Short circuit protection circuit and power terminal
By introducing a current monitoring point and intelligent switch control into the single-pole boost circuit, combined with filtering and absorption circuits, rapid protection and recovery of the circuit during short circuits are achieved, overcoming the shortcomings of existing fuses and relays, and improving the reliability and efficiency of the circuit.
Patent Information
- Application Number
- CN202422680106.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-11-04
AI Technical Summary
In existing short-circuit protection schemes for single-pole boost circuits, fuses lack reset functionality, circuit breakers are bulky and costly, and relays are prone to sticking together, resulting in unreliable and inefficient circuit protection.
Design a short-circuit protection circuit, including a current monitoring point, an energy storage inductor, a first switch, and a second switch. The circuit is quickly cut off by controlling the opening and closing of the switches through current monitoring and is restored after the fault is cleared. An insulated gate bipolar transistor and a metal-oxide-semiconductor field-effect transistor are used as switches, and a filter capacitor and a snubber diode are combined to enhance the circuit stability.
It improves the reliability and efficiency of protection and recovery when the boost circuit output side is short-circuited, simplifies the circuit structure, and avoids problems such as fuse replacement and relay sticking.
Smart Images
Figure CN223527768U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to electronic circuit technical field, especially short -circuit protection circuit and electric power terminal. BACKGROUND
[0002] With the progress of the times, electronic components performance has obtained the rapid development, and unipolar boost circuit (or called unipolar boost circuit), it is a kind of switching DC boost circuit, it can make output voltage higher than input voltage, due to its simple structure, easy control advantage, in various electronic products have been widely used.
[0003] The current unipolar boost circuit often needs to increase fuse, circuit breaker or relay on its output side to carry out short-circuit protection.
[0004] But using existing unipolar boost circuit short-circuit protection scheme, fuse does not have recovery function, needs to replace fuse after fusing and can continue to use, circuit breaker is relatively big in size, cost is relatively high, and relay is easy to be stuck in contact and cannot be disconnected after being used for a period of time, there is a security risk, and all cannot simplify, reliably and efficiently realize circuit protection and recovery. UTILITY MODEL CONTENTS
[0005] The utility model discloses a kind of short-circuit protection circuit and electric power terminal, to improve the reliability and efficiency of boost circuit output side short-circuit protection and recovery, and simplify circuit structure.
[0006] Firstly, the utility model provides a kind of short-circuit protection circuit, comprising: power supply, load, first switch, forward diode, second switch, energy storage inductor;Wherein, current monitoring point is equipped in the short-circuit protection circuit, and the current monitoring point is set at the position close to any end of the load;
[0007] One end of the energy storage inductor is connected with the positive pole of the power supply, the other end of the energy storage inductor is connected with one end of the first switch and the input end of the forward diode, the other end of the first switch is connected with the negative pole of the power supply;
[0008] The forward diode, the second switch and the load are connected in series, and the circuit formed by the series connection of the forward diode, the second switch and the load is connected in parallel with the first switch, wherein one end of the second switch is connected with the output end of the forward diode, the other end of the second switch is connected with one end of the load, and the other end of the load is connected with the negative pole of the power supply and the other end of the first switch.
[0009] In optional implementation, the short-circuit protection circuit further comprises: input filter capacitor and output filter capacitor;
[0010] The input filter capacitor is connected in parallel with the first switch, one end of which is connected with one end of the energy storage inductor and the positive pole of the power supply, and the other end of which is connected with the negative pole of the power supply and the other end of the first switch;
[0011] The output filter capacitor is connected in parallel with the load, one end of which is connected with the other end of the second switch and one end of the load, and the other end of which is connected with the negative pole of the power supply, the other end of the first switch and the other end of the load.
[0012] In an optional embodiment, the short-circuit protection circuit further comprises an absorption capacitor and an absorption diode.
[0013] The absorption capacitor and the absorption diode are connected in series, and the circuit formed by the absorption capacitor and the absorption diode connected in series is connected in parallel with the first switch.
[0014] In an optional embodiment, the short-circuit protection circuit further comprises two voltage monitoring points.
[0015] The two voltage monitoring points are respectively arranged at positions close to two ends of the output filter capacitor.
[0016] In an optional embodiment, the current monitoring point is arranged at a position close to any one end of the energy storage inductor.
[0017] In an optional embodiment, the first switch is an insulated gate bipolar transistor.
[0018] In an optional embodiment, the second switch is a metal-oxide semiconductor field effect transistor.
[0019] In an optional embodiment, the input filter capacitor, the output filter capacitor and the absorption capacitor are non-limited thin film capacitors or electrolytic capacitors.
[0020] In an optional embodiment, the short-circuit protection circuit further comprises a control device.
[0021] The control device is arranged between one end of the first switch and one end of the second switch, is in communication connection with the first switch and the second switch, and is used for controlling opening and closing of the first switch and the second switch according to a sampling value of the current monitoring point.
[0022] In a second aspect, the utility model provides a kind of electric power terminal, comprising the short-circuit protection circuit of any one of the foregoing embodiments.
[0023] The utility model has the advantages of:
[0024] The short-circuit protection circuit provided by the embodiment of the utility model, including: power supply, load, first switch, forward diode, second switch, energy storage inductor, wherein, the short-circuit protection circuit is equipped with current monitoring point, the current monitoring point is arranged in the position of being close to any end of the load, one end of the energy storage inductor is connected with the positive pole of the power supply, the other end of the energy storage inductor is connected with one end of the first switch and the input end of the forward diode, the other end of the first switch is connected with the negative pole of the power supply, the forward diode, the second switch and the load are connected in series, the circuit formed by the forward diode, the second switch and the load are connected in parallel with the first switch, wherein, one end of the second switch is connected with the output end of the forward diode, the other end of the second switch is connected with one end of the load, the other end of the load is connected with the negative pole of the power supply and the other end of the first switch, by using the short-circuit protection circuit, the opening and closing of the first switch and the second switch are controlled according to the monitoring value of the current monitoring point, so that when the short circuit occurs at the load end of the circuit and the current in the circuit increases instantaneously, the circuit is rapidly and completely cut off by disconnecting the first switch and the second switch, and the first switch and the second switch are closed again after the fault is eliminated, thereby improving the reliability and efficiency of protection and recovery when the output side of the boost circuit is short-circuited, and the circuit structure is simplified. BRIEF DESCRIPTION OF DRAWINGS
[0025] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to the structure shown in the drawings without creating labor.
[0026] Figure 1 The short-circuit protection circuit structure schematic diagram provided by an embodiment of the application is shown in the figure.
[0027] Figure 2 The short-circuit protection circuit structure schematic diagram provided by another embodiment of the application is shown in the figure.
[0028] Figure 3 The short-circuit protection circuit structure schematic diagram provided by another embodiment of the application is shown in the figure.
[0029] Figure 4 The short-circuit protection circuit structure schematic diagram provided by another embodiment of the application is shown in the figure.
[0030] Reference signs:
[0031] P - power supply; Ci - input filter capacitor; L - energy storage inductor; S1 - first switch; S2 - second switch; D1 - forward diode; D2 - absorption diode; CL - absorption capacitor; Co - output filter capacitor; RL - load. DETAILED DESCRIPTION
[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0033] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.
[0034] The single-pole boost circuit is a kind of switching DC boost circuit, which can make output voltage higher than input voltage. The existing single-pole boost circuit short circuit protection scheme mainly increases fuse, circuit breaker or relay on the output side (i.e. load side) of the circuit for short circuit protection. However, the fuse does not have a recovery function, and needs to be replaced after melting to continue using, which is low in efficiency. The circuit breaker is large in size, high in cost and not simple in structure. The relay is prone to contact sticking and unable to disconnect after a period of use, which has safety hazards and insufficient stability. The embodiments of the present application aim to provide a short circuit protection circuit, which can improve the reliability and efficiency of protection and recovery when the boost circuit output side is short-circuited, and simplify the circuit structure.
[0035] Figure 1 The air opening detection circuit structure schematic diagram provided by an embodiment of the present application is shown in FIG. 1, which includes a power supply P, a load RL, a first switch S1, a forward diode D1, a second switch S2 and an energy storage inductor L. Figure 1 As shown in the figure, the circuit includes a power supply P, a load RL, a first switch S1, a forward diode D1, a second switch S2 and an energy storage inductor L. In the short circuit protection circuit, a current monitoring point is provided, which is arranged at a position close to either end of the load RL.
[0036] One end of the above-mentioned energy storage inductor L is connected to the positive pole of the above-mentioned power supply P, and the other end of the above-mentioned energy storage inductor L is connected to one end of the above-mentioned first switch S1 and the input end of the above-mentioned forward diode D1. The other end of the above-mentioned first switch S1 is connected to the negative pole of the above-mentioned power supply P.
[0037] The above-mentioned forward diode D1, the above-mentioned second switch S2 and the above-mentioned load RL are connected in series, and the circuit formed by the above-mentioned forward diode D1, the above-mentioned second switch S2 and the above-mentioned load RL is connected in parallel with the above-mentioned first switch S1, wherein one end of the above-mentioned second switch S2 is connected to the output end of the above-mentioned forward diode D1, the other end of the above-mentioned second switch S2 is connected to one end of the above-mentioned load RL, and the other end of the above-mentioned load RL is connected to the negative pole of the above-mentioned power supply P and the other end of the above-mentioned first switch S1.
[0038] Please refer to Figure 1 The above-mentioned circuit can include two loops, one of which can be formed in the order of power supply P→energy storage inductor L→first switch S1→power supply P, and the other of which can be formed in the order of power supply P→energy storage inductor L→forward diode D1→second switch S2→load RL→power supply P. The two loops can be in parallel. It can be understood that the above-mentioned content is only an example, and the specific types, quantities, connection order, etc. of the elements in the circuit can be adjusted and determined according to actual conditions without changing the principles and functions of the circuit, and are not limited by the above-mentioned example.
[0039] The above-mentioned energy storage inductor L can be used to generate a magnetic field and store electrical energy. When the power supply P in the circuit is disconnected, the inductor will put the electrical energy it stores back into the circuit in reverse to ensure the stability of the circuit. Of course, the specific type, model, performance parameters, etc. of the above-mentioned energy storage inductor L can be selected and determined according to actual needs, which are not limited herein.
[0040] For example, a current monitoring device with communication function, such as a current sensor, an electronic ammeter, an electronic ammeter, etc. can be provided at the above-mentioned current monitoring point to feed back the monitored current information to a control device such as an MCU (Microcontroller Unit) or an ECU (Electronic Control Unit). The current monitoring device monitors the current value at the current monitoring point, which can be real-time or periodic, for example, it can be detected once every 1s, every 2s, every 3s. It can be understood that in order to feed back the current information at the fastest speed when the current at the current monitoring point changes, real-time monitoring can be more advantageous than periodic monitoring. The current value at the above-mentioned current monitoring point can be used to reflect the current situation of the load circuit. When the current value at the above-mentioned current monitoring point suddenly increases, it can indicate that a short circuit occurs in the load circuit.
[0041] The first switch S1 and the second switch S2 can be automatic switches with communication connection function, which can automatically realize opening or closing when receiving the opening / closing instruction sent from the control device such as MCU, ECU, etc.
[0042] The communication can be wired communication or wireless communication, and the communication protocol used can be, for example, but not limited to, CAN (Controller Area Network) communication protocol, LIN (Local Interconnect Network) communication protocol, etc. The flow of the communication can be, for example, that after the current monitoring device feeds back the monitored current information to the control device, the control device judges whether a short circuit occurs in the load circuit according to the preset rules, and if a short circuit occurs in the load circuit, the control device sends an opening instruction to the first switch S1 and the second switch S2.
[0043] Of course, the specific current monitoring device arranged at the current monitoring point, how the current monitoring device is connected to the circuit and how the communication function is realized, the specific switch of the first switch S1 and the second switch S2, and how the communication function is realized, etc. can all be selected and determined according to actual needs, and are not limited herein.
[0044] The short-circuit protection circuit provided by the embodiment comprises a power supply P, a load RL, a first switch S1, a forward diode D1, a second switch S2 and an energy storage inductor L.
[0045] Figure 2 The short-circuit protection circuit structure diagram provided by another embodiment of the application is shown in Figure 2 Figure 1 The short-circuit protection circuit provided by the embodiment can further comprise an input filter capacitor Ci and an output filter capacitor Co.
[0046] The input filter capacitor Ci is connected in parallel with the first switch S1, one end of the input filter capacitor Ci is connected with one end of the energy storage inductor L and the positive pole of the power supply P, and the other end of the input filter capacitor Ci is connected with the negative pole of the power supply P and the other end of the first switch S1.
[0047] The output filter capacitor Co is connected in parallel with the load RL, one end of the output filter capacitor Co is connected with the other end of the second switch S2 and one end of the load RL, and the other end of the output filter capacitor Co is connected with the negative pole of the power supply P, the other end of the first switch S1 and the other end of the load RL.
[0048] It can be understood that the above content is only an example, and the specific types, quantities, connection sequences and the like of the elements in the circuit can be adjusted and determined according to the actual situation without changing the principle and function of the circuit, and the above example is not limited.
[0049] The aforementioned input filter capacitor Ci and output filter capacitor Co can be used to filter out high-frequency noise and spurious waves in the circuit, making the output signal of the circuit purer and more stable. It is understood that the specific type, model, performance parameters, etc. of the aforementioned input filter capacitor Ci and output filter capacitor Co can be selected and determined according to actual needs, and no restrictions are imposed here.
[0050] The short-circuit protection circuit provided in this embodiment also includes an input filter capacitor Ci and an output filter capacitor Co. Adding these two capacitors to the circuit can filter out high-frequency noise and interference, resulting in a purer and more stable output signal.
[0051] Furthermore, in Figure 2 Based on the embodiments, such as Figure 3 As shown, the above short-circuit protection circuit may also include: an absorption capacitor CL and an absorption diode D2.
[0052] The absorption capacitor CL and the absorption diode D2 are connected in series, and the circuit formed by the series connection of the absorption capacitor CL and the absorption diode D2 is connected in parallel with the first switch S1.
[0053] Please refer to Figure 3 The specific connection relationship between the absorption capacitor CL and the absorption diode D2 can be as follows: the input terminal of the absorption diode D2 is connected to the other end of the energy storage inductor L, one end of the first switch S1 and the input terminal of the positive capacitor; the output terminal of the absorption diode D2 is connected to one end of the absorption capacitor CL; and the other end of the absorption capacitor CL is connected to the negative terminal of the power supply P, the other end of the input filter capacitor Ci, the other end of the first switch S1, the other end of the output filter capacitor Co and the other end of the load RL.
[0054] It is understood that the above content is only an example. Without changing the circuit principle and function, the specific types, quantities, and connection order of components in the circuit can be adjusted and determined according to the actual situation, and are not limited to the above examples.
[0055] The aforementioned absorption capacitor CL and absorption diode D2 can be used to absorb the energy released instantaneously by the energy storage inductor L, preventing the energy storage inductor L from short-circuiting in the load circuit and the energy (i.e., the impulse voltage) released instantaneously when the first switch S1 and the second switch S2 are opened, thus preventing damage to the first switch S1. It is understood that the specific type, model, performance parameters, etc. of the aforementioned absorption capacitor CL and absorption diode D2 can be selected and determined according to actual needs, and are not restricted here.
[0056] The short-circuit protection circuit provided by the embodiment further comprises an absorption capacitor CL and an absorption diode D2. The absorption capacitor CL and the absorption diode D2 are added to the circuit to absorb the energy released instantaneously by the energy storage inductor L, prevent the energy storage inductor L from releasing energy (i.e., impact voltage) to damage the first switch S1 instantaneously when the first switch S1 and the second switch S2 are disconnected, and enhance the stability of the circuit.
[0057] In addition, on the basis of the embodiment, the short-circuit protection circuit can further comprise two voltage monitoring points, and the two voltage monitoring points can be arranged at positions close to the two ends of the output filter capacitor Co. Figure 2 For example, the voltage monitoring point can be provided with a voltage monitoring device having a communication function, such as a voltage sensor, an electronic voltmeter, an electronic voltage meter, etc., so as to feed back the monitored voltage information to a control device such as an MCU or an ECU. The voltage monitoring device monitors the voltage value at the voltage monitoring point in real time or periodically, for example, once every 1 s, once every 2 s, or once every 3 s. It can be understood that, in order to feed back the voltage information at the fastest speed when the voltage at the voltage monitoring point changes, real-time monitoring is more advantageous than periodic monitoring. The voltage value at the voltage monitoring point can reflect the voltage condition at the two ends of the output filter capacitor Co. When the voltage value at the voltage monitoring point suddenly increases, it can be considered that the output filter capacitor Co releases energy instantaneously, i.e., the load circuit is short-circuited. The voltage value at the voltage monitoring point can be used together with the current value at the current monitoring point to monitor whether the load circuit is short-circuited. Of course, how to use the voltage value at the voltage monitoring point and the current value at the current monitoring point to monitor whether the load circuit is short-circuited can be determined according to the actual situation, which is not limited herein.
[0058] Further, on the basis of the embodiment, the current monitoring point can be arranged at a position close to any end of the energy storage inductor L.
[0059] Figure 2 That is, the current value at the current monitoring point in the embodiment is the current value passing through the energy storage inductor L. In this way, the current monitoring point can be used to monitor whether multiple load circuits are short-circuited at the same time.
[0060] That is, the current value at the current monitoring point in the embodiment is the current value passing through the energy storage inductor L. In this way, the current monitoring point can be used to monitor whether multiple load circuits are short-circuited at the same time.
[0061] Optionally, on the basis of the above embodiment, the first switch S1 can be an insulated gate bipolar transistor, also known as an igbt tube (Insulate-Gate Bipolar Transistor, also known as an insulated gate bipolar transistor), and the second switch S2 can be a metal-oxide semiconductor field effect transistor, also known as a mosfet tube (Metal-Oxide Semiconductor Field Effect Transistor, also known as a metal-oxide semiconductor field effect transistor). The short circuit protection circuit structure in this embodiment can be as shown in Figure 4 It can be understood that Figure 4 The above examples are only examples, and without changing the principles and functions of the circuit, the specific types, quantities, connection order, etc. of the elements in the circuit can be adjusted and determined according to the actual situation, and are not limited to the above examples.
[0062] The first switch S1 is an insulated gate bipolar transistor, and the second switch S2 is a metal-oxide semiconductor field effect transistor, which can be more conducive to controlling the opening and closing of the first switch S1 and the second switch S2 through communication connection.
[0063] Further, on the basis of the Figure 3 embodiment, the input filter capacitor Ci, the output filter capacitor Co, and the absorption capacitor CL can be non-limited thin film capacitors or electrolytic capacitors. Different types of capacitors can be selected according to different application scenarios, which can further enhance the adaptability and stability of the circuit.
[0064] Optionally, the short circuit protection circuit further comprises a control device, which is arranged between one end of the first switch S1 and one end of the second switch S2, and is in communication connection with the first switch S1 and the second switch S2, and is used for controlling the opening and closing of the first switch S1 and the second switch S2 according to the sampling value of the current monitoring point.
[0065] For example, the control device can be one or more of an MCU, an ECU, etc. The control device is arranged between one end of the first switch S1 and one end of the second switch S2, which is more conducive to its communication connection with the first switch S1 and the second switch S2. It can be understood that the control device can also receive the voltage value at the voltage monitoring point and the current value at the current monitoring point, so as to control the first switch S1 and the second switch S2 to be disconnected when the voltage value at the voltage monitoring point and the current value at the current monitoring point suddenly change greatly (for example, the current value at the current monitoring point suddenly increases from 1A to 20A), so as to protect the elements in the circuit, and after the fault in the circuit is eliminated, the first switch S1 and the second switch S2 are controlled to be closed, so as to quickly restore the operation of the circuit.
[0066] Of course, the above control device is specifically how to constitute, specifically how to determine when control the first switch S1 and the second switch S2 open, when control the first switch S1 and the second switch S2 close, can be determined according to the actual situation, not limited here.
[0067] Further, the embodiment of the application also provides a power terminal, comprising the short circuit protection circuit, and the function of the short circuit protection circuit can be realized through the power terminal in the circuit operation process.
[0068] The above only for the preferred embodiments of the present application, not therefore limit the patent range of the present application, all in the inventive concept of the present application, using the present application specification and drawings content made equivalent structure transformation, or direct / indirectly applied in other related technical fields are included in the patent protection scope of the present application.
Claims
1. A short-circuit protection circuit, characterized by comprising: The short-circuit protection circuit comprises a power supply, a load, a first switch, a forward diode, a second switch and an energy storage inductor. One end of the energy storage inductor is connected to the positive pole of the power supply, and the other end of the energy storage inductor is connected to one end of the first switch and the input end of the forward diode. The forward diode, the second switch and the load are connected in series, and the circuit formed by the forward diode, the second switch and the load is connected in parallel with the first switch. One end of the input filter capacitor is connected to one end of the energy storage inductor and the positive pole of the power supply, and the other end of the input filter capacitor is connected to the negative pole of the power supply and the other end of the first switch.
2. The short circuit protection circuit of claim 1, wherein The output filter capacitor is connected in parallel with the load, one end of the output filter capacitor is connected to the other end of the second switch and one end of the load, and the other end of the output filter capacitor is connected to the negative pole of the power supply, the other end of the first switch and the other end of the load. The short-circuit protection circuit further comprises an absorption capacitor and an absorption diode. The absorption capacitor and the absorption diode are connected in series, and the circuit formed by the absorption capacitor and the absorption diode is connected in parallel with the first switch.
3. The short circuit protection circuit of claim 2, wherein The short-circuit protection circuit further comprises two voltage monitoring points. The two voltage monitoring points are respectively arranged near the two ends of the output filter capacitor.
4. The short circuit protection circuit of claim 2, wherein The current monitoring point is arranged near one end of the energy storage inductor. The first switch is an insulated gate bipolar transistor.
5. The short circuit protection circuit of claim 2, wherein The second switch is a metal-oxide semiconductor field effect transistor.
6. The short-circuit protection circuit according to any one of claims 1 to 5, characterized in that The input filter capacitor, the output filter capacitor and the absorption capacitor are non-limited thin film capacitors or electrolytic capacitors.
7. The short-circuit protection circuit according to any one of claims 1 to 5, characterized in that The short-circuit protection circuit further comprises a control device.
8. The short circuit protection circuit of claim 3, wherein The control device is arranged between one end of the first switch and one end of the second switch, and is in communication connection with the first switch and the second switch, and is used for controlling the opening and closing of the first switch and the second switch according to the sampling value of the current monitoring point.
9. The short circuit protection circuit according to any of claims 1 to 5, 8, characterized in that The short-circuit protection circuit comprises the short-circuit protection circuit according to any one of claims 1-9. 10. A power terminal, characterized by