Detection circuit and power converter

Abstract

The utility model discloses a detection circuit and a power converter, which can detect the state of a fuse to be detected. The power supply, the to-be-detected fuse and the switching circuit corresponding to the to-be-detected fuse form a detection loop. When a certain to-be-detected fuse is detected, the control circuit controls the switch circuit in the detection branch where the to-be-detected fuse is located to be switched on, the signal processing circuit collects electrical parameters on the detection loop, whether the current detection loop is open or closed is judged according to the collected electrical parameters, and then the on-off state of the to-be-detected fuse is determined. When the detection circuit detects to-be-detected fuses at different potentials, mutually independent switch circuits can be adopted for detection, and the functional insulation requirement between strong currents is met. Moreover, when to-be-detected fuses with different potentials are detected, the detection circuit can multiplex the power supply, the signal processing circuit, the current-limiting resistor and the control circuit, and the detection circuit does not need to be independently arranged for each to-be-detected fuse, so that the detection cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to a detection circuit and a power converter. Background Technology

[0002] External interference or trigger circuit failures may cause the controller to fail to accurately determine the on / off status of the excitation fuse, potentially leading to system safety hazards and operational instability. Therefore, ensuring the reliability and status monitoring of the excitation fuse is crucial for the safe and stable operation of the entire new energy system. Utility Model Content

[0003] In view of this, the present invention provides a detection circuit and a power converter.

[0004] In a first aspect, this utility model embodiment provides a detection circuit, which includes a signal processing circuit, a control circuit, a current-limiting resistor, M switching circuits, and N protection devices; M is an integer greater than 1; N is an integer greater than or equal to 1;

[0005] The first terminal of each fuse under test is connected to the first terminal of the corresponding protection device, the second terminal of each protection device is connected to the first common terminal, and the second terminal of each fuse under test is connected to the first terminal of the corresponding switching circuit; the second terminals of each switching circuit are connected in parallel to the second common terminal; each fuse under test corresponds to one switching circuit.

[0006] The current-limiting resistor and the power supply are connected in series between the first common terminal and the second common terminal;

[0007] The input terminal of the signal processing circuit is connected between the first common terminal and the second common terminal, and the output terminal of the signal processing circuit is connected to the input terminal of the control circuit.

[0008] The output terminal of the control circuit is connected to the third terminal of each of the switching circuits, and is used to control the i-th switching circuit in the M switching circuits to close and the other switching circuits to open, and to detect the continuity of the i-th fuse under test corresponding to the i-th switching circuit.

[0009] In one possible implementation, the signal processing circuit includes a sampling circuit and a comparison circuit;

[0010] The input terminal of the sampling circuit is connected between the first common terminal and the second common terminal;

[0011] The first input terminal of the comparison circuit is connected to the output terminal of the sampling circuit, the second input terminal of the comparison circuit is connected to the electrical parameter reference value, and the output terminal of the comparison circuit is connected to the input terminal of the control circuit.

[0012] In one possible implementation, the first input terminal of the sampling circuit is connected to the first terminal of the current-limiting resistor, and the second input terminal of the sampling circuit is connected to the second terminal of the current-limiting resistor.

[0013] In one possible implementation, the detection circuit further includes a current sensor;

[0014] The current sensor is disposed between the first common terminal and the second common terminal; the input terminal of the sampling circuit is connected to the current sensor.

[0015] In one possible implementation, the number of the fuse under test is equal to the number of the protection devices, and the fuse under test is connected to the protection devices in a one-to-one correspondence.

[0016] In one possible implementation, N is less than M, and multiple fuses under test are connected to the same protection device.

[0017] In one possible implementation, one end of the current-limiting resistor is connected to a first terminal of the power supply, the other end of the current-limiting resistor is connected to a first common terminal, and a second terminal of the power supply is connected to a second common terminal.

[0018] In one possible implementation, one end of the current-limiting resistor is connected to the second terminal of the power supply, the other end of the current-limiting resistor is connected to the second common terminal, and the first terminal of the power supply is connected to the first common terminal.

[0019] In one possible implementation, the protection device includes an isolation device or a diode, wherein the isolation device includes a switching device.

[0020] In one possible implementation, when the protection device is the diode, the cathode of the diode is connected to the first terminal of the fuse under test, and the anode of the diode is connected to the first common terminal.

[0021] The positive terminal of the power supply is connected to the first common terminal, the negative terminal of the power supply is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor is connected to the second common terminal; or, the positive terminal of the power supply is connected to one end of the current-limiting resistor, the other end of the current-limiting resistor is connected to the first common terminal, and the negative terminal of the power supply is connected to the second common terminal.

[0022] In one possible implementation, the power supply includes an energy storage circuit; the positive terminal of the energy storage circuit is connected to the positive terminal of the auxiliary power supply in the power converter via a first switch, and the negative terminal of the energy storage circuit is connected to the negative terminal of the auxiliary power supply in the power converter via a second switch.

[0023] or,

[0024] The power supply includes an isolated power supply, which is connected to the auxiliary power supply in the power converter.

[0025] Secondly, this utility model embodiment provides a power converter, which includes M fuses to be tested and a detection circuit as described in any one of the first aspects, where M is an integer greater than 1.

[0026] The detection circuit provided by this utility model can detect the status of a fuse under test. The power supply, the fuse under test, and the corresponding switching circuit constitute the detection loop. When testing a fuse under test, the control circuit controls the switching circuit in the detection branch containing the fuse under test to conduct, the signal processing circuit collects the electrical parameters on the detection loop, and determines whether the current detection loop is open or closed based on the collected electrical parameters, thereby determining the on / off state of the fuse under test.

[0027] The detection circuit provided by this invention allows for the use of independent switching circuits when testing fuses at different potentials, thus meeting the functional insulation requirements between high-voltage circuits. Furthermore, when testing fuses at different potentials, the detection circuit can reuse the power supply, signal processing circuit, current-limiting resistor, and control circuit, eliminating the need for a separate detection circuit for each fuse and reducing testing costs. Attached Figure Description

[0028] Figure 1 A first schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0029] Figure 2 A second schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0030] Figure 3 A third schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0031] Figure 4 A fourth schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0032] Figure 5 A fifth schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0033] Figure 6 A sixth schematic diagram of the detection circuit provided for an embodiment of this utility model;

[0034] Figure 7 A seventh schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0035] Figure 8 The eighth schematic diagram provides a detection circuit for an embodiment of this utility model;

[0036] Figure 9 A ninth schematic diagram of the detection circuit provided for an embodiment of this utility model;

[0037] Figure 10 A tenth schematic diagram of the detection circuit is provided for an embodiment of this utility model;

[0038] Figure 11 Eleventh schematic diagram of the detection circuit provided for an embodiment of this utility model;

[0039] Figure 12 The twelfth schematic diagram provides a detection circuit for an embodiment of this utility model. Detailed Implementation

[0040] In inverters, fuses can be located on either the DC or AC side. Taking a centralized inverter as an example, fuses (such as excitation fuses) can be installed on the positive and negative DC terminals and in each phase of the AC terminal. Since each fuse carries high voltage, high voltage insulation is required between them. In some implementations, a separate detection circuit is typically provided for each excitation fuse to achieve functional insulation between high voltage circuits during fuse detection. However, providing independent detection circuits for different excitation fuses not only increases the cost of the inverter but also occupies valuable internal space.

[0041] To address the aforementioned technical problems, this utility model provides a detection circuit and a power converter. When testing fuses at different potentials, independent switching circuits can be used to meet the functional insulation requirements between high-voltage circuits. Furthermore, when testing fuses at different potentials, the detection circuit can reuse the power supply, signal processing circuit, current-limiting resistor, and control circuit, eliminating the need for a separate detection circuit for each fuse and reducing testing costs.

[0042] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the fuse under test described in the embodiments of this application can be an excitation fuse.

[0043] like Figure 1 As shown, Figure 1 This is a schematic diagram of a detection circuit provided in an embodiment of the present invention. The detection circuit includes a signal processing circuit, a current-limiting resistor, a control circuit, M switching circuits, and N protection devices; M is an integer greater than 1, and N is an integer greater than or equal to 1.

[0044] The first terminal of each fuse under test is connected to the first terminal of the corresponding protection device, and the second terminal of each protection device is connected to the first common terminal A. The second terminal of each fuse under test is connected to the first terminal of the corresponding switching circuit; the second terminals of each switching circuit are connected in parallel to the second common terminal B; there is a one-to-one correspondence between the fuse under test and the switching circuit.

[0045] The current-limiting resistor and the power supply are connected in series between the first common terminal A and the second common terminal B.

[0046] The input terminal of the signal processing circuit is connected between the first common terminal A and the second common terminal B, and the output terminal of the signal processing circuit is connected to the input terminal of the control circuit.

[0047] The output of the control circuit is connected to the third terminal of each switching circuit. The control circuit controls the i-th switching circuit among the M switching circuits to close, and the remaining switching circuits to open, detecting the continuity of the i-th fuse under test corresponding to the i-th switching circuit.

[0048] The M fuses under test can include multiple fuses at different potentials.

[0049] Each switching circuit corresponds one-to-one with a fuse under test, with each switching circuit connected in series with one fuse under test to form an independent detection branch. M fuses under test and M switching circuits form M detection branches.

[0050] The first terminal of each test branch is connected to the second terminal of the fuse under test, and the second terminal of the test branch is connected to the second terminal of the switching circuit. The second terminal of the fuse under test in each test branch is connected to the first terminal of the switching circuit. The first terminal of each test branch is connected to the first terminal of the corresponding protection device of the fuse under test, and the second terminal of each test branch is connected to the second common terminal B.

[0051] Protective devices are installed between each fuse under test and the power supply to isolate the potentials of each fuse under test and prevent the potentials of the fuses under test from affecting the power supply. During the testing process, the protective devices isolate the potentials of each testing branch, avoiding short circuits or interference caused by potential differences; in addition, the protective devices can also effectively protect the power supply and testing circuit from abnormal voltage or current surges.

[0052] In one possible implementation, the number of fuses under test and protective devices are equal, and the protective devices are connected in a one-to-one correspondence with the fuses under test, such as... Figure 1 and Figure 2 As shown.

[0053] When the potentials of the fuses under test are different, each fuse under test needs to be configured with a separate protection device to ensure that each fuse under test is completely isolated from other fuses under test during the testing process, so as to avoid interference or short circuit problems caused by different potentials.

[0054] In another possible implementation, the number of protective devices is less than the number of fuses under test, and the number of protective devices is also less than the number of switching devices, i.e., N < M. Multiple fuses under test are connected to the same protective device, such as... Figure 3 and Figure 4 As shown. When the first terminals of multiple fuses under test are connected in parallel, it can be assumed that the potentials of the first terminals of the multiple fuses under test are the same. When the potentials of the first terminals of multiple fuses under test are the same, the first terminals of the multiple fuses under test can be connected in parallel to the same protective device, or the first terminals of the multiple fuses under test can be connected to one end of the same protective device. For example... Figure 3 and Figure 4 The first fuse under test and the second fuse under test are shown. The first terminal of the first fuse under test is connected in parallel with the first terminal of the second fuse under test. Therefore, the first terminal of the first fuse under test and the first terminal of the second fuse under test have the same potential. The first terminal of the first fuse under test and the first terminal of the second fuse under test can be connected to the first terminal of the first protection device.

[0055] If one end of multiple fuses under test is at the same potential (e.g., the first end of the first fuse under test and the first end of the second fuse under test), the ends of these fuses under test with the same potential can be connected to the same protection device, reducing the number of protection devices, lowering hardware costs, simplifying circuit connections, and saving circuit space.

[0056] To improve the stability of the detection circuit, a current-limiting resistor is also included. This current-limiting resistor is connected in series with the power supply between the first common terminal A and the second common terminal B.

[0057] As an example, such as Figure 1 As shown, the first terminal of the current-limiting resistor is connected to the first terminal of the power supply, the second terminal of the current-limiting resistor is connected to the first common terminal A, and the second terminal of the power supply is connected to the second common terminal B. That is, the current-limiting resistor is connected in series between the power supply and the protection device. As another example, such as... Figure 2 As shown, the first end of the current-limiting resistor is connected to the second end of the power supply, the second end of the current-limiting resistor is connected to the second common terminal B, and the first end of the power supply is connected to the first common terminal A. That is, the current-limiting resistor is connected in series between the power supply and the switching circuit.

[0058] A current-limiting resistor is used to limit the current flowing through a detection circuit. During detection, if the fuse under test is in a closed state, the current will flow back to the power supply through the detection branch. By setting an appropriate resistance value, the current can be limited to prevent excessive current from damaging circuit components (such as switching circuits, diodes, etc.).

[0059] During testing, especially in high-voltage environments, current-limiting resistors can protect critical components such as power supplies, switching circuits, and fuses under test from damage caused by overcurrent.

[0060] Instead of using a separate current-limiting resistor for each detection branch, multiple detection branches share the same current-limiting resistor, reducing the number of current-limiting resistors and lowering hardware costs. This not only simplifies circuit connections but also saves space inside the power converter.

[0061] The control circuit can individually control the on / off state of each switching circuit, thereby enabling individual testing of the fuse under test.

[0062] The signal processing circuit is used to collect electrical parameters (such as voltage and current) on the detection branch and determine the status of the fuse under test based on the electrical parameters.

[0063] When a specific fuse needs to be tested, the control circuit sends a control signal to the corresponding switching circuit of that fuse, instructing that circuit to close. At this time, the other switching circuits remain open. The electrical parameter samples collected by the signal processing circuit can then be used to determine the continuity of the fuse. The input terminal of the signal processing circuit is connected between the first common terminal A and the second common terminal B. By controlling the continuity of different switching circuits, the sampling target of the signal processing circuit can be changed.

[0064] by Figure 1 Taking the second fuse under test as an example, the control circuit sends a control signal to the second switching circuit, causing the second switching circuit to close, while the remaining switching circuits (such as the first switching circuit, the third switching circuit, ..., the (M-1)th switching circuit and the Mth switching circuit) open. The power supply, current-limiting resistor, second protective device, second fuse under test, and second switching circuit constitute a detection loop. At this time, the electrical parameter sampling values ​​collected by the signal processing circuit are the electrical parameters in the detection loop formed by the power supply, current-limiting resistor, second protective device, second fuse under test, and second switching circuit. The signal processing circuit can determine the on / off state of the second fuse under test based on the collected electrical parameter sampling values. For example, if the electrical parameter sampling value is a current sampling value, when the current sampling value is non-zero, it can be determined that the second fuse under test is conducting; when the current sampling value is zero, it can be determined that the second fuse under test is open.

[0065] Similarly, when other fuses under test need to be tested, the control circuit can control the corresponding switch circuit to close and the other switch circuits to open. Then, the signal processing circuit determines whether the current test circuit is open or closed based on the collected electrical parameter sampling values, and thus determines the state of the fuse under test (such as whether it is blown).

[0066] It is important to note that each switching circuit corresponds to a fuse under test. Therefore, when the control circuit tests a particular fuse, it only controls the corresponding switching circuit to close, keeping other switching circuits open, thus enabling the individual testing of that fuse.

[0067] The detection circuit provided in this embodiment of the invention reuses the power supply, current-limiting resistor, signal processing circuit, and control circuit, combined with an independent switching circuit. This avoids the need for a separate detection circuit for each fuse under test, significantly reducing hardware costs and saving valuable space within the power converter. Each fuse under test is connected to the detection circuit via an independent switching circuit, ensuring functional insulation between fuses at different potentials and meeting safety detection requirements in high-voltage environments. Furthermore, the control circuit controls the on / off state of different switching circuits to detect specific fuses and quickly determines the on / off state of the fuse using electrical parameters collected by the signal processing circuit, thus achieving state detection of the fuse under test.

[0068] In this embodiment of the invention, the protection device includes an isolation device or a diode, and the isolation device includes a switching device such as a relay or a contactor.

[0069] The unidirectional conductivity of a diode prevents reverse current flow during detection, ensuring each detection branch operates independently and avoiding interference caused by potential differences between detection branches. Simultaneously, the diode also provides protection against abnormal power supply voltage, preventing damage to the detection circuit and power supply from high voltage or reverse voltage. It is important to note that when using a diode as a protection device, the diode's cathode must be connected to the fuse under test for the diode to function effectively. If the diode's anode is connected to the fuse under test, it will not provide protection.

[0070] As an example, such as Figure 5 As shown, the anodes of each diode are connected in parallel to the first common terminal A, and the cathodes of each diode are connected to the corresponding fuse under test. The first end of the current-limiting resistor is connected to the first common terminal A, and the second end of the current-limiting resistor is connected to the positive terminal of the power supply. The negative terminal of the power supply is connected to the second common terminal B.

[0071] As another example, such as Figure 6 As shown, the anodes of each diode are connected in parallel to the first common terminal A, and the cathodes of each diode are connected to the corresponding fuse under test. The first end of the current-limiting resistor is connected to the second common terminal B, and the second end of the current-limiting resistor is connected to the negative terminal of the power supply. The positive terminal of the power supply is connected to the first common terminal A.

[0072] In one possible implementation, the signal processing circuit includes a sampling circuit and a comparison circuit;

[0073] The input terminal of the sampling circuit is connected between the first common terminal A and the second common terminal B;

[0074] The first input terminal of the comparator circuit is connected to the output terminal of the sampling circuit, the second input terminal of the comparator circuit is connected to the electrical parameter reference value, and the output terminal of the comparator circuit is connected to the input terminal of the control circuit.

[0075] The sampling circuit is used to collect electrical parameters in the detection branch as sampled electrical parameter values. The sampling circuit sends these sampled electrical parameter values ​​to the first input terminal of the comparator circuit. The comparator circuit compares the sampled electrical parameter values ​​with reference electrical parameter values ​​and sends the comparison result to the control circuit in the form of a level signal. As an example, the comparator circuit compares the sampled electrical parameter values ​​with the reference electrical parameter values. If it determines that the fuse under test is open, the comparator circuit outputs a high-level signal to the control circuit; if it determines that the fuse under test is closed, the comparator circuit outputs a low-level signal to the control circuit.

[0076] In this embodiment of the invention, the electrical parameter sampling value can be a current sampling value or a voltage sampling value. Correspondingly, when the electrical parameter sampling value is a current sampling value, the electrical parameter reference value is a current reference value; when the electrical parameter sampling value is a voltage sampling value, the electrical parameter reference value is a voltage reference value.

[0077] The reference value of electrical parameters can be determined based on the electrical parameter values ​​when the fuse under test is conducting. This can be understood as using the electrical parameter values ​​in the detection branch when the fuse under test is conducting as a reference, and then the current state of the fuse under test can be determined by comparing the reference value of electrical parameters with the sampled value of electrical parameters.

[0078] In one possible implementation, the sampling circuit is used to acquire the voltage value across the current-limiting resistor as a voltage reference value. For example... Figures 1-6 As shown, the first input terminal of the sampling circuit is connected to the first terminal of the current-limiting resistor, and the second input terminal of the sampling circuit is connected to the second terminal of the current-limiting resistor.

[0079] The electrical parameter sampling value is the current sampling value, and the electrical parameter reference value is the current reference value. When the control circuit closes the switch circuit corresponding to the fuse under test, the sampling circuit can collect the current sampling value in the detection branch as the electrical parameter sampling value. The current reference value is greater than zero, and the current reference value is less than or equal to the current value in the detection branch when the fuse under test is conducting.

[0080] When the sampled current value is less than the reference current value, it can be determined that the fuse under test is open, and the comparator circuit transmits a signal to the control circuit to indicate that the fuse under test is open. When the sampled current value is greater than or equal to the reference current value, it can be determined that the fuse under test is on, and the comparator circuit transmits a signal to the control circuit to indicate that the fuse under test is on.

[0081] In another possible implementation, the sampling circuit is used to acquire the current value in the detection circuit as a current reference value. For example... Figures 7-10 As shown, the detection circuit also includes a current sensor; the current sensor is located between the first common terminal A and the second common terminal B; the input terminal of the sampling circuit is connected to the current sensor.

[0082] The above Figures 7-10 The positions of the current sensors are for illustrative purposes only. The current sensor can be connected in series between the current-limiting resistor and the first common terminal A; the current sensor can be connected in series between the power supply and the second common terminal B; the current sensor can be connected in series between the current-limiting resistor and the second common terminal B; the current sensor can be connected in series between the power supply and the first common terminal A.

[0083] The electrical parameter sampling value is the voltage current sampling value, and the electrical parameter reference value is the voltage reference value. When the control circuit closes the switch circuit corresponding to the fuse under test, the sampling circuit can collect the voltage sampling value across the current-limiting resistor as the electrical parameter sampling value. The voltage reference value is greater than zero, and the voltage reference value is less than or equal to the voltage value across the current-limiting resistor when the fuse under test is conducting.

[0084] When the fuse under test is conducting, its resistance is very low, almost equivalent to a short circuit, resulting in a large voltage drop across the current-limiting resistor. When the fuse under test is open, its resistance is high, resulting in a small voltage drop across the current-limiting resistor. Therefore, when the voltage sample value is greater than or equal to the voltage reference value, the fuse under test is considered conducting, and the comparator circuit transmits a signal to the control circuit indicating that the fuse is conducting. When the voltage sample value is less than the voltage reference value, the fuse under test is considered open, and the comparator circuit transmits a signal to the control circuit indicating that the fuse is open.

[0085] In this embodiment of the invention, the power supply can be an energy storage circuit or an isolated power supply.

[0086] like Figure 11 As shown, the positive terminal of the energy storage circuit is connected to the positive terminal of the auxiliary power supply in the power converter through the first switch S1, and the negative terminal of the energy storage circuit is connected to the negative terminal of the auxiliary power supply in the power converter through the second switch S2.

[0087] Energy storage circuits are devices that can store electrical energy and release it when needed, such as batteries, supercapacitors, and energy storage systems. Energy storage devices can provide independent power support when grid power is unstable or external power is unavailable, making them particularly suitable for portable devices, backup power systems, and renewable energy generation systems. The advantages of energy storage devices lie in their flexibility and sustainability; they can be charged by connecting to an external power source, enabling energy recycling and extending their lifespan.

[0088] like Figure 12 As shown, the isolated power supply is directly connected to the auxiliary power supply in the power converter. An isolated power supply is a type of power supply with a stable voltage output, capable of withstanding input voltage fluctuations, and providing reliable power support for sensitive electronic equipment.

[0089] It should be noted that, Figure 11 and Figure 12 The detection circuit shown is for illustrative purposes only. Figure 11 The positions of the current-limiting resistor and the energy storage circuit can be interchanged. Figure 11 In this configuration, one end of the current-limiting resistor is connected to the first common terminal A, the other end of the current-limiting resistor is connected to one end of the energy storage circuit, and the other end of the energy storage circuit is connected to the second common terminal B. Alternatively, the connection between the current-limiting resistor and the energy storage circuit can be as follows: one end of the current-limiting resistor is connected to the second common terminal B, the other end of the current-limiting circuit is connected to one end of the energy storage circuit, and the other end of the energy storage circuit is connected to the first common terminal A.

[0090] Similarly, Figure 12 The positions of the current-limiting resistor and the isolation power supply can also be interchanged. Figure 12 In this circuit, one end of the current-limiting resistor is connected to the first common terminal A, the other end of the current-limiting resistor is connected to one end of the isolation power supply, and the other end of the isolation power supply is connected to the second common terminal B. Alternatively, the connection between the current-limiting resistor and the isolation power supply can be: one end of the current-limiting resistor is connected to the second common terminal B, the other end of the current-limiting circuit is connected to one end of the isolation power supply, and the other end of the isolation power supply is connected to the first common terminal A.

[0091] Figure 11 and Figure 12 The detection circuit shown may also include a current sensor, which is positioned between the first common terminal A and the second common terminal B; the input terminal of the sampling circuit is connected to the current sensor.

[0092] A current sensor can be connected in series between a current-limiting resistor and a first common terminal A; a current sensor can be connected in series between an energy storage circuit (or an isolation power supply) and a second common terminal B; a current sensor can be connected in series between a current-limiting resistor and a second common terminal B; a current sensor can be connected in series between an energy storage circuit (or an isolation power supply) and a first common terminal A.

[0093] This utility model embodiment Figure 11 and Figure 12 The detection circuit shown is for illustrative purposes only.

[0094] Based on the above embodiments, this utility model further provides a power converter, which includes the detection circuit described in any of the above embodiments and M fuses to be tested;

[0095] The detection circuit consists of M switching circuits and M fuses under test in the power converter, which are connected in series to form M detection branches. The two ends of the M detection branches are connected to the positive and negative terminals of the power supply in the power converter.

[0096] The M fuses under test can include multiple fuses at different potentials. For example, some fuses under test are located on the DC side of the power converter, while the rest are located on the AC side.

[0097] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0098] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A detection circuit, characterized by, The detection circuit comprises a signal processing circuit, a control circuit, a current-limiting resistor, M switch circuits and N protection devices; M is an integer greater than 1; N is an integer greater than or equal to 1; The first end of each to-be-tested fuse is connected to the first end of a corresponding protection device, the second end of each protection device is connected to a first common end, and the second end of each to-be-tested fuse is connected to the first end of a corresponding switch circuit; the second ends of the switch circuits are connected in parallel to a second common end; the to-be-tested fuses and the switch circuits correspond one-to-one; The current-limiting resistor and the power supply are connected in series between the first common end and the second common end; The input end of the signal processing circuit is connected between the first common end and the second common end, and the output end of the signal processing circuit is connected to the input end of the control circuit; The output end of the control circuit is connected to the third end of each switch circuit, and is used for controlling the i-th switch circuit in the M switch circuits to be closed and the remaining switch circuits to be disconnected, so as to detect the on-off of the i-th to-be-tested fuse corresponding to the i-th switch circuit.

2. The detection circuit of claim 1, wherein, The signal processing circuit comprises a sampling circuit and a comparison circuit; The input end of the sampling circuit is connected between the first common end and the second common end; The first input end of the comparison circuit is connected to the output end of the sampling circuit, the second input end of the comparison circuit is connected to an electrical parameter reference value, and the output end of the comparison circuit is connected to the input end of the control circuit.

3. The detection circuit of claim 2, wherein, The first input end of the sampling circuit is connected to the first end of the current-limiting resistor, and the second input end of the sampling circuit is connected to the second end of the current-limiting resistor.

4. The detection circuit of claim 2, wherein, The detection circuit further comprises a current sensor; The current sensor is arranged between the first common end and the second common end, and the input end of the sampling circuit is connected to the current sensor.

5. The detection circuit according to any one of claims 1 to 4, characterized in that, The number of to-be-tested fuses is equal to the number of protection devices, and the to-be-tested fuses and the protection devices correspond one-to-one.

6. The detection circuit according to any one of claims 1 to 4, characterized in that, N is less than M, and a plurality of to-be-tested fuses are connected to the same protection device.

7. The detection circuit of any one of claims 1-4, wherein, One end of the current-limiting resistor is connected to the first end of the power supply, and the other end of the current-limiting resistor is connected to the first common end; the second end of the power supply is connected to the second common end.

8. The detection circuit of any one of claims 1-4, wherein, One end of the current-limiting resistor is connected to the second end of the power supply, and the other end of the current-limiting resistor is connected to the second common end; the first end of the power supply is connected to the first common end.

9. The detection circuit of claim 1, wherein, The protection device comprises an isolation device or a diode, and the isolation device comprises a switch device.

10. The detection circuit of claim 9, wherein, In the case where the protection device is the diode, the cathode of the diode is connected to the first end of a corresponding to-be-tested fuse, and the anode of the diode is connected to the first common end; The positive electrode of the power supply is connected to the first common end, the negative electrode of the power supply is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor is connected to the second common end; or the positive electrode of the power supply is connected to one end of the current-limiting resistor, the other end of the current-limiting resistor is connected to the first common end, and the negative electrode of the power supply is connected to the second common end.

11. The detection circuit of claim 1, wherein, The power supply comprises a storage circuit; a positive pole of the storage circuit is connected to a positive pole of an auxiliary power supply in the power converter through a first switch, and a negative pole of the storage circuit is connected to a negative pole of the auxiliary power supply in the power converter through a second switch; Or, The power supply comprises an isolated power supply connected to the auxiliary power supply in the power converter.

12. A power converter, characterized by The power converter comprises M to-be-tested fuses and the detection circuit according to any one of claims 1-11, and M is an integer greater than 1.

Images