Input oscillation detection circuit

Abstract

The utility model provides an input oscillation detection circuit. After input branches are connected in parallel, one end of each input branch is connected with one end of an input capacitor and a first end of a power conversion branch through a switch branch; the other end of each input branch connected in parallel is connected with the other end of the input capacitor and the second end of the power conversion branch through the other switch branch; the current acquisition unit is used for acquiring current of at least n-1 input branches, acquiring current of at least one of the power conversion branches, and acquiring current of at least one of the two switch branches; namely, by arranging the current acquisition unit, the current of the corresponding branch is directly acquired, so that the current of the input capacitor is determined, whether the input oscillation detection circuit generates a resonance phenomenon or not can be further judged, the failure risk of the input capacitor and the tripping switch is avoided, and the safety of the circuit is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power electronics, and more specifically, relates to an input oscillation detection circuit. Background Art

[0002] In the renewable energy sector, photovoltaic systems are becoming increasingly important as a clean, renewable energy solution. PV strings are often connected to the inverter in multiple parallel configurations to improve the system's overall power generation efficiency. While this configuration offers convenience, it also presents new technical challenges. Traditionally, PV inverters primarily optimize the operating state of PV modules by sampling the current in the maximum power point tracking (MPPT) circuit, ensuring optimal power generation.

[0003] As PV inverter power levels continue to increase and PV input cable lengths increase, the complexity of PV system design is becoming increasingly prominent. First, as cable length increases, its inductance also increases, and the inductance of different cables can vary significantly. This inductance can resonate with the inverter's input capacitance, causing input current waveform distortion. In some cases, the input current can far exceed the rated current of the trip switch, posing a risk of trip switch burnout.

[0004] Since the existing solution only collects the MPPT current and the PV string current, it is impossible to determine the current of the input capacitor, and thus it is impossible to determine whether the input capacitor is oscillating, resulting in the risk of failure of the input capacitor and the trip switch. Utility Model Content

[0005] In view of this, an object of the present invention is to provide an input oscillation detection circuit for determining the current of an input capacitor, and further capable of determining whether the input oscillation detection circuit generates a resonance phenomenon.

[0006] The present application discloses an input oscillation detection circuit, comprising: an input capacitor, a power conversion branch, a current acquisition unit, n input branches and two switch branches; n is an integer greater than 1;

[0007] One end of each of the input branches connected in parallel is connected to one end of the input capacitor and the first end of the power conversion branch through one of the switch branches;

[0008] The other end of each of the input branches connected in parallel is connected to the other end of the input capacitor and the second end of the power conversion branch through another switch branch;

[0009] The current acquisition unit is used to acquire currents of at least n-1 input branches, acquire currents of at least one of the power conversion branches, and acquire currents of at least one of the two switch branches.

[0010] Optionally, the power conversion branch includes: a power conversion inductor and a power conversion switch; the input branch includes: a power supply and an input inductor; the switch branch includes: a trip switch and a common-mode inductor;

[0011] One end of the input inductor is connected to the positive electrode of the power supply;

[0012] The other end of the input inductor is connected to one end of the input capacitor and one end of the power conversion inductor respectively through a trip switch and a common-mode inductor in the switch branch;

[0013] The other end of the power conversion inductor is connected to one end of the power conversion switch;

[0014] The negative electrode of the power supply is connected to the other end of the input capacitor and the other end of the power conversion switch respectively through the trip switch and the common mode inductor in another switch branch.

[0015] Optionally, the current acquisition unit includes at least n+1 differential sampling circuits;

[0016] The n+1 differential sampling circuits correspond one-to-one to the n+1 target branches; the n+1 target branches include: n-1 input branches, 1 switch branch and 1 power conversion branch;

[0017] The n+1 differential sampling circuits are used to collect currents of the corresponding target branches.

[0018] Optionally, the differential sampling circuit includes: a current Hall sensor and a differential operational amplifier circuit;

[0019] The current Hall sensor is arranged on the target branch corresponding to the differential sampling circuit where the current Hall sensor is located;

[0020] The two input terminals of the differential operational amplifier circuit are correspondingly connected to the two terminals of the current Hall sensor;

[0021] The output end of the differential operational amplifier circuit serves as the output end of the differential sampling circuit.

[0022] Optionally, in the differential sampling circuit for collecting the current of the input branch:

[0023] The current Hall sensor is arranged between the power supply and the input inductor in the input branch where the current Hall sensor is located.

[0024] Optionally, in the differential sampling circuit for collecting the current of the switch branch:

[0025] The current Hall sensor is arranged between the trip switch and the input branch in the switch branch where the current Hall sensor is located.

[0026] Optionally, in the differential sampling circuit for collecting the current of the switch branch:

[0027] The current Hall sensor is arranged between the trip switch and the common mode inductor in the switch branch where the current Hall sensor is located.

[0028] Optionally, in the differential sampling circuit for collecting the current of the power conversion branch:

[0029] The current Hall sensor is arranged between the common end of the input capacitor and the common mode inductor and the power conversion inductor.

[0030] Optionally, the differential operational amplifier circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and an operational amplifier; wherein:

[0031] One end of the first resistor is connected to the output end of the current Hall sensor;

[0032] The other end of the first resistor is respectively connected to the first input end of the operational amplifier, one end of the first capacitor and one end of the third resistor;

[0033] One end of the second resistor is connected to the input end of the current Hall sensor;

[0034] The other end of the second resistor is respectively connected to one end of the second capacitor, one end of the fourth resistor and the second input end of the operational amplifier;

[0035] The output end of the operational amplifier is connected to the other end of the third resistor and the other end of the first capacitor respectively;

[0036] The other end of the fourth resistor and the other end of the second capacitor are grounded.

[0037] Optionally, n=2 or n=3.

[0038] From the above technical solution, it can be seen that the utility model provides an input oscillation detection circuit, wherein: one end of each input branch after being connected in parallel is connected to one end of the input capacitor and the first end of the power conversion branch through a switch branch; the other end of each input branch after being connected in parallel is connected to the other end of the input capacitor and the second end of the power conversion branch through another switch branch; the current acquisition unit is used to collect the current of at least n-1 input branches, collect the current of at least one of the power conversion branches, and collect the current of at least one of the two switch branches; that is, by setting the current acquisition unit, the current of the corresponding branch can be directly collected, thereby determining the current of the input capacitor, and further determining whether the input oscillation detection circuit produces a resonance phenomenon, avoiding the risk of failure of the input capacitor and the trip switch, and improving the safety of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 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 description of the prior art. 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 paying any creative work.

[0040] Figure 1 This is a schematic diagram of an input oscillation detection circuit provided by an embodiment of the present utility model;

[0041] Figure 2 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0042] Figure 3 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0043] Figure 4 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0044] Figure 5 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0045] Figure 6 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0046] Figure 7 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0047] Figure 8 This is a schematic diagram of another input oscillation detection circuit provided by an embodiment of the present utility model;

[0048] Figure 9 This is a schematic diagram of a differential operational amplifier circuit involved in an input oscillation detection circuit provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions 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 embodiments described are 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 making creative efforts are within the scope of protection of the present invention.

[0050] In the present application, the term "comprise", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment comprising a series of elements not only include those elements, but also include other elements not clearly listed, or also include elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprising a ..." do not exclude the presence of other identical elements in the process, method, article or equipment comprising the elements. In addition, the terms "first", "second", "third", "fourth" etc. (if present) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein, for example, can be implemented in an order other than those illustrated or described herein.

[0051] An embodiment of the present application discloses an input oscillation detection circuit, which is used to solve the problem in the prior art that only the MPPT current and the photovoltaic string current are collected and the current of the input capacitor cannot be determined, and thus it is impossible to judge whether the input capacitor has oscillations, resulting in the risk of failure of the input capacitor and the trip switch.

[0052] See also Figure 1 The input oscillation detection circuit includes: an input capacitor Cin, a power conversion branch, a current acquisition unit, n input branches and two switch branches; n is an integer greater than 1.

[0053] One end of each input branch connected in parallel is connected to one end of the input capacitor Cin and the first end of the power conversion branch through a switch branch.

[0054] The other end of each input branch connected in parallel is connected to the other end of the input capacitor Cin and the second end of the power conversion branch through another switch branch.

[0055] Specifically, the first ends of the input branches are connected, the connection point is connected to one end of the first switch branch, and the other end of the first switch branch is respectively connected to one end of the input capacitor Cin and the first end of the power conversion branch.

[0056] The second ends of the input branches are connected, and the connection point is connected to one end of the second switch branch; the other end of the second switch branch is respectively connected to the other end of the input capacitor Cin and the second end of the power conversion branch.

[0057] Optionally, n=2 (e.g. Figure 1-Figure 4 As shown) or n=3 (as Figure 5 and Figure 7 Of course, n can also be other values (such as Figure 6 and Figure 8 As shown), such as 5 and 6, etc., will not be described here one by one, and it will depend on the actual situation, and they are all within the scope of protection of this application.

[0058] The current acquisition unit is used to acquire currents of at least n-1 input branches, acquire currents of at least one of the power conversion branches, and acquire currents of at least one of the two switch branches.

[0059] That is to say, for each input branch, current collection can be performed on n-1 input branches, and of course, current collection can be performed on all n input branches.

[0060] For each switch branch, current collection may be performed on one switch branch, or current collection may be performed on both switch branches.

[0061] For the power conversion branch, current can be collected for the power conversion branch.

[0062] Kirchhoff's current law states that at any given moment, the algebraic sum of all branch currents flowing into (or out of) any node is always zero. In other words, the sum of the currents flowing into a node equals the sum of the currents flowing out of it. In practice, when discussing the summation of branch currents to obtain the total branch current, we are typically considering a node (or junction) where multiple branch currents flow into or out of the node, and the focus is on the total branch current flowing out of (or into) the node.

[0063] Therefore, taking a connection point between each input branch and the switch branch as a junction point, the current flowing into and out of the node is equal; therefore, the current of each input branch is equal to the current of the switch branch; taking the connection point between the switch branch and the input capacitor Cin and the power conversion branch as a junction point, the current flowing into and out of the node is equal; therefore, the current of the switch branch is equal to the sum of the current of the input capacitor Cin and the current of the power conversion branch.

[0064] Furthermore, the current of the input capacitor Cin can be determined by the current of the switch branch and the current of the power conversion branch, and whether the input oscillation detection circuit generates resonance can be further determined based on the current of the input capacitor Cin.

[0065] In this embodiment, one end of each input branch after being connected in parallel is connected to one end of the input capacitor Cin and the first end of the power conversion branch through a switch branch; the other end of each input branch after being connected in parallel is connected to the other end of the input capacitor Cin and the second end of the power conversion branch through another switch branch; the current acquisition unit is used to collect the current of at least n-1 input branches, collect the current of at least one of the power conversion branches, and collect the current of at least one of the two switch branches; that is, by setting the current acquisition unit, the current of the corresponding branch can be directly collected, thereby determining the current of the input capacitor Cin, and further determining whether the input oscillation detection circuit generates resonance, avoiding the risk of failure of the input capacitor Cin and the trip switch, and improving the safety of the circuit.

[0066] Optionally, the input branch includes: power supply (such as Figure 1 V1 or V2 as shown) and input inductor (such as Figure 1 Ls1 or Ls2 as shown).

[0067] The negative electrode of the power supply serves as one end of the input branch and is connected to one end of the second switch branch.

[0068] The positive electrode of the power supply is connected to one end of the input inductor, and the other end of the input inductor serves as the other end of the input branch and is connected to one end of the first switch branch.

[0069] Specifically, in the first input branch, the negative electrode of power supply V1 serves as one end of the first input branch and is connected to one end of the second switch branch. The positive electrode of power supply V1 is connected to one end of input inductor Ls1, and the other end of input inductor Ls1 serves as the other end of the first input branch and is connected to one end of the first switch branch.

[0070] In the first input branch, the negative electrode of power supply V2 serves as one end of the second input branch and is connected to one end of the second switch branch. The positive electrode of power supply V2 is connected to one end of input inductor Ls2, and the other end of input inductor Ls2 serves as the other end of the second input branch and is connected to one end of the first switch branch.

[0071] The power conversion branch can be a boost branch or a branch of other conversion forms. We will not elaborate on them one by one here. It depends on the actual situation and is within the scope of protection of this application.

[0072] The power conversion branch includes: a power conversion inductor Lm and a power conversion switch Ss.

[0073] One end of the power conversion inductor Lm serves as the first end of the power conversion branch, and is respectively connected to one end of the input capacitor Cin and the other end of the first switch branch; the other end of the power conversion inductor Lm is connected to one end of the power conversion switch Ss; the other end of the power conversion switch Ss serves as the second end of the power conversion branch, and is respectively connected to the other end of the input capacitor Cin and the other end of the second switch branch.

[0074] When the power conversion branch includes a power conversion inductor Lm and a power conversion switch Ss, the power conversion branch may have a voltage boosting function, that is, the power conversion branch may be a voltage boosting branch.

[0075] The switch branch includes: a trip switch and a common-mode inductor.

[0076] One end of the trip switch serves as one end of the switch branch and is connected to the corresponding end of the input branch; the other end of the trip switch is connected to one end of the common-mode inductor; the other end of the common-mode inductor serves as the other end of the switch branch and is respectively connected to the corresponding end of the input capacitor Cin and the corresponding end of the power conversion branch.

[0077] Specifically, in the first switch branch: one end of the first trip switch S1 serves as one end of the first switch branch and is connected to the other end of the input inductor in the input branch; the other end of the first trip switch S1 is connected to one end of the first common-mode inductor; the other end of the first common-mode inductor serves as the other end of the first switch branch and is respectively connected to one end of the input capacitor Cin and the first end of the power conversion branch.

[0078] In the second switch branch: one end of the second trip switch S2 serves as one end of the second switch branch and is connected to the negative electrode of the power supply in the input branch; the other end of the second trip switch S2 is connected to one end of the second common-mode inductor; the other end of the second common-mode inductor serves as the other end of the second switch branch and is respectively connected to the other end of the input capacitor Cin and the second end of the power conversion branch.

[0079] More specifically, one end of the input inductor is connected to the positive electrode of the power supply.

[0080] The other end of the input inductor is connected to one end of the input capacitor Cin and one end of the power conversion inductor Lm respectively through the trip switch and common-mode inductor in a switch branch (first switch branch); that is, the other end of the input inductor is connected to one end of the first trip switch S1 in the first switch branch, and the other end of the first trip switch S1 is connected to one end of the first common-mode inductor; the other end of the first common-mode inductor is connected to one end of the input capacitor Cin and one end of the power conversion inductor Lm respectively.

[0081] The other end of the power conversion inductor Lm is connected to one end of the power conversion switch Ss.

[0082] The negative electrode of the power supply is connected to the other end of the input capacitor Cin and the other end of the power conversion switch Ss respectively through the trip switch and common-mode inductor in another switch branch (second switch branch); the negative electrode of the power supply is connected to one end of the second trip switch S2 in the second switch branch, and the other end of the second trip switch S2 is connected to one end of the second common-mode inductor; the other end of the second common-mode inductor is connected to the other end of the input capacitor Cin and the other end of the power conversion switch Ss respectively.

[0083] Optionally, the current acquisition unit includes at least n+1 differential sampling circuits.

[0084] The n+1 differential sampling circuits correspond one-to-one to the n+1 target branches; the n+1 target branches include: n-1 input branches, one switch branch, and one power conversion branch. In other words, the 1st to n-1th differential sampling circuits correspond one-to-one to the n-1 input branches; the nth differential sampling circuit corresponds to one switch branch; and the n+1th differential sampling circuit corresponds to the power conversion branch.

[0085] The n+1 differential sampling circuits are used to collect currents of the corresponding target branches.

[0086] That is, n-1 differential sampling circuits are used to collect currents of n-1 input branches.

[0087] The other two differential sampling circuits are used to collect the current of a switch branch and the current of a power conversion branch respectively.

[0088] Specifically, the first differential sampling circuit collects the current of the first input branch; the second differential sampling circuit collects the current of the second input branch, and so on. The n-1th differential sampling circuit collects the current of the n-1th input branch, that is, the 1st to n-1th differential sampling circuits collect the current of n-1 input branches; the nth differential sampling circuit collects the current of a switch branch, for example, it can collect the current of the first switch branch, and it can also collect the current of the second switch branch; the n+1th differential sampling circuit collects the current of the power conversion branch.

[0089] Optionally, the differential sampling circuit includes: a current Hall sensor and a differential operational amplifier circuit.

[0090] The current Hall effect sensors are arranged on the corresponding branches.

[0091] Based on monitoring requirements, current Hall effect sensors are placed on specific branches. Specifically, for current acquisition in the input branch, the current Hall effect sensor is directly connected in series with the corresponding branch to capture current dynamics in real time. For the switching branch, the current Hall effect sensor is also precisely positioned to ensure that current changes during switching are fully captured. And in the power conversion branch, the sensor is firmly installed to continuously track current fluctuations during the power conversion process, greatly improving the targeted and accurate current sampling.

[0092] Specifically, a differential sampling circuit for collecting current from an input branch has a current Hall sensor disposed on the input branch; a differential sampling circuit for collecting current from a switch branch has a current Hall sensor disposed on the switch branch; and a differential sampling circuit for collecting current from a power conversion branch has a current Hall sensor disposed on the power conversion branch.

[0093] In other words, this differential sampling circuit integrates a current Hall effect sensor and a differential operational amplifier circuit to efficiently and accurately collect current information from various branches. This differential sampling circuit can be flexibly deployed in different application scenarios to ensure comprehensive coverage and accuracy of current acquisition.

[0094] The two input terminals of the differential operational amplifier circuit are correspondingly connected to the two terminals of the current Hall sensor.

[0095] Specifically, a first input terminal of the differential operational amplifier circuit is connected to an input terminal of the current Hall sensor, and a second input terminal of the differential operational amplifier circuit is connected to an output terminal of the current Hall sensor.

[0096] In other words, the differential op amp circuit, the core processing unit of the differential sampling circuit, precisely connects its two input terminals to the two ends of the current Hall effect sensor. Specifically, the first input terminal of the differential op amp circuit is connected to the input terminal of the current Hall effect sensor, while the second input terminal is connected to the output terminal of the current Hall effect sensor. This connection method ensures the complete transmission of the differential signal, laying a solid foundation for subsequent signal amplification and processing.

[0097] The output end of the differential operational amplifier circuit serves as the output end of the differential sampling circuit, and transmits the detected current value to a corresponding processing device or control device.

[0098] In other words, the output of the differential op amp circuit, serving as the output port of the entire differential sampling circuit, is responsible for transmitting the accurately detected current value to subsequent processing or control devices. Both the processor for data analysis and the controller for executing control instructions can seamlessly receive current information through this interface, enabling precise monitoring and intelligent control of the entire circuit system.

[0099] In summary, this differential sampling circuit has shown broad application prospects and great practical value in the fields of power monitoring and industrial automation due to its flexible layout strategy, precise connection method and efficient output performance.

[0100] The following describes the location of the current Hall effect sensors corresponding to each branch:

[0101] (1) In the differential sampling circuit for collecting the current of the input branch:

[0102] The current Hall sensor is arranged between the power supply and the input inductor in the input branch where the current Hall sensor is located.

[0103] Specifically, in the input branch: the positive electrode of the power supply is connected to the input inductor through the current Hall sensor.

[0104] That is, in a differential sampling circuit designed specifically for collecting input branch current, the current Hall sensor is placed at a key position in the branch (i.e., at the connection point between the positive pole of the power supply and the input inductor). Specifically, the positive output terminal of the power supply is first connected to one port of the current Hall sensor, and then the other port of the current Hall sensor is connected to the input terminal of the input inductor, thus forming a complete current monitoring path. This design not only simplifies the circuit structure, but also improves the accuracy and reliability of current sampling, providing a solid data foundation for subsequent current analysis, control, or protection.

[0105] The differential sampling circuit realizes real-time and accurate monitoring of the input branch current by setting the detection position of the current Hall sensor, providing strong support for the stable operation and efficient management of the power system.

[0106] (2) In the differential sampling circuit for collecting the current of the switch branch:

[0107] In differential sampling circuits for current acquisition in switch branches, the deployment strategy of current Hall effect sensors demonstrates a high degree of flexibility and adaptability. Depending on the specific design requirements, the sensors can be precisely placed at key nodes in the switch branches to achieve accurate current monitoring.

[0108] There are many ways to deploy this current Hall effect sensor. The following describes two deployment methods:

[0109] like Figure 1 and Figure 2 As shown, one deployment method is: the current Hall sensor can be set between the trip switch and the input branch in the switch branch where it is located. Specifically, in a certain switch branch: one end of the trip switch is connected to the input branch through the current Hall sensor, for example, Figure 1As shown, in the first switch branch: one end of the first trip switch S1 is connected to the input inductor (such as Figure 1 Lm1 and Lm2) shown in FIG; Figure 2 In the second switch branch: one end of the second trip switch S2 is connected to the power supply (such as Figure 1 The negative connection of V1 and V2) is shown.

[0110] Placing the current Hall effect sensor between the trip switch and the input branch means that, in a specific switch branch, one end of the trip switch will first be connected to a key component of the input branch (such as the input inductor or the negative terminal of the power supply, depending on the branch configuration) through the current Hall effect sensor. For example, in the first switch branch, the trip switch may be closely connected to the input inductor through the sensor to detect the current flowing into the input inductor; while in the second switch branch, the sensor may connect the trip switch to the negative terminal of the power supply to detect the current flowing out of the negative terminal of the power supply.

[0111] like Figure 3 and Figure 4 As shown, another deployment method is that the current Hall effect sensor can also be set between the trip switch and the common-mode inductor in the switch branch where it is located. That is, in a certain switch branch, the other end of the trip switch is connected to the common-mode inductor via the current Hall effect sensor. For example, in the first switch branch, one end of the first trip switch S1 is connected to the input inductor, and the other end of the first trip switch S1 is connected to the first common-mode inductor Lcm1 via the current Hall effect sensor. In the second switch branch, one end of the trip switch is connected to the negative electrode of the power supply, and the other end of the second trip switch S2 is connected to the second common-mode inductor Lcm2 via the current Hall effect sensor.

[0112] This arrangement allows the current changes passing through the trip switch to be captured by the Hall effect sensor during switching, and then transmitted to the common-mode inductor for further processing or filtering. Whether it is the connection between the trip switch and the input inductor in the first switching branch, or the connection between the trip switch and the negative terminal of the power supply in the second switching branch, the monitoring capability of the switching branch current can be enhanced by adding a Hall effect sensor in this path.

[0113] In summary, by flexibly adjusting the position of the current Hall effect sensor in the switch branch, the differential sampling circuit can accurately monitor the switch branch current under different configurations, providing important data support for the safe operation and intelligent control of the power system.

[0114] (3) In the differential sampling circuit for collecting the current of the power conversion branch:

[0115] The current Hall sensor is arranged between the common end of the input capacitor Cin and the common mode inductor and the power conversion inductor Lm.

[0116] That is to say, in the differential sampling circuit specifically used to collect the power conversion branch current, the position of the current Hall sensor is carefully selected to ensure that the current changes during the power conversion process can be accurately captured.

[0117] Specifically, in the power conversion branch, one end of the power conversion inductor Lm is connected to one end of the current Hall sensor, and the other end of the current Hall sensor serves as the first end of the power conversion branch, connected to the common end of the input capacitor Cin and the common mode inductor in the switch branch.

[0118] This layout strategy means that during operation of the power conversion branch, one end of the power conversion inductor Lm is directly connected to one end of the current Hall effect sensor, forming a close current monitoring point. The other end of the current Hall effect sensor, serving as a key access point for the power conversion branch, is closely connected to the common end of the input capacitor Cin and the common-mode inductor in the switching branch. This connection not only ensures the complete transmission of the current signal but also enables the differential sampling circuit to accurately capture the current flowing through the power conversion inductor Lm in real time.

[0119] In summary, by cleverly placing the current Hall effect sensor between the input capacitor Cin, the common end of the common-mode inductor, and the power conversion inductor Lm, the differential sampling circuit achieves accurate monitoring of the power conversion branch current, providing strong data support for the stable operation and performance optimization of the power conversion branch.

[0120] Optional, such as Figure 9 As shown, the differential operational amplifier circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2 and an operational amplifier Us; wherein:

[0121] One end of the first resistor R1 is connected to the output end of the current Hall sensor.

[0122] The other end of the first resistor R1 is connected to the first input end of the operational amplifier Us, one end of the first capacitor C1 and one end of the third resistor R3 respectively.

[0123] One end of the second resistor R2 is connected to the input end of the current Hall sensor.

[0124] The other end of the second resistor R2 is connected to one end of the second capacitor C2, one end of the fourth resistor R4 and the second input end of the operational amplifier Us respectively.

[0125] The output end of the operational amplifier Us is connected to the other end of the third resistor R3 and the other end of the first capacitor C1 respectively.

[0126] The other end of the fourth resistor R4 and the other end of the second capacitor C2 are grounded.

[0127] The positive electrode of the power supply terminal of the operational amplifier Us is connected to the power supply VCC, and the negative electrode of the power supply terminal of the operational amplifier Us is grounded. Figure 9 As shown, VOUT is the output signal of the operational amplifier Us.

[0128] In other words, the differential op amp circuit integrates multiple components to achieve high-precision signal differential amplification. Specifically, it consists of a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, and a high-performance operational amplifier Us. These components are interconnected as follows:

[0129] The first resistor R1: One end of the resistor R1 is connected to the output end of the current Hall effect sensor, serving as the positive input path of the differential signal; the other end of the resistor R1 is connected to the non-inverting input end (i.e., the first input end) of the operational amplifier Us, one end of the first capacitor C1, and one end of the third resistor R3, together forming a positive signal transmission and filtering network.

[0130] The second resistor R2 is designed to be connected to the input end of the current Hall sensor and serves as the reference or negative input path of the differential signal; its other end is respectively connected to one end of the second capacitor C2, one end of the fourth resistor R4, and the inverting input end (i.e., the second input end) of the operational amplifier Us to ensure signal integrity and stability while providing the necessary filtering effect.

[0131] Operational amplifier Us: As the core of the circuit, its non-inverting and inverting inputs receive signals from resistors R1 and R2, respectively. Through its internal high-gain amplification mechanism, it accurately amplifies the differential signal. Its output is directly connected to the other end of resistor R3 and capacitor C1, forming a closed-loop feedback loop to stabilize the gain and reduce nonlinear distortion.

[0132] The third resistor R3: as a feedback resistor, it forms a negative feedback network with the output end of the operational amplifier Us and a part of the first resistor R1, which plays a vital role in adjusting the gain, stability and frequency response of the circuit.

[0133] The fourth resistor R4, the second resistor R2, and a portion of the second capacitor C2 together form a reference path on the other side, ensuring the balance of the differential signal and effectively suppressing common-mode interference through grounding.

[0134] The first capacitor C1 and the second capacitor C2 are respectively connected in parallel to the two ends of the differential input to filter out high-frequency noise, improve the signal-to-noise ratio of the signal, protect the operational amplifier Us from transient voltage shocks, and ensure stable operation of the circuit.

[0135] In summary, the differential operational amplifier circuit achieves precise differential amplification of the output signal of the current Hall sensor through carefully designed component layout and interconnection, while effectively suppressing noise interference and improving the accuracy and reliability of signal processing.

[0136] The features described in the various embodiments of this specification can be replaced or combined with each other. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The system and system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0137] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0138] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An input oscillation detection circuit, characterized in that: include: Input capacitor, power conversion branch, current acquisition unit, n input branches and two switch branches; n is an integer greater than 1; One end of each of the input branches connected in parallel is connected to one end of the input capacitor and the first end of the power conversion branch through one of the switch branches; The other end of each of the input branches connected in parallel is connected to the other end of the input capacitor and the second end of the power conversion branch through another switch branch; The current acquisition unit is used to acquire currents of at least n-1 input branches, acquire currents of at least one of the power conversion branches, and acquire currents of at least one of the two switch branches.

2. The input oscillation detection circuit according to claim 1, characterized in that: The power conversion branch includes: a power conversion inductor and a power conversion switch; the input branch includes: a power supply and an input inductor; the switch branch includes: a trip switch and a common-mode inductor; One end of the input inductor is connected to the positive electrode of the power supply; The other end of the input inductor is connected to one end of the input capacitor and one end of the power conversion inductor respectively through a trip switch and a common-mode inductor in the switch branch; The other end of the power conversion inductor is connected to one end of the power conversion switch; The negative electrode of the power supply is connected to the other end of the input capacitor and the other end of the power conversion switch respectively through the trip switch and the common mode inductor in another switch branch.

3. The input oscillation detection circuit according to claim 2, characterized in that: The current acquisition unit includes at least n+1 differential sampling circuits; The n+1 differential sampling circuits correspond one-to-one to the n+1 target branches; the n+1 target branches include: n-1 input branches, 1 switch branch and 1 power conversion branch; The n+1 differential sampling circuits are used to collect currents of the target branches corresponding to them.

4. The input oscillation detection circuit according to claim 3, characterized in that: The differential sampling circuit includes: a current Hall sensor and a differential operational amplifier circuit; The current Hall sensor is arranged on the target branch corresponding to the differential sampling circuit where the current Hall sensor is located; The two input terminals of the differential operational amplifier circuit are correspondingly connected to the two terminals of the current Hall sensor; The output end of the differential operational amplifier circuit serves as the output end of the differential sampling circuit.

5. The input oscillation detection circuit according to claim 4, characterized in that: In the differential sampling circuit for collecting the current of the input branch: The current Hall sensor is arranged between the power supply and the input inductor in the input branch where the current Hall sensor is located.

6. The input oscillation detection circuit according to claim 4, characterized in that: In the differential sampling circuit for collecting the current of the switch branch: The current Hall sensor is arranged between the trip switch and the input branch in the switch branch where the current Hall sensor is located.

7. The input oscillation detection circuit according to claim 4, characterized in that: In the differential sampling circuit for collecting the current of the switch branch: The current Hall sensor is arranged between the trip switch and the common mode inductor in the switch branch where the current Hall sensor is located.

8. The input oscillation detection circuit according to claim 4, characterized in that: In the differential sampling circuit for collecting the current of the power conversion branch: The current Hall sensor is arranged between the common end of the input capacitor and the common mode inductor and the power conversion inductor.

9. The input oscillation detection circuit according to claim 4, characterized in that: The differential operational amplifier circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and an operational amplifier; wherein: One end of the first resistor is connected to the output end of the current Hall sensor; The other end of the first resistor is respectively connected to the first input end of the operational amplifier, one end of the first capacitor and one end of the third resistor; One end of the second resistor is connected to the input end of the current Hall sensor; The other end of the second resistor is respectively connected to one end of the second capacitor, one end of the fourth resistor and the second input end of the operational amplifier; The output end of the operational amplifier is connected to the other end of the third resistor and the other end of the first capacitor respectively; The other end of the fourth resistor and the other end of the second capacitor are grounded.

10. The input oscillation detection circuit according to any one of claims 1 to 9, characterized in that: n=2 or n=3.

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