Protection device based on a multiple switch and a direct current leakage current evaluation model

Abstract

The utility model relates to the field of intelligent switch especially protection device based on multichannel switch and direct current leakage current evaluation model, include: N -way intelligent switch, controller, sampling circuit, conditioning circuit, Mosfet drive circuit, communication circuit, power module, every intelligent switch includes input, output, a group of mechanical contact and a group of Mosfet switch, input and mechanical contact connect, and mechanical contact is connected with output through Mosfet switch, controller is connected with power module, conditioning circuit, Mosfet drive circuit, communication circuit, and conditioning circuit connects intelligent switch through sampling circuit, and Mosfet drive circuit is connected with Mosfet switch, the beneficial effect of the utility model lies in: natural arc extinguishing, response is fast, realizes the high -speed protection of direct current leakage current, improves detection accuracy, promotes device intelligence and integration.

Description

Technical Field

[0001] This utility model relates to the field of intelligent switches, and in particular to a protection device based on a multi-channel switch and a DC leakage current evaluation model. Background Technology

[0002] Leakage current in DC systems has a profound impact on equipment safety, personnel safety, and energy utilization. In severe cases, it may lead to overheating causing equipment shutdown and production stoppage, or grounding causing electric shock and affecting personal safety. Therefore, the detection and prevention of leakage current in DC systems has always been an important research direction in related fields.

[0003] Existing DC system leakage current detection methods primarily rely on leakage current sensors, double insulation, and grounding protection. When the leakage current sensor detects a leakage current exceeding a set protection value, it issues a protection control signal. However, this approach suffers from drawbacks such as long mechanical disconnection times, difficulty in arc extinguishing, and high false alarm rates. Power supply systems utilize circuit breakers, fuses, and insulation testers for system protection. However, due to the numerous power electronic devices present in DC systems, these devices may activate before circuit breakers and other protective devices in the event of a fault, leading to a loss of power supply. Furthermore, if multiple circuits need simultaneous protection, circuit breakers must be installed in each circuit, increasing costs. While high-precision detection equipment can reduce false alarm rates, it requires regular maintenance and calibration. Moreover, existing methods fail to adequately consider the impact of environmental factors, wiring, materials, and power electronic devices on leakage current. Utility Model Content

[0004] To overcome the above-mentioned shortcomings, this utility model aims to provide a protection device based on a multi-channel switch and a DC leakage current assessment model, thereby solving the problems of high false alarm rate, difficulty in arc extinguishing, and low intelligence in existing devices.

[0005] This utility model achieves the above-mentioned objectives through the following scheme: a protection device based on a multi-channel switch and a DC leakage current evaluation model, comprising: N-channel intelligent switches, a controller, a sampling circuit, a conditioning circuit, a MOSFET drive circuit, a communication circuit, and a power module; each intelligent switch includes an input terminal, an output terminal, a set of mechanical contacts, and a set of MOSFET switches; the sampling circuit includes a voltage sampling circuit, a current sampling circuit, a leakage current sampling circuit, and a temperature and humidity sampling circuit; the input terminal and the output terminal are respectively connected to the input and output terminals of a cable, the input terminal is connected to the mechanical contacts, and the mechanical contacts are connected to the output terminal through the MOSFET switches; the controller is connected to the power module, the conditioning circuit, the MOSFET drive circuit, and the communication circuit, the conditioning circuit is connected to the intelligent switches through the sampling circuit, and the MOSFET drive circuit is connected to the MOSFET switches.

[0006] Preferably, the smart switch has four circuits, each of which is independent and contains the same components.

[0007] Preferably, in the sampling circuit described, the voltage sampling circuit collects the input voltage and output voltage, the current sampling circuit collects the input current and output current, and the electrical signal data collected by the sampling circuit is converted into digital signals by the conditioning circuit.

[0008] Preferably, the circuit data collected in real time by the sampling circuit includes: input voltage, input current, output voltage, output current, and leakage current.

[0009] Preferably, the environmental data collected in real time by the sampling circuit includes: temperature, air pressure, and humidity.

[0010] The beneficial effects of this utility model are as follows: 1. The connection and disconnection of the switch are realized by the conduction of the MOSFET, which naturally extinguishes the arc, has a fast response, and achieves high-speed protection of DC leakage current; 2. The influence of environmental, material, and system operating characteristics is considered simultaneously to improve the detection accuracy of leakage current; 3. An evaluation model is established, and the controller determines whether leakage current has occurred through the evaluation strategy and outputs a DO electronic switch disconnect command to reduce the false alarm rate of existing DC system leakage current protection; 4. The intelligence and integration of the device are improved. By setting thresholds, the controller can judge and run the protection automatically without human intervention, while retaining fault information and protection information. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the device module of this utility model;

[0012] Figure 2 This is a circuit diagram of the device of this utility model;

[0013] Figure 3 This is a circuit diagram of the voltage sampling circuit of the device of this utility model;

[0014] Figure 4 This is a circuit diagram of the current sampling circuit of the device of this utility model;

[0015] Figure 5 This is a circuit diagram of the leakage current sampling circuit of the device of this utility model;

[0016] In the diagram: 1. Smart switch; 2. Controller; 3. Sampling circuit; 4. Conditioning circuit; 5. MOSFET driver circuit; 6. Communication circuit; 7. Power module; 11. Input terminal; 12. Mechanical contact; 13. MOSFET switch; 14. Output terminal; 31. Voltage sampling circuit; 32. Current sampling circuit; 33. Leakage current sampling circuit; 34. Temperature and humidity sampling circuit. Detailed Implementation

[0017] The present invention will be further described below with reference to specific implementation examples, but the scope of protection of the present invention is not limited thereto:

[0018] Example: Figure 1 As shown, the protection device based on a multi-channel switch and DC leakage current evaluation model includes: a four-channel intelligent switch 1, a controller 2, a sampling circuit 3, a conditioning circuit 4, a MOSFET drive circuit 5, a communication circuit 6, and a power supply module 7; each branch is independent and contains the same components. Figure 3 As shown, the system includes four smart switches 1. Each smart switch 1 includes an input terminal 11, an output terminal 12, a set of mechanical contacts 13, and a set of MOSFET switches 14. The input terminal 11 and output terminal 14 of each smart switch 1 are connected to the input and output terminals of a cable, respectively. Each smart switch 1 is installed in parallel. The sampling circuit 3 includes a voltage sampling circuit 31, a current sampling circuit 32, a leakage current sampling circuit 33, and a temperature and humidity sampling circuit 34. The voltage sampling circuit 31 collects the input voltage and output voltage, and the current sampling circuit 32 collects the input current and output current. The electrical signal data collected by the sampling circuit 3 is converted into digital signals by the conditioning circuit 4. The controller 2 is connected to the power module 7, the conditioning circuit 4, the MOSFET drive circuit 5, and the communication circuit 6. The conditioning circuit 4 is connected to the smart switches 1 through the sampling circuit 3, and the MOSFET drive circuit 5 is connected to the MOSFET switches 13.

[0019] When in use, first manually push the mechanical device to the closed position. When the device detects no leakage current fault, it issues an electronic switch closing command. At this time, the output and input are connected. When the controller 2 determines that a leakage current fault has occurred, the controller 2 issues an electronic switch opening command. At this time, the output and input are isolated and disconnected, and the status indicator light issues a fault indication.

[0020] In one embodiment, such as Figure 4The diagram shows a voltage sampling circuit 31, which includes: a chip U1, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, and R13, capacitors C1, C2, C3, C4, and C5, and an operational amplifier U1A; the chip U1 is an AMC1200. It contains eight pins. Capacitor C1 is connected to pins VDD1 and GND1 of chip U1. Resistors R1, R2, R3, R4, R5, R6, R7, R8, and R9 are connected in series. Resistor R9 is connected to pin VINN. Capacitor C3 is connected to pins VINP and VINN. Capacitor C3 is also connected to pins VDD2 and GND2. Pin VOUTP is connected to the non-inverting input of operational amplifier U7A through resistor R11. Pin VOUTN is connected to the inverting input of operational amplifier U7A through resistor R10. Capacitor C4 and resistor R12 are connected in parallel between the inverting input and output of operational amplifier U7A. Capacitor C5 and resistor R13 are connected in parallel between the non-inverting input of operational amplifier U7A and analog ground AG.

[0021] In one embodiment, such as Figure 5 The diagram shows a current sampling circuit 32, which includes: a chip U2, capacitors C6, C7, C8, C9, C10, C11, C12, C13, and C14, resistors R14, R15, R16, R17, R18, and R19, and an operational amplifier U1B. The chip U2 is an AMC1200 with eight pins. Capacitor C6 is connected between pin VDD1 and pin GND1, capacitor C7 is connected between pin VDD2 and pin GND2, pin GND2 is connected to analog ground AG, and pins VINP are connected to capacitors... C9, resistor R14, and capacitor C8 are connected. Capacitor C8 is connected to pin VINN. Pin VINN is also connected to resistor R15 and capacitor C10. Pin VOUTP is connected to the non-inverting input of operational amplifier U1B through resistor R17. Pin VOUTN is connected to the inverting input of operational amplifier U1B through resistor R16. Resistor R18 and capacitor C11 are connected in parallel to the inverting input and output of operational amplifier U1B. The positive power supply of operational amplifier U1B is connected to capacitors C13 and C14. Capacitors C13 and C14 are connected to analog ground AG. The negative power supply of operational amplifier U1B is connected to analog ground AG. The non-inverting input of operational amplifier U1B is connected to resistor R19 and capacitor C12.

[0022] In one embodiment, such as Figure 5The diagram shows a leakage current sampling circuit 33, including a control unit M1, resistors R20, R21, R22, R23, R24, and R25, capacitors C15, C16, C17, C18, C19, C20, C21, C22, and C23, diodes D1 and D2, a no-connect pin P1, and an operational amplifier U1C. The control unit M1's VCC pin is connected to a 5V voltage, and capacitors C15, C16, and C17 are connected in parallel. Capacitors C15, C16, and C17 are connected at one end to pin VCC and at the other end to pin Gnd of control unit M1. Pin Gnd is connected to analog ground AG. Pin Vout of control unit M1 is connected to resistor R22, which is connected in series with resistor R20. Resistor R20 is connected to the positive input terminal of operational amplifier U1C. Capacitor C18 is connected to resistor R22 and capacitor C15. Capacitor C19 and capacitor C20 are connected in parallel between pin Vref and analog ground AG. Pin Vref of control unit M1 is also connected to resistor R21, which is connected to the inverting input terminal of operational amplifier U1C. Diodes D1 and D2 are connected in parallel to the amplifier... The inverting and non-inverting input terminals of the amplifier U1C are connected in opposite directions. Diodes D1 and D2 are connected in parallel. Capacitor C22 and resistor R24 ​​are connected in parallel. One end of capacitor C22 and resistor R24 ​​is connected to the non-inverting input terminal of operational amplifier U1C, and the other end is connected to 2.5V-REF. Capacitor C21 and resistor R23 are connected in parallel. One end of capacitor C21 and resistor R23 is connected to the inverting input terminal of operational amplifier U1C, and the other end is connected to the output terminal of operational amplifier U1C. Resistor R25 is connected to the output terminal of operational amplifier U1C. Resistor R25 and capacitor C23 are connected in series. Capacitor C23 is connected to analog ground AG. Pins 6-10 of control unit M1 are connected to unused pin P1.

[0023] This utility model device is used for intelligent switch protection against DC leakage current. The sampling circuit 3 collects electrical signals through the voltage sampling circuit 31, current sampling circuit 32, leakage current sampling circuit 33, and temperature and humidity sampling circuit 34. These signals are then modulated and converted into digital signals by the conditioning module 4. The controller 2 calculates and determines whether leakage current has occurred or is continuously increasing. If so, it outputs a PWM signal to drive the MOSFET drive circuit 5, controlling the MOSFET to not conduct, thereby disconnecting the circuit. The calculation and judgment by the controller 2 can reduce false leakage current detection. At the same time, the electronic switch can achieve intelligent circuit disconnection, which is safer and faster. The parallel design of the multi-channel intelligent switch 1 can realize the switching control of multiple circuits through a single device, saving costs.

[0024] The above description is a specific embodiment of the present utility model and the technical principle used. If changes are made according to the concept of the present utility model, and the resulting functions do not exceed the spirit covered by the specification and drawings, they should still be within the protection scope of the present utility model.

Claims

1. A protection device based on a multiplexer and a DC leakage current evaluation model, characterized in that... include: The system comprises an N-channel intelligent switch (1), a controller (2), a sampling circuit (3), a conditioning circuit (4), a MOSFET driver circuit (5), a communication circuit (6), and a power module (7); each intelligent switch (1) includes an input terminal (11), an output terminal (14), a set of mechanical contacts (12), and a set of MOSFET switches (13); the sampling circuit (3) includes a voltage sampling circuit (31), a current sampling circuit (32), a leakage current sampling circuit (33), and a temperature and humidity sampling circuit (34); the input terminal (11) and output terminal (14) are respectively connected to the input and output terminals of the cable. The input terminal (11) is connected to the mechanical contact (12). The mechanical contact (12) is connected to the output terminal (14) through the MOSFET switch (13). The controller (2) is connected to the power module (7), conditioning circuit (4), MOSFET drive circuit (5), and communication circuit (6). The conditioning circuit (4) is connected to the smart switch (1) through the sampling circuit (3). The MOSFET drive circuit (5) is connected to the MOSFET switch (13).

2. The protection device based on a multi-channel switch and a DC leakage current evaluation model according to claim 1, characterized in that, The smart switch has four circuits, each independent and containing the same components.

3. The protection device based on a multi-channel switch and a DC leakage current evaluation model according to claim 1, characterized in that, In the sampling circuit described, the voltage sampling circuit collects the input voltage and output voltage, the current sampling circuit collects the input current and output current, and the electrical signal data collected by the sampling circuit is converted into digital signals by the conditioning circuit.

4. The protection device based on a multi-channel switch and a DC leakage current evaluation model according to claim 1, characterized in that, The circuit data collected in real time by the sampling circuit includes: input voltage, input current, output voltage, output current, and leakage current.

5. The protection device based on a multi-channel switch and a DC leakage current evaluation model according to claim 1, characterized in that, The environmental data collected in real time by the sampling circuit includes: temperature, air pressure, and humidity.

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