Switching device for insulation detection and insulation detection circuit

Abstract

The utility model provides a switching device for insulation detection and an insulation detection circuit, and the switching device comprises a light transmitting module which is used for receiving an electric signal, converting the electric signal into an optical signal, and outputting the optical signal; the optical receiving module is used for receiving the optical signal and converting the optical signal into a control signal to be output; the switch control module comprises a driving module and a switch module, and the driving module is used for receiving the control signal and controlling the switch-on or switch-off of the switch module according to the control signal; and the spatial distance between the light emitting module and the light receiving module is not less than 30mm. Insulation and voltage resistance of the switching device can be improved, and the insulation detection requirement of the high-voltage battery pack is met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electronic devices, and particularly relates to a switching device for insulation detection and an insulation detection circuit. BACKGROUND

[0002] In the battery management system of an electric vehicle and an energy storage system, insulation detection of a high-voltage battery is an indispensable function. At present, the voltage platform of a battery pack on an electric vehicle is below 1000V, and the voltage platform of an energy storage battery pack is 1000V-3300V. Different voltage platforms have great differences in the insulation withstand voltage requirements of safety devices involved in the circuit. For example, for a voltage platform below 1000V, a commonly used high-voltage switch is a 1500V PhotoMOS (optical relay) or a mechanical relay, and there is no suitable high-voltage switch to choose from for a voltage platform above 2500V.

[0003] The existing PhotoMOS only has a creepage distance of 8mm and an electrical clearance, and such specifications can only meet the voltage system of a battery pack below 1000V. In a large energy storage system, the voltage of a battery pack is commonly 1500V, 2500V, 3300V, etc., and the required electrical clearance is above 20mm, and the existing PhotoMOS cannot meet the requirements. CONTENT OF THE INVENTION

[0004] The application provides a switching device for insulation detection and an insulation detection circuit, so as to improve the insulation withstand voltage of the switching device and meet the insulation detection requirements of a high-voltage battery pack.

[0005] In a first aspect, the application provides a switching device for insulation detection, comprising:

[0006] a light emitting module, configured to receive an electrical signal and convert the electrical signal into a light signal and output the light signal;

[0007] a light receiving module, configured to receive the light signal and convert the light signal into a control signal and output the control signal;

[0008] a switch control module, comprising a driving module and a switch module, wherein the driving module is configured to receive the control signal and control the switch module to be turned on or turned off according to the control signal;

[0009] The space distance between the light emitting module and the light receiving module is not less than 30mm.

[0010] Preferably, the space distance between the light emitting module and the light receiving module is 30mm-100mm.

[0011] Preferably, the switch device further comprises a housing, an input pin and an output pin; the light emitting module and the light receiving module are arranged inside the housing; the input pin is connected with the light emitting module through the housing; and the output pin is connected with the light receiving module through the housing.

[0012] Preferably, two fixing grooves are arranged inside the housing; and the light emitting module and the light receiving module are arranged inside the housing through the two fixing grooves.

[0013] Preferably, the housing is in a round rectangle shape.

[0014] Preferably, the two fixing grooves are arranged at two opposite corners inside the housing, and the light emitting module and the light receiving module are arranged in a diagonal manner.

[0015] Preferably, the two fixing grooves are arranged at two adjacent corners inside the housing, and the light emitting module and the light receiving module are arranged in an adjacent corner manner.

[0016] Preferably, the two fixing grooves are arranged at two adjacent long side corners inside the housing.

[0017] Preferably, the light emitting module and the light propagating module are connected through an optical fiber.

[0018] In a second aspect, an insulation detection circuit is provided in the embodiments of the present application, which comprises the switch device, a to-be-detected insulation resistance and a microcontroller according to the first aspect of the embodiments of the present application; the microcontroller is used to send an electrical signal to control the switch device to be turned on or turned off, so as to measure the to-be-detected insulation resistance.

[0019] It can be seen that, in the embodiments of the present application, the switch device comprises a light emitting module, a light receiving module and a switch control module, and the spatial distance between the light emitting module and the light receiving module is not less than 30 mm, which can improve the insulation withstand voltage of the switch device and meet the insulation detection requirements of the high-voltage battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 is a circuit composition diagram of a switch device for insulation detection provided by the embodiments of the present application;

[0022] Figure 2is a structural diagram of a switch device for insulation detection provided by an embodiment of the present application;

[0023] Figure 3 is another structural diagram of a switch device for insulation detection provided by an embodiment of the present application;

[0024] Figure 4 is an internal structural diagram of a shell provided by an embodiment of the present application;

[0025] Figure 5 is a circuit diagram of an insulation detection circuit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative work fall within the scope of protection of the present application.

[0027] The terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, and are not used to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0028] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] Please refer to Figure 1 , Figure 1 is a circuit composition diagram of a switch device for insulation detection provided by an embodiment of the present application. As shown in Figure 1As shown, the switch device 10 includes a light emitting module 11, a light receiving module 12, and a switch control module 13. The light emitting module 11 can be implemented as a laser diode (LD), for example, an infrared laser light source with a wavelength of 850 nm in a specific embodiment, which is configured to receive an electrical signal and convert the electrical signal into an optical signal output. The light receiving module 12 can be implemented as a photo diode (PD) or an avalanche photo diode (APD), which is configured to receive an optical signal and convert the optical signal into a control signal output. The switch control module 13 includes a driving module 131 and a switch module 132, the driving module 131 is configured to receive the control signal from the light receiving module 12 and control the switch module 132 to be turned on or turned off according to the control signal. The spatial distance between the light emitting module 11 and the light receiving module 12 is not less than 30 mm.

[0030] It has been verified that the switch device implemented by the above scheme can help to realize a circuit scheme with a primary-secondary withstand voltage greater than 9000V and a load withstand voltage greater than 3000V, which meets the insulation detection requirements of a battery management system for a high-voltage platform above 2500V. The primary-secondary withstand voltage refers to the maximum voltage that can be withstood between the primary side and the secondary side in the circuit. For example, in a power adapter, the primary side is connected to the mains, and the secondary side is connected to electronic equipment. A high primary-secondary withstand voltage can ensure that the mains voltage will not be coupled to the electronic equipment side through the circuit, ensuring the safety of the circuit. The load withstand voltage refers to the maximum voltage that can be withstood by the load in the circuit. A high load withstand voltage can ensure that the load will not be damaged due to excessive voltage when the circuit is working, ensuring that the load can work normally.

[0031] As can be seen, in this example, the switch device includes a light emitting module, a light receiving module, and a switch control module. The spatial distance between the light emitting module and the light receiving module is not less than 30 mm, which can improve the insulation withstand voltage of the switch device and meet the insulation detection requirements of a high-voltage battery pack.

[0032] In one possible example, the spatial distance between the light emitting module and the light receiving module is 30-100 mm.

[0033] Wherein, the spatial distance reflects the electrical clearance between the light emitting module and the light receiving module, and a larger electrical clearance can improve the insulation voltage of the switch device. However, in actual application, a too large electrical clearance between the light emitting module and the light receiving module can cause problems such as low optical signal transmission efficiency and increased production cost. After testing, the switch device involved in the present example can stably work when the spatial distance between the light emitting module and the light receiving module is in the range of 30mm-100mm, balancing the insulation withstand voltage capability and the manufacturing cost of the switch device.

[0034] In some embodiments, the light emitting module and the light receiving module can be specifically implemented as two independently packaged devices, respectively mounted on a PCB (Printed Circuit Board), and in an air isolation state after mounting, with a spatial distance of not less than 30mm, improving the overall insulation withstand voltage. In this embodiment, since the light emitting module and the light receiving module are independently mounted on the PCB, existing light emitting module products and light receiving module products can be directly selected for replacement, and at the same time, the user can adjust the spatial distance between the two by changing the mounting position of the light emitting module or the light receiving module on the PCB, thereby adjusting the creepage distance and electrical clearance of the switch device, improving flexibility.

[0035] In some embodiments, the light emitting module and the light receiving module can also be packaged in the same housing, and the spatial distance and the optical signal propagation path between the two can be adjusted by designing the mounting position of the light emitting module and the light receiving module in the housing, realizing the conversion of optoelectronic signals in the circuit.

[0036] In one possible example, as shown in Figure 2 The switch device 10 further includes a housing 21, an input pin 22 and an output pin 23, the light emitting module 11 and the light receiving module 12 are arranged inside the housing 21, the input pin 22 is connected with the light emitting module 11 through the housing 21, and the output pin 23 is connected with the light receiving module 12 through the housing 21.

[0037] Wherein, the input pin 22 is connected with an external circuit, for receiving and conducting the electrical signal transmitted by the external circuit, and the output pin 23 is connected with a switch control module, for receiving and transmitting the control signal output by the light receiving module to the switch control module.

[0038] Optionally, the light emitting module 11 and the light receiving module 12 are correspondingly arranged on the left and right sides inside the housing 21, with a spatial distance d≥30mm between them.

[0039] In one possible example, the shell is internally provided with two fixing grooves; the light emitting module and the light receiving module are arranged inside the shell through the two fixing grooves.

[0040] As shown in Figure 3 The shell 21 is internally provided with a first fixing groove 30 and a second fixing groove 31, the light emitting module 11 is fixed inside the shell 21 through the first fixing groove 30, and the light receiving module 12 is fixed inside the shell 21 through the second fixing groove 31, thereby improving the stability of the light emitting module and the light receiving module inside the shell and avoiding the deviation of the light signal transmission path due to unstable structure. The fixing grooves are made of insulating material.

[0041] In one possible example, the shell is internally in a rounded rectangular shape.

[0042] The rounded rectangular shape of the shell interior can more accurately control the spatial distance between the light emitting module and the light receiving module, and is more conducive to mold forming and potting operation during packaging. For example, when filling the potting material such as epoxy resin, the rectangular space can make the potting material more evenly distributed, ensuring the fixing and insulation performance of the internal components. At the same time, the mold of the rounded rectangle is relatively easy to process and control the size accuracy during manufacturing.

[0043] In one possible example, the two fixing grooves are arranged at two opposite corners inside the shell, and the light emitting module and the light receiving module are arranged in a diagonal manner.

[0044] As shown in Figure 4 The shell 21 internally includes a first rounded corner 41, a second rounded corner 42, a third rounded corner 43, and a fourth rounded corner 44. In this example, the first fixing groove can be arranged at the first rounded corner 41, and the second fixing groove can be arranged at the third rounded corner 43, i.e., the first fixing groove and the second fixing groove are arranged at two opposite corners inside the shell, so that the light emitting module and the light receiving module installed in the first fixing groove and the second fixing groove are arranged in a diagonal manner. It can be understood that the first fixing groove and the second fixing groove can also be arranged at the second rounded corner 42 and the fourth rounded corner 44, respectively, which is not limited herein.

[0045] Further, when the light emitting module and the light receiving module are designed in a diagonal manner, the angle of the light emitting module and the light receiving module can be adjusted by adjusting the angle of the first fixing groove and the second fixing groove arranged inside the shell, so that the light signal generated by the light emitting module can be fully received by the light receiving module.

[0046] In other embodiments, if the light beams emitted by the light emitting module cannot be fully received by the light receiving module by adjusting the installation angle of the fixing slots, the propagation direction of the light beams can be changed by setting a micro mirror inside the shell to achieve light collection, so that the light receiving module can fully receive the light beams emitted by the light emitting module.

[0047] In this way, the light emitting module and the light receiving module are designed in a diagonal layout, which can maximize the spatial distance between the light emitting module and the light receiving module in a limited packaging space, thereby reducing the cost.

[0048] In one possible example, the two fixing slots are arranged at two adjacent corners inside the shell, and the light emitting module and the light receiving module are arranged in an adjacent corner layout.

[0049] In this example, the first fixing slot can be arranged at the first rounded corner 41, and the second fixing slot can be arranged at the second rounded corner 42, i.e., the first fixing slot and the second fixing slot are arranged at two adjacent corners inside the shell, so that the light emitting module and the light receiving module mounted on the first fixing slot and the second fixing slot are arranged in an adjacent corner layout. It can be understood that the second fixing slot can also be arranged at the other adjacent corner of the first rounded corner 41, i.e., the third rounded corner 43, which is not limited herein.

[0050] Further, when the light emitting module and the light receiving module are designed in an adjacent corner layout, the angle of the light emitting module and the light receiving module can be adjusted by adjusting the angle of the first fixing slot and the second fixing slot arranged inside the shell, so that the light signal generated by the light emitting module can be fully received by the light receiving module.

[0051] In other embodiments, if the light beams emitted by the light emitting module cannot be fully received by the light receiving module by adjusting the installation angle of the fixing slots, the propagation direction of the light beams can be changed by setting a micro mirror inside the shell to achieve light collection, so that the light receiving module can fully receive the light beams emitted by the light emitting module.

[0052] In this way, the light emitting module and the light receiving module are designed in an adjacent corner layout, which can reduce the space area corresponding to one adjacent side, thereby further saving the packaging consumption and reducing the cost.

[0053] In one possible example, the two fixing slots are arranged at two adjacent corners of the long sides inside the shell.

[0054] As Figure 4As shown, the first and second rounded corners 41 and 42, and the third and fourth rounded corners 43 and 44 are the long-side adjacent corners, and the first and second fixing grooves can be respectively arranged at the first and second rounded corners 41 and 42, or respectively arranged at the third and fourth rounded corners 43 and 44. In this way, arranging the fixing grooves at the long-side adjacent corners can increase the spatial distance between the light emitting module and the light receiving module, improve the insulation withstand voltage of the switching device, save packaging consumption, and reduce costs.

[0055] In one possible example, the light emitting module and the light propagating module are connected through an optical fiber.

[0056] The optical fiber is a medium for transmitting optical signals, and is not conductive itself. Only the optical signal transmission channels of the two are connected, and the physical distance and electrical connection relationship between them are not changed. The two are still independent of each other in terms of electricity, and the electrical gap will not change due to the connection of the optical fiber. Therefore, the electrical gap between the light emitting module and the light propagating module is still the spatial distance between them. The optical fiber can minimize the loss of optical signals during transmission, and can change the transmission direction of the optical signals to meet various design layouts.

[0057] Please refer to Figure 5 , Figure 5 is a circuit diagram of an insulation detection circuit provided by the embodiment of the present application. As shown in Figure 5As shown, the insulation detection circuit 50 comprises a high-voltage battery pack 51, a positive electrode (Bat+) of the high-voltage battery pack 51 is connected to one end of a first resistor Rp and a first to-be-measured insulation resistance R1, a negative electrode (Bat-) of the high-voltage battery pack 51 is connected to one end of a second resistor Rn and a second to-be-measured insulation resistance R2, the first resistor Rp and the first to-be-measured insulation resistance R1 are connected in parallel, the second resistor Rn and the second to-be-measured insulation resistance R2 are connected in parallel, one end of a first switch S1 is connected to the first to-be-measured insulation resistance R1, one end of a second switch S2 is connected to the second to-be-measured insulation resistance R2, one end of a third switch S3 is connected to the other end of the first switch S1 and the other end of the second switch S2, the other end of the third switch S3 is connected to a microcontroller 52. Wherein, the first switch S1, the second switch S2 and the third switch S3 are specifically implemented as the switch device 10 described in the above embodiments. When the value of the first to-be-measured insulation resistance R1 needs to be read, the first switch S1 and the third switch S3 are controlled to be closed, and the second switch S2 is controlled to be opened; when the value of the second to-be-measured insulation resistance R2 needs to be read, the second switch S2 and the third switch S3 are controlled to be closed, and the first switch S1 is controlled to be opened. Wherein, the first resistor Rp and the second resistor Rn are specifically implemented as known precision resistors, by controlling the conduction or non-conduction of the switch device, the first to-be-measured insulation resistance R1 or the second to-be-measured insulation resistance R2 is calculated according to the value of the first resistor Rp and the second resistor Rn, and then the insulation state of the circuit is judged.

[0058] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art, without departing from the spirit and scope of the present application, can easily think of changes or replacements, which are all within the protection scope of the present application.

Claims

1. A switching device for insulation detection, characterized in that The switch device comprises: a light emitting module for receiving an electrical signal and converting the electrical signal into a light signal output; a light receiving module for receiving the light signal and converting the light signal into a control signal output; a switch control module comprising a driving module and a switch module, the driving module being configured to receive the control signal and control the switch module to be turned on or turned off according to the control signal; a spatial distance between the light emitting module and the light receiving module is not less than 30 mm.

2. The switch device according to claim 1, wherein the spatial distance between the light emitting module and the light receiving module is 30 mm-100 mm.

3. The switching device of claim 2, wherein The switch device further comprises: a housing, an input pin and an output pin; the light emitting module and the light receiving module are arranged inside the housing; the input pin is connected with the light emitting module through the housing; the output pin is connected with the light receiving module through the housing.

4. The switch device according to claim 3, wherein two fixing grooves are arranged inside the housing; the light emitting module and the light receiving module are arranged inside the housing through the two fixing grooves.

5. The switch device according to claim 4, wherein the housing is in a circular-rectangular shape.

6. The switch device according to claim 5, wherein the two fixing grooves are arranged at two opposite corners inside the housing, and the light emitting module and the light receiving module are arranged in a diagonal manner.

7. The switch device according to claim 5, wherein the two fixing grooves are arranged at two adjacent corners inside the housing, and the light emitting module and the light receiving module are arranged in an adjacent manner.

8. The switch device according to claim 7, wherein the two fixing grooves are arranged at two adjacent long corners inside the housing.

9. The switch device according to any one of claims 1-8, wherein the light emitting module and the light receiving module are connected through an optical fiber.

10. An insulation detection circuit, characterized by comprising: The switch device according to any one of claims 1-9, an insulation resistance to be measured and a microcontroller; the microcontroller is configured to send an electrical signal to control the switch device to be turned on or turned off, so as to measure the insulation resistance to be measured. ​

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