Quick turn-off circuit structure for isolation relay and isolation relay

Abstract

The invention discloses a quick turn-off circuit structure for an isolation relay and the isolation relay, the quick turn-off circuit comprises a primary side circuit and a secondary side circuit, and the primary side circuit is coupled with the secondary side circuit through an inductor. The secondary side circuit comprises a rectification module, a boost module, a first resistor, a first capacitor, a second resistor, a second capacitor, a reverse module and an MOS tube. Wherein the rectifier module comprises a first output end and a second output end; the input end of the boost module is connected with the first output end and the second output end. First ends of the first resistor and the first capacitor are connected with the first output end, and second ends are connected with reference ground; first ends of the second resistor and the second capacitor are connected with the second output end, and second ends are connected with reference ground; the anti-phase module is connected with the first output end and the second output end. The problem that operation power consumption is increased or switch-off time is long due to the fact that an optical coupled isolator is achieved through simulation in a circuit mode is solved, and quick response of the isolation relay is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of relays, and in particular to a fast shut-off circuit structure for an isolation relay and an isolation relay. Background Art

[0002] New energy vehicle relays are controlled switching devices on high-voltage circuits, and also play the role of active protection devices in the system. They are used in various switch nodes of high-voltage circuits, such as the main circuit of power batteries, fast charging circuits, motors in high-voltage electrical power supply lines, DCDC (DC to DC), air conditioning compressors, heaters, etc. Like the functions of general relays, new energy vehicle relays play the role of "switch" in the electrical automation industry, that is, the intermediate link of controlling the on-off of one circuit to control the on-off of the next circuit. Therefore, the function of automotive relays is to control the size and on-off of current.

[0003] In the prior art, different isolation relays are used in new energy vehicles, such as optocoupler isolation MOS relays, analog isolation relays that use circuits to simulate optocoupler isolation applications, etc. However, the cycle life of optocoupler isolation MOS relays is limited, and the switching speed is affected due to the long transmission delay of optocouplers. Using circuits to simulate optocoupler isolation relays will increase operating power consumption or cause the switch to be disconnected for a long time.

[0004] Based on this, a new technical solution is needed. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a fast shutdown circuit structure and an isolation relay for an isolation relay, so as to at least solve the problem in the prior art that the circuit form of the optocoupler isolator used to simulate the implementation will increase the operating power consumption or cause the switch to be disconnected for a long time.

[0006] The embodiment of the present invention provides the following technical solutions:

[0007] An embodiment of the present invention provides a fast shutdown circuit structure for an isolation relay, a primary circuit and a secondary circuit, wherein the primary circuit is coupled to the secondary circuit through an inductor, and the secondary circuit comprises:

[0008] A rectifier module, wherein the rectifier module is connected in parallel with the secondary inductor, the rectifier module comprises two first diode series structures, two second diode series structures and an oscillation capacitor, the two ends of the oscillation capacitor are correspondingly connected to the two first diode series structures and the two second diode series structures, the output ends of the first diode series structures are connected to form a first output end, and the output ends of the two second diode series structures are connected to form a second output end, and the rectifier module is used to generate a first power rail voltage through the first output end and generate a second power rail voltage through the second output end after the oscillation capacitor and the secondary inductor oscillate to generate a sinusoidal signal;

[0009] A boost module, wherein the input end of the boost module is connected to the first output end and the second output end respectively, and the output end of the boost module is connected to the discharge circuit module;

[0010] a first resistor, wherein a first end of the first resistor is connected to the first output end, and a second end of the first resistor is connected to a reference ground;

[0011] A first capacitor, wherein a first end of the first capacitor is connected to the first output end, and a second end of the first capacitor is connected to a reference ground;

[0012] a second resistor, wherein a first end of the second resistor is connected to the second output end, and a second end of the second resistor is connected to a reference ground;

[0013] a second capacitor, wherein a first end of the second capacitor is connected to the second output end, and a second end of the second capacitor is connected to a reference ground;

[0014] an inverting module, wherein an input terminal of the inverting module is respectively connected to the first output terminal and the second output terminal, and is used to collect and compare the first power rail voltage and the second power rail voltage;

[0015] A MOS tube, wherein the gate of the MOS tube is connected to the output end of the inverting module, the drain of the MOS tube is connected to the boosting module, and the source is grounded.

[0016] Furthermore, the inductor includes a primary inductor and a secondary inductor, the primary inductor is connected to the primary circuit, and the secondary inductor is connected to the secondary circuit.

[0017] Furthermore, the input ends of the two first diode series structures and the input ends of the two second diode series structures together constitute the input end of the rectifier module;

[0018] The first end of the oscillation capacitor is connected to a first diode series structure and a second diode series structure respectively, and the second end of the oscillation capacitor is connected to another diode series structure and another second diode series structure respectively.

[0019] Furthermore, the first end of the oscillation capacitor is respectively connected to the cathode of the first-end diode in the first diode series structure and the cathode of the first-end diode in the second diode series structure, and the second end of the oscillation capacitor is respectively connected to the cathode of the first-end diode in another diode series structure and the cathode of the first-end diode in another second diode series structure.

[0020] Furthermore, the number of diodes in the first diode series structure is greater than the number of diodes in the second diode series structure.

[0021] Furthermore, the drain of the MOS tube is connected to the gate voltage node of the switch tube in the boost module.

[0022] Furthermore, the MOS tube is an NMOS tube.

[0023] Furthermore, when there is no energy transfer in the primary circuit, the discharge time of the first power rail voltage is proportional to the product of the capacitance of the first capacitor and the resistance of the first resistor, and the discharge time of the second power rail voltage is proportional to the product of the capacitance of the second capacitor and the resistance of the second resistor.

[0024] Furthermore, after the inverting module collects the voltage difference between the first power rail voltage and the second power rail voltage, the inverting module outputs 0 when there is energy transfer in the primary circuit; and outputs 1 when there is no energy transfer in the primary circuit.

[0025] An embodiment of the present invention further provides an isolation relay, comprising any of the above-mentioned fast shutdown circuit structures.

[0026] Compared with the prior art, the at least one technical solution adopted in the embodiment of the present invention can achieve the following beneficial effects:

[0027] A fast shutdown circuit structure for an isolation relay of the present invention generates oscillation by using a secondary inductor and an oscillation capacitor, and enables a rectifier module to generate a first power rail voltage and a second power rail voltage, so that when there is no signal transmission in the primary circuit, a voltage difference is generated by the first power rail voltage and the second power rail voltage to turn on a fast discharge circuit and complete fast discharge, thereby solving the problem in the prior art that the use of circuit form to simulate the implementation of an optocoupler isolator will increase operating power consumption or cause a long switch disconnection time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 The structure of the existing analog optocoupler isolation relay (I);

[0030] Figure 2 The present analog optocoupler isolation relay discharge structure (II);

[0031] Figure 3 A schematic diagram of a fast shut-off circuit structure for an isolation relay of the present invention;

[0032] Figure 4 It is a schematic diagram of the rectifier module in the present invention.

[0033] The accompanying drawings of the present invention are as follows:

[0034] 10. Primary circuit;

[0035] 20. Secondary circuit; 21. Secondary inductor; 22. Rectifier module; 221. First diode series structure; 222. Second diode series structure; 223. Oscillation capacitor; 224. First output terminal; 225. Second output terminal; 23. Boost module; 24. First resistor; 25. First capacitor; 26. Second resistor; 27. Second capacitor; 28. Inverter module; 29. ​​MOS tube. DETAILED DESCRIPTION

[0036] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0037] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0038] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0039] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0040] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the examples can be practiced without these specific details.

[0041] A relay is an electrical control device. When the change of the input quantity (excitation quantity) reaches the specified requirements, it causes the controlled quantity to undergo a predetermined step change in the electrical output circuit. It has an interactive relationship between the control system (also known as the input circuit) and the controlled system (also known as the output circuit). When the relay is used in the automation control circuit, the relay is actually an "automatic switch" that uses a small current to control the operation of a large current, so it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

[0042] New energy vehicle relays are controlled switching devices on high-voltage circuits, and also play the role of active protection devices in the system. They are used in various switch nodes of high-voltage circuits, such as the main circuit of power batteries, fast charging circuits, motors in high-voltage electrical power supply lines, DCDC (DC to DC), air conditioning compressors, heaters, etc. Relays are usually the intermediate link that controls the on-off of one circuit to control the on-off of the next circuit. Therefore, the function of automotive relays is to control the size and on-off of the current.

[0043] Optocoupler isolation MOS (Metal-Oxide-Semiconductor) relays are generally used in existing new energy vehicles. Optocoupler isolation MOS relays use optocouplers to drive transistors, and the microcontroller gives a suitable electrical signal to control the optocoupler end, using light as the medium to transmit electrical signals. When an electrical signal is applied to the input end, the light emitter emits light, and the light receiver generates a photocurrent after receiving the signal, which flows out from the output end, thereby realizing the "light-electricity-light" conversion, thereby driving the transistor to conduct. Optocoupler isolation MOS relays use optical signals as a medium to achieve the coupling and transmission of electrical signals. The input and output are completely isolated electrically, and have the characteristics of strong anti-interference performance. However, compared with modern silicon-based semiconductor devices, optocoupler MOS isolation relays have limited cycle life, and the switching speed is affected due to the long transmission delay of optocouplers.

[0044] like Figure 1 As shown, Figure 1 An existing analog isolation relay that uses a circuit to simulate the application of optocoupler isolation requires an additional shutdown control module. The input of the shutdown control module is connected to a boost module to output a shutdown signal when the input voltage is lower than a preset threshold. In this process, an additional threshold voltage needs to be provided, and a comparison circuit is required to make a voltage high or low judgment, which will undoubtedly increase the operating power consumption.

[0045] like Figure 2 As shown, Figure 2 Another existing analog isolation relay that uses a circuit to simulate the application of optocoupler isolation is used. The discharge is carried out in the form of a pull-down resistor. At this time, the disconnection time of the relay is proportional to the resistance value of the pull-down resistor, and the switch disconnection time is long.

[0046] Based on this, the embodiment of the present invention proposes a processing solution: Figures 3-4 As shown, a fast shutdown circuit structure of an embodiment of the present invention generates a sinusoidal signal through a secondary inductor 21 and an oscillation capacitor 223, and uses a diode to construct a rectifier module 22. Therefore, when there is no energy transfer in the primary circuit 10, the first power rail voltage REC_V and the second power rail voltage DEC_V of the rectifier module 22 begin to discharge through a resistor, and the discharge time is adjusted by adjusting the product of the first resistor 24 and the first capacitor 25 and the product of the second resistor 26 and the second capacitor 27; in addition, the present invention can also pull down the gate voltage node VGATE of the switch tube of the boost module 23 for discharge through the inverting module 28 and the MOS tube 29, thereby realizing fast shutdown of the circuit to solve the problem of long switch disconnection time in the prior art.

[0047] The technical solutions provided by various embodiments of the present application are described below in conjunction with the accompanying drawings.

[0048] like Figures 3-4As shown, a fast shutdown circuit structure for an isolation relay in an embodiment of the present invention includes a primary circuit 10 and a secondary circuit 20. The primary circuit 10 is coupled to the secondary circuit 20 through an inductor. The secondary circuit 20 includes a rectifier module 22, a boost module 23, a first resistor 24, a first capacitor 25, a second resistor 26, a second capacitor 27, an inverting module and a MOS tube 29. Among them, the rectifier module 22 is connected in parallel with the secondary inductor 21, and the rectifier module 22 includes two first diode series structures 221, two second diode series structures 222 and an oscillation capacitor 223. The two ends of the oscillation capacitor 223 are correspondingly connected to the two first diode series structures 221 and the two second diode series structures 222. The output ends of the first diode series structures 221 are connected to form a first output end 224, and the output ends of the two second diode series structures 222 are connected to form a second output end 225. The rectifier module 22 is used to generate a first power rail voltage REC_V through the first output end 224 and a second power rail voltage DEC_V through the second output end 225 after the oscillation capacitor 223 and the secondary inductor 21 oscillate to generate a sinusoidal signal; the input ends of the boost module 23 are respectively connected to the first output end 224. , the second output terminal 225 is connected, the output terminal of the boost module 23 is connected to the discharge circuit module; the first end of the first resistor 24 is connected to the first output terminal 224, and the second end is connected to the reference ground; the first end of the first capacitor 25 is connected to the first output terminal 224, and the second end is connected to the reference ground; the first end of the second resistor 26 is connected to the second output terminal 225, and the second end is connected to the reference ground; the first end of the second capacitor 27 is connected to the second output terminal 225, and the second end is connected to the reference ground; the input end of the inverting module 28 is respectively connected to the first output terminal 224 and the second output terminal 225, for collecting and comparing the first power rail voltage REC_V and the second power rail voltage DEC_V; the gate of the MOS tube 29 is connected to the output end of the inverting module 28, the drain of the MOS tube 29 is connected to the boost module 23, and the source is grounded.

[0049] Among them, when there is energy transfer in the primary circuit 10, the secondary inductor 21 and the oscillation capacitor 223 can generate a sinusoidal signal. Since the rectifier module 22 is composed of a diode, the first output terminal 224 can output the first power rail voltage REC_V, and the second output terminal 225 can output the second power rail voltage DEC_V.

[0050] When there is no energy transfer in the primary circuit 10 , the first power rail voltage REC_V is discharged through the first resistor 24 , and the second power rail voltage DEC_V is discharged through the second resistor 26 .

[0051] Specifically, when there is no energy transfer in the primary circuit 10, the discharge time of the first power rail voltage REC_V is proportional to the product of the capacitance of the first capacitor 25 and the resistance of the first resistor 24, and the discharge time of the second power rail voltage DEC_V is proportional to the product of the capacitance of the second capacitor 27 and the resistance of the second resistor 26. That is, the larger the product of the capacitance and the resistance, the longer the discharge time. Therefore, adjusting the product of the resistance and the capacitance can adjust the discharge time of the first power rail voltage REC_V and the second power rail voltage DEC_V.

[0052] The inductor includes a primary inductor and a secondary inductor 21 . The primary inductor is connected to the primary circuit 10 , and the secondary inductor 21 is connected to the secondary circuit 20 .

[0053] Furthermore, in the rectifier module 22, the input ends of the two first diode series structures 221 and the input ends of the two second diode series structures 222 together constitute the input end of the rectifier module 22; the first end of the oscillation capacitor 223 is respectively connected to a first diode series structure 221 and a second diode series structure 222, and the second end of the oscillation capacitor 223 is respectively connected to another diode series structure and another second diode series structure 222.

[0054] Specifically, the first end of the oscillation capacitor 223 is respectively connected to the cathode of the first-end diode in a first diode series structure 221 and the cathode of the first-end diode in a second diode series structure 222, and the second end of the oscillation capacitor 223 is respectively connected to the cathode of the first-end diode in another diode series structure and the cathode of the first-end diode in another second diode series structure 222.

[0055] Preferably, the number of diodes in the first series diode structure 221 is greater than the number of diodes in the second series diode structure 222 .

[0056] Furthermore, the drain of the MOS tube 29 is connected to the gate voltage node VGATE of the switch tube in the boost module 23 .

[0057] The MOS transistor 29 is an NMOS transistor.

[0058] The inversion module 28 includes devices such as a comparator and an inverter.

[0059] In the fast shutdown circuit structure described in the present invention, after the inverting module 28 collects the voltage difference between the first power rail voltage REC_V and the second power rail voltage DEC_V, the inverting module 28 outputs 0 when there is energy transfer in the primary circuit 10; and outputs 1 when there is no energy transfer in the primary circuit 10.

[0060] Among them, in the present invention, the values ​​of the first capacitor 25, the first resistor 24, the second capacitor 27 and the second resistor 26 can be reasonably configured, and the voltage difference between the first power rail voltage REC_V and the second power rail voltage DEC_V when the switch is disconnected can be smoothly constructed, and then the voltage information is collected through the inverting module 28, so that when there is energy transfer, the output of the inverting module 28 is 0, and when there is no energy transfer, the output of the inverting module 28 is 1. Because the output end of the inverting module 28 is connected to the gate of the MOS tube 29, and the drain of the MOS tube 29 is connected to the gate voltage node VGATE of the switch tube in the boost module 23, when the energy transfer of the primary circuit 10 stops, the MOS tube 29 is turned on, and the gate voltage node VGATE of the switch tube in the boost module 23 is pulled down to discharge, thereby realizing rapid shutdown of the circuit.

[0061] The working principle of the present invention is as follows:

[0062] like Figures 3-4 As shown, when there is energy transfer in the primary circuit 10, the secondary inductor 21 receives energy through coupling and resonates with the oscillating capacitor 223 in the rectifier module 22 to generate a sinusoidal signal with a frequency of f0;

[0063]

[0064] After the sinusoidal signal is rectified by the diodes (the first diode series structure 221 and the second diode series structure 222) of the rectifier module 22, two circuits are formed to supply power to the boost module 23, and the two circuits can output the first power rail voltage REC_V and the second power rail voltage DEC_V respectively;

[0065] When the first diode series structure 221 has n+1 diodes and the second diode series structure 222 has 2 diodes, if the conduction voltage of a single diode is V d When the primary circuit 10 provides energy, the voltage difference between the first power rail voltage REC_V and the second power rail voltage DEC_V is n-1 V d Therefore, if the difference between the first power rail voltage REC_V and the second power rail voltage DEC_V is (n-1)*V d When it is smaller, the inverting module determines that the input is high, and the inverting module 28 outputs low. At this time, the MOS tube 29 is turned off, and the gate voltage node VGATE of the switch tube in the boost module 23 connected to it is high.

[0066] When there is no energy transfer in the primary circuit 10, the first power rail voltage REC_V and the second power rail voltage DEC_V are discharged through the first resistor 24 and the second resistor 26 respectively, and the discharge time is proportional to the product of the capacitor and the resistor. By setting the size of the resistor and the capacitor, the product between the second resistor 26 and the second capacitor 27 can be much smaller than the product between the first resistor 24 and the first capacitor 25, so that during the discharge process, the discharge speed of the second power rail voltage DEC_V is much faster than the first power rail voltage REC_V. Therefore, when the difference between the first power rail voltage REC_V and the second power rail voltage DEC_V is large enough, the input of the inverting module 28 is judged to be low and the output is high. At this time, the MOS tube 29 is turned on, and the gate voltage node VGATE of the switch tube in the boost module 23 is discharged quickly without loss.

[0067] The present invention receives energy transmitted by the primary circuit 10 through the inductor, which can cause the secondary inductor 21 and the capacitor in the rectifier module 22 to oscillate, and then the first output terminal 224 and the second output terminal 225 of the rectifier module 22 will generate a first power rail voltage REC_V and a second power rail voltage DEC_V; when there is no signal transmission in the primary circuit 10, the fast shutdown circuit structure of the present invention can open the fast discharge circuit through the difference between the first power rail voltage REC_V and the second power rail voltage DEC_V to complete the fast discharge.

[0068] The circuit complexity of the present invention is significantly reduced compared to the existing isolation relay, and by optimizing the secondary circuit 20, a rapid shutdown response of the isolation relay is achieved without additional loss of transmitted energy.

[0069] An embodiment of the present invention further provides an isolation relay, comprising any of the above-mentioned fast shutdown circuit structures.

[0070] In this specification, the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the product embodiment described later, since it corresponds to the method, the description is relatively simple, and the relevant parts can be referred to the partial description of the system embodiment.

[0071] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A fast shut-off circuit structure for an isolation relay, comprising a primary circuit and a secondary circuit, wherein the primary circuit is coupled to the secondary circuit via an inductor, characterized in that: The secondary circuit comprises: A rectifier module, the rectifier module is connected in parallel with the secondary inductor, the rectifier module includes two first diode series structures, two second diode series structures and an oscillation capacitor, the two ends of the oscillation capacitor are correspondingly connected to the two first diode series structures and the two second diode series structures, the output ends of the first diode series structures are connected to form a first output end, and the output ends of the two second diode series structures are connected to form a second output end, the rectifier module is used to generate a first power rail voltage through the first output end and a second power rail voltage through the second output end after the oscillation capacitor and the secondary inductor oscillate to generate a sinusoidal signal; a boost module, wherein the input end of the boost module is connected to the first output end and the second output end respectively, and the output end of the boost module is connected to the discharge circuit module; a first resistor, wherein a first end of the first resistor is connected to the first output end, and a second end of the first resistor is connected to a reference ground; a first capacitor, wherein a first end of the first capacitor is connected to the first output end, and a second end of the first capacitor is connected to a reference ground; a second resistor, wherein a first end of the second resistor is connected to the second output end, and a second end of the second resistor is connected to a reference ground; a second capacitor, wherein a first end of the second capacitor is connected to the second output end, and a second end of the second capacitor is connected to a reference ground; an inverting module, wherein an input terminal of the inverting module is connected to the first output terminal and the second output terminal respectively, and is used to collect and compare the first power rail voltage and the second power rail voltage; A MOS tube, wherein the gate of the MOS tube is connected to the output end of the inverting module, the drain of the MOS tube is connected to the boost module, and the source is grounded.

2. The fast shutdown circuit structure according to claim 1, characterized in that: The inductor includes a primary inductor and a secondary inductor, the primary inductor is connected to the primary circuit, and the secondary inductor is connected to the secondary circuit.

3. The fast shutdown circuit structure according to claim 1, characterized in that: The input ends of the two first diode series structures and the input ends of the two second diode series structures together constitute the input end of the rectifier module; The first end of the oscillation capacitor is connected to a first diode series structure and a second diode series structure respectively, and the second end of the oscillation capacitor is connected to another diode series structure and another second diode series structure respectively.

4. The fast shutdown circuit structure according to claim 3, characterized in that: The first end of the oscillation capacitor is respectively connected to the cathode of the first-end diode in the first diode series structure and the cathode of the first-end diode in the second diode series structure, and the second end of the oscillation capacitor is respectively connected to the cathode of the first-end diode in another said diode series structure and the cathode of the first-end diode in another said second diode series structure.

5. The fast shutdown circuit structure according to claim 4, characterized in that: The number of diodes in the first series diode structure is greater than the number of diodes in the second series diode structure.

6. The fast shutdown circuit structure according to claim 1, characterized in that: The drain of the MOS tube is connected to the gate voltage node of the switch tube in the boost module.

7. The fast shutdown circuit structure according to claim 6, characterized in that: The MOS tube is an NMOS tube.

8. The fast shutdown circuit structure according to claim 1, characterized in that: When there is no energy transfer in the primary circuit, the discharge time of the first power rail voltage is proportional to the product of the capacitance of the first capacitor and the resistance of the first resistor, and the discharge time of the second power rail voltage is proportional to the product of the capacitance of the second capacitor and the resistance of the second resistor.

9. The fast shutdown circuit structure according to claim 8, characterized in that: After collecting the voltage difference between the first power rail voltage and the second power rail voltage, the inverting module outputs 0 when energy is transferred to the primary circuit; and outputs 1 when no energy is transferred to the primary circuit.

10. An isolation relay, characterized in that: The invention comprises a fast shutdown circuit structure as claimed in any one of claims 1 to 9.

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