Protection control circuit and carrier power supply system

Abstract

The utility model discloses a protection control circuit and a carrier power supply system. The carrier power supply system comprises a power supply, a positive bus, a negative bus and a communication filtering module, the protection control circuit is connected with the power supply and is connected with the positive bus through the communication filtering module, and the protection control circuit comprises a switch module, an overcurrent detection module, a state detection module and a control module. The over-current detection module is used for detecting the current of a positive electrode bus and generating an over-current signal according to the current, the state detection module is used for detecting the power supply state of a carrier power supply system and generating an enable signal according to the power supply state, and the control module is used for controlling the on-off of the switch module according to the over-current signal or the enable signal. Therefore, the power supply and the anode bus are connected or disconnected. The protection control circuit is arranged at the positive electrode of the carrier power supply system, and can disconnect the carrier power supply system from the equipment when the equipment is short-circuited, overcurrent, reverse connection and other abnormities, thereby realizing protection of the carrier power supply system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carrier communication, in particular to a protection control circuit and a carrier power supply system. BACKGROUND

[0002] At present, modern industrial control has higher and higher requirements for field wiring and communication, and carrier power supply communication is widely used in the industry of building control due to its advantages of simplicity, scalability and easy maintenance. Carrier power supply communication refers to a communication mode that uses a bus or a wire as a communication channel, transmits analog or digital signals through a carrier mode, and simultaneously uses the bus or the wire for power supply. For example, the communication between an indoor unit and a line controller only needs two wires to realize power supply and communication functions.

[0003] However, the power supply solution between the main body and the receptor of the carrier power supply communication is not perfect. In the scene where there are multiple power supply bodies and multiple power receiving bodies, the problems of wiring short circuit, reverse connection or load over-limit (overcurrent) often occur. CONTENT OF THE UTILITY MODEL

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application needs to provide a protection control circuit and a carrier power supply system.

[0005] The protection control circuit of the present application embodiment, the carrier power supply system includes a power supply and a positive bus, a negative bus and a communication filter module, the communication filter module is connected to the positive bus and the negative bus respectively, the protection control circuit is connected to the power supply and connected to the positive bus through the communication filter module, and the protection control circuit includes:

[0006] A switch module connected to the power supply and the positive bus;

[0007] An overcurrent detection module connected to the positive bus, for detecting the current of the positive bus and generating an overcurrent signal according to the voltage;

[0008] A state detection module connected to the positive bus and the negative bus, for detecting the power supply state of the carrier power supply system and generating an enable signal according to the power supply state;

[0009] A control module connected to the overcurrent detection module, the state detection module and the switch module, for controlling the switch module to be on or off according to the overcurrent signal and / or the enable signal, so as to make the power supply and the positive bus conductive or off.

[0010] In some embodiments, the switch module includes:

[0011] a first switch transistor, a first pole of the first switch transistor is connected to the power supply, a second pole of the first switch transistor is connected to the positive bus, and a control pole of the first switch transistor is connected to the control module;

[0012] a first resistor, one end of the first resistor is connected to the first pole of the first switch transistor, and the other end of the first resistor is connected to the control pole of the first switch transistor.

[0013] In some embodiments, the switch module further comprises:

[0014] a transient voltage suppressor, one end of the transient voltage suppressor is connected to the first pole of the first switch transistor, and the other end of the transient voltage suppressor is connected to the second pole of the first switch transistor.

[0015] In some embodiments, the overcurrent protection resistor comprises a plurality of overcurrent protection resistors in parallel.

[0016] In some embodiments, the control module comprises:

[0017] an enable control unit, connected to the state detection module, the first power supply end, and the ground end, for generating a first output control signal according to the enable signal;

[0018] an overcurrent protection unit, connected to the overcurrent detection module, for generating a second output control signal according to the overcurrent signal;

[0019] a push-pull output unit, connected to the first power supply end, the enable control unit, the overcurrent protection unit, and the switch module, for generating a switch signal according to the first output control signal and / or the second output control signal to control the switch module to turn on or off.

[0020] In some embodiments, the enable control unit comprises:

[0021] a second resistor, one end of the second resistor is connected to the first power supply end;

[0022] a second switch transistor, a first pole of the second switch transistor is connected to the other end of the second resistor, a second pole of the second switch transistor is connected to the ground end, and a control pole of the second switch transistor is connected to the state detection module;

[0023] a third switch transistor, a first pole of the third switch transistor is connected to the first power supply end, and a control pole of the second switch transistor is connected to the other end of the second resistor;

[0024] a third resistor, one end of the third resistor is connected to a second pole of the third switch transistor, and the other end of the third resistor is connected to the push-pull output unit.

[0025] In some embodiments, the over-current protection unit comprises:

[0026] a fourth resistor, one end of which is connected to the over-current detection module;

[0027] a fifth resistor, one end of which is connected to the other end of the fourth resistor, and the other end of which is connected to the ground terminal;

[0028] a sixth resistor, one end of which is connected to the other end of the fourth resistor;

[0029] a first capacitor, one end of which is connected to the other end of the sixth resistor, and the other end of which is connected to the ground terminal;

[0030] a fourth switch transistor, a first pole of which is connected to the push-pull output unit, a second pole of which is connected to the ground terminal, and a control pole of which is connected to the other end of the sixth resistor.

[0031] In some embodiments, the push-pull output unit comprises:

[0032] a fifth switch transistor, a first pole of which is connected to the first power supply terminal, and a control pole of which is connected to the enable control unit and the over-current protection unit;

[0033] a sixth switch transistor, a first pole of which is connected to a second pole of the fifth switch transistor, a second pole of which is connected to the ground terminal, and a control pole of which is connected to the enable control unit and the over-current protection unit;

[0034] a seventh resistor, one end of which is connected to the second pole of the fifth switch transistor and the first pole of the sixth switch transistor, and the other end of which is connected to the switch module;

[0035] an eighth resistor, one end of which is connected to the control pole of the sixth switch transistor, and the other end of which is connected to the second pole of the sixth switch transistor.

[0036] In some embodiments, the over-current detection module comprises:

[0037] an over-current protection resistor, which is connected in series to the positive bus;

[0038] a ninth resistor, one end of which is connected to one end of the over-current protection resistor;

[0039] a tenth resistor, one end of which is connected to the other end of the over-current protection resistor;

[0040] a comparator, comprising a first input end, a second input end and an output end, the first input end being connected to the other end of the ninth resistor, the second input end being connected to the other end of the tenth resistor, and the output end being connected to the control module;

[0041] a second capacitor, one end of which is connected to the second input end and the other end of which is connected to the output end;

[0042] an eleventh resistor, one end of which is connected to the second input end and the other end of which is connected to the output end;

[0043] a twelfth resistor, one end of which is connected to the first input end and the other end of which is connected to the ground end.

[0044] In some embodiments, the state detection module comprises:

[0045] a first optocoupler detection unit, connected to the positive bus, the second power supply end and the negative bus, for generating a first logic control signal according to the power supply state of the carrier power supply system;

[0046] a controller, connected to the first optocoupler detection unit and the control module, for generating the enable signal according to the first logic control signal.

[0047] In some embodiments, the state detection module comprises:

[0048] a second optocoupler detection unit, connected to the first optocoupler detection unit, the negative bus and the second power supply end, for generating a second logic control signal according to the power supply state of the carrier power supply system;

[0049] The controller is further connected to the second optocoupler detection unit, for generating the enable signal according to the first logic control signal and the second logic control signal.

[0050] In some embodiments, the first optocoupler detection unit comprises:

[0051] a thirteenth resistor, one end of which is connected to the positive bus;

[0052] a fourteenth resistor, one end of which is connected to the other end of the thirteenth resistor and the other end of which is connected to the negative bus;

[0053] a third capacitor, one end of which is connected to the other end of the thirteenth resistor and the other end of which is connected to the negative bus;

[0054] a first pin of the first optocoupler is connected to the negative bus, a second pin of the first optocoupler is connected to the other end of the thirteenth resistor, and a third pin of the first optocoupler is connected to the ground terminal;

[0055] a fifteenth resistor, one end of the fifteenth resistor is connected to the second power supply terminal, and the other end of the fifteenth resistor is connected to a fourth pin of the first optocoupler;

[0056] a sixteenth resistor, one end of the sixteenth resistor is connected to the other end of the fifteenth resistor, and the other end of the sixteenth resistor is connected to the controller;

[0057] a fourth capacitor, one end of the fourth capacitor is connected to the other end of the sixteenth resistor, and the other end of the fourth capacitor is connected to the ground terminal.

[0058] In some embodiments, the second optocoupler detection unit comprises:

[0059] a second optocoupler, a first pin of the second optocoupler is connected to the other end of the thirteenth resistor, a second pin of the second optocoupler is connected to the negative bus, and a third pin of the second optocoupler is connected to the ground terminal;

[0060] a seventeenth resistor, one end of the seventeenth resistor is connected to the second power supply terminal, and the other end of the seventeenth resistor is connected to a fourth pin of the second optocoupler;

[0061] an eighteenth resistor, one end of the eighteenth resistor is connected to the other end of the eighteenth resistor, and the other end of the eighteenth resistor is connected to the controller;

[0062] a fifth capacitor, one end of the fifth capacitor is connected to the other end of the eighteenth resistor, and the other end of the fifth capacitor is connected to the ground terminal.

[0063] In some embodiments, the protection control circuit further comprises:

[0064] a diode, a positive electrode of the diode is connected to the power supply, and a negative electrode of the diode is connected to the positive bus.

[0065] The carrier power supply system of the embodiments of the present application comprises a power supply, a communication filtering module, a communication module, a positive bus, a negative bus, and the protection control circuit of any of the above embodiments;

[0066] The communication filtering module is connected to the switching module, the positive bus, the negative bus, and the ground terminal, respectively;

[0067] The communication module is connected to the positive bus and the negative bus.

[0068] In the protection control circuit and the carrier power supply system of the embodiment of the present application, the protection control circuit is arranged at the positive pole of the carrier power supply system, that is, the switch module is connected with the power supply and the positive pole bus, when the overcurrent detection module detects that overcurrent or short circuit exists, or the state detection module detects that the power supply state is abnormal (the bus is reversely connected), the control module can control the switch module to be turned off, so that the power supply is disconnected with the positive pole bus, and the protection of the carrier power supply system is realized.

[0069] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0070] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0071] Figure 1 is a schematic diagram of a module of the carrier power supply system of the embodiment of the present application.

[0072] Figure 2 is a schematic diagram of a circuit of the carrier power supply system of the embodiment of the present application.

[0073] Figure 3 is a further schematic diagram of a circuit of the carrier power supply system of the embodiment of the present application.

[0074] Explanation of main element symbols:

[0075] Carrier power supply system 100, protection control circuit 10, power supply DC, positive pole bus BUS+, negative pole bus BUS-, first power supply end VDD1, second power supply end VDD2, communication module 20, first capacitor C11, second capacitor C12, communication filter module 30, common mode inductor L1.

[0076] Switch module 12, first switch transistor Q1, first resistor R1, transient voltage suppressor TVS1, diode D1;

[0077] Overcurrent detection module 14, ninth resistor R9, tenth resistor R10, eleventh resistor R11, twelfth resistor R12, comparator IC3, second capacitor C2, overcurrent protection resistor R21;

[0078] The state detection module 16, the first optocoupler detection unit 162, the second optocoupler detection unit 164, the controller MCU, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, the first optocoupler IC1, the second optocoupler IC2, the filter capacitor C21, and the filter resistor R21.

[0079] The control module 18, the enable control unit 182, the second resistor R2, the third resistor R3, the second switch transistor Q2, the third switch transistor Q3, the overcurrent protection unit 184, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the first capacitor C1, the fourth switch transistor Q4, the push-pull output unit 186, the fifth switch transistor Q5, the sixth switch transistor Q6, the seventh resistor R7, the eighth resistor R8, and the ground terminal GND. DETAILED DESCRIPTION

[0080] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, in which the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are for the purpose of explanation only, and are not to be taken as limiting of the present application.

[0081] Currently, due to the increase of labor and wire costs, more and more communications in the market use carrier power supply communication. For example, the communication between the indoor unit and the line controller only needs two wires to realize power supply + communication, such as Home Bus bus carrier communication, 485 bus carrier communication, KNX bus carrier communication or private carrier communication. Understandably, carrier communication can greatly save wire cost and labor cost.

[0082] Generally, communication chip manufacturers only provide communication solutions, and do not provide control schemes for overload and short circuit protection of power supply. Since the carrier communication system is mostly composed of a power supply device for a plurality of slave power receiving devices, or a plurality of power supply devices for a plurality of power receiving devices. At present, problems such as short circuit of wiring and reverse connection of line often occur.

[0083] In view of this, please combine Figure 1 and Figure 2The embodiment of the present application provides a carrier power supply system 100. The carrier power supply system 100 can comprise a protection control circuit 10, a power supply DC, a bus, a communication module 20 and a communication filter module 30. The bus comprises a positive bus BUS+ and a negative bus BUS-, the positive bus BUS+ and the negative bus BUS- are connected with the communication filter module 30 respectively, the protection control circuit 10 is connected with the power supply DC, and the positive bus BUS+ is connected with the protection control circuit 10 through the communication filter module 30, the negative bus BUS- is connected with the ground terminal GND through the communication filter module 30, and the communication filter module 30 is used for inhibiting interference signals to protect the power supply DC.

[0084] The communication filter module 30 can be a common mode inductor L1, the common mode inductor L1 can comprise two mutual inductance coils, the two mutual inductance coils form two groups of opposite terminals, the power supply DC can be connected with one group of opposite terminals through the protection control circuit 10, and the positive bus BUS+ and the negative bus BUS- are connected with the other group of opposite terminals. It should be noted that when the two mutual inductance coils pass through the current, the current inflow ends of the two coils are called opposite terminals when the magnetic flux directions generated by the two coils are opposite. The positive bus BUS+ and the negative bus BUS- can also be connected with a load device, wherein the load device can be one or more. The communication module 20 can comprise a communication chip 21, a capacitor C11 and a capacitor C12, wherein the communication chip 21 can be connected with the negative bus BUS- through the capacitor C11, and can be connected with the positive bus BUS+ through the capacitor C12, and is used for realizing carrier communication.

[0085] It should be noted that the carrier power supply system 100 adopts carrier power supply communication technology, and the skilled in the art can understand that the carrier power supply communication refers to injecting a high-frequency carrier signal into an electric wire or a communication line through a coupler, then using the electric wire or the communication line as a transmission medium to transmit the signal to a target position, finally demodulating and processing the signal through a corresponding receiving device, so as to realize data transmission and control. In this way, when the power supply DC is electrically connected with the load device through the positive bus BUS+ and the negative bus BUS-, that is, the power supply DC can realize power supply for the load device, and at the same time, communication with the load device can also be realized.

[0086] For example, in some examples, in a central air conditioning system, a wire controller and an indoor unit are included, wherein the wire controller is used as the power supply DC of the indoor unit, the indoor unit is used as a load device, and the wire controller and the indoor unit can be connected through the positive bus BUS+ and the negative bus BUS-, so as to realize power supply for the indoor unit by the wire controller and realize communication between the wire controller and the indoor unit.

[0087] The protection control circuit 10 comprises a switch module 12, an overcurrent detection module 14, a state detection module 16 and a control module 18. The switch module 12 is connected to the power supply DC and the positive bus BUS+, the overcurrent detection module 14 is connected to the positive bus BUS+, and the overcurrent detection module 14 is configured to detect the current of the positive bus BUS+ and generate an overcurrent signal according to the current, the state detection module 16 is connected to the positive bus BUS+ and the negative bus BUS-, and is configured to detect the power supply state of the carrier power supply system 100 and generate an enable signal according to the power supply state, and the control module 18 is connected to the overcurrent detection module 14, the state detection module 16 and the switch module 12, and is configured to control the switch module 12 to be turned on or turned off according to the overcurrent signal and / or the enable signal, so as to turn on or turn off the power supply DC and the positive bus BUS+.

[0088] In the carrier power supply system 100 and the protection control circuit 10 of the embodiment, the protection control circuit 10 is arranged at the positive of the carrier power supply system 100, that is, the switch module 12 is connected to the power supply DC and the positive bus BUS+. When the overcurrent detection module 12 detects that overcurrent exists, or the state detection module 16 detects that the power supply state is abnormal, such as reverse connection, the control module 18 can control the switch module 12 to be turned off, so as to disconnect the power supply DC and the positive bus BUS+, thereby protecting the carrier power supply system 100.

[0089] Specifically, the switch module 12 has a switching function. When the switch module 12 is turned on, the power supply DC is connected to the positive bus BUS+ through the switch module 12. When the switch module 12 is turned off, the power supply DC is disconnected from the positive bus BUS+. The switch module 12 can comprise one of a metal oxide semiconductor (MOS) field effect transistor, a triode or a solid-state relay, and the like. For example, in the embodiment, the switch module 12 can comprise a MOS tube, that is, the power supply DC is connected to the positive bus BUS+ through the MOS tube.

[0090] The overcurrent detection module 14 is connected to the positive bus BUS+, and is configured to detect the current of the positive bus BUS+ and generate an overcurrent signal according to the current. The overcurrent signal can be a voltage signal. It can be understood that the greater the current of the positive bus BUS+, the greater the overcurrent signal, and the smaller the current of the positive bus BUS+, the smaller the overcurrent signal. It can be understood that when the carrier power supply system 100 is short-circuited or overcurrent, the overcurrent signal becomes larger. That is, when the overcurrent signal is greater than a preset value, the carrier power supply system 100 is overcurrent or short-circuited. When the overcurrent signal is low, the carrier power supply system 100 is not overcurrent or short-circuited. Therefore, whether the carrier power supply system 100 is overcurrent or short-circuited can be determined by the overcurrent signal.

[0091] The state detection module 16 is connected to the positive bus BUS+ and the negative bus BUS-, respectively, and can detect the power supply state of the carrier power supply system 100 and generate an enable signal according to the power supply state. The power supply state can include whether the power supply DC is powered, the voltage flow direction of the bus, etc. The enable signal can include a high-level signal and a low-level signal. The high-level signal indicates that the power supply state of the carrier power supply system 100 is that the power supply voltage is not powered or the bus has a forward voltage, i.e. the power supply state of the carrier power supply system 100 is normal. The low-level signal indicates that the power supply state of the carrier power supply system 100 is that the bus has a reverse voltage supply, i.e. the power supply state of the carrier power supply system 100 is abnormal.

[0092] The control module 18 is connected to the overcurrent detection module 14, the state detection module 16 and the switch module 12, respectively. The control module 18 can receive the overcurrent signal sent by the overcurrent detection module 14 and the enable signal generated by the state detection module 16, and can control the conduction or turn-off of the switch module 12 according to the overcurrent signal, and can control the conduction or turn-off of the switch module 12 according to the enable signal detected and sent by the state detection module 16, so that the power supply DC and the positive bus BUS+ are turned on or turned off.

[0093] Further, when the control module 18 receives an overcurrent signal greater than a preset threshold (i.e. when a short circuit or overcurrent occurs), or receives a low-level signal as the enable signal (i.e. when the power supply state is abnormal), the switch module 12 is turned off, so that the power supply DC and the positive bus BUS+ are turned off. When the control module 18 receives an overcurrent signal less than a preset threshold, and receives a high-level signal as the enable signal (i.e. when the power supply state is normal), the switch module 12 is turned on, so that the power supply DC and the positive bus BUS+ are turned on.

[0094] Please refer to Figure 2 Or Figure 3 In some embodiments, the switch module 12 includes a first switch transistor Q1 and a first resistor R1. The first pole of the first switch transistor Q1 is connected to the power supply DC, the second pole of the first switch transistor Q1 is connected to the positive bus BUS+, and the control pole of the first switch transistor Q1 is connected to the control module 18. One end of the first resistor R1 is connected to the first pole of the first switch transistor Q1, and the other end is connected to the control pole of the switch transistor.

[0095] In the embodiment, the first switch transistor Q1 can be a MOS tube, and is a P-channel MOS tube, wherein the first pole is the source of the MOS tube, the second pole is the drain of the MOS tube, and the control pole is the gate of the MOS tube. It can be understood that the MOS tube has the advantages of fast switching speed, low on-resistance, high input impedance, etc., and therefore, through the setting of the first switch transistor Q1, the connection between the power supply DC and the positive bus BUS+ can be quickly disconnected when the carrier power supply system 100 appears abnormal such as overcurrent, short circuit or bus reverse connection, thereby protecting the carrier power supply system 100.

[0096] Further, the switch module 12 further comprises a transient voltage suppressor TVS1, one end of the transient voltage suppressor TVS1 is connected to the first pole of the first switch transistor Q1, and the other end of the transient voltage suppressor TVS1 is connected to the second pole of the first switch transistor Q1. It should be noted that the transient voltage suppressor TVS1 is a widely used protection device in electronic equipment, and the transient voltage suppressor TVS1 can suppress the transient voltage peak value appearing in the circuit to protect sensitive electronic components from overvoltage damage. In this way, damage to the first switch transistor Q1 caused by overvoltage is avoided, the service life of the first switch transistor Q1 is prolonged, and the safety of the carrier power supply system 100 is improved.

[0097] Please refer to Figure 2 or Figure 3 In some embodiments, the control module 18 comprises an enable control unit 182, an overcurrent protection unit 184, and a push-pull output unit 186, wherein the enable control unit 182 is connected to the state detection module 16, the first power supply end VDD1 and the ground end GND, and the enable control unit 182 is used to generate a first output control signal according to the enable signal. The overcurrent protection unit 184 is connected to the overcurrent detection module 14, and is used to generate a second output control signal according to the overcurrent signal. The push-pull output unit 186 is connected to the first power supply end VDD1, the enable control unit 182, the overcurrent protection unit 184 and the switch module 12, and is used to generate a switching signal according to the first output control signal and / or the second output control signal to control the switch module 12.

[0098] It should be noted that the voltage of the first power supply terminal VDD1 can be 12 volts. The first output control signal and the second output control signal can be level signals, including high level signals and low level signals. When the enable signal is a high level signal (1), the first output control signal generated by the enable control unit 182 is a high level signal. When the enable signal is low (0), the first output control signal generated by the enable control unit 182 is a low level signal. When the overcurrent signal is greater than a preset threshold, the second output control signal generated by the overcurrent protection unit 184 is a low level signal. When the overcurrent signal is less than the preset threshold, the second output control signal generated by the overcurrent protection unit 184 is a high level signal. The switch signal can include a conduction signal and an off signal. When the switch signal is the conduction signal, the control switch module 12 is turned on. When the switch signal is the off signal, the control switch module 12 is turned off. When the first output control signal is a high level signal and the second output control signal is a high level signal, the push-pull output unit 186 generates a conduction signal, so that the switch module 12 is turned on. When the second output control signal is a low level signal or the second output control signal is a low level signal, the push-pull output unit 186 generates an off signal, so that the switch module 12 is turned off.

[0099] In some embodiments, the enable control unit 182 includes a second resistor R2, a second switch transistor Q2, a third switch transistor Q3, and a third resistor R3. One end of the second resistor R2 is connected to the first power supply terminal VDD1. The first electrode of the second switch transistor Q2 is connected to the other end of the second resistor R2. The second electrode of the second switch transistor Q2 is connected to the ground terminal GND. The control electrode of the second switch transistor Q2 is connected to the state detection module 16. The first electrode of the third switch transistor Q3 is connected to the first power supply terminal VDD1. The control electrode of the second switch transistor Q2 is connected to the other end of the second resistor R2. One end of the third resistor R3 is connected to the second electrode of the second switch transistor Q2. The other end of the third resistor R3 is connected to the push-pull output unit 186.

[0100] The second switch transistor Q2 and the third switch transistor Q3 are triodes, in which the first electrode is the emitter, the second electrode is the collector, and the control electrode is the base. Moreover, the second switch transistor Q2 can be an NPN type triode, and the third switch transistor Q3 can be a PNP type triode. That is, when the control electrode of the second switch transistor Q2 receives a high level signal, the first electrode and the second electrode of the second switch transistor Q2 are turned on. When the control electrode of the second switch transistor Q2 receives a low level signal, the first electrode and the second electrode of the second switch transistor Q2 are turned off. When the control electrode of the third switch transistor Q3 receives a low level signal, the first electrode and the second electrode of the third switch transistor Q3 are turned on. When the control electrode of the third switch transistor Q3 receives a high level signal, the first electrode and the second electrode of the third switch transistor Q3 are turned off.

[0101] For example, in some examples, when the enable signal is a high level signal, i.e. the control electrode of the second switch transistor Q2 is a high level signal, the first electrode and the second electrode of the second switch transistor Q2 are turned on, and the first power supply end VDD1, the second resistor R2, the second switch transistor Q2 and the ground end GND form a closed loop. At this time, the control electrode of the third switch transistor Q3 is equivalent to the ground, i.e. the control electrode of the third switch transistor Q3 is a low level signal, and the first electrode and the second electrode of the third switch transistor Q3 are turned on. At this time, the first power supply end VDD1, the third switch transistor Q3, the third resistor R3 and the push-pull output unit 186 form a loop. When the enable signal is a low level signal, i.e. the control electrode of the second switch transistor Q2 is a low level signal, the first electrode and the second electrode of the second switch transistor Q2 are turned off. At this time, the control electrode of the third switch transistor Q3 is a high level signal, and the first electrode and the second electrode of the third switch transistor Q3 are turned off.

[0102] In some embodiments, the overcurrent protection unit 184 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1 and a fourth switch transistor Q4. Wherein one end of the fourth resistor R4 is connected to the overcurrent detection module 14; one end of the fifth resistor R5 is connected to the other end of the fourth resistor R4, and the other end of the fifth resistor R5 is connected to the ground end GND; one end of the sixth resistor R6 is connected to the other end of the fourth resistor R4; one end of the first capacitor C1 is connected to the other end of the sixth resistor R6, and the other end of the first capacitor C1 is connected to the ground end GND; the first electrode of the fourth switch transistor Q4 is connected to the push-pull output unit 186, the second electrode of the fourth switch transistor Q4 is connected to the ground end GND, and the control electrode of the fourth switch transistor Q4 is connected to the other end of the sixth resistor R6.

[0103] It should be noted that the sixth resistor R6 and the first capacitor C1 constitute an RC filter circuit for filtering the control electrode of the fourth switch transistor Q4 to ensure the stability of the fourth switch transistor Q4. The fourth switch transistor Q4 is a transistor, and can be an NPN type transistor. When the overcurrent signal is greater than the preset threshold, the first electrode and the second electrode of the fourth switch transistor Q4 are turned on. When the overcurrent signal is less than the preset threshold, the first electrode and the second electrode of the fourth switch transistor Q4 are turned off.

[0104] The push-pull output unit 186 comprises a fifth switch transistor Q5, a sixth switch transistor Q6, a seventh resistor R7 and an eighth resistor R8. The first pole of the fifth switch transistor Q5 is connected to the first power supply end VDD1, the control pole of the fifth switch transistor Q5 is connected to the seventh resistor R7 of the enable control unit 182 and the first pole of the fourth switch transistor Q4 in the overcurrent protection unit 184; the first pole of the sixth switch transistor Q6 is connected to the second pole of the fifth switch transistor Q5, the second pole of the sixth switch transistor Q6 is connected to the ground end GND, the control pole of the sixth switch transistor Q6 is connected to the seventh resistor R7 of the enable control unit 182 and the first pole of the fourth switch transistor Q4 in the overcurrent protection unit 184; one end of the seventh resistor R7 is connected to the second pole of the fifth switch transistor Q5 and the first pole of the sixth switch transistor Q6, the other end of the seventh resistor R7 is connected to the control pole of the first switch transistor Q1 in the switch module 12; one end of the eighth resistor R8 is connected to the control pole of the sixth switch transistor Q6, the other end of the eighth resistor R8 is connected to the second pole of the sixth switch transistor Q6.

[0105] Specifically, the fifth switch transistor Q5 and the sixth switch transistor Q6 are both triodes, wherein the first pole is the emitter, the second pole is the collector and the control pole is the base. Moreover, the fifth switch transistor Q5 is a PNP type triode and the sixth switch transistor Q6 is an NPN type triode, that is, when the control pole of the fifth switch transistor Q5 receives a low level signal, the first pole and the second pole of the fifth switch transistor Q5 are turned on, when a high level signal is received, the first pole and the second pole of the fifth switch transistor Q5 are turned off, when the control pole of the sixth switch transistor Q6 receives a high level signal, the first pole and the second pole of the sixth switch transistor Q6 are turned on, when the control pole of the sixth switch transistor Q6 receives a low level signal, the first pole and the second pole of the sixth switch transistor Q6 are turned off.

[0106] When the enable signal is a high level signal and the overcurrent signal is low, the second switch transistor Q2 is turned on, the third switch transistor Q3 is turned on, the fourth switch transistor is turned off, the first power supply end VDD1, the third switch transistor Q3, the third resistor R3, the seventh resistor R7, the eighth resistor R8 and the ground end GND form a closed loop, at this time, the control poles of the fifth switch transistor Q5 and the sixth switch transistor Q6 have high voltage, the fifth switch transistor Q5 is turned off, the sixth switch transistor Q6 is turned on, so that the control pole of the first switch transistor Q1 is grounded (low level), therefore, the first switch transistor Q1 is turned on.

[0107] When the enable signal is a high voltage signal and the overcurrent signal is high, the second switch transistor Q2 is turned on, the third switch transistor Q3 is turned on, and the fourth switch transistor Q4 is turned off. A closed loop is formed by the first power supply terminal VDD1, the third switch transistor Q3, the third resistor R3, the seventh resistor R7, the fourth switch transistor Q4, and the ground terminal GND. At this time, the control electrodes of the fifth switch transistor Q5 and the sixth switch transistor Q6 are grounded (connected to a low level), the fifth switch transistor Q5 is turned on, and the sixth switch transistor Q6 is turned off. The control electrode of the first switch transistor Q1 is connected to the first power supply terminal VDD1 (connected to a high level), and the first switch transistor Q1 is turned off.

[0108] When the enable signal is a low level signal and the overcurrent signal is low, the second switch transistor Q2 and the third switch transistor Q3 are turned off, and the fourth transistor is turned off. At this time, the control electrodes of the fifth switch transistor Q5 and the sixth switch transistor Q6 are grounded (low level), the fifth switch transistor Q5 is turned on, and the sixth switch transistor Q6 is turned off. The control electrode of the first switch transistor Q1 is connected to the first power supply terminal VDD1, and thus the first switch transistor Q1 is turned off.

[0109] When the enable signal is a low level signal and the overcurrent signal is high, the second switch transistor Q2 and the third switch transistor Q3 are turned off, and the fourth transistor is turned on. At this time, the control electrodes of the fifth switch transistor Q5 and the sixth switch transistor Q6 are grounded (low level), the fifth switch transistor Q5 is turned on, and the sixth switch transistor Q6 is turned off. The control electrode of the first switch transistor Q1 is connected to the first power supply terminal VDD1, and thus the first switch transistor Q1 is turned off.

[0110] In some embodiments, the overcurrent detection module 14 includes an overcurrent protection resistor R21 and a differential amplification circuit. The overcurrent protection resistor R21 is connected in series to the positive bus BUS+, and the differential amplification circuit is connected to both ends of the overcurrent protection resistor R21 and the control module 18, respectively. The differential amplification circuit is used to amplify the difference between the voltages at both ends of the overcurrent protection resistor R21, thereby obtaining an overcurrent signal and outputting it to the control module 18.

[0111] Specifically, the overcurrent protection resistor R21 can be one or multiple, and the number is not limited. The resistance value of the overcurrent protection resistor R21 can be adjusted according to actual use requirements. In this embodiment, the overcurrent protection resistor R21 can be two, and the two overcurrent protection resistors R21 are connected in parallel and then connected in series to the positive bus BUS+. In this way, the power consumption of the overcurrent protection resistor R21 can be reduced to reduce the rated power of the switch module 12, and at the same time, damage to a single overcurrent protection resistor R21 caused by excessive current can be avoided.

[0112] The differential amplification circuit comprises a ninth resistor R9, a tenth resistor R10, a comparator IC3, a second capacitor C2, an eleventh resistor R11 and a twelfth resistor R12. The one end of the ninth resistor R9 is connected to the one end of the overcurrent protection resistor R21, and the one end of the tenth resistor R10 is connected to the other end of the overcurrent protection resistor R21. The comparator IC3 comprises a first input end, a second input end and an output end. The first input end can be a positive input end, and the second input end can be a negative input end. The first input end of the comparator IC3 is connected to the other end of the ninth resistor R9, the second input end of the comparator IC3 is connected to the other end of the tenth resistor R10, and the output end of the comparator IC3 is connected to the control module 18, for outputting an enable signal to the control module 18. The one end of the second capacitor C2 is connected to the second input end, and the other end of the second capacitor C2 is connected to the output end. The one end of the eleventh resistor R11 is connected to the second input end, and the other end of the eleventh resistor R11 is connected to the output end. The one end of the twelfth resistor R12 is connected to the first input end, and the other end of the twelfth resistor R12 is connected to the ground end GND.

[0113] It should be noted that the amplification multiple of the differential amplification circuit can be adjusted according to the actual use requirement of the carrier power supply system 100. Specifically, the amplification multiple is not limited, and the resistance value of the eleventh resistor R11 and the capacitance value of the second capacitor C2 can be adjusted to adjust the amplification multiple of the differential amplification circuit.

[0114] Please refer to Figure 2 In some embodiments, the state detection module 16 comprises a first optocoupler detection unit 162 and a controller MCU. The first optocoupler detection unit 162 is connected to the positive bus BUS+, the negative bus BUS- and the second power supply end VDD2, for detecting the power supply state of the carrier power supply system 100 and generating a first logic control signal. The controller is connected to the first optocoupler detection unit 162 and the control module, for generating an enable signal according to the first logic control signal.

[0115] In this embodiment, the voltage of the second power supply end VDD2 can be 3.3 volts, for supplying power to the first optocoupler detection unit 162. When the power supply state is that the bus has no power supply or the bus has a forward voltage, the first logic control signal generated by the first optocoupler detection unit 162 is a high-level signal. When the power supply state is that the bus has a reverse voltage, the first logic control signal generated by the first optocoupler detection unit 162 is a low-level signal. The enable signal generated by the controller when the first logic control signal is a high-level signal can enable the control module 18 to control the switch module 12 to be turned on. The enable signal generated by the controller when the first logic control signal is a low-level signal can enable the control module 18 to control the switch module 12 to be turned off.

[0116] Please refer to Figure 3In some embodiments, the state detection module 16 comprises a second optocoupler detection unit 164 connected to the first optocoupler detection unit 162, the negative bus BUS- and the second power supply terminal VDD2, for generating a second logic signal according to the power supply state of the carrier power supply system 100, and the controller MCU is further connected to the second optocoupler detection unit 164, for generating an enable signal according to the first logic control signal and the second logic control signal.

[0117] The first logic signal and the second logic signal can each comprise a high level signal and a low level signal, wherein when the first logic signal and the second logic signal are both high level signals, it indicates that the bus is not powered. At this time, the enable signal generated by the controller MCU according to the first logic signal and the second logic signal is a high level signal. When the first logic signal is a high level signal and the second logic signal is a low level signal, it indicates that the bus has a positive voltage, and when multiple power supplies DC are allowed to supply power, the enable signal generated by the controller MCU according to the first logic signal and the second logic signal is a high level signal. When the first logic signal is a low level signal and the second logic signal is a high level signal, it indicates that the bus has a reverse voltage, and the enable signal generated by the controller MCU according to the first logic signal and the second logic signal is a low level signal. When the first logic signal is a low level signal and the second logic signal is a low level signal, the enable signal generated by the controller MCU according to the first logic signal and the second logic signal is a low level signal.

[0118] Please refer to Figure 2 Or Figure 3 Specifically, the first optocoupler detection unit 162 comprises a thirteenth resistor R13, a fourteenth resistor R14, a third capacitor C3, a first optocoupler IC1, a fifteenth resistor R15, a sixteenth resistor R16 and a fourth capacitor C4. One end of the thirteenth resistor R13 is connected to the positive bus BUS+, one end of the fourteenth resistor R14 is connected to the other end of the thirteenth resistor R13, and the other end of the fourteenth resistor R14 is connected to the negative bus BUS-. One end of the third capacitor C3 is connected to the other end of the thirteenth resistor R13, and the other end of the third capacitor C3 is connected to the negative bus BUS-. The first pin of the first optocoupler IC1 is connected to the negative bus BUS-, the second pin of the first optocoupler IC1 is connected to the other end of the thirteenth resistor R13, and the third pin of the first optocoupler IC1 is connected to the ground terminal GND. One end of the fifteenth resistor R15 is connected to the second power supply terminal VDD2, and the other end of the fifteenth resistor R15 is connected to the fourth pin of the first optocoupler IC1. One end of the sixteenth resistor R16 is connected to the other end of the fifteenth resistor R15, and the other end of the sixteenth resistor R16 is connected to the controller MCU. One end of the fourth capacitor C4 is connected to the other end of the sixteenth resistor R16, and the other end of the fourth capacitor C4 is connected to the ground terminal GND.

[0119] Referring to Figure 3 The second optocoupling detection unit 164 comprises a second optocoupling device IC2, a seventeenth resistor R17, an eighteenth resistor R18 and a fifth capacitor C5. The first pin of the second optocoupling device IC2 is connected to the other end of the thirteenth resistor, the second pin of the second optocoupling device IC2 is connected to the negative bus BUS-, and the third pin of the second optocoupling device IC2 is connected to the ground end GND. One end of the seventeenth resistor R17 is connected to the second power supply end VDD2, and the other end of the seventeenth resistor R17 is connected to the fourth pin of the second optocoupling device IC2. One end of the eighteenth resistor R18 is connected to the other end of the seventeenth resistor R17, and the other end of the eighteenth resistor R18 is connected to the MCU. One end of the fourth capacitor C4 is connected to the other end of the eighteenth resistor R18, and the other end of the fourth capacitor C4 is connected to the ground end GND.

[0120] Further referring to Figure 2 Or Figure 3 In some embodiments, the state detection module 16 further comprises an RC filtering unit, which comprises a filtering capacitor C21 and a filtering resistor R22. One end of the filtering resistor R22 is connected to the output end of the comparator IC3, the other end of the filtering resistor R22 is connected to the controller MCU, one end of the filtering capacitor C21 is connected to the other end of the filtering resistor R22, and the other end of the filtering capacitor C21 is connected to the ground end GND. The RC filtering unit is used to filter the overcurrent signal output by the comparator IC3 and then transmit it to the controller. In this way, the controller MCU can realize current sampling and software overcurrent protection control.

[0121] In some embodiments, the protection control circuit 10 further comprises a diode D1. The positive electrode of the diode D1 is connected to the power supply DC, and the negative electrode of the diode D1 is connected to the positive bus BUS+.

[0122] In this way, the reverse voltage existing in the bus can be prevented from flowing back into the power supply DC, thereby protecting the safety of the power supply DC.

[0123] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0124] While the embodiments of the present application have been shown and described, it is to be understood that the embodiments can be varied, modified, substituted and changed by those skilled in the art without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

Claims

1. A protection control circuit for a carrier power supply system, characterized by The carrier power supply system comprises a power supply, a positive bus, a negative bus and a communication filter module, the communication filter module is connected with the positive bus and the negative bus respectively, the protection control circuit is connected with the power supply and the positive bus through the communication filter module, and the protection control circuit comprises: a switch module connected with the power supply and the positive bus; an overcurrent detection module connected with the positive bus, used for detecting the current of the positive bus and generating an overcurrent signal according to the current; a state detection module connected with the positive bus and the negative bus, used for detecting the power supply state of the carrier power supply system and generating an enable signal according to the power supply state; a control module connected with the overcurrent detection module, the state detection module and the switch module, used for controlling the switch module to be turned on or turned off according to the overcurrent signal and / or the enable signal, so that the power supply and the positive bus are turned on or turned off.

2. The protection control circuit of claim 1, wherein, The switch module comprises: a first switch transistor, a first pole of the first switch transistor is connected with the power supply, a second pole of the first switch transistor is connected with the positive bus, and a control pole of the first switch transistor is connected with the control module; a first resistor, one end of the first resistor is connected with the first pole of the first switch transistor, and the other end of the first resistor is connected with the control pole of the switch transistor.

3. A protection control circuit according to claim 2, characterised in that, The switch module further comprises: a transient voltage suppressor, one end of the transient voltage suppressor is connected with the first pole of the first switch transistor, and the other end of the transient voltage suppressor is connected with the second pole of the first switch transistor.

4. The protection control circuit of claim 1, wherein, The control module comprises: an enable control unit connected with the state detection module, a first power supply end and a ground end, used for generating a first output control signal according to the enable signal; an overcurrent protection unit connected with the overcurrent detection module, used for generating a second output control signal according to the overcurrent signal; a push-pull output unit connected with the first power supply end, the enable control unit, the overcurrent protection unit and the switch module, used for generating a switch signal according to the first output control signal and / or the second output control signal, so as to control the switch module to be turned on or turned off.

5. A protection control circuit according to claim 4, characterised in that, The enable control unit comprises: a second resistor, one end of the second resistor is connected with the first power supply end; a second switch transistor, a first pole of the second switch transistor is connected with the other end of the second resistor, a second pole of the second switch transistor is connected with the ground end, and a control pole of the second switch transistor is connected with the state detection module; a third switch transistor, a first pole of the third switch transistor is connected with the first power supply end, and the control pole of the second switch transistor is connected with the other end of the second resistor; a third resistor, one end of the third resistor is connected with a second pole of the third switch transistor, and the other end of the third resistor is connected with the push-pull output unit.

6. The protection control circuit of claim 4, wherein, The overcurrent protection unit comprises: a fourth resistor, one end of the fourth resistor is connected with the overcurrent detection module; a fifth resistor, one end of the fifth resistor is connected with the other end of the fourth resistor, and the other end of the fifth resistor is connected with the ground end; a sixth resistor, one end of the sixth resistor is connected with the other end of the fourth resistor; a first capacitor, one end of the first capacitor is connected with the other end of the sixth resistor, and the other end of the first capacitor is connected with the ground end; A fourth switch transistor, a first pole of the fourth switch transistor is connected to the push-pull output unit, a second pole of the fourth switch transistor is connected to a ground terminal, and a control pole of the fourth switch transistor is connected to the other end of the sixth resistor.

7. A protection control circuit according to any of claims 4-6, characterized in that, The push-pull output unit comprises: A fifth switch transistor, a first pole of the fifth switch transistor is connected to a first power supply terminal, and a control pole of the fifth switch transistor is connected to the enable control unit and the overcurrent protection unit; A sixth switch transistor, a first pole of the sixth switch transistor is connected to a second pole of the fifth switch transistor, a second pole of the sixth switch transistor is connected to a ground terminal, and a control pole of the sixth switch transistor is connected to the enable control unit and the overcurrent protection unit; A seventh resistor, one end of the seventh resistor is connected to the second pole of the fifth switch transistor and the first pole of the sixth switch transistor, and the other end of the seventh resistor is connected to the switch module; An eighth resistor, one end of the eighth resistor is connected to the control pole of the sixth switch transistor, and the other end of the eighth resistor is connected to the second pole of the sixth switch transistor.

8. The protection control circuit of claim 1, wherein, The overcurrent detection module comprises: An overcurrent protection resistor connected in series to the positive bus; A ninth resistor, one end of the ninth resistor is connected to one end of the overcurrent protection resistor; A tenth resistor, one end of the tenth resistor is connected to the other end of the overcurrent protection resistor; A comparator comprising a first input terminal, a second input terminal, and an output terminal, the first input terminal is connected to the other end of the ninth resistor, the second input terminal is connected to the other end of the tenth resistor, and the output terminal is connected to the control module; A second capacitor, one end of the second capacitor is connected to the second input terminal, and the other end of the second capacitor is connected to the output terminal; An eleventh resistor, one end of the eleventh resistor is connected to the second input terminal, and the other end of the eleventh resistor is connected to the output terminal; A twelfth resistor, one end of the twelfth resistor is connected to the first input terminal, and the other end of the twelfth resistor is connected to a ground terminal.

9. The protection control circuit of claim 1, wherein, The state detection module comprises: A first optocoupler detection unit connected to the positive bus, a second power supply terminal, and the negative bus, for generating a first logic control signal according to the power supply state of the carrier power supply system; A controller connected to the first optocoupler detection unit and the control module, for generating the enable signal according to the first logic control signal.

10. The protection control circuit of claim 9, wherein, The state detection module further comprises: A second optocoupler detection unit connected to the first optocoupler detection unit, the negative bus, and the second power supply terminal, for generating a second logic control signal according to the power supply state of the carrier power supply system; The controller is further connected to the second optocoupler detection unit, for generating the enable signal according to the first logic control signal and the second logic control signal.

11. The protection control circuit of claim 10, wherein, The first optocoupler detection unit comprises: A thirteenth resistor, one end of the thirteenth resistor is connected to the positive bus; A fourteenth resistor, one end of the fourteenth resistor is connected to the other end of the thirteenth resistor, and the other end of the fourteenth resistor is connected to the negative bus; A third capacitor, one end of the third capacitor is connected to the other end of the thirteenth resistor, and the other end of the third capacitor is connected to the negative bus; a first pin of the first optocoupler is connected to the negative bus, a second pin of the first optocoupler is connected to the other end of the thirteenth resistor, and a third pin of the first optocoupler is connected to the ground terminal; a fifteenth resistor, one end of the fifteenth resistor is connected to the second power supply terminal, and the other end of the fifteenth resistor is connected to a fourth pin of the first optocoupler; a sixteenth resistor, one end of the sixteenth resistor is connected to the other end of the fifteenth resistor, and the other end of the sixteenth resistor is connected to the controller; a fourth capacitor, one end of the fourth capacitor is connected to the other end of the sixteenth resistor, and the other end of the fourth capacitor is connected to the ground terminal.

12. The protection control circuit of claim 11, wherein, The second optocoupler detection unit comprises: a second optocoupler, a first pin of the second optocoupler is connected to the other end of the thirteenth resistor, a second pin of the second optocoupler is connected to the negative bus, and a third pin of the second optocoupler is connected to the ground terminal; a seventeenth resistor, one end of the seventeenth resistor is connected to the second power supply terminal, and the other end of the seventeenth resistor is connected to a fourth pin of the second optocoupler; an eighteenth resistor, one end of the eighteenth resistor is connected to the other end of the seventeenth resistor, and the other end of the eighteenth resistor is connected to the controller; a fifth capacitor, one end of the fifth capacitor is connected to the other end of the eighteenth resistor, and the other end of the fifth capacitor is connected to the ground terminal.

13. The protection control circuit of claim 1, wherein, The protection control circuit further comprises: a diode, the positive electrode of the diode is connected to the power supply, and the negative electrode of the diode is connected to the positive bus.

14. A carrier powered system, characterized by The carrier power supply system comprises a power supply, a communication filtering module, a communication module, a positive bus, a negative bus, and the protection control circuit according to any one of claims 1-13; The communication filtering module is connected to the switching module, the positive bus, the negative bus, and the ground terminal, respectively. The communication module is connected to the positive bus and the negative bus.

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