit samples the primary current in a specific time period based on a specific switching device (such as a transistor, MOSFET, etc.), thereby selecting a target current in the primary current that meets the excitation current ampere-second balance condition. The switch control signal of the gating circuit comes from a signal in the DC power supply topology structure, and this signal is closely related to the working state of the transformer and the ampere-second balance characteristic of the excitation current. The present invention controls the gating circuit through a driving signal, so that the circuit passes the primary current only in certain specific time periods, and does not sample at other times, thereby focusing on the partial current signal in the primary current that meets the excitation current ampere-second balance condition.

[0081] In the present invention, the selection of the drive signal is very important because it directly affects the accuracy of the time period selected by the gating circuit. The drive signal needs to reflect the ampere-second balance characteristic of the transformer excitation current, that is, the average value of the excitation current in a specific time period is zero. In different embodiments of the present invention, the selected drive signal will vary depending on the different DC power supply topology structures.

[0082] It can be understood that in the present application, the primary current may specifically be the primary inductor current.

[0083] In the dual active bridge topology, the excitation current of the primary inductor is alternately controlled by the secondary drive signal. In each cycle, the secondary drive signal causes the primary current to complete the alternating process of charging and discharging. However, since the primary inductor is first discharged and then charged each time it is turned on, this method makes the positive and negative parts of the excitation current not completely symmetrical, and thus the ampere-second balance condition of the excitation current cannot be guaranteed. In the dual active bridge topology, the secondary drive signal matches the periodic fluctuation of the excitation current. Based on the working principle of the dual active bridge topology, the charging and discharging process of the primary excitation current cannot naturally meet the ampere-second balance condition, so it is necessary to select a specific time period through the secondary drive signal. During these time periods, the secondary drive signal can effectively reflect the symmetry of the excitation current and ensure that the unbalanced part is eliminated in the appropriate time.

[0084] In a series resonant circuit, the primary drive signal controls the charging and discharging process of the transformer, while the secondary side only works during a certain period of the cycle. Specifically, the primary drive signal will alternately control the charging and discharging process of the current, resulting in a strong symmetry in the excitation current of the primary inductor within a cycle. In the series resonant topology, the primary drive signal controls the charging and discharging process of the entire system, so that the positive and negative parts of the excitation current are naturally balanced. Therefore, the primary drive signal can well reflect the ampere-second balance characteristics of the excitation current, and can be directly used for the drive signal of the gating circuit to accurately select the time period that reflects the excitation current.

[0085] Therefore, for the dual active bridge circuit of the present invention, since the excitation current of the primary inductor corresponding to the primary drive signal cannot naturally meet the ampere-second balance condition, it is necessary to select a specific time period related to the excitation current through the secondary drive signal. For the series resonant circuit, since the primary drive signal can directly reflect the ampere-second balance characteristic of the excitation current, the primary drive signal can be used to select the time period reflecting the excitation current.

[0086] In the present invention, the primary side driving signal refers to the driving signal of the primary side switch tube, and the secondary side driving signal refers to the driving signal of the secondary side switch tube.

[0087] Figure 8 Schematic diagram of a dual active bridge circuit according to an embodiment of the present invention. Figure 8 As shown, the dual active bridge circuit includes: a left upper bridge arm switch tube Q1 (hereinafter also referred to as the first switch tube) located at the upper left position of the primary side bridge and responsible for the high voltage opening of the forward bridge arm; a left lower bridge arm switch tube Q2 (hereinafter also referred to as the second switch tube) located at the lower left position of the primary side bridge and responsible for the low potential commutation of the forward bridge arm; a right lower bridge arm switch tube Q3 (hereinafter also referred to as the third switch tube) located at the lower right position of the primary side bridge and responsible for the low potential commutation of the reverse bridge arm; a right upper bridge arm switch tube Q4 (hereinafter also referred to as the third switch tube) located at the upper right position of the primary side bridge and responsible for the high voltage opening of the reverse bridge arm is the fourth switch tube); the upper left bridge arm switch tube S1 (hereinafter also referred to as the fifth switch tube) is located at the upper left position of the secondary bridge, responsible for the high voltage opening of the forward bridge arm; the lower left bridge arm switch tube S2 (hereinafter also referred to as the sixth switch tube) is located at the lower left position of the secondary bridge, responsible for the low potential commutation of the forward bridge arm; the lower right bridge arm switch tube S3 (hereinafter also referred to as the seventh switch tube) is located at the lower right position of the secondary bridge, responsible for the low potential commutation of the reverse bridge arm; the upper right bridge arm switch tube S4 (hereinafter also referred to as the eighth switch tube) is located at the upper right position of the secondary bridge, responsible for the high voltage opening of the reverse bridge arm.

[0088] Q1 and Q3 form a pair of forward-conducting bridge arm switches on the primary side (a pair of switches responsible for generating square wave signals). Q2 and Q4 form a pair of reverse-conducting bridge arm switches on the primary side (responsible for alternating conduction with Q1 and Q3 to achieve current commutation between cycles).

[0089] S1 and S3 form the forward-conducting bridge arm switch pair on the secondary side (a pair of switch tubes responsible for converting the high-frequency square wave transmitted by the transformer into a DC voltage). S2 and S4 form the reverse-conducting bridge arm switch pair on the secondary side (responsible for alternately conducting with S1 and S3 to achieve power commutation and rectification functions).

[0090] The secondary side driving signal mentioned in the present invention refers to the driving signal of the secondary side switch tubes S1, S2, S3 and S4.

[0091] S1 and S3 belong to the same group of bridge arm switches in the secondary circuit. When they are turned on, the secondary side of the secondary transformer forms a voltage polarity corresponding to the primary side. Therefore, the signals of S1 and S3 are synchronized (i.e. the same). S2 and S4 are combined into another group of switches of the same bridge arm. When S2 and S4 are turned on, the current direction of the secondary side is reversed, and a voltage opposite to that of S1 and S3 is generated. Therefore, the signals of S2 and S4 are also the same. S1 and S3 are a group of bridge arm switches on the secondary side. When they are turned on, it means that the secondary current flows in one direction to the primary side of the transformer. S2 and S4 are another group of bridge arm switches. When they are turned on, the secondary current flows in the opposite direction. The signals of the switches in the same group are the same, and the signals of the switches in different groups are opposite. Therefore, the signals of S1 and S3 are opposite to those of S2 and S4.

[0092] Fig. 9 Schematic diagram of dual active bridge circuit signals according to an embodiment of the present invention. Fig. 9 From top to bottom are the primary drive signal, the secondary drive signal, the primary current IL and the excitation current signal Im, and the secondary current I_sec.

[0093] like Figure 8 and Fig. 9 As shown, in the dual active bridge circuit, the primary current IL includes the excitation current Im and the current transmitted to the secondary side (can be bidirectional). The secondary current I_sec can be calculated by obtaining the current portion transmitted to the secondary side. Fig. 9 As shown, during the time period from time t0 to t2, the excitation current Im is symmetrical in positive and negative directions. The primary current during the time period from time t0 to t2 is selected as the target current through the secondary drive signal (S1 and S3), and then the positive and negative parts of the excitation current in the target current are offset by filtering to obtain the current part transmitted from the primary side to the secondary side.

[0094] In one embodiment of the present invention, if the DC power supply adopts a dual active bridge topology, the driving signal of the gating circuit can directly adopt the signal of the upper left bridge arm switch tube S1 or the signal of the lower right bridge arm switch tube S3.

[0095] In another embodiment of the present invention, if the DC power supply adopts a dual active bridge topology structure, the inverse signal of the signal of the lower left bridge arm switch tube S2 can be obtained, and the inverse signal of S2 can be used as the driving signal of the gating circuit, or the inverse signal of the signal of the upper right bridge arm switch tube S4 can be obtained, and the inverse signal of S4 can be used as the driving signal of the gating circuit.

[0096] Fig.10 is a schematic diagram of a series resonant circuit according to an embodiment of the present invention, Fig.10 The meanings of S1 to S4 and Q1 to Q4 are the same as Figure 8 The same as the embodiment, see Figure 8 The embodiments of the present invention will not be described in detail here.

[0097] The primary side driving signal mentioned in the present invention refers to the driving signal of the primary side switching tubes Q1, Q2, Q3 and Q4.

[0098] Fig.11 is a schematic diagram of series resonant circuit signals according to an embodiment of the present invention, Fig.11 From top to bottom are the primary drive signal, the secondary drive signal, the primary current IL and the excitation current signal Im, and the secondary current I_sec.

[0099] like Fig.10 and Fig.11 As shown, in the series resonant circuit, the primary current IL includes the excitation current Im and the current transmitted to the secondary side (can be bidirectional). The secondary current I_sec can be calculated by obtaining the current portion transmitted to the secondary side. Fig.11 As shown, during the time period from time t0 to t2, the excitation current Im is symmetrical in positive and negative directions. The primary current during the time period from time t0 to t2 is selected as the target current through the primary drive signal (Q1 and Q3), and then the positive and negative parts of the excitation current are offset by filtering to obtain the current part transmitted from the primary side to the secondary side.

[0100] In one embodiment of the present invention, the primary switch tube includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4. If the DC power supply is a series resonant topology structure in the above steps, the target current is determined according to the driving signal of the primary switch tube and the primary current, specifically including:

[0101] If the DC power supply is a series resonant topology structure, the target current is determined according to the driving signals of the first switch tube and the third switch tube, or the target current is determined according to the driving signals of the second switch tube and the fourth switch tube.

[0102] In one embodiment of the present invention, if the DC power supply adopts a series resonant topology, the driving signal of the gating circuit can directly adopt the signal of the left upper bridge arm switch tube Q1 or directly adopt the signal of the right lower bridge arm switch tube Q3. That is, if the DC power supply adopts a series resonant topology, the driving signals of the first switch tube Q1 and the third switch tube Q3 can be used as the driving signals of the gating circuit for gating, and the target current is determined from the primary current.

[0103] In another embodiment of the present invention, if the DC power supply adopts a series resonant topology, the inverse signal of the signal of the left lower bridge arm switch tube Q2 can be obtained, and the inverse signal of Q2 can be used as the driving signal of the gating circuit, or the inverse signal of the signal of the right upper bridge arm switch tube Q4 can be obtained, and the inverse signal of Q4 can be used as the driving signal of the gating circuit. That is, if the DC power supply adopts a series resonant topology, the inverse signals of the driving signals of the second switch tube Q2 and the fourth switch tube Q4 can be calculated first, and then the inverse signals can be used as the driving signal of the gating circuit for gating, and the target current can be determined from the primary current.

[0104] In one embodiment of the present invention, the secondary switch tube includes a fifth switch tube S1, a sixth switch tube S2, a seventh switch tube S3 and an eighth switch tube S4. If the DC power supply is a dual active bridge topology structure in the above steps, the target current is determined according to the drive signal of the secondary switch tube and the primary current, specifically including:

[0105] If the DC power supply is a dual active bridge topology structure, the target current is determined according to the drive signals of the fifth switch tube and the seventh switch tube, or the target current is determined according to the drive signals of the sixth switch tube and the eighth switch tube.

[0106] In one embodiment of the present invention, if the DC power supply adopts a dual active bridge topology, the driving signal of the gating circuit can directly adopt the signal of the left upper bridge arm switch tube S1 or directly adopt the signal of the right lower bridge arm switch tube S3. That is, if the DC power supply adopts a dual active bridge topology, the driving signals of the fifth switch tube S1 and the seventh switch tube S3 can be used as the driving signals of the gating circuit for gating, and the target current is determined from the primary current.

[0107] In another embodiment of the present invention, if the DC power supply adopts a dual active bridge topology, the inverse signal of the signal of the left lower bridge arm switch tube S2 can be obtained, and the inverse signal of S2 can be used as the driving signal of the gating circuit, or the inverse signal of the signal of the right upper bridge arm switch tube S4 can be obtained, and the inverse signal of S4 can be used as the driving signal of the gating circuit. That is, if the DC power supply adopts a series resonant topology, the inverse signals of the driving signals of the sixth switch tube S2 and the eighth switch tube S4 can be calculated first, and then the inverse signal can be used as the driving signal of the gating circuit for gating, and the target current can be determined from the primary current.

[0108] Figure 3 is a flow chart of determining the output current according to an embodiment of the present invention. Figure 3 As shown, in one embodiment of the present invention, the above step S103 of determining the secondary current according to the processed target current, and then determining the output current of the DC power supply according to the secondary current, includes step S301 and step S302.

[0109] Step S301, removing the primary side excitation current from the processed target current to obtain the current transmitted to the secondary side.

[0110] In the present invention, since the primary current includes the primary excitation current and the current transferred to the secondary side, the processed target current also includes the primary excitation current portion and the current portion transferred to the secondary side. The present invention can filter the processed target current, remove the primary excitation current portion, and obtain the current portion transferred to the secondary side.

[0111] Step S302, determining a secondary side current according to the current transmitted to the secondary side, and determining an output current of the DC power supply according to the secondary side current and a preset calculation formula.

[0112] In one embodiment of the present invention, this step may convert the current transmitted to the secondary side into the secondary side current of the transformer according to the primary-secondary side current relationship of the transformer.

[0113] In one embodiment of the present invention, the primary-secondary current relationship of the transformer is specifically the turns ratio n of the transformer.

[0114] In one embodiment of the present invention, the preset calculation formula is specifically:

[0115] I_out=a×I_sec

[0116] Wherein, I_out is the output current of the DC power supply, I_sec is the secondary current, and a is the preset coefficient.

[0117] Figure 4 Flow chart of removing primary excitation current according to an embodiment of the present invention. Figure 4 As shown, in one embodiment of the present invention, the above step S301 of removing the primary excitation current from the processed target current to obtain the current transmitted to the secondary side includes step S401 and step S402.

[0118] Step S401, setting the filtering frequency of the filtering circuit according to the frequency characteristics of the primary excitation current.

[0119] Step S402: removing the primary excitation current in the processed target current through the filtering circuit based on the filtering frequency to obtain the current transmitted to the secondary side.

[0120] In one embodiment of the present invention, the present invention sets the filtering frequency of the filtering circuit according to the frequency characteristics of the primary excitation current, and removes the primary excitation current from the processed target current through the filtering circuit.

[0121] In the present invention, the task of the filter circuit is to remove the primary excitation current from the processed target current and retain the current portion transmitted to the secondary side. In order to remove the primary excitation current portion, a high-pass filter or a band-pass filter can be used, which can filter out the low-frequency components in the signal (i.e., the low-frequency portion of the primary excitation current).

[0122] The high-pass filter can remove low-frequency components, which are usually generated by the symmetrical part of the primary excitation current. The cut-off frequency of the high-pass filter is set to be close to or lower than the frequency of the primary excitation current, thereby effectively removing the low-frequency components of the primary excitation current.

[0123] The bandpass filter can selectively filter out the frequency range of the primary excitation current and retain the effective signal of the load current. For example, the bandpass filter can be designed to pass only the signal within the operating frequency range and block the frequency range of the primary excitation current.

[0124] When designing a filter, the key is to select a suitable cutoff frequency. The cutoff frequency is determined based on the periodic characteristics of the excitation current. Usually, a frequency band close to the primary excitation current frequency is selected to ensure that the positive and negative symmetrical parts of the primary excitation current are filtered out.

[0125] In one embodiment of the present invention, the present invention may use analog filtering or digital filtering according to the circuit design and signal sampling method.

[0126] Analog filtering: In analog circuits, high-pass or band-pass filtering can be achieved using traditional analog filtering components such as RC (resistance-capacitance) filters and LC (inductance-capacitance) filters. These filters can directly process the primary current and effectively remove unwanted frequency components.

[0127] Digital filtering: In a digital signal processing system, the primary current is first digitized by an analog-to-digital converter (ADC) and then filtered using a digital signal processing (DSP) algorithm. The digital filtering method is flexible and accurate, and can remove the positive and negative symmetrical parts of the excitation current by designing a digital high-pass filter or a digital band-pass filter.

[0128] After being processed by the filter, the current signal obtained will no longer contain the positive and negative symmetrical components of the primary excitation current. The filtered current signal is the effective signal after removing the excitation current part, which only contains the current part transmitted to the secondary side.

[0129] Figure 2 is a flow chart of processing the target current according to an embodiment of the present invention, such as Figure 2 As shown, in one embodiment of the present invention, the target current is processed in step S102 to obtain the processed target current, which includes step S201 and step S202.

[0130] Step S201, obtaining a target amplifier circuit based on the driving signal, wherein the target amplifier circuit is a non-inverting amplifier circuit or an inverting amplifier circuit.

[0131] Step S202 , amplifying the target current according to the target amplification circuit to obtain an amplified target current.

[0132] In one embodiment of the present invention, in order to improve the effect of removing the primary excitation current, the present invention further amplifies the target current through the above-mentioned steps S201 and S202 before removing the primary excitation current.

[0133] like Figure 6 As shown, the present invention processes the primary current through a gating circuit and a filtering circuit, removes the excitation current part in the primary current, and obtains processed current information. Then, the secondary current can be determined based on the processed current information, and the output current can be determined based on the secondary current.

[0134] Figure 7 It is a schematic diagram of a primary current processing circuit in one embodiment of the present invention.

[0135] Figure 7 The input resistor R1 is used to convert the primary current into a voltage signal and to provide current limiting protection for the input signal to prevent damage to subsequent circuits caused by excessive signal current.

[0136] Figure 7The dotted box in the middle is a gating circuit, which is used to select the target current in the primary current that meets the excitation current ampere-second balance condition. It consists of a control switch and is controlled by the drive signal. Whether the signal passes through the gating is controlled according to the state of the drive signal. When the drive signal is high, the gating switch is closed to allow the signal to pass. When the drive signal is low, the gating switch is opened to prevent the signal from passing.

[0137] Figure 7 The middle resistors R2 and R3 play a voltage dividing role to form a signal voltage divider for adjusting the voltage amplitude of the signal after selection, and at the same time provide a reference voltage (ground EP1) to maintain the stable operation of the selection circuit.

[0138] Figure 7 The operational amplifier OPA and resistor R4 in the circuit amplify the signal to enhance the signal strength and provide a clear signal input for subsequent filtering. The operational amplifier OPA amplifies and isolates the signal after passing through the gate switch, and adjusts the gain of the operational amplifier through the negative feedback resistor R4 to ensure that the output signal has good linear amplification characteristics.

[0139] Figure 7 The resistors R5 and R6 and the capacitors C1 and C2 form a filter circuit. R5 and C1 form a first-level low-pass filter circuit to remove high-frequency noise, and R6 and C2 form a second-level low-pass filter circuit to further smooth the signal. This filter circuit is used to remove high-frequency noise from the selected signal and retain the low-frequency effective components. The two-stage filter further improves the purity of the signal and ensures that the output signal is smooth and has no excess noise.

[0140] In one embodiment of the present invention, the step S101 of obtaining the primary current of the DC power supply includes:

[0141] The primary current collected by the current transformer is obtained.

[0142] Based on the above embodiments, it can be seen that the present invention collects the primary current of the transformer in the DC power supply, processes the primary current, removes the excitation current part of the primary current, and then calculates the secondary current based on the processed primary current, thereby accurately calculating the output current of the DC power supply. The scheme of the present invention reduces the dependence on traditional high current sampling, especially in the application of large DC current, avoids the high loss problem of directly measuring the large secondary current, and helps to reduce the sampling element loss and detection cost of the DC power supply output current detection.

[0143] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0144] Based on the same inventive concept, an embodiment of the present invention further provides an output current detection device, which can be used to implement the output current detection method described in the above embodiment, as described in the following embodiment. Since the principle of solving the problem by the output current detection device is similar to that of the output current detection method, the embodiment of the output current detection device can refer to the embodiment of the output current detection method, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0145] Fig.12 is a structural block diagram of an output current detection device according to an embodiment of the present invention. Fig.12 As shown, in one embodiment of the present invention, the output current detection device of the present invention includes:

[0146] A target current determination unit 1, used to obtain a primary current of a DC power supply, and determine a target current based on a topology of the DC power supply and the primary current, wherein the topology includes a dual active bridge topology and a series resonant topology;

[0147] A current processing unit 2, used for processing the target current to obtain a processed target current;

[0148] The output current determining unit 3 is used to determine the secondary current according to the processed target current, and further determine the output current of the DC power supply according to the secondary current.

[0149] In one embodiment of the present invention, the target current determination unit 1 includes:

[0150] A first target current determination module, configured to determine the target current according to a drive signal of a primary switch tube and the primary current if the DC power supply is a series resonant topology structure, wherein the primary switch tube is a switch tube provided in a primary circuit;

[0151] The second target current determination module is used to determine the target current according to the drive signal of the secondary side switch tube and the primary current if the DC power supply is a dual active bridge topology structure, wherein the secondary side switch tube is a switch tube arranged in the secondary side circuit.

[0152] In one embodiment of the present invention, the primary switch tube includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube;

[0153] The first target current determination module includes:

[0154] The first determination submodule is used to determine the target current according to the drive signals of the first switch tube and the third switch tube if the DC power supply is a series resonant topology structure, or to determine the target current according to the drive signals of the second switch tube and the fourth switch tube.

[0155] In one embodiment of the present invention, the secondary side switch tube includes a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube;

[0156] The second target current determination module includes:

[0157] The second determination submodule is used to determine the target current according to the drive signals of the fifth switch tube and the seventh switch tube if the DC power supply is a dual active bridge topology structure, or to determine the target current according to the drive signals of the sixth switch tube and the eighth switch tube.

[0158] In one embodiment of the present invention, the current processing unit 2 comprises:

[0159] A target amplifier circuit determination module, used to obtain a target amplifier circuit based on the driving signal, wherein the target amplifier circuit is a non-inverting amplifier circuit or an inverting amplifier circuit;

[0160] The current amplification processing module is used to amplify the target current according to the target amplification circuit to obtain the amplified target current.

[0161] In one embodiment of the present invention, the primary current includes the primary excitation current and the current transmitted to the secondary side;

[0162] The output current determination unit 3 comprises:

[0163] A primary side excitation current removal module, used for removing the primary side excitation current from the processed target current to obtain the current transmitted to the secondary side;

[0164] The output current determination module is used to determine the secondary side current according to the current transmitted to the secondary side, and to determine the output current of the DC power supply according to the secondary side current and a preset calculation formula.

[0165] In one embodiment of the present invention, the primary excitation current removal module includes:

[0166] A filter circuit setting submodule, used to set the filter frequency of the filter circuit according to the frequency characteristics of the primary excitation current;

[0167] The filtering processing submodule is used to remove the primary side excitation current in the processed target current through the filtering circuit based on the filtering frequency to obtain the current transmitted to the secondary side.

[0168] In order to achieve the above object, according to another aspect of the present application, an electronic device is also provided. Fig.13 As shown, the electronic device includes a memory, a processor, a communication interface and a communication bus. The memory stores a computer program that can be run on the processor. When the processor executes the computer program, the steps in the above-mentioned embodiment method are implemented.

[0169] The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0170] The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer executable programs and units, such as the corresponding program units in the above method embodiments of the present invention. The processor executes various functional applications of the processor and works data processing by running the non-transitory software programs, instructions and modules stored in the memory, that is, implementing the method in the above method embodiments.

[0171] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0172] The one or more units are stored in the memory, and when executed by the processor, the method in the above embodiment is performed.

[0173] The specific details of the above electronic device can be understood by referring to the corresponding related descriptions and effects in the above embodiments, and will not be repeated here.

[0174] In order to achieve the above purpose, according to another aspect of the present application, a computer-readable storage medium is also provided, wherein the computer-readable storage medium stores a computer program, and the computer program implements the steps in the above-mentioned output current detection method when executed in a computer processor. It can be understood by those skilled in the art that the implementation of all or part of the process in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and the program can include the process of the embodiment of each method as described above when executed. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (Flash Memory), a hard disk (Hard Disk Drive, abbreviated as: HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above-mentioned types of memory.

[0175] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a computer program product is further provided, comprising a computer program / instruction, which implements the steps of the above-mentioned output current detection method when executed by a processor.

[0176] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, and optionally, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0177] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An output current detection method, characterized in that: include: Acquire a primary current of a DC power supply, and determine a target current based on a topology of the DC power supply and the primary current; wherein the topology includes a dual active bridge topology and a series resonant topology; Processing the target current to obtain a processed target current; A secondary current is determined according to the processed target current, and then an output current of the DC power supply is determined according to the secondary current.

2. The output current detection method according to claim 1, characterized in that: The determining of the target current based on the topological structure of the DC power supply and the primary current includes: If the DC power supply is a series resonant topology structure, the target current is determined according to a driving signal of a primary switch tube and the primary current, wherein the primary switch tube is a switch tube arranged in a primary circuit; If the DC power supply is a dual active bridge topology structure, the target current is determined according to a driving signal of a secondary switch tube and the primary current, wherein the secondary switch tube is a switch tube arranged in a secondary circuit.

3. The output current detection method according to claim 2, characterized in that: The primary switch tube includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; If the DC power supply is a series resonant topology structure, determining the target current according to the driving signal of the primary switch tube and the primary current includes: If the DC power supply is a series resonant topology structure, the target current is determined according to the driving signals of the first switch tube and the third switch tube, or the target current is determined according to the driving signals of the second switch tube and the fourth switch tube.

4. The output current detection method according to claim 3, characterized in that: The secondary side switch tubes include a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube; If the DC power supply is a dual active bridge topology structure, determining the target current according to the drive signal of the secondary switch tube and the primary current includes: If the DC power supply is a dual active bridge topology structure, the target current is determined according to the drive signals of the fifth switch tube and the seventh switch tube, or the target current is determined according to the drive signals of the sixth switch tube and the eighth switch tube.

5. The output current detection method according to any one of claims 2 to 4, characterized in that: The processing of the target current to obtain the processed target current includes: Obtaining a target amplifier circuit based on the driving signal, wherein the target amplifier circuit is a non-inverting amplifier circuit or an inverting amplifier circuit; The target current is amplified according to the target amplification circuit to obtain an amplified target current.

6. The output current detection method according to claim 5, characterized in that: The primary current includes the primary excitation current and the current transmitted to the secondary side; The determining of the secondary current according to the processed target current, and further determining the output current of the DC power supply according to the secondary current, comprises: Subtracting the primary side excitation current from the processed target current to obtain the current transmitted to the secondary side; The secondary side current is determined according to the current transmitted to the secondary side, and the output current of the DC power supply is determined according to the secondary side current and a preset calculation formula.

7. The output current detection method according to claim 6, characterized in that: The step of removing the primary side excitation current from the processed target current to obtain the current transmitted to the secondary side includes: Setting the filtering frequency of the filtering circuit according to the frequency characteristics of the primary excitation current; The primary side excitation current in the processed target current is removed by the filter circuit based on the filter frequency to obtain the current transmitted to the secondary side.

8. An output current detection device, characterized in that: include: a target current determination unit, configured to obtain a primary current of a DC power supply, and determine a target current based on a topology of the DC power supply and the primary current, wherein the topology includes a dual active bridge topology and a series resonant topology; a current processing unit, used for processing the target current to obtain a processed target current; The output current determining unit is used to determine the secondary current according to the processed target current, and further determine the output current of the DC power supply according to the secondary current.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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