CN212811280U - Safety detection module for on-cable control and protection device - Google Patents
Safety detection module for on-cable control and protection device Download PDFInfo
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- CN212811280U CN212811280U CN202021574557.3U CN202021574557U CN212811280U CN 212811280 U CN212811280 U CN 212811280U CN 202021574557 U CN202021574557 U CN 202021574557U CN 212811280 U CN212811280 U CN 212811280U
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Abstract
The utility model relates to a safety inspection module for control and protection device on cable, through being connected to control and protection device two part circuit on the cable, respectively to inserting on the cable control and the live wire and the voltage value between the ground wire of protection device circuit on the protection device cable, and the impedance between zero line and the ground wire is gathered and is measured, whether be 0 through judging the voltage value between control and protection device live wire and the ground wire on the cable, and judge whether impedance between zero line and the ground wire is greater than 1.6K, and cut off supply circuit when judging for being. Through the utility model discloses, can be when the ground wire is not gone into, or when having great impedance between ground wire and the zero line, control and protection device's voltage output on the cut-off cable avoids charging process in the trouble take place and arouse the danger that personnel electrocute.
Description
Technical Field
The utility model relates to an electricity safety field especially relates to a safety inspection module that is used for controlling and protection device on cable.
Background
Along with the popularization of electric vehicles, charging equipment such as various charging piles and portable charging cables are gradually developed, because the charging equipment is connected with the power grid voltage, when charging is carried out, the danger of electric shock of personnel caused by faults exists, so that how to improve the safety of the charging equipment is that each charging equipment must complete a task, and the safety of the charging equipment is directly influenced by the safe and reliable connection of the ground wire.
When the expected contact voltage of the live part and the exposed conducting part (or the protective conductor) of the on-cable control and protection device exceeds 50V (effective value) of alternating current, the physiological effect which is enough to cause danger to human bodies can continuously exist, and the situation needs the on-cable control and protection device to automatically cut off the power supply. According to the type of grounding and the safety technical requirement of the GB14050 system, the impedance Z is less than or equal to U0/Ia, wherein U0 is 50V, Ia is the unit of ampere (A) for ensuring that the charging device automatically acts to cut off the power supply in a specified time, and the charging device requires that Ia is 0.03A, so the impedance Z is less than or equal to 50/0.03, namely 1.6K.
Current detection module or check out test set all judge whether the ground wire inserts through the magnitude of voltage that detects live wire and ground wire alone, have not had the relevant detection module yet through the resistance that detects between zero line and the ground wire to confirm the power consumption security.
Therefore, how to detect the resistance value of the electric wire and the zero line and ensure the electricity safety is an urgent problem to be solved.
SUMMERY OF THE UTILITY MODEL
The utility model relates to a developed a safety inspection module that is used for controlling on cable and protection device, set up voltage detection circuit between live wire and ground wire to set up impedance detection circuit between zero line and ground wire, can enough detect whether insert the ground wire, can detect the impedance value between zero line and the ground wire again, fully guaranteed the power consumption security.
The utility model provides a technical scheme does:
a security detection module for an on-cable control and protection device, comprising:
the voltage detection circuit is arranged between a live wire and a ground wire so as to detect the voltage between the live wire and the ground wire and further judge whether the control and protection device on the cable is connected to the ground wire or not;
and the impedance detection circuit is arranged between the zero line and the ground line so as to detect the resistance value between the zero line and the ground line.
Preferably, the voltage detection circuit includes:
one end of the first voltage dividing resistor is electrically connected with a live wire;
one end of the second voltage-dividing resistor is electrically connected with a ground wire, and the other end of the second voltage-dividing resistor and the other end of the first voltage-dividing resistor are connected in series at the voltage sampling detection point;
and the voltage sampling detection point is communicated with a voltage acquisition device, and the voltage between the live wire and the ground wire is calculated according to the voltage of the voltage sampling detection point.
Preferably, the voltage sampling device further comprises a current-limiting protection resistor which is connected in series between the voltage sampling detection point and the voltage acquisition device to protect the voltage acquisition device and avoid overcurrent from damaging the voltage acquisition device.
Preferably, the first divider resistor has a resistance value larger than that of the second divider resistor.
Preferably, the impedance detection circuit includes:
a third voltage dividing resistor, one end of which is connected with the live wire;
one end of the fourth voltage dividing resistor is connected with the ground wire, and the other end of the fourth voltage dividing resistor and the third voltage dividing resistor are connected in series at a VS voltage sampling point;
one end of the fifth voltage-dividing resistor is connected with the VS voltage sampling point;
one end of the impedance detection resistor and the other end of the fifth voltage-dividing resistor are connected in series with a voltage sampling point N1, and the other end of the impedance detection resistor is provided with a voltage sampling point N;
and calculating the impedance value between the ground wire and the live wire according to the voltage difference value between the voltage sampling point N1 and the voltage sampling point N.
Preferably, the voltage sampling circuit further comprises an operational amplifier circuit, a positive input end of the operational amplifier circuit is connected with the voltage sampling point N1, a negative input end of the operational amplifier circuit is connected with the voltage sampling point N, and an output end of the operational amplifier circuit is a voltage difference sampling point;
and the voltage difference sampling points are communicated with a voltage acquisition device to acquire voltage difference values of the voltage sampling points N1 and the voltage sampling points N, and then the impedance value between the PE wire and the live wire is calculated.
Preferably, a voltage dividing resistor or a voltage dividing circuit is provided between the voltage sampling point and the operational amplifier circuit.
Preferably, the differential pressure sampling point and the input end of the operational amplification circuit are provided with current limiting resistors.
Preferably, the method further comprises the following steps:
the anode of the first filter diode is electrically connected with the VS voltage sample, and the cathode of the first filter diode is connected with the ground wire;
the anode of the second filter diode is electrically connected with the VS voltage sampling point, and the cathode of the second filter diode is connected with the voltage sampling point N1;
and the anode of the third filter diode is grounded, and the cathode of the third filter diode is connected with the differential pressure sampling point.
Preferably, the device further comprises a display device which is connected with the controller, can display the detection value and can perform fault alarm.
Beneficial effects of the utility model
Be different from prior art, the utility model discloses a safety inspection device of control and protection device on cable, through being connected to on the cable control and protection device two part circuit, respectively to inserting on the cable control and the protection device cable on the live wire and the ground wire between voltage value between the live wire of control and protection device circuit, and the impedance between zero line and the ground wire gather the measurement, whether be 0 through judging the voltage value between control and protection device live wire and the ground wire on the cable, and whether the impedance between judgement zero line and the ground wire is greater than 1.6K, and cut off supply circuit when judging as being. Through the utility model discloses, can be when the ground wire is not gone into, or when having great impedance between ground wire and the zero line, control and protection device's voltage output on the cut-off cable avoids charging process in the trouble take place and arouse the danger that personnel electrocute.
Drawings
Fig. 1 is a schematic structural view of a safety detection device of an on-cable control and protection device provided by the present invention;
fig. 2 is a schematic circuit diagram of a voltage measurement circuit of a safety detection module for an on-cable control and protection device according to the present invention;
fig. 3 is a schematic circuit structure diagram of a voltage dividing circuit in an impedance measuring circuit of a safety detection module for an on-cable control and protection device provided by the present invention;
fig. 4 is a schematic circuit structure diagram of a signal processing circuit in an impedance measuring circuit of a safety detection module for an on-cable control and protection device provided by the present invention;
fig. 5 is a schematic circuit diagram of a signal processing circuit in an impedance measuring circuit of a safety detection module for an on-cable control and protection device according to another embodiment of the present invention;
fig. 6 is a schematic view of the measurement results of the safety of the on-cable control and protection device in the safety detection module for the on-cable control and protection device provided by the present invention;
fig. 7 is a schematic view of a measurement result when the on-cable control and protection device is abnormal in the safety detection module for the on-cable control and protection device provided by the present invention.
Detailed Description
The present invention is further described in detail below with reference to the drawings so that those skilled in the art can implement the invention with reference to the description.
As shown in fig. 1, the utility model provides a safety inspection module for controlling and protection device on cable, its characterized in that includes: voltage detection circuit 20 and impedance detection circuit 10
The voltage detection circuit 20 is arranged between the live wire and the ground wire, and is used for detecting the voltage between the live wire and the ground wire so as to judge whether the control and protection device on the cable is connected to the ground wire or not; and the impedance detection circuit 10 is arranged between the zero line and the ground line and is used for detecting the resistance value between the zero line and the ground line.
The breaking device 30 is arranged between the input and the output of the control and protection device on the cable; the controller 50 is connected with the voltage detection circuit 20 and the impedance detection circuit 10; the display device 40 is connected to the controller 50 for displaying the detection value and giving a malfunction alarm.
When the expected contact voltage of the live part and the exposed conducting part (or the protective conductor) of the on-cable control and protection device exceeds 50V (effective value) of alternating current, the physiological effect which is enough to cause danger to human bodies can continuously exist, and the situation needs the on-cable control and protection device to automatically cut off the power supply. According to the type of grounding and the safety technical requirement of the GB14050 system, the impedance Z is less than or equal to U0/Ia, wherein U0 is 50V, Ia is the unit of ampere (A) for ensuring that the charging device automatically acts to cut off the power supply in a specified time, and the charging device requires that Ia is 0.03A, so the impedance Z is less than or equal to 50/0.03, namely 1.6K. The utility model discloses not only detected power supply network when not connecting the ground wire, stopped the power supply, still when detecting impedance between zero line and the ground wire and be greater than 1.6k, stopped the power supply.
As shown in fig. 2, the voltage detection circuit 20 includes: a first divider resistor R1 and a second divider resistor R2.
One end of the first voltage dividing resistor R1 is electrically connected with the live wire; one end point of the second voltage-dividing resistor R2 is connected with the ground wire, the other end of the second voltage-dividing resistor R2 and the other end of the first voltage-dividing resistor RI are connected in series with a voltage sampling detection point, and the voltage of the voltage sampling point is the voltage between the live wire and the ground wire; the voltage sampling point ADD0 is communicated with the voltage acquisition device.
Preferably, the voltage sampling device is a voltage sampler, a single chip microcomputer or a controller.
In another embodiment, the device further comprises a voltage division protection resistor R3 which is connected in series between the voltage sampling detection point D0 and the voltage acquisition device and is used for protecting the voltage acquisition device and avoiding overcurrent from damaging the device.
Preferably, the first divider resistor R1 has a larger resistance than the second divider resistor R2
Live wire, zero line, the ground wire of electric wire netting end insert control and protection device on the cable, the utility model discloses in, live wire, zero line and ground wire all indicate the binding post that corresponds respectively of control and protection device input on the cable. In the on-cable control and protection device, the ground is connected to the secondary side 0 potential GND of the transformer. Whether the ground wire exists is judged by detecting the voltages of the live wire and the ground wire, and because no electrical correlation exists between the secondary side 0 potential GND of the transformer and the live wire and the zero wire, when the ground wire is not connected, no voltage exists between the live wire and the ground wire, and the measurement result is close to 0V.
Therefore, in the voltage detection circuit shown in fig. 2, the resistors R1, R2, and R3 are voltage dividing resistors and current limiting resistors, and the signal acquisition unit acquires and measures the voltage after voltage division by the resistor R3 to calculate the voltage value. If the ground wire is not connected, then there is no voltage here because of the electrical isolation, and the measurement result is 0.
As shown in fig. 3, the impedance detection circuit 10 includes: a third voltage dividing resistor R4, a fourth voltage dividing resistor R13, a fifth voltage dividing resistor R10 and a resistance detection resistor R9.
One end of the third voltage dividing resistor R4 is connected with a live wire; one end of the fourth voltage dividing resistor R13 is connected with the ground wire, and the other end and the third voltage dividing resistor are connected in series at the VS voltage sampling point; one end of a fifth voltage-dividing resistor R10 is connected with a VS voltage sampling point; one end of the impedance detection resistor R9 and the other end of the fifth voltage-dividing resistor R10 are connected in series with the voltage sampling point N1, and the other end of the impedance detection resistor R9 is provided with a voltage sampling point N;
and calculating the impedance value between the ground wire and the live wire according to the voltage difference value between the voltage sampling point N1 and the voltage sampling point N.
As shown in fig. 4, the voltage sampling circuit further includes an operational amplifier circuit, a positive input end of which is connected to the voltage sampling point N1, a negative input end of which is connected to the voltage sampling point N, and an output end of which is a differential voltage sampling point; and the voltage difference sampling points are communicated with a voltage acquisition device to acquire voltage difference values of the voltage sampling points N1 and the voltage sampling points N, and then the impedance value between the PE wire and the live wire is calculated. And a divider resistor or a divider circuit is arranged between the voltage sampling point and the operational amplification circuit. The differential pressure sampling point ADC1 and the input end of the operational amplification circuit are provided with voltage dividing resistors.
In another embodiment, further comprising: a first filter diode D3, the anode of which is electrically connected with the VS voltage sample, and the cathode of which is connected with the ground wire; the anode of the second filter diode D1 is electrically connected with a VS voltage sampling point, and the cathode of the second filter diode D1 is connected with the VS voltage sampling point N1; and the anode of the third filter diode D2 is grounded, and the cathode of the third filter diode D2 is connected with the voltage difference sampling point C1.
As shown in fig. 5, in another embodiment, the operational amplification circuit includes resistors R4, R6, R9, R10, and R13, and diodes D1 and D3; one ends of the resistors R4 and R6 are connected in series, and the other end of R4 is connected with a connecting terminal after a live wire is connected to a control and protection device on the cable; the second end of the resistor R9 is connected with one end of the resistor R10 in series, the first end of the resistor R9 is connected with a connecting terminal of a zero line which is connected with a control and protection device on the cable, and the other end of the resistor R10 is connected with the anode of the diode D1; one end of the resistor R13 is connected with the anode of the diode D3, and the other end is connected with a wiring terminal of which the ground wire is connected with the control and protection device on the cable; the cathodes of the diodes D1, D3 and the other end of the resistor R6 are connected to a point VS.
In the safety inspection device of control and protection device on cable, first voltage signal acquisition device ADC0 and second voltage signal acquisition device ADC1 connection director 50, display device 40 is connected to the first output of controller for report to the police when showing operating condition and breaking down. The first voltage signal acquisition device ADC0 and the second voltage signal acquisition device ADC1 may be MCUs with analog-to-digital conversion or dedicated analog-to-digital conversion chips, and when a fault is detected, the power supply line is disconnected to stop supplying power.
As shown in fig. 6-7, in the safety detecting device of the on-cable control and protection device of the present invention, a filter (not shown) is disposed between the first voltage signal collecting device ADC0 and the resistor R3 for filtering.
The ideal TN and TT power supply system is equal potential between the zero line and the ground line, and there is no resistance between the zero line and the ground line, and at this time, if the influence of voltage drop of D1 and D3 is neglected in fig. 2, the voltage at VS is R9+ R10, then R13 is connected in parallel with the resistor R4+ R6 for voltage division, and the voltage at the second end of R9 is equal to the voltage of the zero line and is equal to [ R9/(R9 + R10) ] -VS. One end of the resistor R9 connected with the resistor R10 is set as a second end, and the other end is a first end.
The presence of the diodes D1 and D3 in the figure effectively suppresses the influence of the voltage difference between the neutral and ground lines on the measurement result.
In another embodiment, the signal amplifying circuit comprises resistors R5, R7, R8, R11 and R12, an operational amplifier U1 and a second voltage signal acquisition device ADC 1; one ends of the resistors R5 and R8 are both connected with the inverting input end of the operational amplifier U1, the other end of the resistor R5 is connected with the first end of the resistor R9 in the voltage division circuit, and the other end of the resistor R8 is connected with the output end of the operational amplifier U1; one ends of the resistors R11 and R12 are both connected with the non-inverting input end of the operational amplifier U1, the other end of the resistor R11 is connected with the second end of the resistor R9 in the voltage division circuit, and the other end of the resistor R12 is grounded; one end of the resistor R7 is connected with the second voltage signal acquisition device ADC 1.
The signal processing circuit 22 is configured to amplify the voltage signal at the two ends of the resistor R9, and send the amplified voltage signal to the second voltage signal acquisition device ADC1 after being limited by the resistor R7. The diode D2 clamps the forward conducting voltage of the diode D2 when the operational amplifier U1 outputs a negative voltage signal, so as to prevent the second voltage signal acquisition device ADC1 from being burnt.
In the safety inspection device of control and protection device on cable, the signal processing circuit further includes diode D2, diode D2 negative pole ground connection, second voltage signal acquisition device ADC1 is connected to the positive pole.
When the live wire and the zero wire of the power grid end are reversely connected, the voltages of the ground wires at the two ends of the R9 are the voltage of the power grid end and the voltage close to the power grid end respectively, the voltages are very high, and if the voltages are directly connected to the operational amplifier U1 without being processed, the U1 has the risk of burning. For increasing the safety, the voltage across the R9 is firstly reduced to be within a safety range, and then an operational amplifier is used for differential amplification.
However, it is difficult to realize a rational power utilization environment due to the complexity of the actual use situation. When the resistance between the zero line and the ground line is greater than 1.6K, there is a risk of electric shock to the user, and when the resistance between the zero line and the ground line is equal to 1.6K, the voltage difference across the resistor R9 increases. When the resistance R13 is not much larger than 1.6K, the voltage difference between the two ends of R9 is obviously different when the ideal power network exists at 1.6K between the zero line and the ground line. The difference between the two voltage signals is shown in fig. 6 and 7. The impedance condition between the zero line and the ground wire can be determined through visual display of images, and whether the control and protection device on the cable is safe at the moment is determined.
Control and protection device's safety inspection device on cable in, still include a breaker 30, connect voltage detection circuit 10's first voltage signal acquisition device ADC0 and impedance detection circuit 20's second voltage signal acquisition device ADC1, breaker sets up the position that control and protection device binding post and output binding post are connected on the cable, it does not insert second voltage signal acquisition device ADC1 to gather the ground wire at first voltage signal acquisition device ADC0 and gathers when the impedance is greater than 1.6K, control and protection device binding post and output binding post's being connected on the disconnected cable.
Be different from prior art, the utility model discloses a safety inspection device of control and protection device on cable, through being connected to on the cable control and protection device two part circuit, respectively to inserting on the cable control and the protection device cable on the live wire and the ground wire between voltage value between the live wire of control and protection device circuit, and the impedance between zero line and the ground wire gather the measurement, whether be 0 through judging the voltage value between control and protection device live wire and the ground wire on the cable, and whether the impedance between judgement zero line and the ground wire is greater than 1.6K, and cut off supply circuit when judging as being. Through the utility model discloses, can be when the ground wire is not gone into, or when having great impedance between ground wire and the zero line, control and protection device's voltage output on the cut-off cable avoids charging process in the trouble take place and arouse the danger that personnel electrocute.
While the embodiments of the invention have been described above, it is not intended to be limited to the details shown, or described, but rather to cover all modifications, which would come within the scope of the appended claims, and all changes which come within the meaning and range of equivalency of the art are therefore intended to be embraced therein.
Claims (10)
1. A safety detection module for an on-cable control and protection device, comprising:
the voltage detection circuit is arranged between a live wire and a ground wire so as to detect the voltage between the live wire and the ground wire and further judge whether the control and protection device on the cable is connected to the ground wire or not;
and the impedance detection circuit is arranged between the zero line and the ground line so as to detect the resistance value between the zero line and the ground line.
2. The safety detection module for an on-cable control and protection device of claim 1, wherein the voltage detection circuit comprises:
one end of the first voltage dividing resistor is electrically connected with a live wire;
one end of the second voltage-dividing resistor is electrically connected with a ground wire, and the other end of the second voltage-dividing resistor and the other end of the first voltage-dividing resistor are connected in series at the voltage sampling detection point;
and the voltage sampling detection point is communicated with a voltage acquisition device, and the voltage between the live wire and the ground wire is calculated according to the voltage of the voltage sampling detection point.
3. The safety detection module for the on-cable control and protection device of claim 2, further comprising a current limiting protection resistor connected in series between the voltage sampling detection point and the voltage collection device to protect the voltage collection device from damage due to overcurrent.
4. A safety detection module for an on-cable control and protection device according to claim 2 or 3, wherein the first divider resistor has a resistance value greater than the second divider resistor.
5. The safety detection module for an on-cable control and protection device of claim 1, wherein the impedance detection circuit comprises:
a third voltage dividing resistor, one end of which is connected with the live wire;
one end of the fourth voltage dividing resistor is connected with the ground wire, and the other end of the fourth voltage dividing resistor and the third voltage dividing resistor are connected in series at a VS voltage sampling point;
one end of the fifth voltage-dividing resistor is connected with the VS voltage sampling point;
one end of the impedance detection resistor and the other end of the fifth voltage-dividing resistor are connected in series with a voltage sampling point N1, and the other end of the impedance detection resistor is provided with a voltage sampling point N;
and calculating the impedance value between the ground wire and the live wire according to the voltage difference value between the voltage sampling point N1 and the voltage sampling point N.
6. The safety detection module for the on-cable control and protection device according to claim 5, further comprising an operational amplifier circuit, wherein a forward input end of the operational amplifier circuit is connected with the voltage sampling point N1, a reverse input end of the operational amplifier circuit is connected with the voltage sampling point N, and an output end of the operational amplifier circuit is a differential pressure sampling point;
and the voltage difference sampling points are communicated with a voltage acquisition device to acquire voltage difference values of the voltage sampling points N1 and the voltage sampling points N, and then the impedance value between the PE wire and the live wire is calculated.
7. The safety detection module for the on-cable control and protection device according to claim 6, wherein a voltage dividing resistor or a voltage dividing circuit is arranged between the voltage sampling point and the operational amplification circuit.
8. The safety detection module for the on-cable control and protection device according to claim 7, wherein the differential pressure sampling point and the operational amplification circuit input end are provided with current limiting resistors.
9. The safety detection module for an on-cable control and protection device of claim 6, further comprising:
the anode of the first filter diode is electrically connected with the VS voltage sample, and the cathode of the first filter diode is connected with the ground wire;
the anode of the second filter diode is electrically connected with the VS voltage sampling point, and the cathode of the second filter diode is connected with the voltage sampling point N1;
and the anode of the third filter diode is grounded, and the cathode of the third filter diode is connected with the differential pressure sampling point.
10. The safety detection module for the on-cable control and protection device of claim 1, further comprising a display device connected to a controller, wherein the controller is connected to the voltage detection circuit and the impedance detection circuit, and can display the detection value and perform a fault alarm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021574557.3U CN212811280U (en) | 2020-08-03 | 2020-08-03 | Safety detection module for on-cable control and protection device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021574557.3U CN212811280U (en) | 2020-08-03 | 2020-08-03 | Safety detection module for on-cable control and protection device |
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| CN212811280U true CN212811280U (en) | 2021-03-26 |
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| CN202021574557.3U Active CN212811280U (en) | 2020-08-03 | 2020-08-03 | Safety detection module for on-cable control and protection device |
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Address after: 1st floor, No. 957 Shunda Road, High tech Zone, Changchun City, Jilin Province, 130012 Patentee after: Changchun Jieyi Automobile Technology Co.,Ltd. Address before: 130012 1st floor, 957 Shunda Road, Changchun high tech Development Zone, Jilin Province Patentee before: CHANGCHUN JIEYI AUTO PARTS CO.,LTD. |