A power converter

Abstract

The utility model discloses a kind of power converters. First detection circuit can detect the state of first resistance in first filter circuit, can be found when first resistance overcurrent or damage. Signal is transmitted through first isolation circuit, avoid the damage of high voltage or strong current to controller. Controller takes corresponding protective measures according to detection signal, such as cutting off power supply or starting standby circuit, to avoid noise conduction or radiation to other equipment through cable, prevent the occurrence of equipment short circuit and security risk.

Description

Technical Field

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

[0002] When a power converter is struck by lightning, the RLC filter will also become one of the discharge paths for the residual voltage of the surge protector. At this time, the resistor on the RLC filter will be at risk of overcurrent damage.

[0003] When a resistor fails due to overcurrent, the RLC filter circuit becomes an open circuit, and its filtering function disappears. At this point, noise can be conducted to other devices through cables or emitted into the environment through radiation, affecting the normal operation of surrounding equipment. Damaged resistors also produce debris, which, if trapped inside the device, may cause a short circuit, posing a serious safety hazard. Utility Model Content

[0004] In view of this, the present invention provides a power converter.

[0005] In a first aspect, the present invention provides a power converter, including a power conversion circuit, a first filter circuit, a first detection circuit, a first isolation circuit, and a controller;

[0006] The first filter circuit includes a first resistor and a first capacitor;

[0007] The first capacitor and the first resistor, connected in series, are connected between ground and the AC terminal of the power conversion circuit;

[0008] The input terminal of the first detection circuit is connected to the first filter circuit and is used to detect the continuity of the first resistor; the output terminal of the first detection circuit is connected to the controller through the first isolation circuit.

[0009] In one possible implementation, the first detection circuit includes a first linkage switch, a second linkage switch, an optocoupler, and a comparator; the first linkage switch and the second linkage switch are simultaneously open or simultaneously closed.

[0010] The first input terminal of the optocoupler is connected to the first power supply, the second input terminal of the optocoupler is connected to the first terminal of the first linkage switch, the common terminal of the first output terminal of the optocoupler and the negative input terminal of the comparator is connected to the second power supply, and the second output terminal of the optocoupler is grounded.

[0011] The positive input terminal of the comparator is connected to a third power supply, and the output terminal of the comparator is connected to the input terminal of the first isolation circuit.

[0012] The second terminal of the first linkage switch is connected to the first terminal of the first resistor; the first terminal of the second linkage switch is connected to the second terminal of the first resistor, and the second terminal of the second linkage switch is grounded.

[0013] In one possible implementation, the first detection circuit further includes a second resistor and a third resistor;

[0014] The second resistor and the third resistor, connected in series, are connected between the third power supply and ground.

[0015] The positive input terminal of the comparator is connected to the common terminal of the second resistor and the third resistor.

[0016] In one possible implementation, the first detection circuit further includes a fourth resistor and a fifth resistor;

[0017] The fourth resistor is connected in series between the first input terminal of the optocoupler and the first power supply.

[0018] One end of the fifth resistor is connected to the second power supply, and the other end of the fifth resistor is connected to the first output terminal of the optocoupler and the negative input terminal of the comparator.

[0019] In one possible implementation, the first detection circuit includes a current transformer;

[0020] The current transformer is connected in series in the first filter circuit, and the output terminal of the current transformer is connected to the controller through the first isolation circuit.

[0021] In one possible implementation, the first isolation circuit includes an operational amplifier circuit;

[0022] The output terminal of the current transformer is connected to the input terminal of the operational amplifier circuit, and the output terminal of the operational amplifier circuit is connected to the controller.

[0023] In one possible implementation, the power converter further includes an isolated power supply;

[0024] The isolation power supply is connected to the first output terminal of the optocoupler and the positive input terminal of the comparator.

[0025] In one possible implementation, the controller is a digital signal processing chip.

[0026] In one possible implementation, the first isolation circuit is a digital isolation circuit.

[0027] In one possible implementation, the power converter further includes a second filter circuit, a second detection circuit, and a second isolation circuit;

[0028] The second filter circuit includes a sixth resistor and a second capacitor;

[0029] The second capacitor and the sixth resistor, connected in series, are connected between ground and the DC terminal of the power conversion circuit;

[0030] The input terminal of the second detection circuit is connected to the second filter circuit for acquiring the electrical parameters of the sixth resistor; the output terminal of the second detection circuit is connected to the controller through the second isolation circuit.

[0031] This utility model embodiment provides a power converter. A first detection circuit can detect the state of a first resistor in a first filter circuit, enabling detection of overcurrent or damage to the first resistor. Signal transmission via a first isolation circuit prevents damage to the controller from high voltage or strong current. The controller takes corresponding protective measures based on the detection signal, such as cutting off the power supply or activating a backup circuit, thereby preventing noise from being conducted or radiated to other equipment through cables, and preventing short circuits and safety hazards. Attached Figure Description

[0032] Figure 1 A first schematic diagram of a power converter provided in an embodiment of this utility model;

[0033] Figure 2 A second schematic diagram of a power converter provided in an embodiment of this utility model;

[0034] Figure 3 A third schematic diagram of a power converter provided in an embodiment of this utility model;

[0035] Figure 4 A fourth schematic diagram of a power converter provided in an embodiment of this utility model;

[0036] Figure 5 This is a fifth schematic diagram of a power converter provided in an embodiment of the present utility model. Detailed Implementation

[0037] 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 implementation methods.

[0038] like Figure 1 As shown, Figure 1 This is a schematic diagram of a power converter provided in an embodiment of the present utility model.

[0039] The power converter includes a power conversion circuit, a first filter circuit, a first detection circuit, a first isolation circuit, and a controller.

[0040] The first filter circuit includes a first resistor R1 and a first capacitor C1.

[0041] The first capacitor C1 and the first resistor R1, connected in series, are connected between ground and the AC terminal of the power conversion circuit.

[0042] The input terminal of the first detection circuit is connected to the first filter circuit to collect the electrical parameters of the first resistor R1; the output terminal of the first detection circuit is connected to the controller through the first isolation circuit.

[0043] The first filter circuit can be an RLC filter. The connection relationship between the first resistor R1 and the first capacitor C1 can be as follows: Figure 1 As shown, the first end of the first resistor R1 is connected to one end of the first capacitor C1, the second end of the first resistor R1 is grounded, and the other end of the first capacitor C1 is connected to the AC terminal of the power circuit. The inductance in the RLC filter refers to the stray inductance in the circuit.

[0044] The first detection circuit detects the continuity of the first resistor R1 in the first filter circuit. If the first resistor R1 is open, it indicates that the first resistor R1 is damaged. If the first resistor R1 is closed, it indicates that the first resistor R1 is not damaged.

[0045] The first isolation circuit is used to electrically isolate the detection circuit and the controller, preventing high voltage or strong current from being directly transmitted to the controller, thus avoiding damage to the controller or causing other malfunctions.

[0046] In one possible implementation, the signal transmitted from the first detection circuit to the controller is a digital signal, and the first isolation circuit can be a digital isolation circuit with basic insulation.

[0047] After receiving the signal from the first detection circuit, the controller can determine whether the first resistor in the first filter circuit is damaged. When a damaged resistor in the first filter circuit is detected, the controller can trigger a protection mechanism, such as cutting off the power supply, activating the backup circuit, or issuing an alarm signal.

[0048] In this embodiment of the invention, the first detection circuit can detect the state of the first resistor in the first filter circuit, enabling detection when the first resistor is overcurrent or damaged. Signal transmission via the first isolation circuit prevents damage to the controller from high voltage or strong current. The controller takes corresponding protective measures based on the detection signal, such as cutting off the power supply or activating the backup circuit, thereby preventing noise from being conducted or radiated to other devices through cables, and preventing short circuits and safety hazards.

[0049] In one possible implementation, such as Figure 2 As shown, the first detection circuit includes a first linkage switch S1, a second linkage switch S2, an optocoupler, and a comparator.

[0050] The first input terminal of the optocoupler is connected to the first power supply, the second input terminal of the optocoupler is connected to the first terminal of the first linkage switch S1, the common terminal of the first output terminal of the optocoupler and the negative input terminal of the comparator is connected to the second power supply, and the second output terminal of the optocoupler is grounded.

[0051] The positive input terminal of the comparator is connected to the third power supply, and the output terminal of the comparator is connected to the input terminal of the first isolation circuit.

[0052] The second terminal of the first linkage switch S1 is connected to the first terminal of the first resistor R1; the first terminal of the second linkage switch S2 is connected to the second terminal of the first resistor R1, and the second terminal of the second linkage switch S2 is grounded.

[0053] The first interlocking switch S1 and the second interlocking switch S2 are simultaneously open or simultaneously closed. When S1 is closed, S2 will also be closed; when S1 is open, S2 will also be open. This interlocking mechanism ensures that the two switches operate synchronously, avoiding inconsistencies caused by individual operation.

[0054] When the first linkage switch S1 and the second linkage switch S2 are closed, if the first resistor R1 is not damaged, the input terminal of the optocoupler is connected, and the light-emitting diode inside the optocoupler starts to light up. The phototransistor at the output terminal of the optocoupler is turned on, and the second power supply is grounded both through the phototransistor in the optocoupler and connected to the negative input terminal of the comparator.

[0055] When the first linkage switch S1 and the second linkage switch S2 are closed, if the first resistor R1 is damaged, the input terminal of the optocoupler cannot be connected, and the light-emitting diode inside the optocoupler remains off. The phototransistor at the output terminal of the optocoupler cannot conduct, and the second power supply is directly connected to the negative input terminal of the comparator.

[0056] The positive input of the comparator is connected to a third power supply. This third power supply provides a reference voltage, which is compared with the voltage at the negative input of the comparator.

[0057] When the first resistor R1 is intact, the optocoupler is on, and the comparator outputs a high-level signal. When the first resistor R1 is damaged, the optocoupler is off, and the comparator outputs a low-level signal.

[0058] The voltages of the second and third power supplies are equal. In one possible implementation, the power converter also includes an isolated power supply.

[0059] The output of the isolation power supply is connected to the first input of the optocoupler and the positive input of the comparator. In other words, the isolation power supply is used to provide both a second and a third power supply.

[0060] Isolated power supplies not only provide the necessary power support for optocouplers and comparators, but also ensure electrical isolation between high-voltage and low-voltage circuits, improving the safety and reliability of power converters.

[0061] In one possible implementation, the controller can be a digital signal processing (DSP) chip.

[0062] In one possible implementation, the first isolation circuit can be a digital isolation circuit.

[0063] The first isolation circuit connects the comparator and the controller, used to transmit digital signals between high-voltage and low-voltage circuits to achieve electrical isolation. The detection circuit outputs a detection signal, which is then transmitted to the controller by the digital isolation circuit. The controller generates a control signal based on the detection signal, adjusting the output of the power converter to ensure stable system operation.

[0064] The first filter circuit is used for electromagnetic compatibility filtering. The filtering frequency band of RLC filters is often between 0.15 MHz and 1000 MHz. Within this frequency band, there is noise conducted and radiated interference. If the first filter circuit is tested during operation, it may affect the filtering effect of the first filter circuit.

[0065] During the testing process, this embodiment of the invention directly connects or disconnects the first switching transistor S1 and the second switching transistor S2 via physical means, thereby connecting or disconnecting the detection circuit from the first filter circuit. This avoids the detection circuit affecting the filter characteristics when the filter is working.

[0066] Specifically, to avoid affecting the normal operation of the first filter circuit, the detection operation is set to be performed at specific time intervals. For example, detection can be performed during low-load or no-load periods of the first filter circuit's operating cycle, or during the power converter's idle period. By reasonably setting the detection interval, it can be ensured that the detection operation does not affect the filtering effect of the first filter circuit, while still allowing for timely detection of the first filter circuit.

[0067] In one possible implementation, such as Figure 3 As shown, the first detection circuit also includes a second resistor R2 and a third resistor R3.

[0068] The second resistor R2 and the third resistor R3, connected in series, are connected between the third power supply and ground.

[0069] The positive input terminal of the comparator is connected to the common terminal of the second resistor R2 and the third resistor R3.

[0070] The second resistor R2 and the third resistor R3 serve to limit the current. The current output from the third power supply is constrained by these resistors. Without their current-limiting function, excessive current could occur in the circuit, potentially damaging other components such as the comparator. By using resistors R2 and R3, the current can be limited to a safe range, ensuring the stable operation of the detection circuit.

[0071] The resistance values ​​of the second resistor R2 and the third resistor R3 can be set by technicians according to the actual situation.

[0072] The second resistor R2 and the third resistor R3, connected in series, also act as a voltage divider. The voltage of the third power supply is applied across the second resistor R2 and the third resistor R3. If the resistances of the second resistor R2 and the third resistor R3 are equal, then the voltages across the second resistor R2 and the third resistor R3 are equal; if the resistance of the second resistor R2 is greater than the resistance of the third resistor R3, then the voltage across the second resistor R2 is greater than the voltage across the third resistor R3.

[0073] The positive input terminal of the comparator is connected to the common terminal of the second resistor R2 and the third resistor R3. Therefore, the input voltage at the positive input terminal of the comparator is less than the voltage of the third power supply.

[0074] When the first resistor R1 is conducting, the phototransistor in the optocoupler is turned on, and the second power supply is grounded through the photodiode. The input voltage at the negative input terminal of the comparator approaches zero. At this time, the input voltage at the positive input terminal of the comparator is greater than the input voltage at the negative input terminal, and the comparator outputs a high-level signal.

[0075] When the first resistor R1 is disconnected, the phototransistor in the optocoupler is off, and the second power supply is directly connected to the negative input terminal of the comparator. The input voltage at the negative input terminal of the comparator is equal to the voltage of the second power supply. Since the voltage of the second power supply is equal to the voltage of the third power supply, and the input voltage at the positive input terminal of the comparator is less than the voltage of the third power supply, the input voltage at the negative input terminal of the comparator is greater than the input voltage at the positive input terminal. At this time, the comparator outputs a low-level signal.

[0076] When the controller receives a high-level signal from the comparator, it can determine that the first filter circuit is not damaged; when it receives a low-level signal from the comparator, it can determine that the first filter circuit is damaged.

[0077] In one possible implementation, such as Figure 4 As shown, the first detection circuit also includes a fourth resistor R4 and a fifth resistor R5.

[0078] The fourth resistor R4 is connected in series between the first input terminal of the optocoupler and the first power supply; one end of the fifth resistor R5 is connected to the second power supply, and the other end of the fifth resistor R5 is connected to the first output terminal of the optocoupler and the negative input terminal of the comparator.

[0079] The fourth resistor R4 and the fifth resistor R5 serve to limit current. The fourth resistor R4 is connected in series between the first power supply and the first input terminal of the optocoupler to limit the current flowing through the internal diode of the optocoupler.

[0080] The fifth resistor R5 is connected in series between the second power supply and the first output terminal of the optocoupler, limiting the current flowing through the phototransistor inside the optocoupler. Simultaneously, the fifth resistor R5 is connected in series between the first power supply and the negative input terminal of the comparator, limiting the input current at the negative input terminal of the comparator.

[0081] It should be noted that a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5 can be set simultaneously in a power converter.

[0082] In the above embodiments, the first detection circuit detects the continuity of the first resistor R1 via an optocoupler to determine whether the first filter circuit is damaged. This embodiment also provides an implementation where, when the power converter starts working, a current instantaneously flows through the first filter circuit. By detecting the current in the first filter circuit, it can be determined whether the first filter circuit is damaged.

[0083] In one possible implementation, such as Figure 5 As shown, the first detection circuit includes a current transformer.

[0084] The current transformer is connected in series in the first filter circuit, and the output terminal of the current transformer is connected to the controller through the first isolation circuit.

[0085] The current transformer can be connected in series between the first capacitor C1 and the first resistor R1, or it can be connected in series between the first capacitor C1 and the AC terminal of the power converter, or it can be connected in series between the first resistor R1 and ground.

[0086] The current transformer is used to detect whether current flows through the first filter circuit. The current transformer outputs the current parameters of the first filter circuit to the controller through the first isolation circuit. The controller can determine whether the first filter circuit is damaged based on the current parameters. If the current parameter output by the current transformer is greater than zero, it indicates that the first filter circuit is not damaged; if the current parameter output by the current transformer is zero, it indicates that the first filter circuit is damaged.

[0087] In one possible implementation, the first isolation circuit can be an operational amplifier circuit.

[0088] The output of the current transformer is connected to the input of the operational amplifier circuit, and the output of the operational amplifier circuit is connected to the controller.

[0089] The operational amplifier (op-amp) circuit amplifies and converts the minute current signal output from the current transformer into a voltage signal suitable for the controller to process. By amplifying the signal amplitude, the op-amp circuit ensures that the controller can accurately detect the state of the first filter circuit. Simultaneously, the op-amp circuit can also integrate isolation functionality to achieve electrical isolation between the primary and secondary sides, thereby improving system safety and anti-interference capabilities. Signal processing through the op-amp circuit effectively enhances the stability and accuracy of the detected signal.

[0090] In the above embodiments, the first filter circuit is located at the AC terminal of the power converter. In some scenarios, such as when the AC terminal of the power converter is used to connect a photovoltaic string, a second filter circuit can also be located at the DC terminal of the power converter. Accordingly, the power converter also includes a second detection circuit and a second isolation circuit.

[0091] The second filter circuit may include a sixth resistor and a second capacitor.

[0092] The second capacitor and the sixth resistor, connected in series, are connected between ground and the DC terminal of the power conversion circuit;

[0093] The input of the second detection circuit is connected to the second filter circuit to collect the electrical parameters of the sixth resistor; the output of the second detection circuit is connected to the controller through two isolation circuits.

[0094] The structure of the second filter circuit is the same as that of the first filter circuit. For a description of the second detection circuit, please refer to the description of the first detection circuit in the above embodiments; similarly, for a description of the second isolation circuit, please refer to the description of the first isolation circuit in the above embodiments.

[0095] The first detection circuit and the second detection circuit are independent detection circuits and do not interfere with each other. The first isolation circuit and the second isolation circuit are independent isolation circuits and do not interfere with each other.

[0096] 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.

[0097] 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 power converter, characterized in that, It includes a power conversion circuit, a first filter circuit, a first detection circuit, a first isolation circuit, and a controller; The first filter circuit includes a first resistor and a first capacitor; The first capacitor and the first resistor, connected in series, are connected between ground and the AC terminal of the power conversion circuit; The input terminal of the first detection circuit is connected to the first filter circuit and is used to detect the continuity of the first resistor. The output of the first detection circuit is connected to the controller through the first isolation circuit.

2. The power converter according to claim 1, characterized in that, The first detection circuit includes a first linkage switch, a second linkage switch, an optocoupler, and a comparator; the first linkage switch and the second linkage switch are simultaneously open or simultaneously closed. The first input terminal of the optocoupler is connected to the first power supply, the second input terminal of the optocoupler is connected to the first terminal of the first linkage switch, the common terminal of the first output terminal of the optocoupler and the negative input terminal of the comparator is connected to the second power supply, and the second output terminal of the optocoupler is grounded. The positive input terminal of the comparator is connected to a third power supply, and the output terminal of the comparator is connected to the input terminal of the first isolation circuit. The second terminal of the first linkage switch is connected to the first terminal of the first resistor; the first terminal of the second linkage switch is connected to the second terminal of the first resistor, and the second terminal of the second linkage switch is grounded.

3. The power converter according to claim 2, characterized in that, The first detection circuit also includes a second resistor and a third resistor; The second resistor and the third resistor, connected in series, are connected between the third power supply and ground. The positive input terminal of the comparator is connected to the common terminal of the second resistor and the third resistor.

4. The power converter according to claim 2, characterized in that, The first detection circuit also includes a fourth resistor and a fifth resistor; The fourth resistor is connected in series between the first input terminal of the optocoupler and the first power supply. One end of the fifth resistor is connected to the second power supply, and the other end of the fifth resistor is connected to the first output terminal of the optocoupler and the negative input terminal of the comparator.

5. The power converter according to claim 1, characterized in that, The first detection circuit includes a current transformer; The current transformer is connected in series in the first filter circuit, and the output terminal of the current transformer is connected to the controller through the first isolation circuit.

6. The power converter according to claim 1, characterized in that, The first isolation circuit includes an operational amplifier circuit; The output terminal of the current transformer is connected to the input terminal of the operational amplifier circuit, and the output terminal of the operational amplifier circuit is connected to the controller.

7. The power converter according to claim 2, characterized in that, The power converter also includes an isolation power supply; The isolation power supply is connected to the first output terminal of the optocoupler and the positive input terminal of the comparator.

8. The power converter according to claim 1, characterized in that, The controller is a digital signal processing chip.

9. The power converter according to any one of claims 1-4, characterized in that, The first isolation circuit is a digital isolation circuit.

10. The power converter according to claim 1, characterized in that, The power converter also includes a second filter circuit, a second detection circuit, and a second isolation circuit; The second filter circuit includes a sixth resistor and a second capacitor; The second capacitor and the sixth resistor, connected in series, are connected between ground and the DC terminal of the power conversion circuit; The input terminal of the second detection circuit is connected to the second filter circuit for acquiring the electrical parameters of the sixth resistor; the output terminal of the second detection circuit is connected to the controller through the second isolation circuit.

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