Sampling circuit and power conversion device

Abstract

The utility model provides a sampling circuit and a power conversion device. The sampling circuit is provided with a signal input end and a signal output end; the signal input end is connected with a power electronic circuit; the power electronic circuit includes a power switch operable at a plurality of switching frequencies; the sampling circuit comprises a plurality of trap filter circuits; wherein the plurality of trap filter circuits are connected between the signal input end of the sampling circuit and a grounding point, and / or the plurality of trap filter circuits are connected between the signal output end of the sampling circuit and the grounding point; each wave trap circuit is provided with a corresponding switch unit and a corresponding wave trap unit; the resonant frequencies of the wave trap units in the plurality of wave trap circuits are respectively corresponding to different switching frequencies of the power switch. Therefore, the sampling precision of the electrical parameters of the sampling points in the power electronic circuit can be improved.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and more specifically to a sampling circuit and a power conversion device. Background Technology

[0002] In existing technologies, to achieve precise control of power electronic circuits, it is typically necessary to sample electrical parameters such as voltage or current at pre-set sampling points within the circuit. Furthermore, the control strategy of the power electronic circuit can be adjusted based on the sampled voltage or current parameters. Therefore, the sampling accuracy of electrical parameters such as voltage or current has a significant impact on the operating performance and stability of the power electronic circuit.

[0003] However, the accuracy of electrical parameters obtained by sampling in existing technologies is not high. Utility Model Content

[0004] Several embodiments of this application provide a sampling circuit and a power conversion device that can improve the sampling accuracy of electrical parameters at sampling points in power electronic circuits.

[0005] This application provides a sampling circuit, which includes a signal input terminal and a signal output terminal. The signal input terminal is used to connect to a power electronic circuit. The power electronic circuit includes a power switch capable of operating at multiple switching frequencies. The sampling circuit includes multiple notch filter circuits. The multiple notch filter circuits are connected between the signal input terminal of the sampling circuit and a ground point, and / or, the multiple notch filter circuits are connected between the signal output terminal of the sampling circuit and a ground point. Each notch filter circuit has a corresponding switching unit and a notch filter unit. The resonant frequencies of the notch filter units in the multiple notch filter circuits correspond to different switching frequencies of the power switch.

[0006] In some embodiments, each notch filter circuit has a first terminal and a second terminal as its switching unit; the first terminal of each switching unit is connected to the signal output terminal; and the second terminal of each switching unit is connected to the signal input terminal and the corresponding notch filter unit.

[0007] In some embodiments, the notch filter circuit includes a first notch filter circuit; each first notch filter circuit is formed through a corresponding first notch filter branch; the notch filter unit and the switching unit of the first notch filter circuit are connected in series in the corresponding first notch filter branch.

[0008] In some embodiments, the plurality of notch filter circuits include at least two second notch filter circuits; each second notch filter circuit includes a common segment and a corresponding second notch filter branch; the notch filter units of the at least two second notch filter circuits share a common segment; the notch filter unit of the second notch filter circuit includes a first notch filter subunit and a second notch filter subunit; the notch filter units of the at least two second notch filter circuits share a first notch filter subunit; the first notch filter subunit is disposed in the common segment; and the switching unit of each second notch filter circuit and the second notch filter subunit of the notch filter unit are connected in series in the corresponding second notch filter branch.

[0009] In some embodiments, the common segment includes a first common branch; the first notch filter subunit is disposed in the first common branch; a first end of the first common branch is used to connect the signal input terminal and / or the signal output terminal, a second end of the first common branch is used to connect the first end of each second notch filter branch, and a second end of each second notch filter branch is used to connect the grounding point; or, a first end of the second notch filter branch is used to connect the signal input terminal and / or the signal output terminal, a second end of the second notch filter branch is used to connect the first end of each first common branch, and a second end of each first common branch is used to connect the grounding point.

[0010] In some embodiments, the first notch filter subunit includes an inductor and a resistor connected together, and the second notch filter subunit includes a capacitor; or, the first notch filter subunit includes a capacitor and a resistor connected together, and the second notch filter subunit includes an inductor; or, the first notch filter subunit includes a resistor, and the second notch filter subunit includes an inductor and a capacitor connected together; or, the first notch filter subunit includes an inductor, and the second notch filter subunit includes a resistor and a capacitor connected together; or, the first notch filter subunit includes a capacitor, and the second notch filter subunit includes a resistor and an inductor connected together.

[0011] In some embodiments, the common segment includes a second common branch and a third common branch; the first notch filter subunit includes a first notch filter assembly and a second notch filter assembly; the first notch filter assembly is disposed in the second common branch; the second notch filter assembly is disposed in the third common branch; a first end of the second common branch is used to connect to the signal input terminal and / or the signal output terminal, a second end of the second common branch is used to connect to the first end of each second notch filter branch, and a second end of each second notch filter branch is used to connect to the first end of the third common branch; the second end of the third common branch is used to connect to the grounding point.

[0012] In some embodiments, the first notch filter assembly includes an inductor, the second notch filter assembly includes a resistor, and the second notch filter subunit includes a capacitor; or, the first notch filter assembly includes a resistor, the second notch filter assembly includes an inductor, and the second notch filter subunit includes a capacitor; or, the first notch filter assembly includes a capacitor, the second notch filter assembly includes a resistor, and the second notch filter subunit includes an inductor; or, the first notch filter assembly includes a resistor, the second notch filter assembly includes a capacitor, and the second notch filter subunit includes an inductor.

[0013] In some embodiments, the power electronic circuit includes an inverter circuit and an inductor located on the AC side of the inverter circuit; the signal input terminal of the sampling circuit is used to connect to the inductor.

[0014] This application provides a power conversion device, including: a power electronic circuit; a sampling circuit as described in any of the above embodiments; and a signal input terminal of the sampling circuit for connecting to the power electronic circuit.

[0015] In some embodiments, the power conversion device further includes a controller; the controller is connected to the signal output terminal of the sampling circuit.

[0016] In several embodiments provided in this application, the sampling circuit has a signal input terminal and a signal output terminal; the signal input terminal of the sampling circuit is used to connect to a power electronic circuit. Since the power electronic circuit includes a power switch capable of operating at multiple switching frequencies, harmonics corresponding to the switching frequencies are generated in the power electronic circuit when the power switch operates. Therefore, in several embodiments provided in this application, by setting multiple notch filter circuits in the sampling circuit, each notch filter circuit having a corresponding switching unit and a notch filter unit, and the resonant frequencies of the notch filter units in the multiple notch filter circuits corresponding to different switching frequencies of the power switch, when sampling using the sampling circuit, the corresponding notch filter unit can be controlled to connect between the signal input terminal and the signal output terminal based on the current operating switching frequency of the power switch. This reduces the impact of harmonics on sampling accuracy and improves the sampling accuracy of the electrical parameters at the sampling points in the power electronic circuit. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1aThis is a schematic diagram of a notch filter unit provided in one embodiment of this application.

[0019] Figure 1b This is a schematic diagram of a notch filter unit provided in one embodiment of this application.

[0020] Figure 1c This is a schematic diagram of a notch filter unit provided in one embodiment of this application.

[0021] Figure 1d This is a schematic diagram of a notch filter unit provided in one embodiment of this application.

[0022] Figure 2 A schematic diagram of a sampling circuit provided for one embodiment of this application.

[0023] Figure 3 A schematic diagram of a sampling circuit including a first notch filter circuit is provided for one embodiment of this application.

[0024] Figure 4a A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0025] Figure 4b A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0026] Figure 4c A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0027] Figure 4d A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0028] Figure 5 A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0029] Figure 6a A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0030] Figure 6b A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0031] Figure 7a A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0032] Figure 7b A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0033] Figure 8 A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0034] Figure 9a A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0035] Figure 9b A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0036] Figure 9c A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0037] Figure 9d A schematic diagram of a sampling circuit including a second notch filter circuit is provided for one embodiment of this application.

[0038] Figure 10 This is a schematic diagram of a power conversion device provided for one embodiment of this application. Detailed Implementation

[0039] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0040] In the description of the embodiments of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0041] In related technologies, pulse width modulation (PWM) technology is often used to control power switches in power electronic circuits to achieve the conversion of electrical energy forms.

[0042] However, the frequent switching of power switches generates harmonics, which leads to a decrease in the sampling accuracy of electrical parameters for power electronic circuits.

[0043] Therefore, embodiments of this application improve sampling accuracy by setting a notch filter unit in the sampling circuit to suppress the amplitude of harmonics to an acceptable range.

[0044] In some cases, power switches in power electronic circuits can operate at different switching frequencies, and the frequency range of harmonics caused by different switching frequencies varies. However, some notch filter units have relatively narrow bandwidths, making it difficult to comprehensively suppress harmonics corresponding to different switching frequencies using a single notch filter unit.

[0045] To this end, embodiments of this application include multiple notch filter circuits, each comprising a notch filter unit and a switching unit. Furthermore, the bandwidth of each notch filter circuit corresponds to a different switching frequency. Therefore, when using the sampling circuit provided in this application for sampling, the corresponding notch filter unit can be activated by controlling the switching unit according to the current switching frequency of the power switch, thereby reducing the interference of harmonics at the current switching frequency on the sampling accuracy and improving the sampling accuracy of the electrical parameters at the sampling points in the power electronic circuit.

[0046] This specification provides a sampling circuit with a signal input terminal and a signal output terminal. The signal input terminal is used to connect to a power electronic circuit. The power electronic circuit includes a power switch capable of operating at multiple switching frequencies. The sampling circuit includes multiple notch filter circuits. The multiple notch filter circuits are connected between the signal input terminal of the sampling circuit and a ground point, and / or, the multiple notch filter circuits are connected between the signal output terminal of the sampling circuit and a ground point. Each notch filter circuit has a corresponding switching unit and a notch filter unit. The resonant frequencies of the notch filter units in the multiple notch filter circuits correspond to different switching frequencies of the power switch.

[0047] A sampling circuit is a circuit that samples the electrical parameters of sampling points in a power electronic circuit. The sampling points in a power electronic circuit can be any circuit node or the endpoint of any component within the circuit. The electrical parameters of the sampling points can be voltage or current, etc. This application does not impose specific limitations on these parameters.

[0048] The signal input terminal of the sampling circuit can be connected to the sampling point to sample the electrical parameters of the sampling point.

[0049] Power electronic circuits are circuits that include power switches. Specifically, by controlling the on / off state of the power switches, power electronic circuits can convert the form of electrical energy. For example, a power electronic circuit can be a DC-DC converter circuit, which can boost or buck DC power by controlling the on / off state of the power switches. Alternatively, a power electronic circuit can also be an inverter circuit, which can convert DC power to AC power by controlling the on / off state of the power switches.

[0050] A power switch is a switching element used in power electronic circuits to control the conversion of electrical energy. For example, a power switch can be an insulated-gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0051] Switching frequency is the number of times a power switch switches on and off per unit time. For example, multiple switching frequencies could be 1kHz and 10kHz. This application does not impose a specific limitation here.

[0052] The notch filter circuit includes corresponding switching units and notch filter units. Multiple notch filter circuits are connected between the signal input terminal of the sampling circuit and the ground point. Alternatively, multiple notch filter circuits are connected between the signal output terminal of the sampling circuit and the ground point. Alternatively, when the signal input terminal and signal output terminal are directly connected, one end of each notch filter circuit can be connected to both the signal input terminal and the signal output terminal, and the other end can be connected to the ground point, thus connecting multiple notch filter circuits between the signal input terminal and the ground point of the sampling circuit, and also between the signal output terminal and the ground point of the sampling circuit.

[0053] A switching unit is a component used to control the on / off state of a notch filter circuit. The switching unit can be a semiconductor switch or a mechanical switch. This application does not specifically limit its application to this type of switch.

[0054] In some embodiments, different notch filter circuit switching units can be built using analog channel selectors.

[0055] A notch filter unit can be a resonant circuit used to filter out harmonics within a specific frequency range.

[0056] For example, please see Figure 1a A notch filter unit may include an inductor L, a capacitor C, and a resistor R connected in series.

[0057] Alternatively, please see Figure 1b A notch filter unit may include an inductor L, a capacitor C, and a resistor R. The resistor R and capacitor C are connected in parallel to form a notch filter sub-unit. This notch filter sub-unit is connected in series with the inductor L.

[0058] Alternatively, please see Figure 1c A notch filter unit may include an inductor L, a capacitor C, and a resistor R. The resistor R and the inductor L are connected in parallel to form a notch filter sub-unit. This notch filter sub-unit is connected in series with the capacitor C.

[0059] Alternatively, please see Figure 1dThe notch filter unit may include an inductor L, a capacitor C, and a resistor R. The inductor L and capacitor C are connected in series in one branch. The resistor R is placed in a line intersecting this branch. The two ends of this line can be used to connect to the signal input and signal output terminals of the sampling circuit, respectively.

[0060] The harmonic frequencies to be filtered out can be determined by selecting the appropriate inductor L and capacitor C. Specifically, the harmonic frequency can be calculated using Formula 1 based on the specifications of inductor L and capacitor C. Resistor R is used to suppress the amplitude of the harmonics to an acceptable range.

[0061]

[0062] Since harmonic frequencies are the same as or close to the fundamental frequency, when power switches operate at different switching frequencies, and these switching frequencies have certain differences, the frequencies of the harmonics they cause will also have certain differences.

[0063] To address harmonics caused by different switching frequencies, the sampling circuit in this embodiment incorporates multiple notch filter circuits, each with a corresponding switching unit and a notch filter unit. Furthermore, the resonant frequencies of the notch filter units in each notch filter circuit correspond to different switching frequencies. Therefore, for power switches operating at different switching frequencies, the switching unit can selectively control the conduction of one or more notch filter circuits, thereby filtering out harmonics of different frequencies and improving the sampling accuracy of electrical parameters at sampling points in power electronic circuits.

[0064] In some embodiments, each notch filter circuit has a first terminal and a second terminal as its switching unit; the first terminal of each switching unit is connected to the signal output terminal; and the second terminal of each switching unit is connected to the signal input terminal and the corresponding notch filter unit.

[0065] Please see Figure 2 . Figure 2 The diagram illustrates the connections between notch filter circuits 1, 2, and n and the signal input and output terminals. Here, n is a positive integer. The switching units of the n notch filter circuits can be connected between the signal input and output terminals. Furthermore, a corresponding notch filter unit is connected between one end of each switching unit and the ground point. Specifically, switching unit 1, switching unit 2, and switching unit n correspond to notch filter unit 1, notch filter unit 2, and notch filter unit n, respectively.

[0066] Therefore, when any switch unit is closed, its corresponding notch filter unit will be connected to the sampling circuit. That is, the signal component in the input signal that falls within the bandwidth of the notch filter unit will be transmitted to the ground point through the notch filter unit. As a result, the signal output terminal can output an output signal carrying fewer harmonics, thereby improving sampling accuracy.

[0067] In some embodiments, the notch filter circuit includes a first notch filter circuit; each first notch filter circuit includes a corresponding first notch filter branch; the notch filter unit and the switching unit of the first notch filter circuit are connected in series in the corresponding first notch filter branch.

[0068] The first notch filter circuit can be a notch filter circuit formed by a branch, which can be called the first notch filter branch.

[0069] Please see Figure 3 . Figure 3 The diagram illustrates the connection relationships between the first notch filter circuits 1 to 2n and the signal input and output terminals. The first notch filter circuits 1 to 2n are formed through corresponding branches. The switching units and notch filter units of the first notch filter circuits 1 to 2n are connected in series in their respective branches.

[0070] Specifically, the switching unit 1 and the notch filter unit 1 of the first notch filter circuit 1 are connected in series between the signal input terminal and the ground point. Of course, since the signal input terminal and the signal output terminal are connected, it can also be considered that the switching unit 1 and the notch filter unit 1 are connected in series between the signal output terminal and the ground point.

[0071] Furthermore, the switching unit n and the notch filter unit n of the first notch filter circuit n are connected in series between the signal input terminal and the ground point. Of course, since the signal input terminal and the signal output terminal are connected, it can also be considered that the switching unit n and the notch filter unit n are connected in series between the signal output terminal and the ground point.

[0072] In some embodiments, the notch filter unit can be formed by a resistor, inductor, and capacitor connected in series. For details, please refer to [link to relevant documentation]. Figure 3 Notch filter unit 1 is formed by connecting an inductor L1, a capacitor C1, and a resistor R1 in series. Notch filter unit 2 is formed by connecting an inductor L2, a capacitor C2, and a resistor R2 in series.

[0073] Therefore, when any switch unit is closed, its corresponding notch filter unit will be connected to the sampling circuit. That is, the signal component in the input signal that falls within the bandwidth of the notch filter unit will be transmitted to the ground point through the notch filter unit. As a result, the signal output terminal can output an output signal carrying fewer harmonics, thereby improving sampling accuracy.

[0074] Since the resonant frequency of a notch filter unit can be determined by the values ​​of the inductor, capacitor, or resistor, multiple notch filter circuits can share a single inductor or capacitor, or vice versa. This reduces the cost of the notch filter unit.

[0075] In some embodiments, the plurality of notch filter circuits include at least two second notch filter circuits; each second notch filter circuit includes a second notch filter branch and a common common section; the second notch filter branches of different notch filter circuits are different; the notch filter unit of the second notch filter circuit includes a first notch filter subunit and a second notch filter subunit; the notch filter units of at least two second notch filter circuits share a first notch filter subunit; the shared first notch filter subunit is disposed in the common section; and the switching unit of each second notch filter circuit and the second notch filter subunit of the notch filter unit are connected in series in the corresponding second notch filter branch.

[0076] A second notch filter circuit can be a notch filter circuit formed by a common segment and a corresponding second notch filter branch. The common segment refers to a circuit shared by multiple second notch filter circuits.

[0077] The first notch filter subunit and the second notch filter subunit are each formed by a portion of the components of a notch filter unit. The first notch filter subunit is shared by multiple second notch filter circuits. Different second notch filter circuits have different second notch filter subunits, and at least some of the notch filter components in the second notch filter subunits of different second notch filter circuits have different specifications.

[0078] Please see Figure 4a , Figure 4b , Figure 4c , Figure 4d , Figure 5 , Figure 6a , Figure 6b , Figure 7a and Figure 7b The diagrams illustrate the second notch filter circuit 1 to the second notch filter circuit n in different embodiments.

[0079] The second notch filter circuit 1 is formed via a second notch filter branch 1 and a common section. The notch filter unit of the second notch filter circuit 1 includes a first notch filter sub-unit disposed in the common section and a second notch filter sub-unit 1 disposed in the second notch filter branch 1. The second notch filter circuit n is formed via a second notch filter branch n and a common section. The notch filter unit of the second notch filter circuit n includes a first notch filter sub-unit disposed in the common section and a second notch filter sub-unit n disposed in the second notch filter branch n. The specifications of the notch filter components in any two second notch filter sub-units can be different.

[0080] In some embodiments, the first notch filter subunit includes an inductor and a resistor connected together, and the second notch filter subunit includes a capacitor.

[0081] Please see Figure 4a The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of a capacitor C1. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of a capacitor C1. n Composition. Among them, capacitor C1 and capacitor C... n The capacitance values ​​are different. The common section includes a first notch filter subunit, which includes an inductor L connected in series. shared and resistance R shared .

[0082] Please see Figure 4b Compared to Figure 4a The sampling circuit in the middle, Figure 4b The inductor L in the first notch filter subunit of the provided sampling circuit shared and resistance R shared Parallel connection.

[0083] In some embodiments, the first notch filter subunit includes a capacitor and a resistor connected together, and the second notch filter subunit includes an inductor.

[0084] Please see Figure 4c The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of an inductor L1. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of an inductor L1. n Composition. Among them, inductor L1 and inductor L... n The inductance values ​​are different. The common section includes a first notch filter subunit, which includes a capacitor C connected in series. shared and resistance R shared .

[0085] Please see Figure 4d Compared to Figure 4c The sampling circuit in the middle, Figure 4d The capacitor C in the first notch filter subunit of the provided sampling circuit shared and resistance R shared Parallel connection.

[0086] In some embodiments, the first notch filter subunit includes a resistor, and the second notch filter subunit includes an inductor and a capacitor connected together.

[0087] Please see Figure 5 The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of a capacitor C1 and an inductor L1 connected in series. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of a capacitor C1 and an inductor L1 connected in series. n and inductor L n They are connected in series. Among them, capacitor C1 and capacitor C... n The capacitance values ​​are different, or the capacitance of inductor L1 and inductor L... n The inductance values ​​are different, or both are different. The first notch filter sub-unit in the common section includes a resistor R. shared .

[0088] In some embodiments, the first notch filter subunit includes an inductor, and the second notch filter subunit includes a resistor and a capacitor connected together.

[0089] Please see Figure 6a The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of a capacitor C1 and a resistor R1 connected in series. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of a capacitor C1 and a resistor R1 connected in series. n and resistance R n They are connected in series. Among them, capacitor C1 and capacitor C... n The capacitance values ​​are different. The first notch filter subunit in the common section includes an inductor L. shared .

[0090] Please see Figure 6b Compared to Figure 6a The sampling circuit in the middle, Figure 6b In the provided sampling circuit, capacitor C1 and resistor R1 in the second notch filter subunit are connected in parallel, and capacitor C... n and resistance R n Parallel connection.

[0091] In some embodiments, the first notch filter subunit includes a capacitor, and the second notch filter subunit includes a resistor and an inductor connected in series.

[0092] Please see Figure 7a The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of an inductor L1 and a resistor R1 connected in series. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of an inductor L1 and a resistor R1 connected in series. nand resistance R n They are connected in series. Specifically, inductor L1 and inductor L... n The inductance values ​​are different. The first notch filter subunit in the common section includes capacitor C. shared .

[0093] Please see Figure 7b Compared to Figure 7a The sampling circuit in the middle, Figure 7b In the provided sampling circuit, the inductor L1 and resistor R1 in the second notch filter subunit are connected in parallel, and the inductor L... n and resistance R n Parallel connection.

[0094] By reusing the first notch filter subunit in the first common branch, the cost of multiple second notch filter circuits can be reduced. The reused first notch filter subunit can be formed using capacitors, inductors, resistors, combinations of capacitors and resistors, or combinations of inductors and resistors, offering high flexibility and reducing the complexity of component selection. Reusing the first common branch for multiple second notch filter circuits simplifies the circuit structure, optimizes the harmonic propagation path, reduces the interference of line parasitic parameters on the resonant frequency, and enables each notch filter unit to more accurately suppress harmonics at its corresponding resonant frequency.

[0095] In some embodiments, the common road segment includes a first common branch; a first notch filter subunit is disposed in the first common branch; a first end of the first common branch is used to connect a signal input terminal and / or a signal output terminal, a second end of the first common branch is used to connect to the first end of each second notch filter branch, and a second end of each second notch filter branch is used to connect to a ground point; or, a first end of a second notch filter branch is used to connect a signal input terminal and / or a signal output terminal, a second end of a second notch filter branch is used to connect to the first end of each first common branch, and a second end of each first common branch is used to connect to a ground point.

[0096] Please see Figure 5 The second notch branch of each second notch filter circuit can be directly connected to the signal input terminal. Alternatively, the second notch branch of each second notch filter circuit can be directly connected to the signal output terminal. Alternatively, the second notch branch of each second notch filter circuit can be directly connected to both the signal input terminal and the signal output terminal.

[0097] In some embodiments, the signal input terminal and the signal output terminal can be connected via a signal transmission line. Accordingly, the second notch branch of each second notch filter circuit can be directly connected to the signal transmission line.

[0098] In addition, the common section of the second notch filter circuit can be formed by the first common branch, which can connect each second notch filter branch to the ground point.

[0099] Please see Figure 8 The second notch branch of each second notch filter circuit can be directly connected to the ground point.

[0100] The first common branch of the second notch filter circuit can connect each second notch branch to the signal input terminal. Alternatively, the first common branch of the second notch filter circuit can connect each second notch branch to the signal output terminal. Alternatively, the first common branch of the second notch filter circuit can connect each second notch branch to both the signal input terminal and the signal output terminal.

[0101] In some embodiments, the signal input terminal and the signal output terminal can be connected via a signal transmission line. Correspondingly, the first common branch of the second notch filter circuit can connect each second notch filter branch to the signal transmission line.

[0102] Depending on the different circuit design requirements, the first common branch can be flexibly configured between the signal transmission line and the second notch branch, or between the second notch branch and the grounding point, providing high design flexibility and adaptability for different application scenarios.

[0103] In some embodiments, the common road segment includes a second common branch and a third common branch; the first notch filter subunit includes a first notch filter assembly and a second notch filter assembly; the first notch filter assembly is disposed in the second common branch; the second notch filter assembly is disposed in the third common branch; the first end of the second common branch is used to connect to a signal input terminal and / or a signal output terminal, the second end of the second common branch is used to connect to the first end of each second notch filter branch, and the second end of each second notch filter branch is used to connect to the first end of the third common branch; the second end of the third common branch is used to connect to a grounding point.

[0104] In some cases, a common road segment may include a second common branch and a third common branch. A second trap branch may connect the second common branch and the third common branch.

[0105] The second common branch can be directly connected to the signal input terminal. Alternatively, the second common branch can be directly connected to the signal output terminal. Alternatively, the second common branch can be connected to both the signal input terminal and the signal output terminal.

[0106] In some embodiments, the second common branch can be directly connected to the signal transmission line between the signal input terminal and the signal output terminal.

[0107] The first notch filter subunit installed in a common road segment may include a first notch filter assembly and a second notch filter assembly. The first and second notch filter assemblies are components constituting the first notch filter subunit. The first notch filter assembly may be installed in a second common branch of the common road segment. The second notch filter assembly may be installed in a third common branch of the common road segment.

[0108] The first notch filter assembly and the second notch filter assembly are different. In some embodiments, the first notch filter assembly is an inductor, the second notch filter assembly is a resistor, and the second notch filter subunit is formed by a capacitor.

[0109] Please see Figure 9a The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of a capacitor C1. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of a capacitor C1. n Composition. Among them, capacitor C1 and capacitor C... n The capacitance values ​​are different. The first notch filter assembly in the second common branch consists of inductor L. shared Composition. The second notch filter assembly in the third common branch consists of resistor R. shared constitute.

[0110] In some embodiments, the first notch filter component is a resistor, the second notch filter component is an inductor, and the second notch filter subunit is formed by a capacitor.

[0111] Please see Figure 9b Compared to Figure 9a The sampling circuit in the middle, Figure 9b The first notch filter component in the second common branch of the provided sampling circuit consists of resistor R. shared Composition. The second notch filter assembly in the third common branch consists of inductor L. shared constitute.

[0112] In some embodiments, the first notch filter component of the first notch filter subunit is a capacitor, the second notch filter component of the first notch filter subunit is a resistor, and the second notch filter subunit is formed by an inductor.

[0113] Please see Figure 9c The second notch filter branch 1 and the second notch filter branch n are connected in parallel. The second notch filter branch 1 contains a switching unit 1 and a second notch filter subunit 1 connected in series. The second notch filter subunit 1 is composed of an inductor L1. The second notch filter branch n contains a switching unit n and a second notch filter subunit n connected in series. The second notch filter subunit n is composed of an inductor L1. n Composition. Among them, inductor L1 and inductor L... nThe capacitance values ​​are different. The first notch filter assembly in the second common branch consists of capacitor C. shared Composition. The second notch filter assembly in the third common branch consists of resistor R. shared constitute.

[0114] In some embodiments, the first notch filter component is a resistor, the second notch filter component is a capacitor, and the second notch filter subunit is formed by an inductor.

[0115] Please see Figure 9d Compared to Figure 9c The sampling circuit in the middle, Figure 9d The first notch filter component in the second common branch of the provided sampling circuit consists of resistor R. shared Composition. The second notch filter assembly in the third common branch consists of capacitor C. shared constitute.

[0116] By reusing the first notch filter component in the second common branch and the second notch filter component in the third common branch, the cost of multiple second notch filter circuits can be reduced. The first and second notch filter components can be flexibly configured, thereby reducing the complexity of component selection. Assigning the first and second notch filter components to different common branches also facilitates independent adjustment of the parameters of the notch filter components in different common branches by relevant personnel.

[0117] In some embodiments, the power electronic circuit includes an inverter circuit and an inductor located on the AC side of the inverter circuit; the signal input terminal of the sampling circuit is used to connect to the inductor.

[0118] In some cases, when using control algorithms to perform PWM control on power electronic circuits, it is necessary to collect the current on the output side of the power electronic circuit in real time. An inductor may be provided on the output side of the power electronic circuit. Therefore, the signal input terminal of the sampling circuit is connected to the inductor. The sampling circuit provided in this application embodiment can obtain more accurate sampling results of the inductor current, thereby achieving precise control of the operating conditions of the power electronic circuit.

[0119] Please see Figure 10 This specification also provides a power conversion device, including: a power electronic circuit; a sampling circuit as described in any embodiment of this application; and a signal input terminal of the sampling circuit for connecting to the power electronic circuit.

[0120] The power conversion device can be a photovoltaic inverter, an energy storage converter, or a DC-DC converter, etc. Correspondingly, the power electronic circuit can be an inverter circuit or a DC-DC converter, etc. This embodiment does not impose specific limitations.

[0121] In some embodiments, the power conversion device further includes a controller; the controller is connected to the signal output terminal of the sampling circuit. Thus, the controller can achieve precise control of the operating conditions of the power electronic circuit based on the real-time sampling results of the sampling circuit.

[0122] For a description of the sampling circuit in the power conversion device, please refer to other embodiments of this application. This application will not elaborate further here.

[0123] It is understood that the "connection" in the above embodiments should be understood as "electrical connection" or "communication connection" if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0124] It is understood that the specific examples in this document are only intended to help those skilled in the art better understand this application, and not to limit the scope of this application.

[0125] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application.

[0126] It is understood that the various embodiments described in this application can be implemented individually or in combination, and this application does not limit them.

[0127] Unless otherwise stated, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0128] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0129] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0130] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0131] The units described as separate components may or may not be physically separate. 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0132] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A sampling circuit, characterized by comprising: The sampling circuit comprises a signal input end and a signal output end; the signal input end is used for connecting the power electronic circuit; the power electronic circuit comprises power switches capable of working at multiple switching frequencies; The sampling circuit comprises multiple trap circuit; The multiple trap circuits are connected between the signal input end and the ground of the sampling circuit, and / or the multiple trap circuits are connected between the signal output end and the ground of the sampling circuit; each trap circuit is provided with a corresponding switching unit and a trap unit; the resonant frequencies of the trap units in the multiple trap circuits correspond to different switching frequencies of the power switches respectively.

2. The sampling circuit of claim 1, wherein, The switching unit of each trap circuit has a first end and a second end; the first end of each switching unit is connected to the signal output end; the second end of each switching unit is connected to the signal input end and the corresponding trap unit.

3. The sampling circuit according to claim 1, characterized in that, The trap circuit comprises first trap circuits; each first trap circuit is formed through a corresponding first trap branch; the trap unit and the switching unit of the first trap circuit are arranged in series in the corresponding first trap branch.

4. The sampling circuit according to claim 1, characterized in that, The multiple trap circuits comprise at least two second trap circuits; each second trap circuit comprises a common section and a corresponding second trap branch; the at least two second trap circuits share one common section; the trap unit of the second trap circuit comprises a first trap subunit and a second trap subunit; the multiple trap units of the at least two second trap circuits share one first trap subunit; the first trap subunit is arranged in the common section; and the switching unit and the second trap subunit of the trap unit of each second trap circuit are arranged in series in the corresponding second trap branch.

5. The sampling circuit of claim 4, wherein, The common section comprises a first common branch; the first trap subunit is arranged in the first common branch; The first end of the first common branch is used for connecting the signal input end and / or the signal output end, and the second end of the first common branch is used for connecting the first end of each second trap branch; the second end of each second trap branch is used for connecting the ground; Or, The first end of the second trap branch is used for connecting the signal input end and / or the signal output end, and the second end of the second trap branch is used for connecting the first end of each first common branch; the second end of each first common branch is used for connecting the ground.

6. The sampling circuit according to claim 4, characterized in that, The first trap subunit comprises an inductor and a resistor connected in series, and the second trap subunit comprises a capacitor; or, The first trap subunit comprises a capacitor and a resistor connected in series, and the second trap subunit comprises an inductor; or, The first trap subunit comprises a resistor, and the second trap subunit comprises a connected inductor and capacitor; or, The first trap subunit comprises an inductor, and the second trap subunit comprises a connected resistor and capacitor; or, The first trap subunit comprises a capacitor, and the second trap subunit comprises a connected resistor and inductor.

7. The sampling circuit of claim 4, wherein, The common section comprises a second common branch and a third common branch; the first trap subunit comprises a first trap component and a second trap component; the first trap component is arranged in the second common branch; the second trap component is arranged in the third common branch; The first end of the second common branch is used for connecting the signal input end and / or the signal output end, the second end of the second common branch is used for connecting the first end of each second trap branch, the second end of each second trap branch is used for connecting the first end of the third common branch; and the second end of the third common branch is used for connecting the grounding point.

8. The sampling circuit according to claim 7, wherein, The first trap component is an inductor, the second trap component is a resistor, and the second trap subunit is formed by a capacitor; or, The first trap component is a resistor, the second trap component is an inductor, and the second trap subunit is formed by a capacitor; or, The first trap component is a capacitor, the second trap component is a resistor, and the second trap subunit is formed by an inductor; or, The first trap component is a resistor, the second trap component is a capacitor, and the second trap subunit is formed by an inductor.

9. The sampling circuit of any one of claims 1 to 8, wherein, The power electronic circuit comprises an inverter circuit and an inductor located at the AC side of the inverter circuit; and the signal input end of the sampling circuit is used for connecting the inductor.

10. A power conversion device, characterized by, The power electronic circuit comprises: A power electronic circuit; The sampling circuit according to any one of claims 1 to 9; and the signal input end of the sampling circuit is used for connecting the power electronic circuit.

11. The power conversion device of claim 10, wherein, The power conversion device further comprises: A controller; the controller is connected to the signal output end of the sampling circuit. The power conversion device further comprises: A controller; the controller is connected to the signal output end of the sampling circuit.

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