High-voltage high-power anti-backflow solid relay circuit

Abstract

The utility model discloses a high-voltage high-power anti-backflow solid relay circuit, which comprises a main power switch circuit, a current detection circuit, a short-circuit tripping judgment circuit, a tripping locking circuit, an overcurrent delay protection circuit, a tripping state indication circuit and a power switch driving circuit, the current detection circuit is connected with the main power switch circuit and collects current signals of the main power switch circuit. According to the utility model, the basic functions of a traditional electromechanical contactor can be realized, the functions of state monitoring, over-current protection and short-circuit protection are realized at the same time, electric load non-arc control, over-current protection and short-circuit protection are realized, the reliability of a system and a product is improved, the health management requirement of electric equipment is met, the service life is prolonged, and the cost is reduced. Volume and weight of finished products are reduced.

Description

Technical Field

[0001] The utility model relates to the field of high-voltage and high-power solid-state relay circuits, in particular to a high-voltage and high-power backflow prevention solid-state relay circuit. Background Art

[0002] Traditional electromechanical DC high-power contactors are large in size and weight, and are prone to arcing when the contacts operate, which will have a certain impact on the power load and the power grid. In addition, contactors are life-limited electromechanical components and require regular maintenance, which seriously affects product quality, resulting in high product maintenance costs and low overall reliability, which is not conducive to the development of modern advanced equipment. Utility Model Content

[0003] The purpose of the utility model is to provide a high-voltage, high-power anti-backflow solid-state relay circuit to solve the problems proposed in the above background technology that the contactor requires regular maintenance, has a short service life, affects product quality, has high maintenance costs, and has low overall reliability.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A high-voltage, high-power, backflow-proof solid-state relay circuit, comprising:

[0006] Main power switching circuit,

[0007] a current detection circuit, the current detection circuit being connected to the main power switch circuit and collecting a current signal of the main power switch circuit;

[0008] a short-circuit tripping judgment circuit, the short-circuit tripping judgment circuit being connected to the current detection circuit and receiving a current signal;

[0009] a trip lock circuit, the trip lock circuit being connected to the short circuit trip judgment circuit;

[0010] An overcurrent delay protection circuit, wherein the overcurrent delay protection circuit is connected to the current detection circuit and the trip lock circuit respectively;

[0011] A trip state indicating circuit, the trip state indicating circuit being connected to the short circuit trip judgment circuit;

[0012] A power switch drive circuit, wherein the power switch drive circuit is connected to the main power switch circuit and the trip lock circuit respectively;

[0013] The input end of the trip lock circuit is connected to a command control circuit, and the command control circuit sends an on / off control command to the power switch drive circuit.

[0014] Further, the instruction control circuit includes an optocoupler G1 and a resistor R7. The input terminal of the optocoupler G1 inputs a control instruction CON1. The control instruction CON1 is connected to one end of the resistor R7. The other end of the resistor R7 is connected to the first pin terminal of the optocoupler G1. The second pin terminal of the optocoupler G1 is connected to the ground of the control instruction CON1.

[0015] Further, the overcurrent delay protection circuit includes a resistor R1, a resistor R4, a resistor R9, a resistor R11, a resistor R15, a capacitor C1, a capacitor C5, and a voltage comparator U3A. The resistor R1 is connected to the resistor R4. The other end of the resistor R4 is connected to the capacitor C1. One end of the resistor R4 is also connected to the fourth pin terminal of the voltage comparator U3A. The capacitor C1 is connected to the power supply ground GND1. The fifth pin terminal of the voltage comparator U3A is respectively connected to the resistor R9 and the resistor R11. The other end of the resistor R9 is connected to the power supply VCC. The other end of the resistor R11 is connected to the power supply ground GND1. The twelfth pin terminal of the voltage comparator U3A is connected to the power supply ground. The third pin terminal of the voltage comparator U3A is connected to the power supply VCC.

[0016] Further, the current detection circuit includes an operational amplifier U1B, an operational amplifier U1A, a resistor R5, a resistor R6, a resistor R10, a resistor R14, a capacitor C3, and three groups of resistors R16 - R18. The seventh pin terminal of the operational amplifier U1B is connected to the resistor R1 in the overcurrent delay protection circuit. The sixth pin terminal of the operational amplifier U1B is respectively connected to the resistor R5 and the resistor R6. The other end of the resistor R5 is connected to the power supply ground GND1. The other end of the resistor R6 is connected to the reference power supply. The fifth pin terminal of the operational amplifier U1B is respectively connected to the capacitor C3 and the resistor R10. The other end of the capacitor C3 is connected to the power supply ground GND1. And the other end of the resistor R10 is respectively connected to the operational amplifier U1A, the resistor R14, and the capacitor C4. The other end of the resistor R14 is respectively connected to the other end of the capacitor C3 and the second pin terminal of the operational amplifier U1A.

[0017] Further, the third pin terminal of the operational amplifier U1A is respectively connected to the resistor R16 and the resistor R18. The other end of the resistor R16 is connected to the power supply ground GND1. The second pin terminal of the operational amplifier U1A is connected to the resistor R17. The resistor 17 and the other end of the resistor R18 are connected to the main power switch circuit. The eighth pin terminal of the operational amplifier U1A is connected to the power supply VCC. The fourth pin terminal of the operational amplifier U1A is connected to the power supply ground GND1.

[0018] Further, the main power switch circuit includes resistor R26, resistor R27, resistor R34, resistor R37, resistor R41, shunt resistors RS1, four groups of resistors R19 - R22, two groups of capacitors C6 - C7, three groups of diodes D2 - D4, two groups of triodes T2 - T3, two groups of triodes T5 - T6, and four groups of field effect transistors M1 - M4. One end of the shunt resistor RS1 is respectively connected to resistor 17 and resistor R18, and one end of capacitor C7 is respectively connected to the anode of diode D4 and the high - voltage power supply ground PGND.

[0019] Further, the short - circuit trip judgment circuit includes voltage comparator U2A, resistor R2, resistor R5, resistor R8, resistor R12, resistor R13, capacitor C2, and triode T1. The first pin of the voltage comparator U2A is respectively connected to resistor R1 and resistor R13, and the eighth pin of the voltage comparator U2A is respectively connected to power supply Vcc, capacitor C2, and resistor R12.

[0020] Further, the trip state indication circuit includes voltage comparator U2B, resistor R24, resistor R25, resistor R35, resistor R33, resistor R28, triode T4, and opto - coupler G2. The second pin of the opto - coupler G2 is connected to the third pin of the triode T4; the second pin of the triode T4 is connected to the power supply ground GND1.

[0021] Further, the power switch drive circuit includes triode T7, triode T8, diode V1, zener diode Z1, zener diode Z2, resistor R39, resistor R40, and capacitor C8. The third pin of the triode T7 is connected to the power supply Vcc, and the second pin of the triode T7 is respectively connected to the second pin of the triode T8, the anode of the zener diode Z1, resistors R19, R20, R21, R22 in the main power switch circuit, the first pin of the triode T5, the first pin of the triode T2, and the first pin of the triode T3.

[0022] Further, the trip lock - in circuit includes four groups of resistors R29 - R32, resistor R23, resistor R36, resistor R38, diode D1, voltage comparator U3B, voltage comparator U3C, and voltage comparator U3D. One end of the resistor R8 is respectively connected to the thirteenth pin of the voltage comparator U3D, resistors R39 and R40 in the power switch drive circuit, resistor R31, and the first pin of the voltage comparator U3B. The other end of the resistor R31 is respectively connected to the seventh pin of the voltage comparator U3B, resistor R15 in the over - current delay protection circuit, the second pin of the voltage comparator U3A, the third pin of the triode T1 in the short - circuit trip judgment circuit, and resistor R24 in the trip state indication circuit.

[0023] The beneficial effects of the present utility model are as follows: The present utility model can achieve the basic functions of traditional electromechanical contactors, and at the same time has functions of status monitoring, overcurrent protection, and short-circuit protection, realizing arc-free control, overcurrent protection, and short-circuit protection for electrical loads, improving the reliability of the system and products, meeting the health management requirements of electrical equipment, protecting electrical equipment, and using solid-state relays to achieve high-voltage high-power control to avoid the influence of arcs during switching, increasing the service life, reducing the volume and weight of the finished product, preventing the reverse input of electrical energy by the subsequent load after shutdown, and being conducive to the popularization and use of this high-voltage high-power anti-backflow solid-state relay circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the principle block diagram of the high-voltage high-power anti-backflow solid-state relay circuit of the present utility model;

[0025] Figure 2 is the combined circuit diagram of the present utility model without connecting the current detection circuit and the main power switch circuit;

[0026] Figure 3 is the combined circuit diagram of the current detection circuit and the main power switch circuit of the present utility model.

[0027] In the figure: 1 instruction control circuit, 2 trip locking circuit, 3 overcurrent delay protection circuit, 4 power switch drive circuit, 5 short-circuit trip judgment circuit, 6 trip status indication circuit, 7 current detection circuit, 8 main power switch circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0029] Please refer to Figure 1-3, which provides a technical solution for the present utility model. A high-voltage high-power anti-backflow solid relay circuit includes a main power switch circuit 8, a current detection circuit 7, a short-circuit trip judgment circuit 5, a trip locking circuit 2, an overcurrent delay protection circuit 3, a trip status indication circuit 6, and a power switch drive circuit 4; the current detection circuit 7 is connected to the main power switch circuit 8 and collects the current signal of the main power switch circuit 8. The current detection circuit 7 includes an operational amplifier U1B, an operational amplifier U1A, a resistor R5, a resistor R6, a resistor R10, a resistor R14, a capacitor C3, and three groups of resistors R16 - R18. The seventh pin of the operational amplifier U1B is connected to the resistor R1 in the overcurrent delay protection circuit 3. The sixth pin of the operational amplifier U1B is respectively connected to the resistor R5 and the resistor R6. The other end of the resistor R5 is connected to the power supply ground GND1, and the other end of the resistor R6 is connected to the reference power supply. The fifth pin of the operational amplifier U1B is respectively connected to the capacitor C3 and the resistor R10. The other end of the capacitor C3 is connected to the power supply ground GND1, and the other end of the resistor R10 is respectively connected to the operational amplifier U1A, the resistor R14, and the capacitor C4. The other end of the resistor R14 is respectively connected to the other end of the capacitor C3 and the second pin of the operational amplifier U1A. The third pin of the operational amplifier U1A is respectively connected to the resistor R16 and the resistor R18. The other end of the resistor R16 is connected to the power supply ground GND1. The second pin of the operational amplifier U1A is connected to the resistor R17. The other end of the resistor 17 and the other end of the resistor R18 are connected to the main power switch circuit 8. The eighth pin of the operational amplifier U1A is connected to the power supply VCC, and the fourth pin of the operational amplifier U1A is connected to the power supply ground GND1.

[0030] It should be noted that the seventh pin of the operational amplifier U1B is connected to the other end of the resistor R1; the sixth pin of the operational amplifier U1B is respectively connected to one end of the resistor R5 and the resistor R6; the other end of the resistor R5 is connected to the source ground GND1; the other end of the resistor R6 is connected to the reference power supply; the fifth pin of the operational amplifier U1B is respectively connected to one end of the capacitor C3 and the resistor R10; the other end of the capacitor C3 is connected to the power supply ground GND1; the other end of the resistor R10 is respectively connected to the first pin of the operational amplifier U1A, the resistor R14, and one end of the capacitor C4; the other end of the resistor R14 is respectively connected to the capacitor C14, the second pin of the operational amplifier U1B, and one end of the resistor R17; the third pin of the operational amplifier U1A is respectively connected to one end of the resistor R16 and the resistor R18; the eighth pin of the operational amplifier U1A is connected to the power supply Vcc; the fourth pin of the operational amplifier U1A is connected to the power supply ground GND1.

[0031] In this embodiment, the mentioned short - circuit trip judgment circuit 5 is connected to the current detection circuit 7 and receives a current signal; the trip locking circuit 2 is connected to the short - circuit trip judgment circuit 5, and the input end of the trip locking circuit 2 is connected to the command control circuit 1, and the command control circuit 1 issues a turn - on / turn - off control command to the power switch drive circuit 4; the command control circuit 1 includes an optocoupler G1 and a resistor R7. The input end of the optocoupler G1 inputs a control command CON1. The control command CON1 is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the first pin of the optocoupler G1, and the second pin of the optocoupler G1 is connected to the ground of the control command CON1; the input control command CON1 is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the first pin of the optocoupler G1, the second pin of the optocoupler G1 is connected to the ground of the control command CON1, the third pin is connected to the ground of the power switch drive circuit 4, the fourth pin is connected to one end of the resistor R29 and the eighth pin of the voltage comparator U3C; the other end of the resistor R29 is connected to the power supply Vcc.

[0032] Among them, the trip locking circuit 2 includes four groups of resistors R29 - R32, a resistor R23, a resistor R36, a resistor R38, a diode D1, a voltage comparator U3B, a voltage comparator U3C, and a voltage comparator U3D. One end of the resistor R8 is respectively connected to the thirteenth pin of the voltage comparator U3D, the resistors R39 and R40 in the power switch drive circuit 4, the resistor R31, and the first pin of the voltage comparator U3B. The other end of the resistor R31 is respectively connected to the seventh pin of the voltage comparator U3B, the resistor R15 in the over - current delay protection circuit 3, the second pin of the voltage comparator U3A, the third pin of the triode T1 in the short - circuit trip judgment circuit 5, and the resistor R24 in the trip state indication circuit 6.

[0033] It should be noted that one end of the resistor R29 is connected to the power supply Vcc, and the other end is connected to the eighth pin of the voltage comparator; the ninth pin of the voltage comparator U3B is connected to one end of the resistor R30 and the reference voltage source Vref, and the fourteenth pin of the voltage comparator U3B is connected to one end of the resistor R36, one end of the resistor R32, and the cathode of the diode D1; the other end of the resistor R30 is connected to one end of the resistor R23, the anode of the diode D1, and the sixth pin of the voltage comparator U3B; the other end of the resistor R36 is connected to the power supply Vcc, one end of the resistor R38, and one pin of the diode V1; the other end of the resistor R23 is connected to the power supply ground GND1; the other end of the resistor R38 is connected to the thirteenth pin of the voltage comparator U3D, one end of the resistor R39, and one end of the resistor R40; the tenth pin of the voltage comparator U3D is connected to the reference voltage source Vref, the eleventh pin is connected to the other end of the resistor R32, one end of the resistor R31, and the first pin of the voltage comparator U3B; the other end of the resistor R31 is connected to the seventh pin of the voltage comparator U3B, one end of the resistor R15, the second pin of the voltage comparator U3A, the third pin of the triode T1, and one end of the resistor R24.

[0034] In this embodiment, the overcurrent delay protection circuit 3 mentioned is respectively connected to the current detection circuit 7 and the trip locking circuit 2. The overcurrent delay protection circuit 3 includes a resistor R1, a resistor R4, a resistor R9, a resistor R11, a resistor R15, a capacitor C1, a capacitor C5, and a voltage comparator U3A. The resistor R1 is connected to the resistor R4, the other end of the resistor R4 is connected to the capacitor C1, one end of the resistor R4 is also connected to the fourth pin of the voltage comparator U3A, the capacitor C1 is connected to the power supply ground GND1, the fifth pin of the voltage comparator U3A is respectively connected to the resistor R9 and the resistor R11, the other end of the resistor R9 is connected to the power supply VCC, the other end of the resistor R11 is connected to the power supply ground GND1, the twelfth pin of the voltage comparator U3A is connected to the power supply ground, and the third pin of the voltage comparator U3A is connected to the power supply VCC; among them, one end of the resistor R1 is connected to one end of the resistor R4, the other end of the resistor R4 is connected to one end of the capacitor C1 and the fourth pin of the voltage comparator U3A; the other end of the capacitor C1 is connected to the power supply ground GND1; the fifth pin of the power supply comparator U3A is connected to one end of the resistor R9 and one end of the resistor R11; the other end of the resistor R9 is connected to the power supply Vcc; the other end of the resistor R11 is connected to the power supply ground GND1; the twelfth pin of the voltage comparator U3A is connected to the power supply ground; the third pin of the voltage comparator U3A is connected to the power supply Vcc.

[0035] In this embodiment, the mentioned trip state indication circuit 6 is connected to the short - circuit trip judgment circuit 5. The short - circuit trip judgment circuit 5 includes a voltage comparator U2A, resistors R2, R5, R8, R12, R13, a capacitor C2, and a triode T1. One pin of the voltage comparator U2A is respectively connected to resistors R1 and R13, and the eighth pin of the voltage comparator U2A is respectively connected to the power supply Vcc, the capacitor C2, and the resistor R12. The other end of the resistor R13 is connected to one pin of the triode T1; the second pin of the triode T1 is connected to the power supply ground GND1; the trip state indication circuit 6 includes a voltage comparator U2B, resistors R24, R25, R35, R33, R28, a triode T4, and an optocoupler G2. The second pin of the optocoupler G2 is connected to the third pin of the triode T4; the second pin of the triode T4 is connected to the power supply ground GND1; the other end of the resistor R24 is connected to the sixth pin of the voltage comparator U2B; one end of the resistor R25 is connected to the reference power supply; the other end of the resistor R25 is connected to one end of the resistor R28 and to the fifth pin of the voltage comparator U2B; the other end of the resistor R28 is connected to the power supply ground GND1; the seventh pin of the voltage comparator U2B is connected to one end of the resistor R33 and to one pin of the triode T4; the other end of the resistor R33 is connected to the power supply Vcc and to one end of the resistor R35; the other end of the resistor R35 is connected to the first pin of the optocoupler G2; the second pin of the optocoupler G2 is connected to the third pin of the triode T4; the second pin of the triode T4 is connected to the power supply ground GND1.

[0036] In this embodiment, the power switch drive circuit 4 is connected to the main power switch circuit 8 and the trip lock circuit 2 respectively; the power switch drive circuit 4 includes a transistor T7, a transistor T8, a diode V1, a voltage regulator diode Z1, a voltage regulator diode Z2, a resistor R39, a resistor R40 and a capacitor C8, the three pins of the transistor T7 are connected to the power supply Vcc, the two pins of the transistor T7 are connected to the two pins of the transistor T8, the anode of the voltage regulator diode Z1, the resistor R19, the resistor R20, the resistor R21, the resistor R22 in the main power switch circuit 8, one pin of the transistor T5, one pin of the transistor T2, and one pin of the transistor T3; the two pins of the diode V1 are connected to one end of the resistor R39, and the three pins of the diode V1 are connected to the three pins of the transistor T3. One pin of the transistor T7 is connected, the three pins of the transistor V1 are connected to one pin of the transistor T8, the three pins of the transistor V1 are connected to the other end of the resistor R40, and the three pins of the transistor V1 are connected to one end of the capacitor C8; the three pins of the transistor T7 are connected to the power supply Vcc, the two pins of the three pins of the transistor T7 are connected to the two pins of the transistor T8, the three pins of the transistor T7 are connected to the anode of the Zener diode Z1, the three pins of the transistor T7 are connected to one end of the resistor R19 in the main power switch circuit 8, the three pins of the transistor T7 are connected to one end of the resistor R20, to one end of the resistor R21, to one end of the resistor R22, to one pin of the transistor T5, to one pin of the transistor T2, and to one pin of the transistor T3.

[0037] In this embodiment, the main power switch circuit 8 includes resistors R26, R27, R34, R37, and R41, a shunt resistor RS1, four resistors R19-R22, two capacitors C6-C7, three diodes D2-D4, two transistors T2-T3, two transistors T5-T6, and four field-effect transistors M1-M4. One end of the shunt resistor RS1 is connected to the resistor 17 and the resistor R18, respectively. One end of the capacitor C7 is connected to the anode of the diode D4 and the high-voltage power ground PGND, respectively.

[0038] It should be noted that one end of resistor R19 is connected to one end of resistor R37, the second terminal of triode T5, and the first terminal of field effect transistor M3 respectively; the other end of resistor R37 is connected to the third terminal of triode T5, the third terminal of triode T2, the third terminal of field effect transistor M3, the third terminal of field effect transistor M1, one end of resistor R26, the terminal of shunt resistor RS1, and the other end of resistor R18 respectively; the other end of resistor R20 is connected to resistor R26, the second terminal of triode T2, and the first terminal of field effect transistor M1 respectively; the third terminal of field effect transistor M1 is connected to the third terminal of field effect transistor M3, the cathode of diode D2, resistor R4, capacitor C7, the cathode of diode D4, and high voltage power supply Vin respectively; the other end of resistor R21 is connected to resistor R27, the second terminal of triode T3, and the first terminal of field effect transistor M2 respectively; the other end of resistor R22 is connected to one end of resistor R4, the second terminal of triode T6, and the first terminal of field effect transistor M4 respectively; the other end of resistor R27 is connected to the third terminal of triode T3, the second terminal of field effect transistor M2, shunt resistor RS1, resistor R17, resistor R4, the third terminal of triode T6, and the second terminal of field effect transistor M4 respectively.

[0039] Among them, the third terminal of field effect transistor M2 is connected to the third terminal of field effect transistor M4, the cathode of diode D3, capacitor C6, and high voltage output terminal Vout respectively; the anode of diode D3 is connected to high voltage power ground PGND; the other end of capacitor C6 is connected to resistor R41 and the anode of diode D2 respectively; the other end of capacitor C7 is connected to the anode of diode D4 and high voltage power ground PGND respectively.

[0040] For the working process of the command control circuit 1 of this high voltage high power anti-backflow solid state relay circuit: when the small signal command CON1 is at high level "1", a current flows through the primary of optocoupler G1, the light emitting diode works, and the internal photosensitive triode senses the light emitted by the light emitting diode, making the photosensitive triode in the conducting state and sending out a connection control command. On the contrary, the photosensitive triode is in the cut-off state and sends out a turn-off control command; for the working process of the power switch drive circuit 4: when the control signal CON is "1", the fourteenth terminal of voltage comparator U3C jumps to "1", making the thirteenth terminal of voltage comparator U3D jump to '1'. The high level signal charges capacitor C8 through current limiting resistor R40. After the charging voltage is greater than 0.7V, triode T7 of the push-pull circuit conducts and triode T8 cuts off, and the output power switch is turned on; on the contrary, when the control signal CON is "0", triode T7 of the push-pull circuit cuts off and triode T8 conducts, and the output power switch is turned off.

[0041] The working process of trip lock circuit 2: When the seventh pin of voltage comparator U3C receives the overcurrent trip or short circuit trip signal '0', the first pin of voltage comparator U3B jumps to '0'; at this time, the potential of the sixth pin of voltage comparator U3B is always kept higher than the potential of the seventh pin through diode D1, thereby keeping the first pin of voltage comparator U3B continuously at a low level. Even if the trip signal returns to '0', it will not change accordingly, thus achieving the purpose of locking.

[0042] The working principle of the overcurrent delay protection circuit 3 is as follows: the current detection circuit 7 detects the current signal and sends it to the overcurrent delay protection circuit 3. After being delayed by resistors R1, R4 and C1, it is sent to the fourth pin of the voltage comparator U3A; it is compared with the reference voltage at the fifth pin of the voltage comparator U3A. When the overcurrent signal is greater than the reference signal, the second pin of the voltage comparator U3A jumps to a low level '0' and is sent to the trip lock circuit 2 to implement the protection function.

[0043] The working principle of the short-circuit trip judgment circuit 5 is as follows: the current detection circuit 7 detects the current signal and sends it to the short-circuit trip judgment circuit 5. If the detected current signal is greater than the current signal reference during the short circuit, the trip lock circuit 2 is triggered to realize the short-circuit trip protection function.

[0044] The working principle of the trip status indication circuit 6 is as follows: when an overcurrent signal or a short-circuit signal is received, the six-pin terminal of the trigger voltage comparator U2B jumps to a low level '0', and the 7-pin jumps to a high level '1'. At this time, the transistor T4 is turned on, and the photocoupler G2 outputs the status signal; the working principle of the current detection circuit 7 is as follows: a differential amplifier is used to collect the potential difference signal across the main power bus shunt resistor, and after signal amplification, it is sent to the overcurrent delay protection circuit 3 and the short-circuit trip judgment circuit 5 respectively.

[0045] The main power switch circuit 8 operates as follows: upon receiving a high-level '1' signal from the power switch drive circuit 4, the gate-source voltage of the reverse-connected power switch MOSFETs M1, M2, M3, and M4 becomes high, turning on the power switch MOSFETs M1, M2, M3, and M4 to provide power to the downstream load. Conversely, the drive circuit outputs a low-level '0' signal, turning off the power switch MOSFETs M1, M2, M3, and M4, disconnecting the downstream load from power supply.

[0046] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above embodiments only represent the preferred embodiments of the present utility model, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. In the present utility model, unless otherwise clearly specified and defined, the terms "installation", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection. Among them, there are various ways of detachable installation. For example, it can be in a way of cooperation between plugging and buckling, or in a way of bolt connection, etc.

[0048] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A high-voltage high-power anti-backflow solid-state relay circuit, characterized in that, Comprising: Main power switch circuit, Current detection circuit, which is connected to the main power switch circuit and collects the current signal of the main power switch circuit; Short-circuit trip judgment circuit, which is connected to the current detection circuit and receives the current signal; Trip locking circuit, which is connected to the short-circuit trip judgment circuit; Overcurrent delay protection circuit, which is respectively connected to the current detection circuit and the trip locking circuit; Trip state indication circuit, which is connected to the short-circuit trip judgment circuit; Power switch drive circuit, which is respectively connected to the main power switch circuit and the trip locking circuit; Wherein, an instruction control circuit is connected to the input end of the trip locking circuit, and the instruction control circuit issues an on / off control instruction to the power switch drive circuit.

2. The high-voltage high-power anti-backflow solid-state relay circuit according to claim 1, wherein: The instruction control circuit includes an optocoupler G1 and a resistor R7. The input end of the optocoupler G1 inputs a control instruction CON1. The control instruction CON1 is connected to one end of the resistor R7, the other end of the resistor R7 is connected to the first pin end of the optocoupler G1, and the second pin end of the optocoupler G1 is connected to the ground of the control instruction CON1.

3. The high-voltage high-power anti-backflow solid relay circuit according to claim 1, wherein: The overcurrent delay protection circuit includes resistors R1, R4, R9, R11, R15, capacitors C1, C5 and a voltage comparator U3A. The resistor R1 is connected to the resistor R4, the other end of the resistor R4 is connected to the capacitor C1, one end of the resistor R4 is also connected to the fourth pin end of the voltage comparator U3A, the capacitor C1 is connected to the power supply ground GND1, the fifth pin end of the voltage comparator U3A is respectively connected to the resistors R9 and R11, the other end of the resistor R9 is connected to the power supply VCC, the other end of the resistor R11 is connected to the power supply ground GND1, the twelfth pin end of the voltage comparator U3A is connected to the power supply ground, and the third pin end of the voltage comparator U3A is connected to the power supply VCC.

4. The high-voltage high-power anti-backflow solid relay circuit according to claim 1, wherein: The current detection circuit includes operational amplifiers U1B, U1A, resistors R5, R6, R10, R14, capacitor C3 and three groups of resistors R16 - R18. The seventh pin end of the operational amplifier U1B is connected to the resistor R1 in the overcurrent delay protection circuit. The sixth pin end of the operational amplifier U1B is respectively connected to the resistors R5 and R6. The other end of the resistor R5 is connected to the power supply ground GND1, and the other end of the resistor R6 is connected to the reference power supply. The fifth pin end of the operational amplifier U1B is respectively connected to the capacitor C3 and the resistor R10. The other end of the capacitor C3 is connected to the power supply ground GND1, and the other end of the resistor R10 is respectively connected to the operational amplifier U1A, the resistor R14 and the capacitor C4. The other end of the resistor R14 is respectively connected to the other end of the capacitor C3 and the second pin end of the operational amplifier U1A.

5. The high-voltage high-power anti-backflow solid relay circuit according to claim 4, characterized in that: The three - terminal of the operational amplifier U1A is respectively connected to the resistor R16 and the resistor R18. The other end of the resistor R16 is connected to the power supply ground GND1. The two - terminal of the operational amplifier U1A is connected to the resistor R17. The other ends of the resistor 17 and the resistor R18 are connected to the main power switch circuit. The eight - terminal of the operational amplifier U1A is connected to the power supply VCC, and the four - terminal of the operational amplifier U1A is connected to the power supply ground GND1.

6. The high-voltage high-power anti-backflow solid relay circuit according to claim 1, wherein: The main power switch circuit includes resistors R26, R27, R34, R37, R41, a shunt resistor RS1, four groups of resistors R19 - R22, two groups of capacitors C6 - C7, three groups of diodes D2 - D4, two groups of triodes T2 - T3, two groups of triodes T5 - T6, and four groups of field - effect transistors M1 - M4. One end of the shunt resistor RS1 is respectively connected to the resistor 17 and the resistor R18. One end of the capacitor C7 is respectively connected to the anode of the diode D4 and the high - voltage power supply ground PGND.

7. The high-voltage high-power anti-backflow solid-state relay circuit according to claim 1, characterized in that: The short - circuit trip judgment circuit includes a voltage comparator U2A, resistors R2, R5, R8, R12, R13, a capacitor C2, and a triode T1. The one - terminal of the voltage comparator U2A is respectively connected to the resistor R1 and the resistor R13, and the eight - terminal of the voltage comparator U2A is respectively connected to the power supply Vcc, the capacitor C2, and the resistor R12.

8. The high-voltage high-power anti-backflow solid relay circuit according to claim 1, wherein: The trip state indication circuit includes a voltage comparator U2B, resistors R24, R25, R35, R33, R28, a triode T4, and an opto - coupler G2. The two - terminal of the opto - coupler G2 is connected to the three - terminal of the triode T4; the two - terminal of the triode T4 is connected to the power supply ground GND1.

9. The high-voltage high-power anti-backflow solid-state relay circuit according to claim 1, wherein: The power switch drive circuit includes a triode T7, a triode T8, a diode V1, a zener diode Z1, a zener diode Z2, resistors R39, R40, and a capacitor C8. The three - terminal of the triode T7 is connected to the power supply Vcc. The two - terminal of the triode T7 is respectively connected to the two - terminal of the triode T8, the anode of the zener diode Z1, the resistors R19, R20, R21, R22 in the main power switch circuit, the one - terminal of the triode T5, the one - terminal of the triode T2, and the one - terminal of the triode T3.

10. The high-voltage high-power anti-backflow solid relay circuit according to claim 1, wherein: The trip lock - in circuit includes four groups of resistors R29 - R32, a resistor R23, resistors R36, R38, a diode D1, a voltage comparator U3B, a voltage comparator U3C, and a voltage comparator U3D. One end of the resistor R8 is respectively connected to the thirteen - terminal of the voltage comparator U3D, the resistors R39 and R40 in the power switch drive circuit, the resistor R31, and the one - terminal of the voltage comparator U3B. The other end of the resistor R31 is respectively connected to the seven - terminal of the voltage comparator U3B, the resistor R15 in the over - current delay protection circuit, the two - terminal of the voltage comparator U3A, the three - terminal of the triode T1 in the short - circuit trip judgment circuit, and the resistor R24 in the trip state indication circuit.

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