Protection circuit, power supply circuit and charging pile

Abstract

This invention discloses a protection circuit, a power supply circuit, and a charging pile. The protection circuit connects to a power switch module and includes a main control module, a sticking detection module, and a short-circuit detection module. The sticking detection module, connected to the power switch module, performs sticking detection on the power switch module and outputs a sticking detection signal. The short-circuit detection module, also connected to the power switch module, performs short-circuit detection on the power switch module and outputs a short-circuit detection signal. The main control module controls the short-circuit detection module to be disabled when the sticking detection signal is a sticking signal, and controls the power switch module to be disabled when the short-circuit detection signal is a short-circuit signal. This protection circuit prevents relay sticking from harming short-circuit detection and prevents relay sticking from causing component burnout in the short-circuit detection module, thus improving the safety and reliability of short-circuit detection.

Description

Technical Field

[0001] This invention relates to the field of charging pile technology, and in particular to a protection circuit, a power supply circuit, and a charging pile. Background Technology

[0002] With the increasing popularity of electric vehicles, charging stations, as an important supporting facility for electric vehicles, have attracted much attention regarding their safety and stability.

[0003] If a short circuit exists at the output terminal of the power relay before the charging station is powered on, a large current may be generated when the relay closes to energize, potentially damaging the equipment or even causing a safety accident. Currently, existing charging stations typically use voltage or current detection methods to check for output short circuits before powering on. However, these methods are unreliable. When other faults exist in the circuit, such as a stuck relay, existing detection methods may not be able to effectively detect the short circuit and could even cause other hazards. Summary of the Invention

[0004] This invention provides a protection circuit, a power supply circuit, and a charging pile to solve the problem of poor reliability in existing short circuit detection methods.

[0005] This invention provides a protection circuit for connecting a power switch module. The protection circuit includes a main control module, an adhesion detection module, and a short circuit detection module.

[0006] The adhesion detection module is connected to the power switch module and is used to perform adhesion detection on the power switch module and output an adhesion detection signal.

[0007] The short-circuit detection module is connected to the power switch module and is used to perform short-circuit detection on the power switch module and output a short-circuit detection signal.

[0008] The main control module is connected to the adhesion detection module and the short circuit detection module, and is also used to connect to the power switch module. When the adhesion detection signal is an adhesion signal, the main control module controls the short circuit detection module to be disabled, and when the short circuit detection signal is a short circuit signal, the main control module controls the power switch module to be disabled.

[0009] Preferably, the main control module includes a signal interlock unit and a main control chip;

[0010] The signal interlock unit is connected to the adhesion detection module, the short circuit detection module, and the main control chip. It is used to output a first enable signal to the main control chip when the adhesion detection signal is a non-adhesion signal; output a first disable signal to the main control chip when the adhesion detection signal is an adhesion signal; output a second enable signal to the main control chip when the short circuit detection signal is a non-short circuit signal; and output a second disable signal to the main control chip when the short circuit detection signal is a short circuit signal.

[0011] The main control chip is connected to the short-circuit detection module and the power switch module. Based on the first enable signal, it outputs a first detection control signal to the short-circuit detection module to enable the short-circuit detection module to perform short-circuit detection on the power switch module; based on the first disable signal, it outputs a second detection control signal to the short-circuit detection module to disable the short-circuit detection module; based on the second enable signal, it outputs a first output control signal to the power switch module to enable the power switch module; and based on the second disable signal, it outputs a second output control signal to the power switch module to disable the power switch module.

[0012] Preferably, the main control module is further configured to connect to the alarm module, and send an alarm signal to the alarm module when the adhesion detection signal is an adhesion signal or the short circuit detection signal is a short circuit signal, so that the alarm module performs an alarm operation.

[0013] Preferably, the power switch module includes a power relay;

[0014] The adhesion detection module is connected to the two normally open contacts of the power relay and is used to detect the adhesion detection result on the two normally open contacts of the power relay. If the adhesion detection result is that the power relay is in an adhesion state, the adhesion detection signal is an adhesion signal; if the adhesion detection result is that the power relay is not in an adhesion state, the adhesion detection signal is a non-adhesion signal.

[0015] Preferably, the relay adhesion detection module includes an optocoupler unit;

[0016] The light-emitting part of the optocoupler unit is connected to the two normally open contacts of the power relay, and the light-receiving part of the optocoupler unit is connected to the main control module. It is used to detect the adhesion detection result between the two normally open contacts of the power relay. If the adhesion detection result is that the two contacts are in an adhesion state, the adhesion detection signal is an adhesion signal; if the adhesion detection result is that the two contacts are not in an adhesion state, the adhesion detection signal is a non-adhesion signal.

[0017] Preferably, the short-circuit detection module is connected to the two normally open contacts of the power relay and is used to detect the short-circuit detection result between the two normally open contacts of the power relay. If the short-circuit detection result indicates that the power relay is in a short-circuit state, the short-circuit detection signal is a short-circuit signal; if the short-circuit detection result indicates that the power relay is not in a short-circuit state, the short-circuit detection signal is a non-short-circuit signal.

[0018] Preferably, the short-circuit detection module includes a pre-detection relay and a signal comparison circuit;

[0019] The pre-detection relay is connected to the output terminal of the signal comparison circuit and the power switch module, and is also connected to the main control module. It is used to activate under the control of the main control module so that the signal comparison circuit is connected to the output terminal of the power switch module, or to deactivate under the control of the main control module so that the signal comparison circuit is disconnected from the output terminal of the power switch module.

[0020] The signal comparison circuit is connected to the main control module and is used to perform short-circuit detection on the power switch module when the pre-detection relay is energized, and output a short-circuit detection signal to the main control module.

[0021] Preferably, the signal comparison circuit includes a voltage divider unit and an operational amplifier;

[0022] The voltage divider unit is connected to the pre-detection relay and the operational amplifier, and is used to output a detection voltage signal to the operational amplifier based on the short-circuit detection result between the two normally open contacts of the power relay;

[0023] The operational amplifier is connected to the main control module and is used to amplify the detection voltage signal to obtain a short-circuit detection signal, and output the short-circuit detection signal to the main control module.

[0024] Preferably, the voltage divider unit includes a first voltage divider resistor, a second voltage divider resistor, and a third voltage divider resistor;

[0025] The first voltage divider resistor, the second voltage divider resistor, and the third voltage divider resistor are connected in series between the power supply terminal and ground;

[0026] The connection point between the first voltage divider resistor and the second voltage divider resistor is connected to the output neutral line of the power switch module.

[0027] The connection point between the second voltage divider resistor and the third voltage divider resistor is connected to the output live wire of the power switch module and also to the operational amplifier.

[0028] This invention also provides a power supply circuit, including a power switch module and the protection circuit described in any of the above embodiments;

[0029] The input terminal of the power switch module is used to connect to the mains power circuit, and the output terminal of the power switch module is used to connect to the device to be charged.

[0030] The protection circuit is connected to the output terminal of the power switch module and is used to perform adhesion detection and short circuit detection on the power switch module, obtain a short circuit detection signal, and control the power switch module to be in a disabled state when the short circuit detection signal is a short circuit signal.

[0031] This invention also provides a charging pile, including the power supply circuit described above, wherein one end of the power supply circuit is used to connect to the mains power circuit, and the other end is used to connect to the device to be charged.

[0032] This invention provides a protection circuit, a power supply circuit, and a charging pile. The protection circuit can detect relay sticking in the power switch module before the power switch module closes and outputs power, and continues to detect short circuits in the power switch module after detecting no relay sticking. This protection circuit can detect and eliminate both relay sticking and short circuit faults to ensure the safety of power output. Furthermore, it can prevent relay sticking from harming short circuit detection, preventing damage to components in the short circuit detection module caused by relay sticking, thus improving the safety and reliability of short circuit detection. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a block diagram of the protection circuit in one embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the power supply circuit in one embodiment of the present invention.

[0036] In the diagram: 1. Main control module; 11. Signal interlock unit; 12. Main control chip; 2. Adhesion detection module; 3. Short circuit detection module; 31. Signal comparison circuit; 311. Voltage divider unit; 4. Power switch module. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] It should be understood that the invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0039] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this invention, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0040] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0042] To fully understand this invention, detailed structures and steps will be presented in the following description to illustrate the technical solution proposed by this invention. Preferred embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0043] This invention provides a protection circuit, including a main control module 1, an adhesion detection module 2, and a short-circuit detection module 3. The adhesion detection module 2 is connected to a power switch module 4, performs adhesion detection on the power switch module 4, and outputs an adhesion detection signal check_sta. The short-circuit detection module 3 is connected to the power switch module 4, performs short-circuit detection on the power switch module 4, and outputs a short-circuit detection signal SOP_sta. The main control module 1 is connected to the adhesion detection module 2 and the short-circuit detection module 3, and is also connected to the power switch module 4. When the adhesion detection signal check_sta is an adhesion signal, it controls the short-circuit detection module 3 to be in a disabled state; when the short-circuit detection signal SOP_sta is a short-circuit signal, it controls the power switch module 4 to be in a disabled state.

[0044] As an example, the protection circuit includes a main control module 1, an adhesion detection module 2, and a short-circuit detection module 3. The adhesion detection module 2 is connected to the power switch module 4 to perform adhesion detection on the power switch module 4; the short-circuit detection module 3 is connected to the power switch module 4 to perform short-circuit detection on the power switch module 4. The power switch module 4 may include a power relay K1 for performing power output switching functions. The power relay K1 can be controlled to engage / disengage by an MCU to achieve the power output switching function. The MCU may be included in the main control module 1 of the protection circuit, so that the main control module 1 can directly control the switching of the power relay K1 while performing circuit safety protection. Alternatively, when the MCU is a control chip independent of the main control module 1, the main control module 1 can control the MCU to enable or disable the control function of the power relay K1 to achieve circuit safety protection.

[0045] The sticking detection module 2 is used to detect whether there is relay sticking in the power switch module 4 and feeds back the corresponding sticking detection signal check_sta to the main control module 1. Specifically, when the relay in the power switch module 4 is in a sticking state, the sticking detection module 2 can detect the sticking state and feed back a sticking signal to the main control module 1. Conversely, when the relay in the power switch module 4 is in a non-sticking state, the sticking detection module 2 will not detect the sticking state and will feed back a non-sticking signal to the main control module 1. The short circuit detection module 3 is used to detect whether there is a short circuit in the power switch module 4 and feeds back the corresponding short circuit detection signal SOP_sta to the main control module 1. Specifically, when there is a short circuit in the power switch module 4, the short circuit detection module 3 can detect the short circuit state and feed back a short circuit signal to the main control module 1. Conversely, when there is no short circuit in the power switch module 4, the short circuit detection module 3 will not detect the short circuit state and will feed back a non-short circuit signal to the main control module 1.

[0046] The main control module 1 is connected to the adhesion detection module 2 and the short circuit detection module 3. Before the power relay K1 in the power switch module 4 is activated, the adhesion detection module 2 is controlled to perform adhesion detection first. If there is no relay adhesion, the short circuit detection module 3 is controlled to perform short circuit detection. If there is relay adhesion, the short circuit detection module 3 is not controlled to perform short circuit detection. If a short circuit is detected after short circuit detection, the power relay K1 is not activated, or the power relay K1 activation control function of the MCU that controls the activation of power relay K1 is disabled. If no short circuit is detected after short circuit detection, the power relay K1 is activated normally.

[0047] In this example, the protection circuit can detect relay sticking in the power switch module 4 before the power switch module 4 is closed and power output is performed. After detecting that there is no relay sticking, it continues to detect short circuit in the power switch module 4. On the one hand, the protection circuit can detect and eliminate both relay sticking and short circuit faults to ensure the safety of power output. On the other hand, it can also prevent relay sticking from harming short circuit detection and prevent relay sticking from causing device burnout in the short circuit detection module 3, thus improving the safety and reliability of short circuit detection.

[0048] In one embodiment, the main control module 1 includes a signal interlock unit 11 and a main control chip 12. The signal interlock unit 11 is connected to the adhesion detection module 2, the short circuit detection module 3, and the main control chip 12. It is used to output a first enable signal to the main control chip 12 when the adhesion detection signal check_sta is a non-adhesion signal; output a first disable signal to the main control chip 12 when the adhesion detection signal check_sta is an adhesion signal; output a second enable signal to the main control chip 12 when the short circuit detection signal SOP_sta is a non-short circuit signal; and output a second disable signal to the main control chip 12 when the short circuit detection signal SOP_sta is a short circuit signal. The main control chip 12 is connected to the short-circuit detection module 3 and the power switch module 4. Based on a first enable signal, it outputs a first detection control signal to the short-circuit detection module 3 to enable the short-circuit detection module 3 to perform short-circuit detection on the power switch module 4; based on a first disable signal, it outputs a second detection control signal to the short-circuit detection module 3 to disable the short-circuit detection module 3; based on the second enable signal, it outputs a first output control signal to the power switch module 4 to enable the power switch module 4; and based on the second disable signal, it outputs a second output control signal to the power switch module 4 to disable the power switch module 4.

[0049] As an example, the main control module 1 includes a signal interlock unit 11 and a main control chip 12. The signal interlock unit 11 is used to control the main control chip 12 based on the adhesion detection signal check_sta, so that the main control chip 12 controls the short circuit detection module 3 to be in an available / disabled state.

[0050] Specifically, as an example, when the adhesion detection signal check_sta is a non-adhesion signal, the signal interlock unit 11 outputs a first enable signal to the main control chip 12. Based on this first enable signal, the main control chip 12 can output a first detection control signal to the short-circuit detection module 3, making the short-circuit detection module 3 available and capable of performing short-circuit detection on the power switch module 4. When the adhesion detection signal check_sta is an adhesion signal, the signal interlock unit 11 outputs a first disable signal to the main control chip 12. Based on this first disable signal, the main control chip 12 can output a second detection control signal to the short-circuit detection module 3, making the short-circuit detection module 3 disabled and preventing short-circuit detection, thus preventing the relay from sticking and causing the components in the short-circuit detection module 3 to burn out. Furthermore, the main control chip 12 can also output a second output control signal to the power switch module 4 based on the first disable signal, making the power switch module 4 disabled and unable to output power.

[0051] After the short-circuit detection module 3 performs short-circuit detection, the signal interlock unit 11 can continue to detect the short-circuit detection signal SOP_sta. When the short-circuit detection signal SOP_sta is a non-short-circuit signal, the signal interlock unit 11 outputs a second enable signal to the main control chip 12. Based on the second enable signal, the main control chip 12 can output a first output control signal to the power switch module 4 so that the power switch module 4 is in an available state and can output power normally. When the short-circuit detection signal SOP_sta is a short-circuit signal, the signal interlock unit 11 outputs a second disable signal to the main control chip 12. Based on the second disable signal, the main control chip 12 can output a second output control signal to the power switch module 4 so that the power switch module 4 is in a disabled state and cannot output power, thus ensuring circuit safety.

[0052] As another example, the adhesion signal can be a low-level signal and the non-adhesion signal can be a high-level signal; the short-circuit signal can be a low-level signal and the non-short-circuit signal can be a high-level signal; the main control chip 12 controls the short-circuit detection module 3 to be in an available state, and the first enable signal for short-circuit detection can be a high-level signal; the main control chip 12 controls the short-circuit detection module 3 to be in a disabled state, and the first disable signal is a low-level signal; the main control chip 12 controls the power switch module 4 to be in an available state, and the second enable signal is a high-level signal; the main control chip 12 controls the power switch module 4 to be in a disabled state, and the second disable signal is a low-level signal. At this time, the interlocking unit can be a logic control module used to interlock the adhesion detection signal check_sta and the signal output by the main control chip 12 for controlling the short circuit detection module 3 (making them at the same level), and to interlock the short circuit detection signal SOP_sta and the signal output by the main control chip 12 for controlling the power switch module 4 (making them at the same level). This ensures that when the adhesion detection signal check_sta is low, the main control chip 12 outputs a first disable signal that is also low; when the adhesion detection signal check_sta is high, the main control chip 12 outputs a first enable signal that is also high, controlling the short circuit detection module 3 to perform short circuit detection; when the short circuit detection signal SOP_sta is low, the main control chip 12 outputs a second disable signal that is also low; and when the short circuit detection signal SOP_sta is high, the main control chip 12 outputs a second enable signal that is also high, controlling the power relay K1 in the power switch module 4 to engage and output power.

[0053] In one embodiment, the main control module 1 is further configured to connect to the alarm module and send an alarm signal to the alarm module when the adhesion detection signal check_sta is an adhesion signal or the short circuit detection signal SOP_sta is a short circuit signal, so that the alarm module performs an alarm operation.

[0054] As an example, the main control module 1 is also used to connect to the alarm module and receive the adhesion detection signal check_sta output by the adhesion detection module 2 and the short circuit detection signal SOP_sta output by the short circuit detection module 3. When the adhesion detection signal check_sta is an adhesion signal or the short circuit detection signal SOP_sta is a short circuit signal, the main control module 1 can send an alarm signal to the alarm module so that the alarm module can perform an alarm operation.

[0055] In one embodiment, the power switch module 4 includes a power relay K1; the adhesion detection module 2 is connected to two normally open contacts of the power relay K1 and is used to detect the adhesion detection result between the two normally open contacts of the power relay K1. If the adhesion detection result is that the power relay K1 is in an adhesion state, the adhesion detection signal check_sta is an adhesion signal; if the adhesion detection result is that the power relay K1 is not in an adhesion state, the adhesion detection signal check_sta is a non-adhesion signal.

[0056] As an example, the power switch module 4 includes a power relay K1. The power relay K1 includes a first magnetic core and two first normally open contacts located on the neutral and live wires. Magnetic attraction allows the normally open contacts to close under the control of the main control module 1, enabling circuit continuity and power output. The adhesion detection module 2 is connected to the two normally open contacts of the power relay K1 and is used to detect the adhesion detection result on the two normally open contacts of the power relay K1. If the adhesion detection result indicates that the device is in an adhesion state, the adhesion detection signal check_sta is an adhesion signal; if the adhesion detection result indicates that the device is not in an adhesion state, the adhesion detection signal check_sta is a non-adhesion signal.

[0057] In one embodiment, the relay adhesion detection module 2 includes an optocoupler unit U1; the light-emitting part of the optocoupler unit U1 is connected to the two normally open contacts of the power relay K1, and the light-receiving part of the optocoupler unit U1 is connected to the main control module 1, for detecting the adhesion detection result between the two normally open contacts of the power relay K1. If the adhesion detection result is that it is in an adhesion state, then the adhesion detection signal check_sta is an adhesion signal; if the adhesion detection result is that it is not in an adhesion state, then the adhesion detection signal check_sta is a non-adhesion signal.

[0058] As an example, the relay adhesion detection module 2 includes an optocoupler unit U1. The light-emitting part of the optocoupler unit U1 is connected to the two normally open contacts of the power relay K1, and the light-receiving part of the optocoupler unit U1 is connected to the main control module 1. It is used to detect the adhesion detection result on the two normally open contacts of the power relay K1. If the two normally open contacts of the power relay K1 are in an adhesion state, the light-emitting part of the optocoupler unit U1 will conduct and emit light, causing the light-receiving part to conduct accordingly. At this time, the output adhesion detection signal check_sta is an adhesion signal. If the two normally open contacts of the power relay K1 are not in an adhesion state, the light-emitting part of the optocoupler unit U1 will not conduct and emit light, and the light-receiving part will be in a cut-off state. At this time, the output adhesion detection signal check_sta is a non-adhesion signal.

[0059] In one embodiment, the short-circuit detection module 3 is connected to the two normally open contacts of the power relay K1 and is used to detect the short-circuit detection result between the two normally open contacts of the power relay K1. If the short-circuit detection result is that it is in a short-circuit state, the short-circuit detection signal SOP_sta is a short-circuit signal; if the short-circuit detection result is that it is not in a short-circuit state, the short-circuit detection signal SOP_sta is a non-short-circuit signal.

[0060] As an example, the short-circuit detection module 3 is connected to the two normally open contacts of the power relay K1 to detect the short-circuit detection result between the two normally open contacts of the power relay K1. If the short-circuit detection result indicates a short circuit, the short-circuit detection signal SOP_sta is a short-circuit signal; if the short-circuit detection result indicates no short circuit, the short-circuit detection signal SOP_sta is a non-short-circuit signal. Furthermore, the short-circuit state can include a short circuit from the live wire to ground, a short circuit from the neutral wire to ground, or a short circuit between the live wire and the neutral wire. When any of these short-circuit states occur, the short-circuit detection signal SOP_sta is a short-circuit signal.

[0061] In one embodiment, the short-circuit detection module 3 includes a pre-detection relay K2 and a signal comparison circuit 31. The pre-detection relay K2 is connected to the output terminal of the signal comparison circuit 31 and the power switch module 4, and is also connected to the main control module 1. It is used to be activated under the control of the main control module 1 to connect the signal comparison circuit 31 to the output terminal of the power switch module 4, or to be deactivated under the control of the main control module 1 to disconnect the signal comparison circuit 31 from the output terminal of the power switch module 4. The signal comparison circuit 31 is connected to the main control module 1 and is used to perform short-circuit detection on the power switch module 4 when the pre-detection relay K2 is activated, and to output a short-circuit detection signal SOP_sta to the main control module 1.

[0062] As an example, the short-circuit detection module 3 includes a pre-detection relay K2 and a signal comparison circuit 31. The pre-detection relay K2 may include a second magnetic core and two second normally open contacts connected to the live and neutral wires at the output terminal of the power switch module 4. The pre-detection relay K2 is connected to the main control module 1 and is used to briefly engage and then disengage (engagement time less than or equal to 200ms) under the control of the main control module 1 when there is no relay sticking in the power switch module 4. This allows the signal comparison circuit 31 to briefly connect to the output terminal of the power switch module 4, perform short-circuit detection on the neutral and live wires at the output terminal of the power switch module 4, and output a short-circuit detection signal SOP_sta to the main control module 1.

[0063] In one embodiment, the signal comparison circuit 31 includes a voltage divider unit 311 and an operational amplifier U2; the voltage divider unit 311 is connected to the pre-detection relay K2 and the operational amplifier U2, and is used to output a detection voltage signal to the operational amplifier U2 based on the short-circuit detection result between the two normally open contacts of the power relay K1; the operational amplifier U2 is connected to the main control module 1, and is used to amplify the detection voltage signal to obtain the short-circuit detection signal SOP_sta, and output the short-circuit detection signal SOP_sta to the main control module 1.

[0064] As an example, the signal comparison circuit 31 includes a voltage divider unit 311 and an operational amplifier U2. The voltage divider unit 311 is connected to the pre-detection relay K2 and the operational amplifier U2, and is used to output a corresponding detection voltage signal to the operational amplifier U2 at the moment when the pre-detection relay K2 is briefly closed, based on the short-circuit state of the live wire and neutral wire connected to the output terminal of the power switch module 4. The operational amplifier U2 is connected to the main control module 1, and is used to amplify the detection voltage signal to obtain the short-circuit detection signal SOP_sta that can be normally processed and received by the main control chip 12 in the main control module 1, and output the short-circuit detection signal SOP_sta to the main control module 1.

[0065] In one embodiment, the voltage divider unit 311 includes a first voltage divider resistor R1, a second voltage divider resistor R2, and a third voltage divider resistor R3; the first voltage divider resistor R1, the second voltage divider resistor R2, and the third voltage divider resistor R3 are connected in series between the power supply terminal and ground; the connection node between the first voltage divider resistor R1 and the second voltage divider resistor R2 is connected to the neutral wire of the output terminal of the power switch module 4; the connection node between the second voltage divider resistor R2 and the third voltage divider resistor R3 is connected to the live wire of the output terminal of the power switch module 4, and is also connected to the operational amplifier U2.

[0066] As an example, the voltage divider unit 311 includes a first voltage divider resistor R1, a second voltage divider resistor R2, and a third voltage divider resistor R3; the first voltage divider resistor R1, the second voltage divider resistor R2, and the third voltage divider resistor R3 are connected in series between the power supply terminal VCC (5V low voltage source) and ground; the connection node between the first voltage divider resistor R1 and the second voltage divider resistor R2 is connected to the output neutral line of the output terminal of the power switch module 4; the connection node between the second voltage divider resistor R2 and the third voltage divider resistor R3 is connected to the output live line of the output terminal of the power switch module 4, and is also connected to the comparator operational amplifier U2. When the live wire is short-circuited to ground, the third voltage divider resistor R3 is short-circuited, and the voltage value obtained by the operational amplifier U2 is 0. When the neutral wire is short-circuited to ground, both the second and third voltage divider resistors R2 and R3 are short-circuited, and the voltage value obtained by the operational amplifier U2 is also 0. When the live wire and the neutral wire are short-circuited, the second voltage divider resistor R2 is short-circuited. At this time, only the first and third voltage divider resistors R1 and R3 divide the voltage provided by the power supply terminal VCC, and the voltage value obtained by the operational amplifier U2 is the voltage across the third voltage divider resistor R3. When there is no short circuit at the output terminal of the power switch module 4, the first, second, and third voltage divider resistors R1, R2, and R3 divide the voltage provided by the power supply terminal VCC, and the voltage value obtained by the operational amplifier U2 is the voltage across the third voltage divider resistor R3.

[0067] This invention also provides a power supply circuit, including a power switch module 4 and the aforementioned protection circuit; the input terminal of the power switch module 4 is used to connect to the mains circuit, and the output terminal of the power switch module 4 is used to connect to the device to be charged; the protection circuit is connected to the output terminal of the power switch module 4, and is used to perform adhesion detection and short circuit detection on the power switch module 4, obtain the short circuit detection signal SOP_sta, and control the power switch module 4 to be in a disabled state when the short circuit detection signal SOP_sta is a short circuit signal.

[0068] As an example, the power supply circuit includes a power switch module 4 and the aforementioned protection circuit. The input terminal of the power switch module 4 is connected to the mains power circuit, and the output terminal of the power switch module 4 is connected to the device to be charged, which can be a vehicle or a portable energy storage device. The protection circuit is connected to the output terminal of the power switch module 4 and is used to perform adhesion detection and short circuit detection on the power switch module 4, obtain the short circuit detection signal SOP_sta, and control the power switch module 4 to be in a disabled state when the short circuit detection signal SOP_sta is a short circuit signal. In this example, the protection circuit in the power supply circuit can perform adhesion detection on the power relay in the power switch module 4 before the power switch module 4 closes and outputs power, and continue to perform short circuit detection on the power switch module 4 after detecting that there is no relay adhesion. This protection circuit can detect and eliminate both relay adhesion and short circuit faults to ensure the safety of power output. On the other hand, it can also prevent relay adhesion from harming short circuit detection and prevent relay adhesion from causing device burnout in the short circuit detection module 3, thereby improving the safety and reliability of short circuit detection.

[0069] This invention also provides a charging pile, including the aforementioned power supply circuit. One end of the power supply circuit is connected to the mains power circuit, and the other end is connected to the device to be charged. In this example, the protection circuit in the charging pile can perform a sticking detection on the power relay in the power switch module 4 before the power switch module 4 closes and outputs power to the device to be charged. After detecting that there is no relay sticking, it continues to perform short-circuit detection on the power switch module 4. This protection circuit can detect and eliminate both relay sticking and short-circuit faults to ensure the safety of power output. On the other hand, it can also prevent relay sticking from harming short-circuit detection and prevent relay sticking from causing components in the short-circuit detection module 3 to burn out, thereby improving the safety and reliability of short-circuit detection.

[0070] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A protection circuit, characterized in that, The protection circuit is used to connect to the power switch module and includes a main control module, an adhesion detection module, and a short circuit detection module. The adhesion detection module is connected to the power switch module and is used to perform adhesion detection on the power switch module and output an adhesion detection signal. The short-circuit detection module is connected to the power switch module and is used to perform short-circuit detection on the power switch module and output a short-circuit detection signal. The main control module is connected to the adhesion detection module and the short circuit detection module, and is also used to connect to the power switch module. When the adhesion detection signal is an adhesion signal, the short circuit detection module is controlled to be disabled. When the short circuit detection signal is a short circuit signal, the power switch module is controlled to be disabled. The main control module includes a signal interlock unit and a main control chip; The signal interlock unit is connected to the adhesion detection module, the short circuit detection module, and the main control chip. It is used to output a first enable signal to the main control chip when the adhesion detection signal is a non-adhesion signal; output a first disable signal to the main control chip when the adhesion detection signal is an adhesion signal; output a second enable signal to the main control chip when the short circuit detection signal is a non-short circuit signal; and output a second disable signal to the main control chip when the short circuit detection signal is a short circuit signal. The main control chip is connected to the short-circuit detection module and the power switch module, and is used to output a first detection control signal to the short-circuit detection module based on the first enable signal, so that the short-circuit detection module is in an available state and performs short-circuit detection on the power switch module; and to output a second detection control signal to the short-circuit detection module based on the first disable signal, so that the short-circuit detection module is in a disabled state. Based on the second enable signal, a first output control signal is output to the power switch module to make the power switch module available; based on the second disable signal, a second output control signal is output to the power switch module to make the power switch module disabled.

2. The protection circuit according to claim 1, characterized in that, The main control module is also used to connect to the alarm module, and when the adhesion detection signal is an adhesion signal or the short circuit detection signal is a short circuit signal, it sends an alarm signal to the alarm module so that the alarm module performs an alarm operation.

3. The protection circuit according to claim 1, characterized in that, The power switch module includes a power relay; The adhesion detection module is connected to the two normally open contacts of the power relay and is used to detect the adhesion detection result on the two normally open contacts of the power relay. If the adhesion detection result is that the power relay is in an adhesion state, the adhesion detection signal is an adhesion signal; if the adhesion detection result is that the power relay is not in an adhesion state, the adhesion detection signal is a non-adhesion signal.

4. The protection circuit according to claim 3, characterized in that, The relay adhesion detection module includes an optocoupler unit; The light-emitting part of the optocoupler unit is connected to the two normally open contacts of the power relay, and the light-receiving part of the optocoupler unit is connected to the main control module. It is used to detect the adhesion detection result between the two normally open contacts of the power relay. If the adhesion detection result is that the two contacts are in an adhesion state, the adhesion detection signal is an adhesion signal; if the adhesion detection result is that the two contacts are not in an adhesion state, the adhesion detection signal is a non-adhesion signal.

5. The protection circuit according to claim 3, characterized in that, The short-circuit detection module is connected to the two normally open contacts of the power relay and is used to detect the short-circuit detection result between the two normally open contacts of the power relay. If the short-circuit detection result is that the power relay is in a short-circuit state, then the short-circuit detection signal is a short-circuit signal. If the short circuit detection result indicates that the circuit is not in a short circuit state, then the short circuit detection signal is a non-short circuit signal.

6. The protection circuit according to claim 5, characterized in that, The short-circuit detection module includes a pre-detection relay and a signal comparison circuit; The pre-detection relay is connected to the output terminal of the signal comparison circuit and the power switch module, and is also connected to the main control module. It is used to activate under the control of the main control module so that the signal comparison circuit is connected to the output terminal of the power switch module, or to deactivate under the control of the main control module so that the signal comparison circuit is disconnected from the output terminal of the power switch module. The signal comparison circuit is connected to the main control module and is used to perform short-circuit detection on the power switch module when the pre-detection relay is energized, and output a short-circuit detection signal to the main control module.

7. The protection circuit according to claim 6, characterized in that, The signal comparison circuit includes a voltage divider unit and an operational amplifier; The voltage divider unit is connected to the pre-detection relay and the operational amplifier, and is used to output a detection voltage signal to the operational amplifier based on the short-circuit detection result between the two normally open contacts of the power relay; The operational amplifier is connected to the main control module and is used to amplify the detection voltage signal to obtain a short-circuit detection signal, and output the short-circuit detection signal to the main control module.

8. The protection circuit according to claim 7, characterized in that, The voltage divider unit includes a first voltage divider resistor, a second voltage divider resistor, and a third voltage divider resistor; The first voltage divider resistor, the second voltage divider resistor, and the third voltage divider resistor are connected in series between the power supply terminal and ground; The connection point between the first voltage divider resistor and the second voltage divider resistor is connected to the output neutral line of the power switch module. The connection point between the second voltage divider resistor and the third voltage divider resistor is connected to the output live wire of the power switch module and also to the operational amplifier.

9. A power supply circuit, characterized in that, Includes a power switch module and the protection circuit as described in any one of claims 1-8; The input terminal of the power switch module is used to connect to the mains power circuit, and the output terminal of the power switch module is used to connect to the device to be charged. The protection circuit is connected to the output terminal of the power switch module and is used to perform adhesion detection and short circuit detection on the power switch module, obtain a short circuit detection signal, and control the power switch module to be in a disabled state when the short circuit detection signal is a short circuit signal.

10. A charging pile, characterized in that, The device includes the power supply circuit as described in claim 9, wherein one end of the power supply circuit is used to connect to the mains power circuit and the other end is used to connect to the device to be charged.

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