Solar inverter

Abstract

A solar inverter includes a housing, at least one circuit board disposed in the housing, a current sensor disposed on the circuit board, an arc detection coil disposed on the circuit board, a self-test circuit disposed on the circuit board, and at least one DC input terminal disposed on the housing and connected to the circuit board. The self-test circuit is configured to deliver a test signal for the arc detection coil to sense. The DC input terminal is configured to deliver current through the arc detection coil, and the current sensor is configured to detect the magnitude of the current through the DC input terminal.

Description

Technical Field

[0001] This disclosure relates to a solar inverter. Background Technology

[0002] In a solar power system, solar panels are installed outdoors and connected to components such as inverters and batteries via cables. Outdoor environments make these cables susceptible to damage, and cable breakage can lead to electric arcs, which is extremely dangerous. Summary of the Invention

[0003] In view of this, one objective of this disclosure is to propose a solar inverter with an arc detection mechanism.

[0004] To achieve the above objectives, according to some embodiments of this disclosure, a solar inverter includes a housing, at least one circuit board disposed within the housing, a current sensor disposed on the circuit board, an arc detection coil disposed on the circuit board, a self-test circuit disposed on the circuit board, and at least one DC input terminal disposed on the housing and connected to the circuit board. The self-test circuit is configured to deliver a test signal to the arc detection coil for sensing. The DC input terminal is configured to deliver current through the arc detection coil, and the current sensor is configured to detect the magnitude of the current passing through the DC input terminal.

[0005] In summary, unlike existing solar inverters that use arc detection coils wound around a ring core, the solar inverter disclosed herein integrates the arc detection coil and self-testing circuit on a circuit board. This approach helps save costs and space, and makes it easier to perform arc detection and self-function testing for each solar string. Attached Figure Description

[0006] To make the above and other objects, features, advantages and embodiments of this disclosure more apparent and understandable, the accompanying drawings are described below:

[0007] Figure 1 A schematic diagram illustrating a solar power system according to an embodiment of the present disclosure.

[0008] Figure 2 To show Figure 1 The diagram shows the internal structure of a solar inverter in a solar power system.

[0009] Figure 3 This is a partially enlarged cross-sectional view of a solar inverter according to another embodiment of the present disclosure.

[0010] Figure 4 This is a partially enlarged cross-sectional view of a solar inverter according to another embodiment of the present disclosure.

[0011] Figure 5 To show Figure 4 The front view of the solar inverter shown.

[0012] Figure 6 This is a partially enlarged cross-sectional view of a solar inverter according to another embodiment of the present disclosure.

[0013] Figure 7 To show Figure 6 The front view of the second circuit board of the solar inverter shown.

[0014] Figure 8 This is a partially enlarged cross-sectional view of a solar inverter according to another embodiment of the present disclosure.

[0015] Figure 9 This is a partially enlarged cross-sectional view of a solar inverter according to another embodiment of the present disclosure.

[0016] Figure 10 This is a partially enlarged cross-sectional view of a solar inverter according to another embodiment of the present disclosure.

[0017] Figure 11 This is a partially enlarged cross-sectional view of a circuit board according to an embodiment of the present disclosure.

[0018] Figure 12 This is a partially enlarged cross-sectional view of a circuit board according to another embodiment of the present disclosure.

[0019] Figure 13 This is a partially enlarged cross-sectional view of a circuit board according to another embodiment of the present disclosure.

[0020] Explanation of reference numerals in the attached figures:

[0021] 10: Solar power system

[0022] 11: Solar panels

[0023] 12: Solar Inverter

[0024] 13: Arc Detection Unit

[0025] 14: DC switch

[0026] 15: Detection circuit controller

[0027] 20: Shell

[0028] 25: DC input terminal

[0029] 30: Circuit board

[0030] 50: Circuit board

[0031] 31: Opening

[0032] 53: Opening

[0033] 32: Internal wiring

[0034] 57: Internal wiring

[0035] 33: Current sensor

[0036] 35: Arc detection coil

[0037] 38: Self-testing circuit

[0038] 56: Arc detection coil

[0039] 58: Self-test circuit

[0040] 37: Connecting terminal

[0041] 39: Electromagnetic Interference Suppression Capacitor

[0042] 60: Cable

[0043] 65: Cables

[0044] 70: Electrical connector

[0045] 90: Fasteners

[0046] L1~L6: Layers

[0047] AC: Air Shaft Detailed Implementation

[0048] To make the description of this disclosure more detailed and complete, reference may be made to the accompanying drawings and the various embodiments described below. The elements in the drawings are not drawn to scale and are provided for illustrative purposes only. Numerous practical details are described below to provide a comprehensive understanding of this disclosure; however, those skilled in the art will understand that this disclosure may be practiced without one or more of these practical details, and therefore, such details should not be used to limit this disclosure.

[0049] Please refer to Figure 1The solar power system 10 includes a plurality of solar panels 11 and a solar inverter 12. The solar inverter 12 is connected to the solar panels 11 and configured to convert the direct current (DC) generated by the solar panels 11 into alternating current (AC), and then output the AC power to the power grid or electrical devices. The solar inverter 12 includes an arc detection unit 13, configured to determine whether an arc fault has occurred in the line between the solar inverter 12 and the solar panels 11. The solar inverter 12 also includes a DC switch 14. When the arc detection unit 13 determines that an arc fault has occurred in the line between the solar inverter 12 and the solar panels 11, the DC switch 14 is configured to cut off the DC power supplied by the solar panels 11 to the solar inverter 12. The solar inverter 12 also includes a detection circuit controller 15. The detection circuit controller 15 is configured to use a self-testing circuit (e.g., Figure 2 The self-test circuit 38) is fed with a white noise or high-frequency signal to detect whether the arc detection unit 13 is functioning properly.

[0050] Furthermore, when the arc detection unit 13 determines that an arc fault has occurred in the line between the solar inverter 12 and the solar panel 11, the solar inverter 12 can stop receiving energy from the solar panel 11 (for example, the solar inverter 12 can be turned off and stop operating, or the power supply from the solar panel 11 to the solar inverter 12 can be cut off by the DC switch 14). Since the solar panel 11 is a passive component, it generates electricity when exposed to sunlight, unlike other DC power supplies such as power supplies and batteries that can be turned off when an abnormality is detected. Therefore, the solar power system 10 of this disclosure integrates the arc detection function into the solar inverter 12, which detects the arc fault and cuts off the power (stops drawing current from the solar panel 11) when an arc fault occurs, in order to protect the solar power system 10.

[0051] Please refer to Figure 2 The solar inverter 12 includes a housing 20 and one or more DC input terminals 25. The DC input terminals 25 are disposed on the wall of the housing 20 and connected to the solar panel 11. Figure 2 The text is incomplete and lacks detail; please see the attached image. Figure 1 The DC input terminal 25 is connected to a solar string, which may contain one or more solar panels 11. In some embodiments, each DC input terminal 25 is connected to a solar string, and each string may contain one or more solar panels 11.

[0052] like Figure 2As shown, the solar inverter 12 also includes a circuit board 30, which is disposed in the housing 20 facing the DC input terminal 25 and connected to the DC input terminal 25. In this embodiment, the DC input terminal 25 is connected to the circuit board 30 via a cable 60. Specifically, the circuit board 30 has an opening 31, one end of which is connected to the DC input terminal 25 and extends through the opening 31 through the circuit board 30. In some embodiments, the cable 60 connects to a connection interface (e.g., connection terminal 37) on the circuit board 30 after passing through it.

[0053] like Figure 2 As shown, the solar inverter 12 also includes a current sensor 33 (illustrated only, specific structure not shown) mounted on the circuit board 30. The current sensor 33 is configured to detect the magnitude of the current passing through the DC input terminal 25. In other words, the circuit board 30 has the function of detecting the input current of the DC input terminal 25.

[0054] like Figure 2 As shown, the solar inverter 12 also includes an arc detection coil 35, which is disposed on the circuit board 30 and surrounds an opening 31 in the circuit board 30. Therefore, the DC input terminal 25 can supply current through / through the arc detection coil 35 via a cable 60. In some embodiments, the arc detection coil 35 may be disposed on the surface of the circuit board 30. In other embodiments, the arc detection coil 35 may be embedded within the circuit board 30. The solar inverter 12 also includes a self-detection circuit 38, which is also disposed on the circuit board 30 and within a portion of the arc detection coil 35. The self-detection circuit 38 receives a white noise or high-frequency signal to detect whether the arc detection coil 35 can detect the white noise or high-frequency signal.

[0055] The arc detection coil 35 is, for example, a Rogowski coil. The arc detection coil 35 can be connected to the arc detection unit 13 via a signal line (see reference). Figure 1 The arc detection unit 13 can be mounted on the circuit board 30 or on other circuit boards. The arc detection unit 13 is configured to receive signals (e.g., voltage signals) from the arc detection coil 35 and perform signal processing and spectrum analysis on the received signals to determine whether an arc fault has occurred in the series corresponding to the DC input terminal 25. The arc detection unit 13 may include filters, amplifiers, digital signal processors, or other electronic components to perform filtering, amplification, and Fourier analysis to perform spectrum analysis and determine whether an arc fault has occurred.

[0056] In the design of solar inverters, the current practice is to use an arc detection coil wound around a ring core for arc detection, while the self-test circuit 38 is a section of the ring core. However, this type of arc detection coil is bulky, the wiring of the self-test circuit 38 is very messy, and the cost is also high. The solar inverter 12 disclosed herein integrates the arc detection coil 35 and the self-test circuit 38 together on the circuit board 30. This approach saves assembly space for the arc detection coil and the self-test circuit, and the cost is lower compared to the ring core type arc detection coil. Moreover, the arc detection coil 35 only needs to be installed on the DC input terminal 25 on the circuit board 30 to perform arc detection individually for the corresponding string group.

[0057] Furthermore, Figure 2 The embodiment shown integrates the arc detection coil 35 and the self-test circuit 38 onto the original circuit board 30, which is used to match the DC input terminal 25 and has a current detection function, making the structure of the solar inverter 12 more streamlined.

[0058] It should be noted that, Figure 2 The diagram only shows one DC input terminal 25 connected to the circuit board 30 via a cable 60, and the arc detection coil 35 and self-test circuit 38 corresponding to one DC input terminal 25. In actual products, each DC input terminal 25 of the solar inverter 12 can be connected to a cable 60, and the circuit board 30 can be provided with a plurality of arc detection coils 35. Each arc detection coil 35 passes through one DC input terminal 25 (that is, around one of the cables 60) and has a self-test circuit 38 surrounding a section of the arc detection coil 35.

[0059] In some embodiments, circuit board 30 is a busbar circuit board. Specifically, circuit board 30 is configured to receive current from a plurality of DC input terminals 25 and output current via at least one output terminal (e.g., connection terminal 37) disposed on circuit board 30, wherein the number of output terminals is less than the number of DC input terminals 25. Therefore, in these embodiments, the arc detection coil 35 and the self-detection circuit 38 are integrated on the existing busbar circuit board, making the structure of the solar inverter 12 more streamlined.

[0060] In some embodiments, the solar inverter 12 further includes an electromagnetic interference suppression capacitor 39 disposed on the circuit board 30. Therefore, in these embodiments, the arc detection coil 35 is integrated into the existing circuit board 30, which is used to pair with the DC input terminal 25 and has electromagnetic interference suppression function, making the structure of the solar inverter 12 more streamlined.

[0061] Please refer to Figure 3 Unlike the previous embodiments, in this embodiment, two or more DC input terminals 25 share a single arc detection coil 35. Specifically, the circuit board 30 has multiple openings 31, each allowing a cable 60 to pass through, and each cable 60 connects to a different DC input terminal 25. The arc detection coil 35 is arranged around the multiple openings 31, allowing current to be supplied through the arc detection coil 35 via multiple cables 60 from the multiple DC input terminals 25. The arc detection coil 35 can be connected to an arc detection unit via signal lines. The arc detection unit is configured to receive signals from the arc detection coil 35 and perform signal processing and spectrum analysis on the received signals to determine whether an arc fault has occurred in the string corresponding to one of the DC input terminals 25. A portion of the arc detection coil 35 also has a self-testing circuit 38 arranged around it to provide self-testing functionality for both the arc detection coil 35 and the arc detection unit.

[0062] Please refer to Figure 4 as well as Figure 5 Unlike the previous embodiments where a cable 60 was used to connect the DC input terminal 25, in this embodiment, the circuit board 30 is fixed to the DC input terminal 25. In some embodiments, the DC input terminal 25 is inserted into the opening 31 of the circuit board 30, and a fastener 90 (e.g., a screw) is tightened at the end of the DC input terminal 25, thereby securing the circuit board 30 to the DC input terminal 25.

[0063] like Figure 4 and Figure 5As shown, the solar inverter 12 further includes a connection terminal 37 disposed on a circuit board 30 and electrically connected to a DC input terminal 25 via internal wiring 32 (shown in dashed lines) of the circuit board 30. Therefore, current flows sequentially through the DC input terminal 25, the internal wiring 32 of the circuit board 30, and the connection terminal 37. The connection terminal 37 can be connected to an external cable 65 to deliver current to other components of the solar inverter 12 (e.g., a DC switch). An arc detection coil 35 is disposed around the DC input terminal 25 and the connection terminal 37, allowing current from the DC input terminal 25 to pass through the arc detection coil 35. A section of the arc detection coil 35 is also provided with a self-testing circuit 38 to provide self-testing functionality for the arc detection coil 35 and the arc detection unit. In some embodiments, the spiral coil formed by the arc detection coil 35 on the circuit board is a closed rectangular loop, and the self-testing circuit 38 is disposed in a section of the closed loop. In some embodiments, the closed loop of the arc detection coil 35 can also be circular, elliptical, square, or triangular. In some other embodiments, the spiral coil formed by the arc detection coil 35 on the circuit board can also be an open rectangular loop, circular loop, elliptical loop, square loop, or triangular loop.

[0064] Please refer to Figure 6 as well as Figure 7 This embodiment is similar to... Figure 2 The difference in the illustrated embodiment is that the arc detection coil and the current sensor are mounted on different circuit boards. Specifically, in this embodiment, the current sensor is mounted on circuit board 30 (see [link to embodiment]). Figure 2 The solar inverter further includes a circuit board 50, on which an arc detection coil 56 and its self-testing circuit 58 are disposed. The circuit board 50 has an opening 53 around which the arc detection coil 56 is disposed. The circuit board 50 is sleeved on a cable 60 connected to a DC input terminal 25; in other words, the cable 60 passes through the opening 53 of the circuit board 50, allowing the arc detection coil 56 to surround the cable 60. Therefore, current from the DC input terminal 25 can pass through the arc detection coil 56 via the cable 60. A section of the arc detection coil 56 is provided with a self-testing circuit 58 to provide self-testing functionality for the arc detection coil 56 and the arc detection unit.

[0065] Please refer to Figure 7 as well as Figure 8 This embodiment is similar to... Figure 4 The difference in the illustrated embodiment is that the arc detection coil and the current sensor are mounted on different circuit boards. Specifically, in this embodiment, the current sensor is mounted on circuit board 30 (see [link to embodiment]). Figure 2The solar inverter further includes a circuit board 50, on which an arc detection coil 56 is disposed. The circuit board 50 has an opening 53 around which the arc detection coil 56 is disposed. The circuit board 50 is fitted onto a cable 65 connected to a connection terminal 37 on the circuit board 30; in other words, the cable 65 passes through the opening 53 of the circuit board 50, causing the arc detection coil 56 to surround the cable 65. Therefore, current from the DC input terminal 25 can pass through the arc detection coil 56 via the cable 65.

[0066] Please refer to Figure 9 In this embodiment, the current sensor (see...) Figure 2 An arc detection coil 56 and a self-test circuit 58 are respectively disposed on circuit boards 30 and 50, with circuit board 50 located between circuit board 30 and DC input terminal 25. DC input terminal 25 is connected to circuit board 30 via cable 60. Specifically, one end of cable 60 is fixedly connected to DC input terminal 25, extends through opening 53 of circuit board 50, and the other end is fixedly connected to circuit board 30. The solar inverter further includes an electrical connector 70, which connects circuit boards 30 and 50 and is electrically connected to the arc detection coil 56 disposed around opening 53 via internal wiring 57 of circuit board 50. Electrical connector 70 may include a plurality of pins, and the sensing signal generated by arc detection coil 56 can be transmitted to circuit board 30 via internal wiring 57 of circuit board 50 and electrical connector 70.

[0067] In some embodiments, an arc detection unit (not shown) is mounted on circuit board 30. The sensing signal generated by arc detection coil 56 is transmitted to the arc detection unit on circuit board 30 for analysis via electrical connector 70. In other embodiments, the arc detection unit may be mounted on other circuit boards. The sensing signal generated by arc detection coil 56 is first transmitted to circuit board 30 via electrical connector 70, and then transmitted to the arc detection unit mounted on other circuit boards for analysis via other lines. In some embodiments, a detection circuit controller (not shown) is mounted on circuit board 30. The detection circuit controller 15 injects a white noise or high-frequency signal through self-test circuit 58 via electrical connector 70 and internal circuit 59 of circuit board 50 to provide self-testing functionality for arc detection coil 56 and arc detection unit.

[0068] Please refer to Figure 10 Unlike Figure 9In the illustrated embodiment, circuit board 30 is fixed to DC input terminal 25 (e.g., by fasteners 90 such as screws). Circuit board 50 is located between circuit board 30 and the wall of housing 20 where DC input terminal 25 is located, and is fitted onto DC input terminal 25 (in other words, DC input terminal 25 extends through opening 53 of circuit board 50). Circuit boards 30 and 50 are connected by electrical connector 70, and electrical connector 70 is electrically connected to arc detection coil 56 disposed around opening 53 via internal wiring 57 of circuit board 50. A section of arc detection coil 56 is provided with self-testing circuit 58 to provide self-testing function for arc detection coil 56 and arc detection unit.

[0069] Please refer to Figure 11 This figure shows a partially enlarged cross-sectional view of a circuit board 30 / 50 according to an embodiment of the present disclosure. The figure shows a cross-sectional view of a six-layer (L1-L6) copper foil circuit board 30 / 50, this portion including the aforementioned arc detection coil 35 / 56 and self-test circuit 38 / 58. In this embodiment, the arc detection coil 35 / 56 is formed between layers L2 and L5 to form a spiral coil, and the self-test circuit 38 / 58 is formed between layers L1 and L6 to form a spiral coil and surrounds a portion of the arc detection coil. In this embodiment, the spiral coils of the arc detection coil 35 / 56 and the self-test circuit 38 / 58 are coaxial (e.g., both centered on the air shaft AC). The self-test circuit 38 / 58 is configured to inject a white noise or high-frequency signal into the air shaft AC, thereby detecting whether the arc detection coil 35 / 56 can detect the white noise or high-frequency signal in the air shaft AC, to provide a self-test function for the arc detection coil and the arc detection unit.

[0070] Please refer to Figure 12 This shows a partially enlarged cross-sectional view of a circuit board 30 / 50 according to another embodiment of the present disclosure. Unlike... Figure 11 In the illustrated embodiment, an arc detection coil 35 / 56 is formed between layers L2 and L5 to form a helical coil, and a self-detection circuit 38 / 58 is formed between layers L3 and L4 to form a helical coil and is located within a portion of the arc detection coil. In this embodiment, the helical coils of the arc detection coil 35 / 56 and the self-detection circuit 38 / 58 are coaxial (e.g., both centered on the air shaft AC). The self-detection circuit 38 / 58 is configured to inject a white noise or high-frequency signal into the air shaft AC, thereby detecting whether the arc detection coil 35 / 56 can detect the white noise or high-frequency signal in the air shaft AC, thus providing a self-detection function for the arc detection coil and the arc detection unit.

[0071] Please refer to Figure 13The diagram shows a partially enlarged cross-sectional view of a circuit board 30 / 50 according to another embodiment of the present disclosure. Unlike the embodiments shown in Figures 11 and 12, in this embodiment, the circuit board 30 / 50 is only a circuit board with four layers (L1 to L4) of copper foil. An arc detection coil 35 / 56 is formed between layers L2 and L3 to form a spiral coil, and a self-detection circuit 38 / 58 is formed between layers L1 and L4 to form a spiral coil and surrounds a portion of the arc detection coil. In other embodiments, similar to... Figure 12 In one embodiment, an arc detection coil 35 / 56 is formed between layers L1 and L4 to form a spiral coil, and a self-detection circuit 38 / 58 is formed between layers L2 and L3 to form a spiral coil and is located in the inner loop of a portion of the arc detection coil.

[0072] In summary, unlike existing solar inverters that use arc detection coils wound around a ring core, the solar inverter disclosed herein integrates the arc detection coil and self-testing circuit on a circuit board. This approach helps save costs and space, and makes it easier to perform arc detection and self-function testing for each solar string.

[0073] Although this disclosure has been provided above with reference to embodiments, it is not intended to limit this disclosure. Any person skilled in the art may make various changes and modifications without departing from the concept and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be determined by the claims.

Claims

1. A solar inverter, comprising: A shell; At least one circuit board is housed within the housing; A current sensor is disposed on the at least one circuit board; An arc detection coil is mounted on at least one circuit board; A self-test circuit is disposed on the at least one circuit board; and At least one DC input terminal is disposed on the housing and connected to the at least one circuit board, wherein the self-detection circuit is configured to deliver a test signal to the arc detection coil, the DC input terminal is configured to deliver a current through the arc detection coil, and the current sensor is configured to detect the magnitude of the current passing through the DC input terminal. The arc detection coil and the self-detection circuit are coaxial with the spiral coil formed on at least one circuit board.

2. The solar inverter of claim 1, wherein the at least one circuit board includes a first circuit board, and the current sensor, the self-detection circuit and the arc detection coil are disposed on the first circuit board.

3. The solar inverter of claim 2, further comprising a cable connected to the DC input terminal, wherein the first circuit board has an opening through which the cable extends, the arc detection coil is disposed around the opening, and the self-detection circuit is disposed in a portion of the arc detection coil.

4. The solar inverter as claimed in claim 2, further comprising a connection terminal, wherein the first circuit board is fixed on the DC input terminal, the connection terminal is disposed on the first circuit board and electrically connected to the DC input terminal through an internal circuit of the first circuit board, and the arc detection coil is disposed around the DC input terminal and the connection terminal.

5. The solar inverter of claim 2, wherein there are a plurality of at least DC input terminals, the first circuit board is configured to receive current from the DC input terminals and output current via at least one output terminal, wherein the number of the at least one output terminal is less than the number of the DC input terminals.

6. The solar inverter as claimed in claim 2 further includes an electromagnetic interference suppression capacitor disposed on the first circuit board.

7. The solar inverter of claim 1, wherein the at least one circuit board includes a first circuit board and a second circuit board, the current sensor is disposed on the first circuit board, the arc detection coil and the self-detection circuit are disposed on the second circuit board, and the self-detection circuit is disposed in a portion of the arc detection coil.

8. The solar inverter of claim 7, further comprising a cable connected to the DC input terminal and extending through the first circuit board, wherein the second circuit board is sleeved on the cable.

9. The solar inverter of claim 7 further includes a connection terminal and a cable, wherein the first circuit board is fixed on the DC input terminal, the connection terminal is disposed on the first circuit board and electrically connected to the DC input terminal through an internal circuit of the first circuit board, the cable is connected to the connection terminal, and the second circuit board is sleeved on the cable.

10. The solar inverter of claim 7 further includes a cable and an electrical connector, the cable connecting the DC input terminal and the first circuit board and passing through the second circuit board, the electrical connector connecting the first circuit board and the second circuit board and electrically connecting the arc detection coil through an internal circuit of the second circuit board.

11. The solar inverter of claim 7, wherein the first circuit board is fixed to the DC input terminal, the second circuit board is located between the first circuit board and a wall of the housing and is sleeved on the DC input terminal, and the solar inverter further includes an electrical connector that connects the first circuit board and the second circuit board and is electrically connected to the arc detection coil through an internal circuit of the second circuit board.

12. The solar inverter of claim 1, wherein the DC input terminal is configured to connect to a solar panel, the solar inverter further comprising an arc detection unit configured to receive a signal from the arc detection coil and determine, based on the signal, whether an arc fault has occurred in the line between the solar inverter and the solar panel, wherein the solar inverter is configured to stop receiving energy from the solar panel when an arc fault occurs.

13. The solar inverter of claim 1, wherein the arc detection coil is a ring-shaped spiral coil formed on the at least one circuit board, and the self-detection circuit is disposed in a portion of the ring-shaped section.

Images