Intelligent Electrical Safety Protection Device

Abstract

The object of the present invention is that in the electrical safety intelligent protection device, we have solved the problem of automatically detecting the insulation between the electrical appliances including motors and between each circuit line and the ground insulation under the power-off condition through intelligent control by a single-chip microcomputer. Then, a structure including temperature detection of the terminal block, a protection circuit for detecting the current of a three-phase single-pulse sine-wave motor, a main housing, and a display is provided. In the electrical safety intelligent protection device, a temperature sensor is added to the terminal block and controlled by a single-chip microcomputer to protect the temperature of the terminal block. When the temperature of the terminal block exceeds the specified value, the power supply is cut off to avoid unexpected fires caused by serious overheating of the terminal block, so that personal and property are not severely damaged. The protection circuit for detecting the current of a three-phase single-pulse sine-wave motor adds a reference voltage to the center line of the three-phase current transformer in the motor protection circuit. Its circuit is simple, and the current sampling outputs a complete three-phase pulsating single sine wave, which enters the single-chip microcomputer for processing to achieve over-current and overload protection of the three-phase working current of the motor and unbalance protection of the three-phase current.

Description

Technical Field

[0001] The present invention relates to the field of safe electricity use and motor protection, in particular to an intelligent electrical safety protection device. Background Art

[0002] At present, in the fields of safe electricity use protection and motor protection, as well as with high-power electrical appliances entering ordinary households, the electricity load of municipal commercial facilities has increased, and the complexity of electricity use in the production process has increased. These high-load electricity uses and complex environments are prone to insulation damage, causing electrical fires. There are a large number of wiring terminals in power supply and electrical equipment, such as the main switch of the power supply incoming line, circuit breakers and contactors in the distribution cabinet. Overheating caused by excessive current or loose wiring will also cause electrical fires. Although there are many products with different brand names in the field of motor protection, in fact, the circuit structures are mostly the same, with little difference and no characteristics. Summary of the Invention

[0003] The object of the present invention is to address the above-mentioned defects. In the intelligent electrical safety protection device, we have solved the problem of automatically detecting the insulation between electrical appliances including motors and between each circuit line and the ground under power-off conditions through intelligent control by a single-chip microcomputer. If the insulation does not meet the standard, the intelligent control will disconnect the actuator or the electrical safety protection measurement and control device, or prevent the circuit breaker from closing or turn off the contactor, and take preventive measures in advance to avoid accidents such as electric shock casualties, equipment damage, and electrical fires easily caused by insulation damage in complex environments, realizing safe electricity use and ensuring the safety of personnel, machines and equipment. The present invention further provides an intelligent electrical safety protection device and a three-phase single-phase pulsating sine-wave motor current detection and protection circuit. The intelligent electrical safety protection device adds a temperature sensor to the wiring terminal and is controlled by a single-chip microcomputer to protect the temperature of the wiring terminal. When the temperature of the wiring terminal exceeds the specified value, the power supply is cut off to avoid unexpected fires caused by serious overheating of the wiring terminal and prevent serious losses to personnel and property. The three-phase single-phase pulsating sine-wave motor current detection and protection circuit adds a reference voltage to the center line of the three-phase mutual inductor in the motor protection circuit. Its circuit is simple, and the current sampling outputs a complete three-phase pulsating single-phase sine wave, which enters the single-chip microcomputer for processing to achieve over-current and overload protection of the three-phase working current of the motor and three-phase current imbalance protection.

[0004] The technical solution of the present invention is an electrical safety intelligent protection device, including the structure of temperature detection of wiring terminals, three-phase single-phase pulsating sine wave motor current detection and protection circuit, main housing and display. It is characterized in that the electrical safety intelligent protection device adds temperature sensors on the wiring terminals, which are controlled by a single-chip microcomputer to protect the temperature of the wiring terminals. When the temperature of the wiring terminals exceeds the specified value, the power supply is cut off to avoid unexpected fires caused by serious overheating of the wiring terminals, so that personal and property are not severely damaged. The temperature sensor RF1 is closely attached to the power supply incoming line terminal A1, the temperature sensor RF2 is closely attached to the power supply incoming line terminal B1, the temperature sensor RF3 is closely attached to the power supply incoming line terminal C1, the temperature sensor RF4 is closely attached to the motor outgoing line terminal A2, the temperature sensor RF5 is closely attached to the motor outgoing line terminal B2, and the temperature sensor RF6 is closely attached to the motor outgoing line terminal C2 to detect the temperature of each wiring terminal respectively. The detection results are processed by the single-chip microcomputer chip MCU. If the overheating of a certain wiring terminal exceeds the specified value due to excessive current or poor contact, the contactor JQ1 is controlled to disconnect, effectively avoiding the occurrence of fires or other accidents. The circuit structure is that 6 identical temperature detection circuits detect 6 wiring terminals respectively. One of the temperature detection circuits is the temperature detection circuit of the power supply incoming line terminal A1, where the temperature sensor RF1 is closely attached to the power supply incoming line terminal A1, the temperature sensor RF1 is connected to the resistor RF7, the resistor RF8, and the capacitor CF1. The other end of the resistor RF7 is connected to the positive power supply Vcc, the other end of the resistor RF8 is connected to the capacitor CF2 and the single-chip microcomputer chip MCU, and the other ends of the temperature sensor RF1, the capacitor CF1, and the capacitor CF2 are connected to the common terminal V0. The A-phase connection line Ja of the wiring terminal, the B-phase connection line Jb of the wiring terminal, and the C-phase connection line Jc of the wiring terminal are connected to the contactor JQ1, and the wiring terminal skeleton 20 is fixed with screws using the fixing holes 21 of the wiring terminal skeleton.

[0005] The described electrical safety intelligent protection device is characterized in that the three-phase single-phase pulsating sine wave motor current detection and protection circuit and the electrical safety intelligent protection device are installed in the same housing. A positive voltage is applied to the center lines of the split current transformers LA, LB, and LC. During detection and sampling, three-phase single-phase pulsating sine wave current signals are obtained respectively. The working principle is that the positive voltage value obtained by the voltage division of resistor R4 and resistor R5 is output through the operational amplifier follower U2D and applied to a positive voltage on the center lines of the current transformers LA, LB, and LC. The motor working current detected by the three-phase current transformers is then output as three-phase single-phase pulsating sine wave current signals by the operational amplifier follower U2A, operational amplifier follower U2B, and operational amplifier follower U2C respectively. The full-wave detection of the three-phase current is realized by a simple circuit with one operational amplifier follower for each phase and enters the single-chip microcomputer chip MCU for processing. The single-chip microcomputer chip MCU controls the contactor JQ1 to perform protection against overcurrent, overload, locked rotor, short circuit, phase loss, and unbalanced three-phase current. The contactors JQ2, JQ3, and JQ4 are used to control the forward and reverse rotation and the reduced-voltage starting and running of the motor. The circuit structure is as follows: Phase A power supply A is connected to the contactor JQ1 through the power supply incoming line terminal A1 and the phase A connecting line Ja. Phase B power supply B is connected to the contactor JQ1 through the power supply incoming line terminal B1 and the phase B connecting line Jb. Phase C power supply C is connected to the contactor JQ1 through the power supply incoming line terminal C1 and the phase C connecting line Jc. The other ends of the contacts of the contactor JQ1 are respectively connected to the motor phase A connecting line A3, the motor phase B connecting line B3, and the motor phase C connecting line C3. The motor phase A connecting line A3 passes through the current transformer LA and is connected to the motor outgoing line terminal A2. The motor phase B connecting line B3 passes through the current transformer LB and is connected to the motor outgoing line terminal B2. The motor phase C connecting line C3 passes through the current transformer LC and is connected to the motor outgoing line terminal C2. The motor outgoing line terminals A2, B2, and C2 are connected to the motor M. Resistor R4 is connected to resistor R5, capacitor C8, and the positive input terminal of the operational amplifier follower U2D. The other end of resistor R4 is connected to the positive power supply Vcc. The other ends of resistor R5 and capacitor C8 are connected to the common terminal V0. The negative input terminal of the operational amplifier follower U2D is connected to the output terminal of the operational amplifier follower U2D, the positive electrode of diode D8, the negative electrode of diode D7, capacitor C7, and inductor L4. The negative electrode of diode D8 is connected to the positive power supply Vcc. The positive electrode of diode D7 and the other end of capacitor C7 are connected to the common terminal V0. One end of the current transformer LA, one end of the current transformer LB, and one end of the current transformer LC are connected together as the center lines of the current transformers LA, LB, and LC. The other end of inductor L4 is connected to the center lines of the current transformers LA, LB, and LC. The other end of the current transformer LA is connected to inductor L1.The other end of the inductor L1 is connected to the positive electrode of the diode D2, the negative electrode of the diode D1, the capacitor C1, and the positive input terminal of the operational amplifier follower U2A. The negative input terminal of the operational amplifier follower U2A is connected to the output terminal of the operational amplifier follower U2A, the resistor R1, and the capacitor C2 and enters the microcontroller chip MCU. The negative electrode of the diode D2 is connected to the positive power supply Vcc. The positive electrode of the diode D1 and the other end of the capacitor C1 are connected to the common terminal V0. The other end of the capacitor C2 is connected to the common terminal V0. The other end of the mutual inductor LB is connected to the inductor L2. The other end of the inductor L2 is connected to the positive electrode of the diode D4, the negative electrode of the diode D3, the capacitor C3, and the positive input terminal of the operational amplifier follower U2B. The negative input terminal of the operational amplifier follower U2B is connected to the output terminal of the operational amplifier follower U2B, the resistor R2, and the capacitor C4 and enters the microcontroller chip MCU. The negative electrode of the diode D4 is connected to the positive power supply Vcc. The positive electrode of the diode D3 and the other end of the capacitor C3 are connected to the common terminal V0. The other end of the capacitor C4 is connected to the common terminal V0. The other end of the mutual inductor LC is connected to the inductor L3. The other end of the inductor LC is connected to the positive electrode of the diode D6, the negative electrode of the diode D5, the capacitor C5, and the positive input terminal of the operational amplifier follower U2C. The negative input terminal of the operational amplifier follower U2C is connected to the output terminal of the operational amplifier follower U2C, the resistor R3, and the capacitor C6 and enters the microcontroller chip MCU. The negative electrode of the diode D6 is connected to the positive power supply Vcc. The positive electrode of the diode D5 and the other end of the capacitor C5 are connected to the common terminal V0. The other end of the capacitor C6 is connected to the common terminal V0. The output control of the microcontroller chip MCU is connected to the resistor JR1. The other end of the resistor JR1 is connected to the base of the triode JBG1. The collector of the triode JBG1 is connected to the coil of the contactor JQ1, the positive electrode of the diode JD1, and the negative electrode of the electrolytic capacitor JC1. The other end of the coil of the contactor JQ1, the negative electrode of the diode JD1, and the positive electrode of the capacitor JC1 are connected to the positive power supply 12V. The emitter of the triode JBG1 is connected to the common terminal V0. One end of the start button QA is connected to the microcontroller chip MCU. One end of the stop button QT is connected to the microcontroller chip MCU. The other ends of the start button QA and the stop button QT are connected to the common terminal V0.,

[0006] The described intelligent electrical safety protection device is characterized in that the main housing and the display of the intelligent electrical safety protection device and the motor multi-functional protection device are installed in the same housing, and data is also displayed on the same display. The structure of the main housing and the display is composed of an upper housing 2 and a lower housing 1, which are connected and fixed together by fixing screws through the main housing connection screw holes 3 and the main housing fixing screw holes. The circuit boards are respectively fixedly installed in the main housing. The terminal plugs 8, 9, 10, 11, 12, 13, 14, and 15 on the circuit boards are respectively arranged compactly on both sides of the main housing and exposed. The display connection socket 6 and the function indicator lamp 5 are also exposed on the main housing. The structure of the display mainly consists of a display housing 16, a display screen 17, and a fixing buckle 18.

[0007] The purpose of the present invention is that in the intelligent electrical safety protection device, we have solved the problem of automatically detecting the insulation between the electrical appliances including the motor and the insulation between each circuit line and the ground under the power-off condition through single-chip microcomputer intelligent control. Then, a structure including terminal temperature detection, three-phase single-pulse sinusoidal motor current detection protection circuit, main housing, and display is provided. The intelligent electrical safety protection device adds a temperature sensor to the terminal and is controlled by a single-chip microcomputer to protect the terminal temperature. When the terminal temperature exceeds the specified value, the power supply is cut off to avoid unexpected fires caused by severe heating of the terminal, so that personal and property are not severely damaged. The three-phase single-pulse sinusoidal motor current detection protection circuit adds a reference voltage to the center line of the three-phase current transformer in the motor protection circuit. Its circuit is simple, and the current sampling outputs a complete three-phase pulsating single-phase sine wave, which enters the single-chip microcomputer for processing to achieve over-current and overload protection of the three-phase working current of the motor and three-phase current imbalance protection. Description of the Drawings

[0008] Figure 1 Schematic Diagram of Terminal Temperature and Motor Protection Circuit

[0009] Figure 2 Schematic Diagram of Terminal Temperature Detection Structure

[0010] Figure 3 External View of the Main Housing of the Intelligent Electrical Safety Protection Device

[0011] Figure 4 External View of the Display Housing of the Intelligent Electrical Safety Protection Device

[0012] Figure 1-2In: R1 - R5 resistors, RF1 - RF6 temperature sensors, RF7 - RF18 resistors, JR1 - JR4 resistors, C1 - C8 capacitors, CF1 - CF12 capacitors, JC1 - JC4 electrolytic capacitors, D1 - D8 diodes, JD1 - JD4 diodes, JBG1 - JBG4 transistors, U2A operational amplifier follower, U2B operational amplifier follower, U2C operational amplifier follower, U2D operational amplifier follower, MCU single - chip microcomputer chip, LA transformer, LB transformer, LC transformer, L1 - L4 inductors, JQ1 - JQ4 contactors, A phase A power supply, B phase B power supply, C phase C power supply, N power supply neutral line, A1 power supply incoming line connection terminal, B1 power supply incoming line connection terminal, C1 power supply incoming line connection terminal, A2 motor outgoing line connection terminal, B2 motor outgoing line connection terminal, C2 motor outgoing line A3 motor phase A connection line, B3 motor phase B connection line, C3 motor phase C connection line, Ja connection terminal phase A connection line, Jb connection terminal phase B connection line, Jc connection terminal phase C connection line, V + 24 positive power supply, Vcc positive power supply, V0 common terminal, E ground wire, QA start button, QT stop button, display screen EGB, M motor, 20 connection terminal skeleton, 21 connection terminal skeleton fixing hole.

[0013] Figure 3-4 In: 1 lower housing, 2 upper housing, 3 main housing connection screw holes, 4 nameplate position, 5 function indicator lights, 6 display connection socket, 7 bus interface hole, 8 connection terminal plug, 9 connection terminal plug, 10 connection terminal plug, 11 connection terminal plug, 12 connection terminal plug, 13 connection terminal plug, 14 connection terminal plug, 15 connection terminal socket, 16 display housing, 17 display screen, 18 fixing buckle.

[0014] Figure 1 It is the schematic diagram of the connection terminal temperature and motor protection circuit, Figure 2 It is the schematic diagram of the connection terminal temperature detection structure.

[0015] The electrical safety intelligent protection device adds temperature sensors to the wiring terminals and is controlled by a single-chip microcomputer to protect the wiring terminals from overheating. When the temperature of the wiring terminal exceeds the specified value, the power supply is cut off to avoid unexpected fires caused by severe overheating of the wiring terminals, so that personal and property are not severely damaged. The temperature sensor RF1 is closely attached to the power supply incoming line terminal A1, the temperature sensor RF2 is closely attached to the power supply incoming line terminal B1, the temperature sensor RF3 is closely attached to the power supply incoming line terminal C1, the temperature sensor RF4 is closely attached to the motor outgoing line terminal A2, the temperature sensor RF5 is closely attached to the motor outgoing line terminal B2, and the temperature sensor RF6 is closely attached to the motor outgoing line terminal C2 to detect the temperature of each wiring terminal respectively. The detection results are processed by the single-chip microcomputer chip MCU. If the overheating of a certain wiring terminal exceeds the specified value due to excessive current or poor contact, the contactor JQ1 is controlled to disconnect, effectively avoiding the occurrence of fires or other accidents.

[0016] The three-phase single-phase pulsating sine wave motor current detection and protection circuit and the electrical safety intelligent protection device are installed in the same housing. A positive voltage is applied to the center lines of the split transformers LA, LB, and LC. During detection and sampling, three-phase single-phase pulsating sine wave current signals are obtained respectively. The working principle is that the positive voltage value obtained by the voltage division of resistor R4 and resistor R5 is output by the operational amplifier follower U2D and applied to a positive voltage on the center lines of the transformers LA, LB, and LC. The motor working current detected by the three-phase transformers is then output as three-phase single-phase pulsating sine wave current signals by the operational amplifier followers U2A, U2B, and U2C respectively. The full-wave detection of the three-phase current is realized by a simple circuit with one operational amplifier follower for each phase and enters the single-chip microcomputer chip MCU for processing. The single-chip microcomputer chip MCU controls the contactor JQ1 to protect against overcurrent, overload, locked rotor, short circuit, phase loss, and unbalanced three-phase currents. The contactors JQ2, JQ3, and JQ4 are used to control the forward and reverse rotation and reduced voltage starting operation of the motor. Specific implementation mode

[0017] The temperature detection circuit structure of the terminal is that six identical temperature detection circuits respectively detect six terminals. One of the temperature detection circuits, which is the temperature detection circuit of the power supply incoming terminal A1, has a temperature sensor RF1 closely attached to the power supply incoming terminal A1. The temperature sensor RF1 is connected to a resistor RF7, a resistor RF8, and a capacitor CF1. The other end of the resistor RF7 is connected to the positive power supply Vcc. The other end of the resistor RF8 is connected to the capacitor CF2 and the single-chip microcomputer chip MCU. The other ends of the temperature sensor RF1, the capacitor CF1, and the capacitor CF2 are connected to the common terminal V0. The phase A connection line Ja of the terminal, the phase B connection line Jb of the terminal, and the phase C connection line Jc of the terminal are connected to the contactor JQ1. The terminal skeleton 20 is fixed by using the fixing holes 21 of the terminal skeleton with screws.

[0018] The circuit structure of the three-phase single-pulse sinusoidal motor current detection and protection is that the A-phase power supply A is connected to the contactor JQ1 through the power supply incoming line terminal A1 and the A-phase connection line Ja of the terminal, the B-phase power supply B is connected to the contactor JQ1 through the power supply incoming line terminal B1 and the B-phase connection line Jb of the terminal, the C-phase power supply C is connected to the contactor JQ1 through the power supply incoming line terminal C1 and the C-phase connection line Jc of the terminal. The other ends of the contacts of the contactor JQ1 are respectively connected to the A-phase connection line A3 of the motor, the B-phase connection line B3 of the motor, and the C-phase connection line C3 of the motor. The A-phase connection line A3 of the motor passes through the current transformer LA and is connected to the motor outgoing line terminal A2, the B-phase connection line B3 of the motor passes through the current transformer LB and is connected to the motor outgoing line terminal B2, the C-phase connection line C3 of the motor passes through the current transformer LC and is connected to the motor outgoing line terminal C2. The motor outgoing line terminals A2, B2, and C2 are connected to the motor M. The resistor R4 is connected to the resistor R5, the capacitor C8, and the positive input terminal of the operational amplifier follower U2D. The other end of the resistor R4 is connected to the positive power supply Vcc. The other ends of the resistor R5 and the capacitor C8 are connected to the common terminal V0. The negative input terminal of the operational amplifier follower U2D is connected to the output terminal of the operational amplifier follower U2D, the positive electrode of the diode D8, the negative electrode of the diode D7, the capacitor C7, and the inductor L4. The negative electrode of the diode D8 is connected to the positive power supply Vcc. The positive electrode of the diode D7 and the other end of the capacitor C7 are connected to the common terminal V0. One end of the current transformer LA, one end of the current transformer LB, and one end of the current transformer LC are connected together as the center line of the current transformers LA, LB, and LC. The other end of the inductor L4 is connected to the center line of the current transformers LA, LB, and LC. The other end of the current transformer LA is connected to the inductor L1. The other end of the inductor L1 is connected to the positive electrode of the diode D2, the negative electrode of the diode D1, the capacitor C1, and the positive input terminal of the operational amplifier follower U2A. The negative input terminal of the operational amplifier follower U2A is connected to the output terminal of the operational amplifier follower U2A, the resistor R1, and the capacitor C2 and enters the single-chip microcomputer chip MCU. The negative electrode of the diode D2 is connected to the positive power supply Vcc. The positive electrode of the diode D1 and the other end of the capacitor C1 are connected to the common terminal V0. The other end of the capacitor C2 is connected to the common terminal V0. The other end of the current transformer LB is connected to the inductor L2. The other end of the inductor L2 is connected to the positive electrode of the diode D4, the negative electrode of the diode D3, the capacitor C3, and the positive input terminal of the operational amplifier follower U2B. The negative input terminal of the operational amplifier follower U2B is connected to the output terminal of the operational amplifier follower U2B, the resistor R2, and the capacitor C4 and enters the single-chip microcomputer chip MCU. The negative electrode of the diode D4 is connected to the positive power supply Vcc. The positive electrode of the diode D3 and the other end of the capacitor C3 are connected to the common terminal V0. The other end of the capacitor C4 is connected to the common terminal V0. The other end of the current transformer LC is connected to the inductor L3. The other end of the inductor LC is connected to the positive electrode of the diode D6, the negative electrode of the diode D5, the capacitor C5, and the positive input terminal of the operational amplifier follower U2C.The negative input terminal of the operational amplifier follower U2C is connected to the output terminal of the operational amplifier follower U2C, resistor R3, and capacitor C6 and enters the microcontroller chip MCU. The negative electrode of diode D6 is connected to the positive power supply Vcc. The positive electrode of diode D5 and the other end of capacitor C5 are connected to the common terminal V0. The other end of capacitor C6 is connected to the common terminal V0. The output control of the microcontroller chip MCU is connected to resistor JR1. The other end of resistor JR1 is connected to the base of triode JBG1. The collector of triode JBG1 is connected to the coil of contactor JQ1, the positive electrode of diode JD1, and the negative electrode of electrolytic capacitor JC1. The other end of the coil of contactor JQ1, the negative electrode of diode JD1, and the positive electrode of capacitor JC1 are connected to the positive power supply 12V. The emitter of triode JBG1 is connected to the common terminal V0. One end of the start button QA is connected to the microcontroller chip MCU. One end of the stop button QT is connected to the microcontroller chip MCU. The other ends of the start button QA and the stop button QT are connected to the common terminal V0.,

[0019] Figure 3-4 It is the external view of the main housing and the display housing of the electrical safety intelligent protection device.

[0020] The structures of the main housing and the display of the electrical safety intelligent protection device and the motor multi-functional protection device are installed in the same housing, and the data is also displayed on the same display. The structures of the main housing and the display are connected and fixed together by the upper housing 2 and the lower housing 1 with fixing screws through the main housing connection screw holes 3 and the main housing fixing screw holes. The circuit boards are respectively fixedly installed in the main housing. The terminal block plug sockets 8, 9, 10, 11, 12, 13, 14, and 15 on the circuit boards are respectively arranged compactly on both sides of the main housing and exposed. The display connection socket 6 and the function indicator light 5 are also exposed on the main housing. The structure of the display is mainly composed of the display housing 16, the display screen 17, and the fixing buckle 18.

Claims

1. An electrical safety intelligent protection device, comprising a structure of a wiring terminal temperature detection and a three-phase single-phase pulsating sine wave motor current detection and protection circuit, a main housing and a display, characterized in that The three-phase single-phase pulsating sine wave motor current detection and protection circuit and the electrical safety intelligent protection device are installed in the same housing. A positive voltage is applied to the center lines of the split current transformers LA, LB, and LC. During detection and sampling, three-phase single-phase pulsating sine wave current signals are obtained respectively. The working principle is that the positive voltage value obtained by the voltage division of resistor R4 and resistor R5 is output by the operational amplifier follower U2D and applied as a positive voltage to the center lines of the current transformers LA, LB, and LC. The motor working current detected by the three-phase current transformers is then output as three-phase single-phase pulsating sine wave current signals by the operational amplifier followers U2A, U2B, and U2C respectively. The full-wave detection of the three-phase current is realized by a simple circuit with one operational amplifier follower for each phase, and it enters the single-chip microcomputer chip MCU for processing. The single-chip microcomputer chip MCU controls the contactor JQ1 to perform protection against overcurrent, overload, locked rotor, short circuit, open phase, and unbalanced three-phase current. Resistor R4 is connected to the positive input terminal of resistor R5, capacitor C8, and operational amplifier follower U2D. The other end of resistor R4 is connected to the positive power supply Vcc. The other ends of resistor R5 and capacitor C8 are connected to the common terminal V0. The negative input terminal of operational amplifier follower U2D is connected to the output terminal of operational amplifier follower U2D, the positive electrode of diode D8, the negative electrode of diode D7, capacitor C7, and inductor L4. The negative electrode of diode D8 is connected to the positive power supply Vcc. The positive electrode of diode D7 and the other end of capacitor C7 are connected to the common terminal V0. One end of current transformer LA, one end of current transformer LB, and one end of current transformer LC are connected together to form the center lines of current transformers LA, LB, and LC. The other end of inductor L4 is connected to the center lines of current transformers LA, LB, and LC.

2. The electrical safety intelligent protection device according to claim 1, characterized in that The electrical safety intelligent protection device adds temperature sensors on the wiring terminals and is controlled by a single-chip microcomputer to protect the wiring terminals against overheating. When the temperature of a wiring terminal exceeds the specified value, the power supply is cut off. The temperature sensor RF1 is closely attached to the power supply incoming wiring terminal A1, the temperature sensor RF2 is closely attached to the power supply incoming wiring terminal B1, the temperature sensor RF3 is closely attached to the power supply incoming wiring terminal C1, the temperature sensor RF4 is closely attached to the motor outgoing wiring terminal A2, the temperature sensor RF5 is closely attached to the motor outgoing wiring terminal B2, and the temperature sensor RF6 is closely attached to the motor outgoing wiring terminal C2 to detect the temperature of each wiring terminal respectively. The detection results are processed by the single-chip microcomputer chip MCU. If the overheating of a certain wiring terminal due to excessive current or poor contact exceeds the specified value, the contactor JQ1 is controlled to disconnect. The temperature sensor RF1 is connected to the resistor RF7, the resistor RF8, and the capacitor CF1. The other end of the resistor RF7 is connected to the positive power supply Vcc, the other end of the resistor RF8 is connected to the capacitor CF2 and the single-chip microcomputer chip MCU, and the other ends of the temperature sensor RF1, the capacitor CF1, and the capacitor CF2 are connected to the common terminal V0. The phase A connection line Ja, the phase B connection line Jb, and the phase C connection line Jc of the wiring terminal are connected to the contactor JQ1, and the wiring terminal skeleton (20) is fixed with screws using the fixing holes (21) of the wiring terminal skeleton; Contactor JQ2, contactor JQ3, and contactor JQ4 are used to control the forward and reverse rotation and reduced-voltage starting operation of the motor. The circuit structure is that phase A power supply A is connected to contactor JQ1 through power supply incoming terminal A1 and phase A connection line Ja of the terminal, phase B power supply B is connected to contactor JQ1 through power supply incoming terminal B1 and phase B connection line Jb of the terminal, phase C power supply C is connected to contactor JQ1 through power supply incoming terminal C1 and phase C connection line Jc of the terminal. The other ends of the contacts of contactor JQ1 are respectively connected to motor phase A connection line A3, motor phase B connection line B3, and motor phase C connection line C3. Motor phase A connection line A3 passes through current transformer LA and is connected to motor outgoing terminal A2, motor phase B connection line B3 passes through current transformer LB and is connected to motor outgoing terminal B2, motor phase C connection line C3 passes through current transformer LC and is connected to motor outgoing terminal C2. Motor outgoing terminals A2, motor outgoing terminal B2, and motor outgoing terminal C2 are used to connect to motor M. The other end of current transformer LA is connected to inductor L1. The other end of inductor L1 is connected to the positive electrode of diode D2, the negative electrode of diode D1, capacitor C1, and the positive input terminal of operational amplifier follower U2A. The negative input terminal of operational amplifier follower U2A is connected to the output terminal of operational amplifier follower U2A, resistor R1, and capacitor C2 and enters the single-chip microcomputer chip MCU. The negative electrode of diode D2 is connected to positive power supply Vcc. The positive electrode of diode D1 and the other end of capacitor C1 are connected to common terminal V0. The other end of capacitor C2 is connected to common terminal V0. The other end of current transformer LB is connected to inductor L2. The other end of inductor L2 is connected to the positive electrode of diode D4, the negative electrode of diode D3, capacitor C3, and the positive input terminal of operational amplifier follower U2B. The negative input terminal of operational amplifier follower U2B is connected to the output terminal of operational amplifier follower U2B, resistor R2, and capacitor C4 and enters the single-chip microcomputer chip MCU. The negative electrode of diode D4 is connected to positive power supply Vcc. The positive electrode of diode D3 and the other end of capacitor C3 are connected to common terminal V0. The other end of capacitor C4 is connected to common terminal V0. The other end of current transformer LC is connected to inductor L3. The other end of inductor LC is connected to the positive electrode of diode D6, the negative electrode of diode D5, capacitor C5, and the positive input terminal of operational amplifier follower U2C. The negative input terminal of operational amplifier follower U2C is connected to the output terminal of operational amplifier follower U2C, resistor R3, and capacitor C6 and enters the single-chip microcomputer chip MCU. The negative electrode of diode D6 is connected to positive power supply Vcc. The positive electrode of diode D5 and the other end of capacitor C5 are connected to common terminal V0. The other end of capacitor C6 is connected to common terminal V0. The output control of the single-chip microcomputer chip MCU is connected to resistor JR1. The other end of resistor JR1 is connected to the base of triode JBG1. The collector of triode JBG1 is connected to the coil of contactor JQ1, the positive electrode of diode JD1, and the negative electrode of electrolytic capacitor JC1. The other end of the coil of contactor JQ1, the negative electrode of diode JD1, and the positive electrode of capacitor JC1 are connected to positive power supply 12V.The emitter of the triode JBG1 is connected to the common terminal V0. One end of the start button QA is connected to the single-chip microcomputer chip MCU, and one end of the stop button QT is connected to the single-chip microcomputer chip MCU. The other ends of the start button QA and the stop button QT are connected to the common terminal V0., 3. An electrical safety intelligent protection device according to claim 1, characterized in that The structure of the main housing and the display of the electrical safety intelligent protection device is installed in the same housing as the motor multi-functional protection device, and the data is also displayed on the same display. The structure of the main housing and the display is formed by fixing the upper housing (2) and the lower housing (1) together with fixing screws through the main housing connection screw holes (3) and the main housing fixing screw holes. The circuit boards are respectively fixedly installed in the main housing. The wiring terminal plug sockets (8), (9), (10), (11), (12), (13), (14), and (15) on the circuit boards are respectively arranged closely on both sides of the main housing and exposed. The display connection socket (6) and the function indicator light (5) are also exposed on the main housing. The structure of the display mainly consists of the display housing (16), the display screen (17), and the fixing buckle (18).

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