Overcurrent protection circuit of converter device and converter device

Abstract

The utility model discloses an over-current protection circuit of a converter device and an alternating current device, the over-current protection circuit is used for connecting a plurality of power circuit modules of the converter device to a control chip, and the over-current protection circuit is provided with an over-current protection signal output terminal used for being connected with an IO pin of the control chip; the over-current protection circuit comprises a first resistor and a plurality of branches which are connected in parallel, each branch comprises an over-current protection signal input terminal, a second resistor and a diode which are sequentially connected in series, the over-current protection signal input terminal of each branch is configured to be connected with one power circuit module, the negative electrode of the diode is connected to the second resistor, and the negative electrode of the diode is connected to the first resistor. The anodes of the diodes of the plurality of branches are connected in parallel with one end of the first resistor, and the other end of the first resistor is connected with the overcurrent protection signal output terminal. The overcurrent protection circuit of the utility model can reduce the occupation of IO pins on the control chip.

Description

Technical Field

[0001] The utility model belongs to the technical field of electronic power, and in particular relates to an overcurrent protection circuit of a current conversion device and the current conversion device. Background Art

[0002] The converter device has an overcurrent protection circuit, which is used to connect the overcurrent protection signals of multiple power circuits of the converter device to the control chip. Each power circuit module is connected to a corresponding overcurrent protection signal input terminal. Currently, one overcurrent protection signal input terminal corresponds to one overcurrent protection signal output terminal, that is, the number of overcurrent protection signal input terminals is the same as the number of overcurrent protection signal output terminals. Since the overcurrent protection signal output terminal is connected to the IO pin of the control chip, this directly leads to the occupation of more IO pins. Utility Model Content

[0003] In order to solve the above technical problems, the utility model provides an overcurrent protection circuit of a current conversion device and a current conversion device, which reduce the occupation of IO pins of a control chip.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] An overcurrent protection circuit for a current converter device is used to connect overcurrent protection signals of multiple power circuits of the current converter device to a control chip. The overcurrent protection circuit has an overcurrent protection signal output terminal for connecting to an IO pin of the control chip.

[0006] The overcurrent protection circuit includes a first resistor and multiple branches connected in parallel, each branch includes an overcurrent protection signal input terminal, a second resistor and a diode connected in series in sequence, the overcurrent protection signal input terminal of each branch is configured to be connected to one of the power circuit modules, the cathode of the diode is connected to the second resistor, the anodes of the diodes of the multiple branches are connected in parallel to one end of the first resistor, and the other end of the first resistor is connected to the overcurrent protection signal output terminal.

[0007] In a preferred embodiment, the overcurrent protection circuit further includes a DC source input terminal, and the DC source input terminal is connected to a connection point between each branch and the first resistor via a third resistor.

[0008] In a preferred embodiment, the DC source input terminal is a high-level input terminal, and the overcurrent protection signal input terminal is a low-level input terminal.

[0009] In a preferred embodiment, the overcurrent protection circuit further includes a first filter capacitor, one end of which is connected to the connector between the overcurrent protection signal output terminal and the first resistor, and the other end is grounded.

[0010] In a preferred embodiment, each of the branches further includes a second filter capacitor, one end of the second filter capacitor is connected to the connection point of the second resistor and the diode, and the other end is grounded.

[0011] This embodiment also adopts the following technical solutions:

[0012] A current conversion device includes a control chip and a power unit, the power unit including multiple power circuit modules, the overcurrent protection signals of the multiple power circuit modules are connected to the control chip through an overcurrent protection circuit, the multiple power circuit modules are respectively connected one-to-one with multiple overcurrent protection signal input terminals of the overcurrent protection circuit, and a single overcurrent protection signal output terminal of the overcurrent protection circuit is incorporated into an IO pin of the control chip.

[0013] In a preferred embodiment, the overcurrent protection circuit is the overcurrent protection circuit mentioned above.

[0014] In a preferred embodiment, the control chip is arranged on the control circuit board of the converter device, the multiple power circuit modules and the overcurrent protection circuit are arranged on the power circuit board of the converter device, and the multiple overcurrent protection signals are connected to an IO pin of the control chip through a single cable.

[0015] In a preferred embodiment, the power circuit module includes one or more of an inverter circuit, a DAB circuit, a boost circuit, a buck circuit, and a buck-boost circuit of a power conversion device; the power conversion device also includes a battery; the control chip is a DSP chip, and the IO pin is a GPIO pin.

[0016] In a preferred embodiment, the multiple power circuits include a buck-boost circuit, a DAB circuit and an inverter circuit connected in sequence, each of the power circuits includes a Hall chip with an overcurrent detection function, and the output end of the Hall chip of each power circuit is connected to one of the overcurrent protection signal input ends of the overcurrent protection circuit.

[0017] The present invention adopts the above solution, which has the following advantages compared with the prior art:

[0018] The overcurrent protection circuit of the present invention has multiple overcurrent protection signal input terminals, and the multiple overcurrent protection signal input terminals are connected to one overcurrent protection signal output terminal. The overcurrent protection signal output terminal is connected to an IO pin of the control chip, thereby reducing the number of IO pins used on the control chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A topological diagram of an AC device connecting a photovoltaic module, a power grid, and a load according to an embodiment of the present utility model;

[0021] Figure 2 is a circuit diagram of an overcurrent protection circuit according to an embodiment of the present utility model;

[0022] Figure 3 The figure is a circuit board wiring diagram of an AC device according to an embodiment of the present utility model.

[0023] in,

[0024] 1. Power circuit module; 11. Inverter circuit; 12. DAB circuit; 13. Buck-boost circuit; 2. Battery; 3. Control chip; 4. Overcurrent protection signal output terminal; 5. First resistor; 6. Branch; 61. Overcurrent protection signal input terminal; 62. Second resistor; 63. Diode; 7. DC source input terminal; 71. Third resistor; 8. First filter capacitor; 9. Second filter capacitor; 10. Control circuit board; 101. Power circuit board; 102. Cable; 103. Signal interface. DETAILED DESCRIPTION

[0025] The following describes in detail preferred embodiments of the present invention in conjunction with the accompanying drawings to make the advantages and features of the present invention more easily understood by those skilled in the art. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0026] Reference Figures 1 to 3 As shown, this embodiment provides a current conversion device, including a control chip 3, an inverter unit and a battery 2.

[0027] Furthermore, the control chip is a DSP chip. Figure 1 and Figure 2As shown, the power unit includes multiple power circuit modules 1, and the overcurrent protection signals of the multiple power circuit modules 1 are connected to the control chip 3 through an overcurrent protection circuit. The multiple power circuit modules 1 are respectively connected to the multiple overcurrent protection signal input terminals 61 of the overcurrent protection circuit in a one-to-one correspondence. A single overcurrent protection signal output terminal 4 of the overcurrent protection circuit is connected to an IO pin of the control chip 3, wherein the IO pin is a GPIO pin, specifically Figure 3 The overcurrent protection circuit of the converter device is used to connect multiple power circuit modules 1 of the inverter to a control chip 3. The overcurrent protection circuit has an overcurrent protection signal output terminal 4 for connecting to an IO pin of the control chip 3. That is, this embodiment has only one overcurrent protection output terminal 4, which only requires one GPIO pin, reducing the GPIO pin usage on the control chip 3.

[0028] Reference Figure 3 As shown, the control chip 3 is arranged on the control circuit board 10 of the converter device, and multiple power circuit modules 1 and the overcurrent protection circuit are arranged on the power circuit board 101 of the converter device. Multiple overcurrent protection signals are connected to an IO pin of the control chip 3 with the help of the overcurrent protection circuit and through a single cable 102, thereby reducing the wiring between the power circuit board 101 and the control circuit board 10 and reducing the interconnected ports between the power circuit board 101 and the control circuit board 10, which is beneficial to the wiring of the control circuit board 10.

[0029] Furthermore, a signal interface 103 is respectively provided on the power circuit board 101 and the control circuit board 10, and the cable 102 passes through the signal interface 103 on the power circuit board 101 and the control circuit board 10 in sequence and is electrically connected to the GPIO pin. Compared with the prior art, this embodiment can reduce the interfaces for wiring between circuit boards. The GPIO pin of the DSP chip is an interface for simple digital communication with external devices. The GPIO pin can be configured as input or output, and is used to read external signals or send internal signals to external devices. The GPIO pin of this embodiment is used to read the overcurrent detection signal, and the input is a low level. When the input is a low level, the relevant GPIO level of the DSP changes, and the wave is quickly reacted to protect the circuit components from damage due to overcurrent.

[0030] Reference Figure 2 As shown, the overcurrent protection circuit includes a first resistor 5 (as Figure 2 R1 shown) and multiple branches 6 connected in parallel, each branch 6 includes an overcurrent protection signal input terminal 61 (such as Figure 2HALL_BST1_OCP, HALL_BST2_OCP, HALL_INV_BUS_OCP, HALL_INV_L_OCP and HALL_LOAD_L_OCP as shown), the second resistor 62 (as Figure 2 R3, R4, R5, R6 and R7) and diode 63 (as shown Figure 2 D1, D2, D3, D4 and D5 shown in the figure), the overcurrent protection signal input terminal 61 of each branch 6 is configured to be connected to one of the power circuit modules 1, the cathode of the diode 63 is connected to the second resistor 62, the anodes of the diodes 63 of the multiple branches 6 are connected in parallel to one end of the first resistor 5, and the other end of the first resistor 5 is connected to the overcurrent protection signal output terminal 4. The overcurrent protection circuit also includes a DC source input terminal 7, which is connected to the connection point of each branch 6 and the first resistor 5 through a third resistor 71. The DC source input terminal 7 is a high-level input terminal, and the overcurrent protection signal input terminal 61 is a low-level input terminal. The overcurrent protection circuit also includes a first filter capacitor 8 (such as Figure 2 One end of the first filter capacitor 8 is connected to the connector of the overcurrent protection signal output terminal 4 and the first resistor 5, and the other end is grounded. Each branch 6 also includes a second filter capacitor 9 (as shown in FIG. Figure 2 C1, C2, C3, C4 and C5 shown in the figure), one end of the second filter capacitor 9 is connected to the connection point of the second resistor 62 and the diode 63, and the other end is grounded.

[0031] Reference Figure 1 As shown, the power circuit module 1 includes an inverter circuit 11 of a converter device, a DAB circuit (bidirectional full-bridge isolated DC-DC converter) 12, a boost circuit, a buck circuit, and one or more of a buck-boost circuit. The overcurrent protection signal includes an OCP signal (overcurrent protection signal) of the buck-boost circuit, an OCP signal of the DAB circuit, an OCP signal of the inverter path, and an OCP signal of the output side or more overcurrent signals. Specifically in this embodiment, multiple power circuit modules 1 include buck-boost circuits 13 (such as Figure 1 BUCK-BOOST circuit shown), DAB circuit 12 and inverter circuit 11 (as shown Figure 1 INV circuit shown).

[0032] Furthermore, each power circuit module includes a Hall chip with overcurrent detection functionality. The Hall chip's fast overcurrent signal output terminal in each power circuit module 1 is connected to one of the overcurrent protection signal input terminals 4 of the overcurrent protection circuit. The Hall chip has a protection threshold. When the current exceeds the protection threshold, the Hall chip outputs an overcurrent protection signal, which flips in level, causing diode 63 to conduct, thus changing the GPIO level. The DSP quickly responds and shuts down the protection device. Specifically, after the machine is powered on, if a large current flows anywhere, such as in the PV1-side buck-boost circuit, the Hall chip detects that the current exceeds its protection threshold, and the overcurrent protection signal flips from high to low. Diode 63 then conducts, sending the signal to the control chip 3, causing the GPIO to go low, and the DSP quickly shuts down the signal. If the current detected by the Hall chip does not exceed the protection threshold, the overcurrent detection signal remains high, the diode does not conduct, and the GPIO maintains a high level through the DC power input terminal 7, which is specifically a 3.3V high-level signal.

[0033] The working principle of the AC device in this embodiment is as follows:

[0034] First, the converter includes two buck-boost circuits 13, a DAB circuit 12, and an inverter circuit 11. PV panels connected to PV1 and PV2 are bucked and boosted by the two buck-boost circuits 13 before being connected to the low-voltage DC bus. Battery 2 is also connected to the low-voltage DC bus. The DAB circuit 12 boosts the voltage to the high-voltage bus before inverting and outputting it to the grid or load. A Hall effect chip with overcurrent detection is used for current sampling. When the Hall effect chip detects that the current exceeds its protection threshold, the overcurrent signal detection pin changes level from high to low, and these signals are then sent to the control chip 3 for processing.

[0035] Figure 2 The current sampling of the medium buck-boost circuit 13 is located before the inductors L1 and L2, and the overcurrent detection signals are HALL_BST1_OCP and HALL_BST2_OCP. The output current sampling on the high-voltage side of the DAB circuit 12 is located after T10, and the overcurrent detection signal is HALL_INV_BUS_OCP. The current sampling in the inverter circuit 11 is located after the LC filter L4, and the overcurrent detection signal is HALL_INV_L_OCP. For the output side current sampling, the overcurrent detection signal is HALL_LOAD_L_OCP.

[0036] When the converter is powered on, the auxiliary power source works. Since the Hall chip does not detect overcurrent, these OCP signals are all in a high-level state. After the machine is turned on, if a large current appears at any point, such as the PV1 side BUCK-BOOST, the Hall chip detects that the current exceeds its protection threshold, and the overcurrent detection signal, HALL_BST1_OCP, flips from high to low. Then D1 turns on, causing GPIO1 to become low, and the DSP quickly responds to block the protection device. If there are multiple overcurrents, or the system is more complex and the overcurrent signals are more severe, they can be merged into one signal and sent to the control chip 3 for processing, which can reduce the GPIO occupancy. Multiple overcurrent protection signals only require one trace from the power circuit board 101 to the control circuit board 10, reducing the number of ports for wiring between boards and being more beneficial to PCB layout.

[0037] As used in this specification and claims, the terms "comprises" and "include" merely indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list; a method or apparatus may also include other steps or elements. The term "and / or" as used herein includes any combination of one or more of the associated listed items.

[0038] It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. In addition, the terms "upper," "lower," "left," and "right" used in this utility model are only used with respect to the relative positions of the components of the utility model in the accompanying drawings.

[0039] The above embodiment is intended only to illustrate the technical concept and features of the present invention and is a preferred embodiment. Its purpose is to enable those familiar with the art to understand the content of the present invention and implement it accordingly. It is not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. An overcurrent protection circuit for a current conversion device, characterized in that: Used to connect multiple overcurrent protection signals of multiple power modules in the converter device to a control chip, the overcurrent protection circuit having an overcurrent protection signal output terminal for connecting to an IO pin of the control chip; The overcurrent protection circuit includes a first resistor and multiple branches connected in parallel, each branch includes an overcurrent protection signal input terminal, a second resistor and a diode connected in series in sequence, the overcurrent protection signal input terminal of each branch is configured to be connected to one of the power circuit modules, the cathode of the diode is connected to the second resistor, the anodes of the diodes of the multiple branches are connected in parallel to one end of the first resistor, and the other end of the first resistor is connected to the overcurrent protection signal output terminal.

2. The overcurrent protection circuit according to claim 1, characterized in that: The overcurrent protection circuit further includes a DC source input terminal, which is connected to a connection point between each branch and the first resistor via a third resistor.

3. The overcurrent protection circuit according to claim 2, wherein: The DC source input terminal is a high-level input terminal, and the overcurrent protection signal input terminal is a low-level input terminal.

4. The overcurrent protection circuit according to any one of claims 1 to 3, characterized in that: The overcurrent protection circuit further includes a first filter capacitor, one end of which is connected to the connector between the overcurrent protection signal output terminal and the first resistor, and the other end of which is grounded.

5. The overcurrent protection circuit according to any one of claims 1 to 3, characterized in that: Each of the branches further includes a second filter capacitor, one end of the second filter capacitor is connected to the connection point of the second resistor and the diode, and the other end is grounded.

6. A current conversion device, comprising a control chip and a power unit, characterized in that: The power unit includes multiple power circuit modules, the overcurrent protection signals of the multiple power circuit modules are connected to the control chip through an overcurrent protection circuit, the multiple power circuit modules are respectively connected one-to-one with the multiple overcurrent protection signal input terminals of the overcurrent protection circuit, and the single overcurrent protection signal output terminal of the overcurrent protection circuit is incorporated into an IO pin of the control chip.

7. The current conversion device according to claim 6, characterized in that: The overcurrent protection circuit is the overcurrent protection circuit according to any one of claims 1 to 5.

8. The current conversion device according to claim 6 or 7, characterized in that: The control chip is arranged on the control circuit board of the converter device, the multiple power circuit modules and the overcurrent protection circuit are arranged on the power circuit board of the converter device, and the multiple overcurrent protection signals are connected to an IO pin of the control chip through a single cable.

9. The current conversion device according to claim 6 or 7, characterized in that: The power circuit module includes one or more of an inverter circuit, a DAB circuit, a boost circuit, a buck circuit, and a buck-boost circuit of a current conversion device; the current conversion device includes a battery; the control chip is a DSP chip, and the IO pins are GPIO pins.

10. The current conversion device according to claim 9, characterized in that: The multiple power circuit modules include a buck-boost circuit, a DAB circuit and an inverter circuit connected in sequence. Each power circuit module includes a Hall chip with an overcurrent detection function. The output end of the Hall chip of each power circuit module is connected to one of the overcurrent protection signal input terminals of the overcurrent protection circuit.

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