A cable multifunction grounding box device circuit based on free switching of grounding topologies

Abstract

The utility model relates to a kind of cable multifunctional grounding box device circuit based on grounding topology free switching, including grounding box main ground return circuit, MCU main control IC circuit, button input signal monitoring circuit, TA current sampling circuit, air switch driving circuit, air switch opening and closing in position signal circuit and 4G wireless transmission circuit;Button input signal monitoring circuit passes to the button state signal to MCU main control IC circuit generation air switch control signal and drives air switch opening and closing;Air switch opening and closing in position signal monitoring circuit returns air switch opening and closing in position signal;TA current sampling circuit collects cable inner and outer core grounding protection current and is transmitted to MCU main control IC circuit;4G wireless transmission circuit uploads the data received by MCU main control IC circuit to host computer monitoring, while returning grounding topology switching signal, so that MCU main control IC circuit executes switching action.The utility model effectively solves the trouble that current grounding box needs to be removed or reconstructed when line is adjusted.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-voltage cable electrical equipment, and particularly relates to a circuit of a cable multi-functional grounding box device based on free switching of grounding topology. Background Technique

[0002] When a high-voltage single-core power cable is in operation, a certain induced voltage is generated on its metal sheath. Generally, the induced voltage to the ground is dozens of volts, and the current is several amperes to more than a dozen amperes. In practical applications, the metal sheath of a high-voltage single-core power cable generally adopts single-end grounding, double-end grounding, neutral point grounding, and cross-connected grounding methods to reduce the induced voltage of the sheath. Traditional grounding box devices are designed separately, and different grounding box devices cannot be converted and used interchangeably. During line maintenance and grounding box replacement, personnel need to carry multiple different grounding boxes, and each grounding box is separated by a certain distance. If the grounding methods of multiple grounding boxes need to be switched, it will increase a large amount of workload and consume a large amount of manpower and material resources.

[0003] At present, the high-voltage cable grounding box devices on the market are mainly divided into direct grounding boxes, protective grounding boxes, and cross-connected grounding boxes, etc. During the laying process of high-voltage lines, it is often necessary to install corresponding grounding boxes according to different lengths, line loads, etc. to eliminate induction defects in a timely manner and ensure the long-term stable operation of the cable; and during line adjustment, the original grounding box needs to be disassembled and replaced with a grounding box suitable for the requirements. There are many types, and the corresponding grounding conditions cannot be viewed remotely. When problems occur, a large number of staff are required to conduct line inspections.

[0004] Therefore, there is an urgent need for a grounding box device circuit that integrates the traditional grounding box schemes required in current practical applications, can be used for multiple purposes with one box, can quickly adjust the current grounding scheme of the box, and has a remote transmission communication function, integrates intelligent monitoring and control functions in the box, has preset logic information, and linkage control. The grounding state of the corresponding grounding box can be completed with simple operation. Content of the Utility Model

[0005] In order to solve the problems existing in the above-mentioned prior art, the utility model provides a circuit of a cable multi-functional grounding box device based on free switching of grounding topology.

[0006] The technical solution of the utility model is as follows: A circuit of a cable multi-functional grounding box device based on free switching of grounding topology includes a grounding box main grounding circuit, an MCU main control IC circuit, a signal monitoring circuit, a TA current sampling circuit, an air switch driving circuit, and a 4G wireless transmission circuit, wherein: The grounding box main grounding circuit includes circuit breakers QF1 and QF2 and inner and outer cable cores; the signal monitoring circuit includes a key input signal monitoring circuit and a circuit breaker opening / closing position signal monitoring circuit; the output of the key input signal monitoring circuit is connected to the input of the MCU main control IC circuit, used to transmit the key status signal to the MCU main control IC circuit; the MCU main control IC circuit generates a circuit breaker control signal based on the key status signal, and its output is connected to the input of the circuit breaker drive circuit, transmitting the circuit breaker control signal to the circuit breaker drive circuit; the circuit breaker drive circuit drives the circuit breaker to perform opening and closing actions according to the circuit breaker control signal; the circuit breaker opening / closing position signal monitoring circuit monitors the opening and closing actions performed by the circuit breaker opening / closing... The circuit breaker (CB) generates a tripping signal, and its output is connected to the input of the MCU main control IC circuit, transmitting the CB tripping signal to the MCU main control IC circuit. The current sampling circuit (TA) collects the grounding protection current of the inner and outer cores of the cable, and its output is connected to the input of the MCU main control IC circuit, transmitting the grounding protection current to the MCU main control IC circuit. The 4G wireless transmission circuit communicates with the MCU main control IC circuit, transmitting the CB tripping signal and the grounding protection current from the MCU main control IC circuit to the host computer for operational status monitoring, and returning a grounding topology switching signal to the MCU main control IC circuit. The MCU main control IC circuit then performs a grounding topology switching action based on the grounding topology switching signal.

[0007] More preferably, the MCU main control IC circuit includes an MCU main control IC module, a button bus, a current acquisition bus, and a drive signal bus, wherein: The button bus is used to transmit the button status signal to the MCU main control IC circuit; the drive signal bus is used to transmit the circuit breaker control signal to the circuit breaker drive circuit; and the current acquisition bus is used to transmit the ground protection current to the MCU main control IC circuit.

[0008] More preferably, the circuit breaker opening / closing position signal monitoring circuit includes a first current-limiting resistor, a second current-limiting resistor, a third current-limiting resistor, a fourth current-limiting resistor, a pull-down resistor, an isolation optocoupler, a first filter capacitor, a second filter capacitor, a first diode, and a first transistor. The isolation optocoupler includes a light-emitting diode and a phototransistor, wherein: One end of the third current-limiting resistor is connected to the circuit breaker's open / close signal input terminal, and the other end is electrically connected to the negative terminal of the first diode; the positive terminal of the first diode is connected to the power supply voltage and is electrically connected to one end of the first current-limiting resistor; the other end of the first current-limiting resistor is electrically connected to the collector of the first transistor; the base of the first transistor is electrically connected to one end of the second current-limiting resistor, and the emitter of the first transistor is electrically connected to the positive terminal of the light-emitting diode; the first filter capacitor is connected in parallel with the fourth current-limiting resistor, one end of which is electrically connected to the other end of the second current-limiting resistor, and the other end of which is electrically connected to the negative terminal of the light-emitting diode and then grounded; the light-emitting diode and the phototransistor are isolated by a transparent insulator, the collector of the phototransistor is connected to a 3.3V power supply, and the emitter of the phototransistor is electrically connected to one end of the pull-down resistor and one end of the second filter capacitor, respectively; the other end of the pull-down resistor is connected to the other end of the second filter capacitor and then grounded.

[0009] More preferably, the key input signal monitoring circuit and the circuit breaker opening / closing position signal monitoring circuit have the same structure, except that the circuit breaker opening / closing position signal input terminal is replaced with the key signal input terminal.

[0010] More preferably, the TA current sampling circuit includes a TA current transformer TA1, a sampling power resistor, a third filter capacitor, a fourth filter capacitor, a fifth filter capacitor, an operational amplifier, a first peripheral resistor of the operational amplifier, a second peripheral resistor of the operational amplifier, and a third peripheral resistor of the operational amplifier, wherein; The secondary output current of the current transformer TA1 is input to both ends of the sampling power resistor. The sampling power resistor is connected in parallel with the third, fourth, and fifth filter capacitors. One end of the parallel connection is electrically connected to one end of the first peripheral resistor of the operational amplifier, and the other end is electrically connected to one end of the second peripheral resistor of the operational amplifier and then grounded. The other end of the first peripheral resistor of the operational amplifier is electrically connected to the non-inverting input terminal of the operational amplifier, and the other end of the second peripheral resistor of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier. The positive power supply terminal of the operational amplifier is connected to a 3.3V power supply, and the negative power supply terminal is grounded. Its output terminal is electrically connected to one end of the third peripheral resistor of the operational amplifier, and the other end of the third peripheral resistor of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier.

[0011] More preferably, the circuit breaker driving circuit is divided into a QF1 circuit breaker driving circuit and a QF2 circuit breaker driving circuit. The QF1 circuit breaker driving circuit and the QF2 circuit breaker driving circuit have the same structure. The QF1 circuit breaker driving circuit includes a control disconnection logic circuit and a control closure logic circuit. The control disconnection logic circuit is composed of a first relay, a first driving resistor, a first driving switch, and a second diode. The control closure logic circuit is composed of a second relay, a second driving resistor, a second driving switch, and a third diode. One coil terminal of the first relay is electrically connected to a 5V power supply and the negative terminal of the second diode, respectively; the other coil terminal of the first relay is electrically connected to the collector of the first driving switch and the positive terminal of the second diode; the normally closed terminal of the first relay is connected to the common terminal of the second relay; one end of the first driving resistor is electrically connected to the base of the first driving switch. One coil terminal of the second relay is electrically connected to a 5V power supply and the negative terminal of the third diode, respectively. The other coil terminal of the second relay is electrically connected to the collector of the second driving switch and the positive terminal of the third diode. The common terminal of the second relay is connected to the normally closed port of the first relay. One end of the second driving resistor is electrically connected to the base of the second driving switch.

[0012] More preferably, the circuit breaker drive circuit is divided into a QF1 circuit breaker drive circuit and a QF2 circuit breaker drive circuit, and the QF1 circuit breaker drive circuit and the QF2 circuit breaker drive circuit have the same structure.

[0013] More preferably, the 4G wireless transmission circuit includes a 4G wireless transmission module, a first power supply filter capacitor, a second power supply filter capacitor, a first resistor, a second resistor, and a second transistor. The 4G wireless transmission module includes a universal asynchronous receiver transmission port, a universal asynchronous transmitter transmission port, a GND port, a reset signal input terminal, a reset signal output terminal, a first DC power supply input port, and a second DC power supply input port, wherein: The universal asynchronous receiver / transmitter port receives the circuit breaker closing / opening signal and the grounding protection current; the universal asynchronous transmitter / transmitter port transmits the circuit breaker closing / opening signal and the grounding protection current; the GND port is grounded; the reset signal input port is electrically connected to one end of the first resistor and the collector of the second transistor; the first DC power input port is connected to a 5V power supply; the second DC power input port is electrically connected to one end of the first power supply filter capacitor and the second power supply filter capacitor, and the other ends of the first power supply filter capacitor and the second power supply filter capacitor are grounded; the other end of the first resistor is connected to a 5V power supply; the base of the second transistor is electrically connected to one end of the second resistor; the emitter of the second transistor is grounded; and the other end of the second resistor is connected to the reset signal output terminal.

[0014] More preferably, the grounding circuit of the grounding box body also includes one set of protectors and two sets of protectors, which are used to protect the circuits corresponding to circuit breakers QF1 and QF2, respectively.

[0015] This utility model has the following beneficial effects: 1. This utility model provides a multi-functional grounding box device circuit for cables based on free switching of grounding topology. By setting up a key input signal monitoring circuit, as well as a circuit breaker opening / closing position signal circuit and a circuit breaker drive circuit, it can achieve multiple uses in one box. When adjusting the line, it avoids the trouble caused by the need to remove the current grounding box on site or to modify the current grounding box on site.

[0016] 2. This utility model provides a multi-functional grounding box device circuit for cables based on freely switchable grounding topology. It employs a current sampling circuit with a high-precision current transformer and a multi-stage filtering and amplification structure to effectively improve the sampling accuracy and anti-interference capability of the grounding current. The circuit breaker drive circuit uses a dual-relay interlocking structure, combined with diodes and drive switching transistors, to ensure the stability and response speed of the circuit breaker operation. The signal monitoring circuit based on optocoupler isolation achieves electrical isolation and reliable signal transmission between strong and weak current systems through the coordinated design of current-limiting resistors, filter capacitors, and pull-down resistors. Furthermore, the device provides graded protection for the circuit breaker circuit through built-in sets 1 and 2 protectors. Combined with the preset logic control program of the MCU main control IC circuit, it can effectively prevent equipment damage under malfunctions and abnormal operating conditions, significantly improving the system's safety and fault tolerance. Attached Figure Description

[0017] Figure 1 The control system architecture diagram provided by this utility model; Figure 2 The main grounding circuit of the grounding box provided by this utility model; Figure 3 This is a circuit diagram of the key input monitoring module according to Embodiment 1 of this utility model; Figure 4 This is a circuit diagram of the circuit breaker opening / closing position signal module according to Embodiment 1 of this utility model; Figure 5 This is a partial circuit schematic diagram of the MCU main control IC in Embodiment 1 of this utility model; Figure 6 This is a circuit schematic diagram of the TA current sampling module according to Embodiment 1 of this utility model; Figure 7 This is a schematic diagram of the circuit of the circuit breaker drive module according to Embodiment 1 of this utility model; Figure 8 This is a circuit diagram of the 4G wireless transmission module according to Embodiment 1 of this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0020] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0022] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.

[0023] Example 1 See Figure 1 A multi-functional cable grounding box device circuit based on freely switchable grounding topology, characterized in that it includes a grounding box main grounding circuit, an MCU main control IC circuit, a signal monitoring circuit, a TA current sampling circuit, a circuit breaker drive circuit, and a 4G wireless transmission circuit, wherein: The grounding box main grounding circuit includes circuit breakers QF1 and QF2 and inner and outer cable cores; the signal monitoring circuit includes a key input signal monitoring circuit and a circuit breaker opening / closing position signal monitoring circuit; the output of the key input signal monitoring circuit is connected to the input of the MCU main control IC circuit, used to transmit the key status signal to the MCU main control IC circuit; the MCU main control IC circuit generates a circuit breaker control signal based on the key status signal, and its output is connected to the input of the circuit breaker drive circuit, transmitting the circuit breaker control signal to the circuit breaker drive circuit; the circuit breaker drive circuit drives the circuit breaker to perform opening and closing actions according to the circuit breaker control signal; the circuit breaker opening / closing position signal monitoring circuit monitors the opening and closing actions performed by the circuit breaker opening / closing... The circuit breaker (CB) generates a tripping signal, and its output is connected to the input of the MCU main control IC circuit, transmitting the CB tripping signal to the MCU main control IC circuit. The current sampling circuit (TA) collects the grounding protection current of the inner and outer cores of the cable, and its output is connected to the input of the MCU main control IC circuit, transmitting the grounding protection current to the MCU main control IC circuit. The 4G wireless transmission circuit communicates with the MCU main control IC circuit, transmitting the CB tripping signal and the grounding protection current from the MCU main control IC circuit to the host computer for operational status monitoring, and returning a grounding topology switching signal to the MCU main control IC circuit. The MCU main control IC circuit then performs a grounding topology switching action based on the grounding topology switching signal.

[0024] The circuit of this embodiment will be described in detail below: A1. Grounding circuit of the grounding box main body: See Figure 2 The grounding circuit of the grounding box includes circuit breakers QF1 and QF2, outer core of phase TA1A, outer core of phase TA2B, outer core of phase TA3C, inner core of phase TA1B, inner core of phase TA2C, inner core of phase TA3A, one set of protectors, and two sets of protectors; each of circuit breakers QF1 and QF2 contains three switches. The three internal switches of circuit breaker QF1 are connected at one end to the inner cores of phases TA1B, TA2C, and TA3A, respectively. One end of the first set of protectors is grounded, and the other end is connected to the inner cores of phases TA1B, TA2C, and TA3A, respectively. The other end of the three internal switches of circuit breaker QF1 is connected to the outer cores of phases TA1A, TA2B, and TA3C, respectively. One end of the internal switch of circuit breaker QF2 is connected to the outer cores of phases TA1A, TA2B, and TA3C, and the other end is grounded to one end of the second set of protectors. The other ends of the second set of protectors are connected to the outer cores of phases TA1A, TA2B, and TA3C, respectively.

[0025] A2. Signal monitoring circuit: The signal monitoring circuit includes a key input signal monitoring circuit and a circuit breaker opening / closing position signal monitoring circuit. Specifically: The key input signal monitoring circuit includes a first current-limiting resistor, a second current-limiting resistor, a third current-limiting resistor, a fourth current-limiting resistor, a pull-down resistor, an isolation optocoupler, a first filter capacitor, a second filter capacitor, a first diode, and a first transistor. The isolation optocoupler includes a light-emitting diode and a phototransistor. One end of the third current-limiting resistor is connected to the circuit breaker's open / close signal input terminal, and the other end is electrically connected to the negative terminal of the first diode; the positive terminal of the first diode is connected to the power supply voltage and is electrically connected to one end of the first current-limiting resistor; the other end of the first current-limiting resistor is electrically connected to the collector of the first transistor; the base of the first transistor is electrically connected to one end of the second current-limiting resistor, and the emitter of the first transistor is electrically connected to the positive terminal of the light-emitting diode; the first filter capacitor is connected in parallel with the fourth current-limiting resistor, one end of which is electrically connected to the other end of the second current-limiting resistor, and the other end of which is electrically connected to the negative terminal of the light-emitting diode and then grounded; the light-emitting diode and the phototransistor are isolated by a transparent insulator, the collector of the phototransistor is connected to a 3.3V power supply, and the emitter of the phototransistor is electrically connected to one end of the pull-down resistor and one end of the second filter capacitor, respectively; the other end of the pull-down resistor is connected to the other end of the second filter capacitor and then grounded.

[0026] The key input signal monitoring circuit and the circuit breaker opening / closing position signal monitoring circuit have the same structure, except that the circuit breaker opening / closing position signal input terminal is replaced with the key signal input terminal.

[0027] To facilitate understanding, further explanation is provided below with reference to the illustrations: A21. Key input signal monitoring circuit: Preferred, see Figure 3 In the key input signal monitoring circuit of this embodiment, the first current limiting resistor is R1, the second current limiting resistor is R3, the third current limiting resistor is R4, the fourth current limiting resistor is R7, the pull-down resistor is R9, the isolation optocoupler is U1, the first filter capacitor is C1, the second filter capacitor is C3, the first diode is D1, and the first transistor is Q1.

[0028] When button 1 is pressed, ports AN1_1 and AN1_IN are turned on. At this time, the driving voltage drives Q0 to turn on through R3, which in turn drives the LED in U1 to turn on. The LED then emits light, activating the phototransistor on the other side of U1. After receiving light, the phototransistor changes from the cutoff state to the on state. At this time, port AN1 outputs the button status signal.

[0029] It should be noted that there are a total of 6 key input signal monitoring circuits in this embodiment, corresponding to keys 1-6 respectively. Keys 1-6 correspond to six different grounding box states: cross-interconnected grounded via protector, direct grounded, grounded via protection, grounded via protection (disconnected operation), left protection right direct grounded, and one-key grounded. The key input signal monitoring circuits of keys 1-6 have the same structure. The above description only uses key 1 as an example. The structure and function of key input signal monitoring circuits of keys 2-6 will not be described in detail here.

[0030] A22. Circuit breaker opening / closing position input signal monitoring circuit: Preferred, see Figure 4 In this embodiment, the circuit breaker opening / closing signal monitoring circuit has the following components: first current limiting resistor R2, second current limiting resistor R5, third current limiting resistor R6, fourth current limiting resistor R8, pull-down resistor R10, isolation optocoupler U2, first filter capacitor C2, second filter capacitor C4, first diode D2, and first transistor Q2.

[0031] A3. MCU Main Control IC Circuit: The MCU main control IC circuit includes an MCU main control IC module, a button bus, a current acquisition bus, and a drive signal bus, wherein: The button bus is used to transmit the button status signal to the MCU main control IC circuit; the drive signal bus is used to transmit the circuit breaker control signal to the circuit breaker drive circuit; and the current acquisition bus is used to transmit the ground protection current to the MCU main control IC circuit.

[0032] Preferred, see Figure 5 In this embodiment, the MCU main control IC module adopts the mainstream control ICSTM32F1103RCT6, including an I / O input / output module, an internal multi-channel analog-to-digital converter (ADC) module, and a serial communication module, wherein: The button bus includes IN_1 to IN_6, which is used to transmit button status signals to the MCU main control IC module STM32F1103RCT6; the drive signal bus is JDQ_C, which is used to transmit circuit breaker control signals to the circuit breaker drive circuit; the current acquisition bus includes ADC_1 to ADC_6, which is used to transmit the grounding protection current to the MCU main control IC module STM32F1103RCT6.

[0033] Preferred, see Figure 4-5QF1_KW and QF2_KW represent the signals indicating whether the circuit breakers QF1 and QF2 are in the correct opening / closing state, respectively. These are crucial closed-loop input signals in the control logic. 4G_TX and 4G_RX utilize the internal serial communication module to package data for wireless transmission via a fixed command protocol. When the circuit breakers are in the correct opening / closing state, QF1_K1 and QF1_K2 are turned on. At this time, the driving voltage is turned on through Q2, further driving the LED in U2 to turn on. The LED then emits light, activating the phototransistor on the other side of U2. Upon receiving light, the phototransistor changes from a cutoff state to a conducting state. The QF1_KW port outputs the circuit breaker opening / closing state signal. When the MCU main control IC module detects the signal input at its I / O input / output port, it determines whether the circuit breakers QF1 and QF2 are in the correct opening / closing state according to preset logic.

[0034] A4. Current sampling circuit for transformer (TA): Preferred, see Figure 6 In this embodiment, the TA current sampling circuit includes a TA current transformer TA1, a sampling power resistor R12, a third filter capacitor C5, a fourth filter capacitor C6, a fifth filter capacitor C7, an operational amplifier U3, a first peripheral resistor R11 of the operational amplifier, a second peripheral resistor R13 of the operational amplifier, and a third peripheral resistor R14 of the operational amplifier. The secondary output current of the current transformer TA1 is input to both ends of the sampling power resistor. The sampling power resistor R12 is connected in parallel with the third filter capacitor C5, the fourth filter capacitor C6, and the fifth filter capacitor C7. One end of the parallel connection is electrically connected to one end of the first peripheral resistor R11 of the operational amplifier, and the other end is electrically connected to one end of the second peripheral resistor R13 of the operational amplifier and then grounded. The other end of the first peripheral resistor R11 of the operational amplifier is electrically connected to the non-inverting input terminal of the operational amplifier U3, and the other end of the second peripheral resistor R13 of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier U3. The positive power supply terminal of the operational amplifier U3 is connected to a 3.3V power supply, and the negative power supply terminal is grounded. Its output terminal is electrically connected to one end of the third peripheral resistor R14 of the operational amplifier, and the other end of the third peripheral resistor R14 of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier U3.

[0035] See Figure 6The input signal at the input terminal of the TA current sampling circuit is the output current of the secondary side of the TA current transformer TA1. The TA current transformer TA1 adopts the II mode, that is, current-to-current conversion, to achieve the current conversion ratio. The sampling power resistor R12 is used to convert the current into a voltage signal. The operational amplifier U3 and the external resistors R11, R13 and R14 of the operational amplifier constitute a non-inverting amplifier circuit to improve the sampling accuracy.

[0036] A5. Circuit breaker drive circuit: The circuit breaker drive circuit is divided into a QF1 circuit breaker drive circuit and a QF2 circuit breaker drive circuit. The QF1 circuit breaker drive circuit and the QF2 circuit breaker drive circuit have the same structure. The QF1 circuit breaker drive circuit includes a control disconnection logic circuit and a control closure logic circuit. The control disconnection logic circuit is composed of a first relay, a first driving resistor, a first driving switch, and a third diode. The control closure logic circuit is composed of a second relay, a second driving resistor, a second driving switch, and a third diode. One coil terminal of the first relay is electrically connected to a 5V power supply and the negative terminal of the second diode, respectively. The other coil terminal of the first relay is electrically connected to the collector of the first driving switch and the positive terminal of the second diode. The normally closed terminal of the first relay is connected to the common terminal of the second relay. One end of the first driving resistor is electrically connected to the base of the first driving switch, and the emitter of the first driving switch is grounded. One coil terminal of the second relay is electrically connected to a 5V power supply and the negative terminal of the third diode, respectively. The other coil terminal of the second relay is electrically connected to the collector of the second driving switch and the positive terminal of the third diode. The common terminal of the second relay is connected to the normally closed port of the first relay. One end of the second driving resistor is electrically connected to the base of the second driving switch, and the emitter of the second driving switch is grounded.

[0037] Preferred, see Figure 7 In this embodiment, the first relay of the QF1 circuit breaker drive circuit is K1, the first drive resistor is R17, the first drive switch is Q4, the second diode is D3, the second relay is K2, the second drive resistor is R18, the second drive switch is Q5, and the third diode is D4; the first relay of the QF2 circuit breaker drive circuit is K3, the first drive resistor is R19, the first drive switch is Q6, the second diode is D5, the second relay is K4, the second drive resistor is R20, the second drive switch is Q7, and the third diode is D6.

[0038] It should be noted that this embodiment uses two sets of relays to control two circuit breakers respectively; K1 and K2 form one set to control circuit breaker QF1, and K3 and K4 form another set to control circuit breaker QF2; QF1 and QF2 are driven by node control, such as... Figure 2 In the diagram S1, S2, and S3, S1 is the common terminal. When S1 and S2 are connected, the circuit breaker closes. When S1 and S3 are connected, the circuit breaker opens. Due to mechanical errors, the action time varies slightly, with a typical error of 1-2 seconds. The total action time of this type of mechanism is approximately 6 seconds. Considering the error time, the preset conduction time is 10 seconds. If the time is set too long, the next action will have to wait until this time has elapsed, affecting efficiency. This is to ensure that the circuit breaker operates completely. K1 controls the opening logic of circuit breaker QF1, and K2 controls the closing logic of circuit breaker QF1. The normally closed port of K1 is connected to the common terminal of K2. Therefore, if QF1 needs to be closed, K1 must be in its normally closed state to enable K2 to conduct, thus achieving QF1 closure. This ensures that the priority of opening is greater than the priority of closing, further guaranteeing the dead time of the entire control loop and preventing abnormal phenomena such as simultaneous on and off states. R17, R18, R19, and R20 are driving resistors, driving the switching transistors Q4, Q5, Q6, and Q7 to conduct and cut off, respectively. Four diodes D3, D4, D5, and D6 are reverse-connected to the coil terminals of the relay to absorb the coil's potential energy and protect the relay.

[0039] A6, 4G wireless transmission circuit: Preferably, the 4G wireless transmission circuit includes a 4G wireless transmission module, a first power supply filter capacitor, a second power supply filter capacitor, a first resistor, a second resistor, and a second transistor. The 4G wireless transmission module includes a universal asynchronous receiver transmission port, a universal asynchronous transmitter transmission port, a GND port, a reset signal input terminal, a reset signal output terminal, a first DC power supply input port, and a second DC power supply input port, wherein: The universal asynchronous receiver / transmitter port receives the circuit breaker closing / opening signal and the grounding protection current; the universal asynchronous transmitter / transmitter port transmits the circuit breaker closing / opening signal and the grounding protection current; the GND port is grounded; the reset signal input port is electrically connected to one end of the first resistor and the collector of the second transistor; the first DC power input port is connected to a 5V power supply; the second DC power input port is electrically connected to one end of the first power supply filter capacitor and the second power supply filter capacitor, and the other ends of the first power supply filter capacitor and the second power supply filter capacitor are grounded; the other end of the first resistor is connected to a 5V power supply; the base of the second transistor is electrically connected to one end of the second resistor; the emitter of the second transistor is grounded; and the other end of the second resistor is connected to the reset signal output terminal.

[0040] Preferred, see Figure 8 In this embodiment, the 4G wireless transmission module is U4, the first power supply filter capacitor is C8, the second power supply filter capacitor is C9, the first resistor is R15, the second resistor is R16, and the second transistor is Q3. Considering the application layer relationship, the 4G wireless transmission module uses the WH-LTE-7S0 module for data transmission. Due to its communication stability and mature data packetization mode, the serial port data interaction mode is directly used to control the corresponding logic. R15, R16, and Q3 form a driver circuit to reset the 4G wireless transmission module when the communication device malfunctions.

[0041] Pin 7 of the 4G wireless transmission module WH-LTE-7S0 receives data, pin 6 of the 4G wireless transmission module WH-LTE-7S0 transmits data, and pins 11 and 12 are grounded; pin 19 of the 4G wireless transmission module WH-LTE-7S0 is electrically connected to one end of R15 and the collector of Q3; pin 14 of the 4G wireless transmission module WH-LTE-7S0 is connected to a 5V power supply; C8 and C9 are connected in parallel, with one end grounded and the other end connected to pins 13 and 14 of the 4G wireless transmission module WH-LTE-7S0 and the 5V power supply; the other end of R15 is connected to a 5V power supply; the base of Q3 is electrically connected to one end of R16, and the emitter of Q3 is grounded.

[0042] Preferably, the 4G wireless transmission module WH-LTE-7S0 supports communication with China Mobile, China Unicom, and China Telecom IoT cards. Its communication is stable, its data packetization mode is mature, and it can directly control the corresponding logic using serial port data interaction. Specifically, the host computer can collect the grounding protection current of the inner and outer cores in real time through six sets of inner and outer core current acquisition modules, obtain the data, and transmit it to the MCU main control IC. The MCU main control IC sends the data to the 4G wireless transmission module WH-LTE-7S0 via serial port. The 4G wireless transmission module uses its wireless transmission function to send the data in real time, thereby realizing real-time monitoring of grounding. Check for any abnormalities in the grounding box; when abnormal data indicating an abnormality occurs, the 4G wireless transmission module WH-LTE-7S0 sends a command from the host computer, which is to change the grounding state of the grounding box. After the command is received by the 4G wireless transmission module WH-LTE-7S0, it sends data to the MCU main control IC through pin 6 of the 4G wireless transmission module WH-LTE-7S0. The MCU main control IC processes the input according to preset logic and outputs control commands to the circuit breaker drive module to control the opening and closing states of circuit breakers QF1 and QF2, thereby changing the grounding state of the grounding box.

[0043] The principle of this utility model is as follows: The core MCU main control IC coordinates various functional modules to achieve dynamic switching and real-time monitoring of the grounding status of high-voltage single-core power cables. It begins with user input: local button presses or remote commands. When on-site personnel select a grounding status such as cross-interconnection via the button module, the MCU main control IC receives the signal. The button module employs optocoupler isolation to ensure signal stability and avoid external interference. The MCU main control IC processes the input according to preset logic and outputs control commands to the circuit breaker drive module. The circuit breaker drive module controls the opening and closing states of circuit breakers QF1 and QF2 through a relay group, with a preset 10-second conduction time to ensure complete circuit breaker operation. Simultaneously, the current acquisition module monitors the inner and outer core currents in real time, uses a current transformer (TA) to convert the current signal into voltage, improves accuracy through a non-inverting amplifier circuit, and converts the data into a digital signal through the ADC interface of the MCU main control IC. The circuit breaker status confirmation signal module feeds back to the MCU main control IC after confirming the circuit breaker status, forming a closed-loop control. All data is transmitted to a remote server via a 4G wireless transmission module, supporting remote viewing and adjustment. Ultimately, in the main grounding circuit of the grounding box, the state combination of circuit breakers QF1 and QF2 dynamically changes the connection method between the inner and outer core paths and the protector group, eliminating the induced voltage of the cable sheath. The overall architecture is managed by the MCU main control IC unified management module interaction.

[0044] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0045] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0046] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A cable multifunction grounding box device circuit based on free switching of grounding topology, characterized by, It includes the grounding box main grounding circuit, MCU main control IC circuit, signal monitoring circuit, TA current sampling circuit, circuit breaker drive circuit and 4G wireless transmission circuit, among which: The grounding box main grounding circuit includes circuit breakers QF1 and QF2 and inner and outer cable cores; the signal monitoring circuit includes a key input signal monitoring circuit and a circuit breaker opening / closing position signal monitoring circuit; the output of the key input signal monitoring circuit is connected to the input of the MCU main control IC circuit, used to transmit the key status signal to the MCU main control IC circuit; the MCU main control IC circuit generates a circuit breaker control signal based on the key status signal, and its output is connected to the input of the circuit breaker drive circuit, transmitting the circuit breaker control signal to the circuit breaker drive circuit; the circuit breaker drive circuit drives the circuit breaker to perform opening and closing actions according to the circuit breaker control signal; the circuit breaker opening / closing position signal monitoring circuit monitors the opening and closing actions performed by the circuit breaker opening / closing... The circuit breaker (CB) generates a tripping signal, and its output is connected to the input of the MCU main control IC circuit, transmitting the CB tripping signal to the MCU main control IC circuit. The current sampling circuit (TA) collects the grounding protection current of the inner and outer cores of the cable, and its output is connected to the input of the MCU main control IC circuit, transmitting the grounding protection current to the MCU main control IC circuit. The 4G wireless transmission circuit communicates with the MCU main control IC circuit, transmitting the CB tripping signal and the grounding protection current from the MCU main control IC circuit to the host computer for operational status monitoring, and returning a grounding topology switching signal to the MCU main control IC circuit. The MCU main control IC circuit then performs a grounding topology switching action based on the grounding topology switching signal.

2. A cable multifunction grounding box device circuit based on free switching of grounding topology according to claim 1, characterized in that, The MCU main control IC circuit includes an MCU main control IC module, a button bus, a current acquisition bus, and a drive signal bus, wherein: The button bus is used to transmit the button status signal to the MCU main control IC circuit; the drive signal bus is used to transmit the circuit breaker control signal to the circuit breaker drive circuit; and the current acquisition bus is used to transmit the ground protection current to the MCU main control IC circuit.

3. A cable multifunction grounding box device circuit based on free switching of grounding topology according to claim 1, characterized in that, The circuit breaker opening / closing position signal monitoring circuit includes a first current-limiting resistor, a second current-limiting resistor, a third current-limiting resistor, a fourth current-limiting resistor, a pull-down resistor, an isolation optocoupler, a first filter capacitor, a second filter capacitor, a first diode, and a first transistor. The isolation optocoupler includes a light-emitting diode and a phototransistor. One end of the third current-limiting resistor is connected to the circuit breaker's open / close signal input terminal, and the other end is electrically connected to the negative terminal of the first diode; the positive terminal of the first diode is connected to the power supply voltage and is electrically connected to one end of the first current-limiting resistor; the other end of the first current-limiting resistor is electrically connected to the collector of the first transistor; the base of the first transistor is electrically connected to one end of the second current-limiting resistor, and the emitter of the first transistor is electrically connected to the positive terminal of the light-emitting diode; the first filter capacitor is connected in parallel with the fourth current-limiting resistor, one end of which is electrically connected to the other end of the second current-limiting resistor, and the other end of which is electrically connected to the negative terminal of the light-emitting diode and then grounded; the light-emitting diode and the phototransistor are isolated by a transparent insulator, the collector of the phototransistor is connected to a 3.3V power supply, and the emitter of the phototransistor is electrically connected to one end of the pull-down resistor and one end of the second filter capacitor, respectively; the other end of the pull-down resistor is connected to the other end of the second filter capacitor and then grounded.

4. A cable multifunction grounding box device circuit based on free switching of grounding topology according to claim 3, characterized in that, The key input signal monitoring circuit and the circuit breaker opening / closing position signal monitoring circuit have the same structure, except that the circuit breaker opening / closing position signal input terminal is replaced with the key signal input terminal.

5. The cable multifunction grounding box device circuit based on free switching of grounding topology of claim 1, wherein, The TA current sampling circuit includes a TA current transformer TA1, a sampling power resistor, a third filter capacitor, a fourth filter capacitor, a fifth filter capacitor, an operational amplifier, a first peripheral resistor of the operational amplifier, a second peripheral resistor of the operational amplifier, and a third peripheral resistor of the operational amplifier, wherein; The secondary output current of the current transformer TA1 is input to both ends of the sampling power resistor. The sampling power resistor is connected in parallel with the third, fourth, and fifth filter capacitors. One end of the parallel connection is electrically connected to one end of the first peripheral resistor of the operational amplifier, and the other end is electrically connected to one end of the second peripheral resistor of the operational amplifier and then grounded. The other end of the first peripheral resistor of the operational amplifier is electrically connected to the non-inverting input terminal of the operational amplifier, and the other end of the second peripheral resistor of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier. The positive power supply terminal of the operational amplifier is connected to a 3.3V power supply, and the negative power supply terminal is grounded. Its output terminal is electrically connected to one end of the third peripheral resistor of the operational amplifier, and the other end of the third peripheral resistor of the operational amplifier is electrically connected to the inverting input terminal of the operational amplifier.

6. A cable multifunction grounding box device circuit based on free switching of grounding topology according to claim 1, characterized in that, The circuit breaker drive circuit is divided into a QF1 circuit breaker drive circuit and a QF2 circuit breaker drive circuit. The QF1 circuit breaker drive circuit and the QF2 circuit breaker drive circuit have the same structure. The QF1 circuit breaker drive circuit includes a control disconnection logic circuit and a control closure logic circuit. The control disconnection logic circuit is composed of a first relay, a first driving resistor, a first driving switch, and a third diode. The control closure logic circuit is composed of a second relay, a second driving resistor, a second driving switch, and a third diode. One coil terminal of the first relay is electrically connected to a 5V power supply and the negative terminal of the second diode, respectively; the other coil terminal of the first relay is electrically connected to the collector of the first driving switch and the positive terminal of the second diode; the normally closed terminal of the first relay is connected to the common terminal of the second relay; one end of the first driving resistor is electrically connected to the base of the first driving switch. One coil terminal of the second relay is electrically connected to a 5V power supply and the negative terminal of the third diode, respectively. The other coil terminal of the second relay is electrically connected to the collector of the second driving switch and the positive terminal of the third diode. The common terminal of the second relay is connected to the normally closed port of the first relay. One end of the second driving resistor is electrically connected to the base of the second driving switch.

7. A cable multifunction grounding box device circuit based on free switching of grounding topology according to claim 1, characterized in that, The 4G wireless transmission circuit includes a 4G wireless transmission module, a first power supply filter capacitor, a second power supply filter capacitor, a first resistor, a second resistor, and a second transistor. The 4G wireless transmission module includes a universal asynchronous receiver transmission port, a universal asynchronous transmitter transmission port, a GND port, a reset signal input terminal, a reset signal output terminal, a first DC power supply input port, and a second DC power supply input port, wherein: The universal asynchronous receiver / transmitter port receives the circuit breaker closing / opening signal and the grounding protection current; the universal asynchronous transmitter / transmitter port transmits the circuit breaker closing / opening signal and the grounding protection current; the GND port is grounded; the reset signal input port is electrically connected to one end of the first resistor and the collector of the second transistor; the first DC power input port is connected to a 5V power supply; the second DC power input port is electrically connected to one end of the first power supply filter capacitor and the second power supply filter capacitor, and the other ends of the first power supply filter capacitor and the second power supply filter capacitor are grounded; the other end of the first resistor is connected to a 5V power supply; the base of the second transistor is electrically connected to one end of the second resistor; the emitter of the second transistor is grounded; and the other end of the second resistor is connected to the reset signal output terminal.

8. The cable multifunction grounding box device circuit based on free switching of grounding topologies according to claim 1, characterized in that, The grounding circuit of the grounding box also includes one set of protectors and two sets of protectors, which are used to protect the circuits corresponding to circuit breakers QF1 and QF2, respectively.

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