CN210775656U - Electrical insulation inspection device - Google Patents
Electrical insulation inspection device Download PDFInfo
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- CN210775656U CN210775656U CN201921530632.3U CN201921530632U CN210775656U CN 210775656 U CN210775656 U CN 210775656U CN 201921530632 U CN201921530632 U CN 201921530632U CN 210775656 U CN210775656 U CN 210775656U
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Abstract
The utility model discloses an electrical insulation inspection device belongs to electric power technical field, including insulation resistance test network, total voltage detection circuit, logic switch circuit, bridge circuit voltage detection circuit, relay control circuit, high impedance amplifier, MCU, display element and communication unit, solved the AD interface through an MCU and can realize that the bridge balance principle carries out the technical problem that detects to insulation resistance, the utility model discloses a measuring method of unbalanced bridge can detect the condition that the positive negative pole of electrical power source all insulated and reduce, the utility model discloses only adopt an AD interface can realize the detection to insulation resistance, very big reduction the use of MCU interface, simplified circuit design.
Description
Technical Field
The utility model belongs to the technical field of electric power, especially, relate to an electrical insulation inspection device.
Background
The electrical insulation detection is a method for evaluating the quality of electrical insulation by testing the insulation resistance to ground of an electrical power supply system.
The existing method for detecting the insulation of the direct current system mainly has a bridge balance principle, the insulation resistance of the detected gas relative to the ground is detected according to the balance of a bridge, the bridge balance principle cannot detect the condition that the insulation of the anode and the cathode of the direct current system is equally reduced, and the bridge balance principle needs to detect a total voltage value and a bridge circuit voltage division value respectively, so that the condition that two AD interfaces are required to be possessed for an MCU is limited, and the requirement of a design port of the MCU is increased.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing an electrical insulation inspection device has solved the AD interface through a MCU and can realize carrying out the technical problem that detects to insulation resistance.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
an electrical insulation inspection device comprises an insulation resistance test network, a total voltage detection circuit, a logic switch circuit, a bridge circuit voltage detection circuit, a relay control circuit, a high-impedance amplifier, an MCU, a display unit and a communication unit;
the insulation resistance test network comprises a resistor R2, a resistor R14, a resistor R3, a resistor R4, a resistor R15, a resistor R16, a relay J1 and a relay J2, wherein a pin 1 of the resistor R2 is connected with the anode of a tested power supply B1, a pin 2 of the resistor R14 is connected with a pin 1 of a resistor R14 through a relay J1, a pin 2 of the resistor R14 is connected with the cathode of the tested power supply B1 through a relay J2, a pin 1 of the resistor R3 is connected with the anode of the tested power supply B1, a pin 2 of the resistor R14 is connected, a pin 2 of the resistor R14 is connected with a pin 1 of the resistor R15, a pin 2 of the resistor R15 is connected with a pin 1 of the resistor R16, and a pin 2 of the resistor R16 is connected with;
the total voltage detection circuit comprises a resistor R5 and a resistor R6, one end of the resistor R5 is connected with the anode of a detected power supply B1, the other end of the resistor R6 is connected with the cathode of the detected power supply, and a pin 1 of the resistor R14 and a pin 1 of the resistor R15 are both connected with a ground wire DD;
the bridge circuit voltage detection circuit comprises a resistor R15 and a resistor R16;
the relay control circuit comprises a triode Q3, a triode Q4, a resistor R26, a resistor R27, a resistor R24 and a resistor R25, the base of the triode Q3 is connected with one IO port of the MCU through a resistor R24, the collector of the triode Q3 is connected with one end of a coil of a relay J1 through a resistor R26, the other end of the coil of the relay J1 is connected with a power supply VCC, the base of the triode Q4 is connected with one IO port of the MCU through a resistor R25, the collector of the triode Q4 is connected with one end of the coil of the relay J2 through a resistor R27, and the other end of the coil of the relay;
the emitter of the triode Q3 and the emitter of the triode Q4 are both connected with a first ground wire;
the logic switch circuit comprises an AND gate U1A, an inverter U2A, a field effect tube Q1, a field effect tube Q2, a diode D1 and a diode D2, wherein a pin 1 and a pin 2 of the AND gate U1A are respectively connected with a collector of a triode Q3 and a collector of a triode Q4, the output end of the AND gate U1A is connected with a G pole of a field effect tube Q1, a pin 1 of a resistor R6 is connected with a D pole of the field effect tube Q1, a pin S pole of the diode D1 is connected with an anode of the diode D1, the output end of the AND gate U1A is also connected with a G pole of a field effect tube Q2 through an inverter U2A, a pin 1 of a resistor R16 is connected with a D pole of the field effect tube Q;
the high-impedance amplifier comprises a resistor R7, a resistor R17, a resistor R18, a resistor R19 and an amplifier IC1, wherein one end of the resistor R17 is connected with the positive input end of the amplifier IC1, the other end of the resistor R18 is connected with a second ground wire, the connection node of the resistor R17 and the resistor R18 is also connected with the output end of the amplifier IC1 through the resistor R19, the resistor R7 is connected between the negative input end and the output end of the amplifier IC1, the negative electrode of the diode D1 and the negative electrode of the diode D2 are both connected with the positive input end of the amplifier IC1, and the output end of the amplifier IC1 is connected with an AD interface;
the display unit and the communication unit are both connected with the MCU.
Preferably, still include power module, power module includes positive 15V stabiliser, burden 15V stabiliser and 5V stabiliser, and the input of positive 15V stabiliser, the input of burden 15V stabiliser and the input of 5V stabiliser are all connected by survey power B1 positive pole, and positive 15V stabiliser and burden 15V stabiliser are the power supply of amplifier IC1, and 5V stabiliser does logic switch circuit relay control circuit MCU the display element with the communication unit power supply.
Preferably, the communication unit is a serial port communication chip MAX485, and is connected with the MCU through a serial port; the display unit is an LCD liquid crystal lattice display screen.
Preferably, the model of the and gate U1A is 74F08, the model of the inverter is 74F04, and the model of the MCU is AT91SAM7S 512; the type of the field effect transistor Q1 and the type of the field effect transistor Q2 are both 2N 4091.
Preferably, the first ground wire is a ground wire provided by a negative electrode of the measured power supply B1, the second ground wire is an independent ground wire, the ground wire DD is connected to the ground, and the first ground wire and the second ground wire are connected through a 0 ohm resistor or a magnetic bead.
An electrical insulation inspection device, solved the AD interface through an MCU and can realize that the balanced principle of bridge carries out the technical problem that detects to insulation resistance, the utility model discloses a measuring method of unbalanced bridge can detect the condition that the positive negative pole of electrical power source all insulation reduces, the utility model discloses only adopt an AD interface can realize the detection to insulation resistance, very big reduction the use of MCU interface, simplified circuit design, the utility model discloses a high impedance amplifier enlargies detection voltage, makes and is surveyed the end and have almost not the partial pressure, has guaranteed voltage data's the degree of accuracy, the utility model discloses a logic circuit controls detection circuit to adopt the field effect transistor to realize signal transmission, on-resistance has accomplished to be less than 30 ohm, assurance measuring accuracy that can be fine.
Drawings
Fig. 1 is a block diagram of the circuit diagram of the present invention;
fig. 2 is a circuit diagram of the insulation resistance test network, the total voltage detection circuit, the logic switch circuit, the bridge circuit voltage detection circuit and the relay control circuit of the present invention;
fig. 3 is a circuit diagram of the high impedance amplifier of the present invention.
Detailed Description
An electrical insulation inspection apparatus as shown in fig. 1 to 3 includes an insulation resistance test network, a total voltage detection circuit, a logic switch circuit, a bridge circuit voltage detection circuit, a relay control circuit, a high impedance amplifier, an MCU, a display unit, and a communication unit;
the insulation resistance test network comprises a resistor R2, a resistor R14, a resistor R3, a resistor R4, a resistor R15, a resistor R16, a relay J1 and a relay J2, wherein a pin 1 of the resistor R2 is connected with the anode of a tested power supply B1, a pin 2 of the resistor R14 is connected with a pin 1 of a resistor R14 through a relay J1, a pin 2 of the resistor R14 is connected with the cathode of the tested power supply B1 through a relay J2, a pin 1 of the resistor R3 is connected with the anode of the tested power supply B1, a pin 2 of the resistor R14 is connected, a pin 2 of the resistor R14 is connected with a pin 1 of the resistor R15, a pin 2 of the resistor R15 is connected with a pin 1 of the resistor R16, and a pin 2 of the resistor R16 is connected with;
the total voltage detection circuit comprises a resistor R5 and a resistor R6, one end of the resistor R5 is connected with the anode of a detected power supply B1, the other end of the resistor R6 is connected with the cathode of the detected power supply, and a pin 1 of the resistor R14 and a pin 1 of the resistor R15 are both connected with a ground wire DD;
in order to measure the condition that the electric power positive negative pole all reduced, the utility model discloses an insulation resistance test network be an unbalanced bridge, as shown in fig. 3, resistance R1 and resistance R2 are the insulation resistance of the positive pole relatively big ground of quilt survey power supply B1 and the insulation resistance of the negative pole relatively big ground respectively, when the test, adopt relay J1 and relay J2 to control the break-make of bridge circuit, it switches on the internal resistance very little, does not influence the test.
Firstly, the relay J1 and the relay J2 are completely disconnected, and the MCU can obtain the total voltage Um of the power supply B1 to be detected through measuring the voltage division on the resistor R6;
then the relay J1 is disconnected, the relay J2 is closed, and at the moment, the voltage value UJ1 is obtained by the MCU through measuring the voltage division on the resistor R16;
then the relay J2 is disconnected, the relay J1 is closed, and at the moment, the voltage value UJ2 is obtained by the MCU through measuring the voltage division on the resistor R16;
in the bridge, the resistance values of the resistor R2 and the resistor R14 are equal, the resistance value of the meter resistor R2 is Rs, the sum of the resistor R3 and the resistor R4 is equal to the sum of the resistor R15 and the resistor R16, and the sum of the meter resistor R3 and the resistor R4 is R, then the following formula is obtained:
R1＝[(UJ2-UJ1)×Rs×R]÷[UJ1×(Rs+R)-UJ2×Rs]；
R13＝[(UJ2-UJ1)×Rs×R]÷[R×Um-(UJ1+UJ2)×(Rs+R)]；
therefore, the value of the insulation resistance R1 of the positive electrode of the tested power supply B1 relative to the ground and the value of the insulation resistance R13 of the negative electrode of the tested power supply B1 relative to the ground can be obtained, and further the electrical insulation of the tested power supply B1 is judged.
The bridge circuit voltage detection circuit comprises a resistor R15 and a resistor R16;
the relay control circuit comprises a triode Q3, a triode Q4, a resistor R26, a resistor R27, a resistor R24 and a resistor R25, the base of the triode Q3 is connected with one IO port of the MCU through a resistor R24, the collector of the triode Q3 is connected with one end of a coil of a relay J1 through a resistor R26, the other end of the coil of the relay J1 is connected with a power supply VCC, the base of the triode Q4 is connected with one IO port of the MCU through a resistor R25, the collector of the triode Q4 is connected with one end of the coil of the relay J2 through a resistor R27, and the other end of the coil of the relay;
the emitter of the triode Q3 and the emitter of the triode Q4 are both connected with a first ground wire;
the logic switch circuit comprises an AND gate U1A, an inverter U2A, a field effect tube Q1, a field effect tube Q2, a diode D1 and a diode D2, wherein a pin 1 and a pin 2 of the AND gate U1A are respectively connected with a collector of a triode Q3 and a collector of a triode Q4, the output end of the AND gate U1A is connected with a G pole of a field effect tube Q1, a pin 1 of a resistor R6 is connected with a D pole of the field effect tube Q1, a pin S pole of the diode D1 is connected with an anode of the diode D1, the output end of the AND gate U1A is also connected with a G pole of a field effect tube Q2 through an inverter U2A, a pin 1 of a resistor R16 is connected with a D pole of the field effect tube Q;
the utility model discloses a logic switch circuit has realized the linkage between relay J1 and relay J2 and MCU's an AD and has detected, when MCU passes through IO mouth control relay J1 and relay J2 and all breaks off, triode Q3 and triode Q4 all end this moment, the VCC power is directly loaded to two inputs of AND gate U1A, because the input of AND gate U1A is 1 level, AND gate output is 1, field effect tube Q1 switches on this moment, and long-term response pipe Q2 is because the reversal of phase inverter, it is 0 level that its G utmost point obtained still, long effect tube Q2 ends, then only resistance R6's partial pressure value can transmit the high impedance amplifier, measured voltage is Um this moment;
on the contrary, when the MCU controls the relay J1 or the relay J2 to be closed through the IO port alone, the outputs of the and gates U1A are both 0, the fet Q1 is turned off, the fet Q2 is turned on, and the measured value is the UJ1 or the UJ 2.
The utility model discloses a logic switch circuit is very big has saved the AD port on the MCU, has simplified circuit design, the utility model discloses a field effect transistor Q1 and field effect transistor Q2 be 2N4091, and its on-resistance is less than 30 ohm, has neglected the condition of measuring signal partial pressure completely, and it is minimum to leak current, has guaranteed measurement accuracy.
The high-impedance amplifier comprises a resistor R7, a resistor R17, a resistor R18, a resistor R19 and an amplifier IC1, wherein one end of the resistor R17 is connected with the positive input end of the amplifier IC1, the other end of the resistor R18 is connected with a second ground wire, the connection node of the resistor R17 and the resistor R18 is also connected with the output end of the amplifier IC1 through the resistor R19, the resistor R7 is connected between the negative input end and the output end of the amplifier IC1, the negative electrode of the diode D1 and the negative electrode of the diode D2 are both connected with the positive input end of the amplifier IC1, and the output end of the amplifier IC1 is connected with an AD interface;
the utility model discloses an amplifier IC1 has constituted a high impedance amplifier, and its model is TA7505M, and its amplifier for having field effect transistor input level has guaranteed measurement accuracy.
The display unit and the communication unit are both connected with the MCU.
The utility model discloses still have external communication function, can transmit measured data for the host computer through communication unit's 485 modules.
Preferably, still include power module, power module includes positive 15V stabiliser, burden 15V stabiliser and 5V stabiliser, and the input of positive 15V stabiliser, the input of burden 15V stabiliser and the input of 5V stabiliser are all connected by survey power B1 positive pole, and positive 15V stabiliser and burden 15V stabiliser are the power supply of amplifier IC1, and 5V stabiliser does logic switch circuit relay control circuit MCU the display element with the communication unit power supply.
Preferably, the communication unit is a serial port communication chip MAX485, and is connected with the MCU through a serial port; the display unit is an LCD liquid crystal lattice display screen.
Preferably, the model of the and gate U1A is 74F08, the model of the inverter is 74F04, and the model of the MCU is AT91SAM7S 512; the type of the field effect transistor Q1 and the type of the field effect transistor Q2 are both 2N 4091.
Preferably, the first ground wire is a ground wire provided by a negative electrode of the measured power supply B1, the second ground wire is an independent ground wire, the ground wire DD is connected to the ground, and the first ground wire and the second ground wire are connected through a 0 ohm resistor or a magnetic bead.
The utility model discloses independently part the ground wire of relay and measuring voltage's ground wire, guaranteed measuring voltage's signal purity.
The solution can realize the technical problem that the bridge balance principle detected insulation resistance through an MCU's AD interface, the utility model discloses an unbalanced bridge's measurement mode can detect the condition that the positive negative pole of electrical power source all insulated and reduce, the utility model discloses only adopt an AD interface can realize the detection to insulation resistance, very big reduction the use of MCU interface, simplified circuit design, the utility model discloses a high impedance amplifier enlargies detection voltage, makes and is surveyed the end and hardly have the partial pressure, has guaranteed voltage data's the degree of accuracy, the utility model discloses a logic circuit controls detection circuitry to adopt field effect transistor to realize signal transmission, on-resistance has accomplished to be less than 30 ohm, assurance measuring accuracy that can be fine.
Claims (5)
1. An electrical insulation inspection apparatus, characterized in that: the device comprises an insulation resistance test network, a total voltage detection circuit, a logic switch circuit, a bridge circuit voltage detection circuit, a relay control circuit, a high-impedance amplifier, an MCU (microprogrammed control unit), a display unit and a communication unit;
the insulation resistance test network comprises a resistor R2, a resistor R14, a resistor R3, a resistor R4, a resistor R15, a resistor R16, a relay J1 and a relay J2, wherein a pin 1 of the resistor R2 is connected with the anode of a tested power supply B1, a pin 2 of the resistor R14 is connected with a pin 1 of a resistor R14 through a relay J1, a pin 2 of the resistor R14 is connected with the cathode of the tested power supply B1 through a relay J2, a pin 1 of the resistor R3 is connected with the anode of the tested power supply B1, a pin 2 of the resistor R14 is connected, a pin 2 of the resistor R14 is connected with a pin 1 of the resistor R15, a pin 2 of the resistor R15 is connected with a pin 1 of the resistor R16, and a pin 2 of the resistor R16 is connected with;
the total voltage detection circuit comprises a resistor R5 and a resistor R6, one end of the resistor R5 is connected with the anode of a detected power supply B1, the other end of the resistor R6 is connected with the cathode of the detected power supply, and a pin 1 of the resistor R14 and a pin 1 of the resistor R15 are both connected with a ground wire DD;
the bridge circuit voltage detection circuit comprises a resistor R15 and a resistor R16;
the relay control circuit comprises a triode Q3, a triode Q4, a resistor R26, a resistor R27, a resistor R24 and a resistor R25, the base of the triode Q3 is connected with one IO port of the MCU through a resistor R24, the collector of the triode Q3 is connected with one end of a coil of a relay J1 through a resistor R26, the other end of the coil of the relay J1 is connected with a power supply VCC, the base of the triode Q4 is connected with one IO port of the MCU through a resistor R25, the collector of the triode Q4 is connected with one end of the coil of the relay J2 through a resistor R27, and the other end of the coil of the relay;
the emitter of the triode Q3 and the emitter of the triode Q4 are both connected with a first ground wire;
the logic switch circuit comprises an AND gate U1A, an inverter U2A, a field effect tube Q1, a field effect tube Q2, a diode D1 and a diode D2, wherein a pin 1 and a pin 2 of the AND gate U1A are respectively connected with a collector of a triode Q3 and a collector of a triode Q4, the output end of the AND gate U1A is connected with a G pole of a field effect tube Q1, a pin 1 of a resistor R6 is connected with a D pole of the field effect tube Q1, a pin S pole of the diode D1 is connected with an anode of the diode D1, the output end of the AND gate U1A is also connected with a G pole of a field effect tube Q2 through an inverter U2A, a pin 1 of a resistor R16 is connected with a D pole of the field effect tube Q;
the high-impedance amplifier comprises a resistor R7, a resistor R17, a resistor R18, a resistor R19 and an amplifier IC1, wherein one end of the resistor R17 is connected with the positive input end of the amplifier IC1, the other end of the resistor R18 is connected with a second ground wire, the connection node of the resistor R17 and the resistor R18 is also connected with the output end of the amplifier IC1 through the resistor R19, the resistor R7 is connected between the negative input end and the output end of the amplifier IC1, the negative electrode of the diode D1 and the negative electrode of the diode D2 are both connected with the positive input end of the amplifier IC1, and the output end of the amplifier IC1 is connected with an AD interface;
the display unit and the communication unit are both connected with the MCU.
2. An electrical insulation inspection apparatus as defined in claim 1, wherein: still include power module, power module includes positive 15V stabiliser, burden 15V stabiliser and 5V stabiliser, and the input of positive 15V stabiliser, the input of burden 15V stabiliser and the input of 5V stabiliser are all connected the positive pole of being surveyed power B1, and positive 15V stabiliser and burden 15V stabiliser are the power supply of amplifier IC1, and the 5V stabiliser does logic switch circuit relay control circuit MCU the display element with the communication unit power supply.
3. An electrical insulation inspection apparatus as defined in claim 1, wherein: the communication unit is a serial port communication chip MAX485 and is connected with the MCU through a serial port; the display unit is an LCD liquid crystal lattice display screen.
4. An electrical insulation inspection apparatus as defined in claim 1, wherein: the model of the AND gate U1A is 74F08, the model of the inverter is 74F04, and the model of the MCU is AT91SAM7S 512; the type of the field effect transistor Q1 and the type of the field effect transistor Q2 are both 2N 4091.
5. An electrical insulation inspection apparatus as defined in claim 1, wherein: the first ground wire is a ground wire provided by the negative electrode of the tested power supply B1, the second ground wire is an independent ground wire, the ground wire DD is connected with the ground, and the first ground wire is connected with the second ground wire through a 0-ohm resistor or a magnetic bead.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921530632.3U CN210775656U (en) | 2019-09-16 | 2019-09-16 | Electrical insulation inspection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921530632.3U CN210775656U (en) | 2019-09-16 | 2019-09-16 | Electrical insulation inspection device |
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| Publication Number | Publication Date |
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| CN210775656U true CN210775656U (en) | 2020-06-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201921530632.3U Active CN210775656U (en) | 2019-09-16 | 2019-09-16 | Electrical insulation inspection device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022022038A1 (en) * | 2020-07-27 | 2022-02-03 | 宁德时代新能源科技股份有限公司 | Insulation resistance detection circuit and method |
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2019
- 2019-09-16 CN CN201921530632.3U patent/CN210775656U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022022038A1 (en) * | 2020-07-27 | 2022-02-03 | 宁德时代新能源科技股份有限公司 | Insulation resistance detection circuit and method |
| US11733279B2 (en) | 2020-07-27 | 2023-08-22 | Contemporary Amperex Technology Co., Limited | Circuit and method for detecting insulation resistance |
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