CN102830283A - Insulating detection device and detection method for direct-current power supply - Google Patents
Insulating detection device and detection method for direct-current power supply Download PDFInfo
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Abstract
The invention discloses an insulating detection device for a direct-current power supply, which comprises an insulating detection circuit, an earthing abnormality detection circuit and a voltage adopting circuit, wherein the insulating detection circuit comprises a first detection branch circuit, a second detection branch circuit and a first earth wire K1; the earthing abnormality detection circuit comprises a third detection resistor R3, a fourth detection resistor R4, a third switch S3 and a second earth wire K2; and the voltage sample circuit is used for measuring voltage of two ends of the third detection resistor R3 or the fourth detection resistor R4. The invention also discloses an earthing abnormality detection method and an insulating detection method adopting the insulating detection device for the direct-current power supply. By adopting the device and method disclosed by the invention, no matter whether the signal earth of the insulating detection device for the direct-current power supply in a suspension state or a fixed potential state, the abnormal condition of the earth wire can be accurately detected; and furthermore, a unilateral branch circuit insulating detection method is provided, so that the insulating detection accuracy is improved and the polling time is shortened.
Description
Technical Field
The invention belongs to the technical field of measurement and test, and particularly relates to a direct-current power supply insulation detection device and detection thereof.
Background
The main power supply network, the control signal power supply system and the branch power supply network in the direct current power supply system are quite large, and a common fault is a point of ground fault. In general, grounding at one point does not affect the operation of the dc power supply system, but if a ground fault point cannot be found and repaired quickly, a short circuit may occur when another ground fault occurs. Therefore, insulation detection of a direct current power supply system is necessary.
The current popular DC power insulation detector on the market has the working principle that: and detecting the insulation resistance of the direct current bus and the positive and negative poles of each branch circuit to the ground, and giving an alarm when the insulation resistance is lower than a set value. Therefore, when the grounding wire of the insulation monitor is disconnected, the true value of the insulation resistor cannot be accurately detected, and serious potential safety hazards exist. Therefore, it is necessary to detect whether the ground line of the insulation detector is disconnected.
The current common ground wire disconnection detection method is to detect the voltage of the ground point relative to the signal ground of the insulation monitor, as shown in fig. 1, where the signal ground of the insulation monitor is the reference point of zero potential. S1 and S2 in fig. 1 are detection switches; r1 and R2 are positive and negative bus detection resistors respectively; k1 denotes a ground line. The voltage of the grounding point relative to the signal ground can be obtained by sampling through a voltage sampling circuit. When the grounding point is grounded normally, the S1 is firstly kept, the S2 is disconnected, and then the S1 is closed, the sampling voltage value is increased, and similarly, the S1 is kept, the S2 is disconnected, and the S2 is closed, the sampling voltage value is reduced. The judgment criterion is that after the grounding point is switched on and off respectively at S1 and S2, the sampling voltage of the grounding point has a certain change value, a change value Us is preset, and when the measured variation quantity delta U of the grounding point is larger than Us, the grounding line is judged to be disconnected. The grounding wire disconnection detection method requires that the signal ground is a fixed potential or an equipotential relative to the ground, and when the signal ground of the insulation monitor is in a suspension state, the voltages of the positive and negative buses and the ground relative to the signal ground are in a change state, so that the judgment criterion is not applicable. Therefore, the above method for determining whether the ground line is disconnected has limitations.
The common detection method of branch insulation resistance is a leakage current detection method, which comprises the following basic steps of firstly connecting a detection resistor between a positive bus and the ground, then detecting the leakage current of the branch, simultaneously measuring the voltage value of the positive bus and the negative bus to the ground, and disconnecting the detection resistor after the measurement is finished; and connecting a detection resistor between the negative bus and the ground, detecting the leakage current of the branch again, measuring the voltage value of the positive bus and the negative bus to the ground, and disconnecting the detection resistor after the measurement is finished. And obtaining the insulation resistance of the branch circuit to the ground through a simultaneous equation. Generally, a direct-current power supply system has many branches and also has factors such as switching delay, and a common branch insulation resistance detection method needs to switch a ground resistance twice for each branch, so that the one-time polling time of the power supply system is long.
Disclosure of Invention
The invention aims to solve the technical problem of the prior art and provides a direct-current power supply insulation detection device and a detection method thereof.
As an aspect of the present invention, there is provided a dc power insulation detection apparatus including an insulation detection circuit and a ground abnormality detection circuit;
the insulation detection circuit comprises a first detection branch, a second detection branch and a first grounding wire K1; one end of the first detection branch is connected with a positive bus, and the other end of the first detection branch is connected with one end of the first grounding wire K1; one end of the second detection branch is connected with the negative bus, and the other end of the second detection branch is connected with the end of the first grounding wire K1; the other end of the first grounding wire K1 is grounded;
the grounding abnormity detection circuit comprises a third detection resistor R3, a fourth detection resistor R4, a third switch S3 and a second grounding wire K2; one end of the third detection resistor R3 is connected with a positive bus, and the other end is connected with one end of the third switch S3; one end of the fourth detection resistor R4 is connected with a negative bus, and the other end is connected with the end of the third switch S3; the other end of the third switch S3 is connected with one end of the second grounding wire K2; the other end of the second grounding line K2 is grounded.
Further, the first detection branch comprises a first switch S1 and a first detection resistor R1 connected in series; the second detection branch comprises a second switch S2 and a second detection resistor R2 which are connected in series.
Further, the resistance of the first detection resistor R1 is equal to the resistance of the second detection resistor R2.
Furthermore, the insulation detection device for the direct current power supply further comprises a voltage sampling circuit, and the voltage sampling circuit is used for measuring the voltage at two ends of the third detection resistor R3 or the fourth detection resistor R4.
Furthermore, the insulation detection device for the direct-current power supply further comprises a leakage current sensor for detecting the magnitude of the leakage current of each branch of the direct-current power supply to the ground.
As another aspect of the present invention, there is provided a ground fault detection method using the dc power insulation detection apparatus, including the steps of:
closing the third switch S3, opening the first detection branch, determining whether the voltage across the fourth detection resistor R4 changes when the second detection branch is opened and closed, and if not, at least one of the first ground line K1 and the second ground line K2 is abnormal; or,
and closing the third switch S3, opening the second detection branch, and determining whether the voltage across the third detection resistor R3 changes when the first detection branch is opened and closed, and if not, at least one of the first ground line K1 and the second ground line K2 is abnormal.
As still another aspect of the present invention, there is provided an insulation detecting method using the dc power supply insulation detecting apparatus, including the steps of:
firstly, detecting equivalent insulation resistances of a positive bus and a negative bus, comparing the detected equivalent insulation resistances of the positive bus and the negative bus with a preset alarm resistance value, and if only one of the equivalent insulation resistances of the positive bus and the negative bus is lower than the alarm resistance value, then only detecting the corresponding positive insulation resistance or negative insulation resistance of each branch, namely adopting a single-side branch detection method; and if the equivalent insulation resistance of the positive bus and the equivalent insulation resistance of the negative bus are lower than the alarm resistance value, detecting the positive insulation resistance and the negative insulation resistance of each branch, namely adopting a bilateral branch detection method.
Further, the method for detecting the equivalent insulation resistance of the bus comprises the following steps:
making the first sensing resistor R1 of the first sensing branch equal to the second sensing resistor R2 of the second sensing branch;
opening the third switch S3;
switching on the first detection circuit, switching off the second detection circuit, and sampling to obtain the voltage U of the positive bus to the earth1+And the voltage U of the negative bus to the earth1-；
Switching off the first detection circuit, switching on the second detection circuit, and sampling to obtain a positive bus-to-ground voltage U2+And the voltage U of the negative bus to earth2-；
Calculating the equivalent insulation resistance R of the positive bus according to the following formula+Equivalent insulation resistance R of negative bus-：
Further, the following step of detecting only the corresponding positive insulation resistance or negative insulation resistance of each branch circuit includes:
if only the equivalent insulation resistance of the positive bus is lower than the alarm resistance value in the equivalent insulation resistances of the positive bus and the negative bus, the third switch is switched off S3, the first detection branch is switched off, the second detection branch is switched on, the leakage current of each branch is respectively detected, and the voltage U + of the positive bus to the ground is detected at the same time, and the leakage current of each branch is divided by the U + to obtain the positive insulation resistance of each branch to the ground;
if only the equivalent insulation resistance of the negative bus is lower than the alarm resistance value in the equivalent insulation resistances of the positive bus and the negative bus, the third switch S3 is switched off, the first detection branch is switched on, the second detection branch is switched off, the leakage current of each branch is respectively detected, the voltage U-to-ground of the negative bus is detected, and the leakage current of each branch is divided by the U-to-ground voltage of each branch to obtain the insulation resistance of the negative end of each branch to the ground.
Further, the following step of detecting both the positive insulation resistance and the negative insulation resistance of each branch circuit includes:
opening the third switch S3, closing the first detection branch, opening the second detection branch, and measuring the voltage U of the positive bus to the ground1+And the voltage U of the negative bus to earth1-And leakage current I of branch nn1；
Opening the third switch S3, opening the first detection branch, closing the second detection branch, and measuring the voltage U of the positive bus to the ground2+And the voltage U of the negative bus to earth2-And leakage current I of branch nn2；
Calculating the insulation resistance of each branch according to the following formula:
wherein R isn+Positive insulation resistance for branch n, Rn-Is the negative insulation resistance of branch n.
The invention has the beneficial effects that:
the invention adds a grounding abnormity detection circuit to the DC power supply insulation detection device, and the basic detection principle is as follows: under the normal condition that the first ground line K1 and the second ground line K2 are both grounded, the on and off of the first switch S1 and the second switch S2 can cause the voltage across the third detection resistor R3 and the fourth detection resistor R4 to change; when any one of the first ground line K1 and the second ground line K2 is disconnected, the voltages at the two ends of the third detection resistor R3 and the fourth detection resistor R4 are not changed by the on/off of the first switch S1 and the second switch S2. And the change mode has no relation with the state of the signal ground of the direct current power supply insulation detection device, so the direct current power supply insulation detection device has the advantages of wide adaptability, high reliability and the like.
Meanwhile, the invention provides a single-side branch detection method and a double-side branch detection method, wherein the single-side branch detection method is started under the condition that the bus insulation detection judges that only one side of resistance is reduced, and the double-side branch detection method is the same as a normal leakage current detection method. Different detection methods are suitable for different conditions, and the inspection time can be shortened. The invention provides a novel insulation detection process by combining the ground wire abnormality detection, which can improve the accuracy of insulation detection and shorten the polling time.
Drawings
FIG. 1 is a schematic diagram illustrating a conventional ground fault detection principle;
FIG. 2 is a schematic structural diagram of the insulation detection device for DC power supply of the present invention;
FIG. 3 is a schematic diagram of the insulation detection of the present invention;
FIG. 4 is a block diagram of the overall structure of the DC power insulation detection device of the present invention;
FIG. 5 is a flow chart of the insulation detection method of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
FIG. 2 is a schematic structural diagram of the DC power insulation detection device of the present invention, in FIG. 2, BUS + is a positive BUS, BUS-is a negative BUS, PE is the ground, and R + and R-are the total equivalent insulation resistance of the positive BUS to the ground and the negative BUS to the ground, respectively; r1, R2 is an insulation resistance value detection resistor, wherein R1 is a first detection resistor, and R2 is a second detection resistor; r3 and R4 are ground wire abnormality detection resistors, wherein R3 is a third detection resistor, and R4 is a fourth detection resistor; k1 and K2 are grounding wires, wherein K1 is a first grounding wire, and K2 is a second grounding wire; s1, S2 is a detection switch, S3 is a ground line abnormality detection switch, wherein S1 is a first switch, S2 is a second switch, and S3 is a third switch. S3 is closed when the ground line abnormality is detected, and S3 is opened when the bus insulation detection and the branch insulation detection are performed.
One end of the S1 is connected with the positive bus, and the other end is connected with the R1; one end of the S2 is connected with the negative bus, and the other end is connected with the R2; the other ends of R1 and R2 are connected with K1, and the other end of K1 is connected with the ground. One end of R3 is connected with the positive bus; one end of R4 is connected with the negative bus, the other ends of R3 and R4 are connected with S3, the other end of S3 is connected with one end of K2, and the other end of K2 is connected with the ground.
As shown in fig. 2, the insulation detection device for dc power supply of the present invention includes an insulation detection circuit, a ground fault detection circuit, and a voltage sampling circuit.
The insulation detection circuit comprises a first detection branch, a second detection branch and a first grounding wire K1; one end of the first detection branch is connected with the positive bus, and the other end of the first detection branch is connected with one end of a first grounding wire K1; one end of the second detection branch is connected with the negative bus, and the other end of the second detection branch is connected with the end of the first grounding wire K1; the other end of the first ground line K1 is grounded. The first detection branch comprises a first switch S1 and a first detection resistor R1 which are connected in series; the second detection branch comprises a second switch S2 and a second detection resistor R2 which are connected in series.
The ground fault detection circuit comprises a third detection resistor R3, a fourth detection resistor R4, a third switch S3 and a second grounding wire K2; one end of the third detection resistor R3 is connected with the positive bus, and the other end is connected with one end of the third switch S3; one end of the fourth detection resistor R4 is connected with the negative bus, and the other end is connected with the end of the third switch S3; the other end of the third switch S3 is connected to one end of the second ground line K2; the other end of the second ground line K2 is grounded.
For convenience of insulation detection calculation, the resistance value of the first detection resistor R1 and the resistance value of the second detection resistor R2 may be equal.
The voltage sampling circuit is used for measuring the voltage at two ends of the third detection resistor R3 or the fourth detection resistor R4.
The direct-current power supply insulation detection device also comprises a leakage current sensor which is used for detecting the magnitude of the leakage current of each branch of the direct-current power supply to the ground.
The detection principle of the method for detecting the grounding abnormity of the direct current power supply insulation detection device is as follows: under the normal condition that the grounding wires K1 and K2 are grounded, S2 is opened, S3 is closed and keeps the state unchanged, and under the opening and closing states of S1, the voltage at two ends of R3 changes; s2 is opened, S3 is closed and the state is kept unchanged, and when any one of the grounding wires K1 and K2 is opened, the voltage of the two ends of the R3 cannot be changed due to the opening and closing of the S1. S1 and S2 have symmetry, the S1 is kept to be open, the S3 is kept to be closed, the S2 is switched on and off, and correspondingly detected voltage changes of two ends of the R4. Taking the switching of S1 as an example, the implementation steps are described in detail as follows:
opening S2, closing S3 and keeping the state unchanged, and measuring the voltage at two ends of R3 under the condition that S1 is opened to obtain a voltage value V1; keeping the S2 disconnected, keeping the S3 closed state unchanged, and measuring the voltage at two ends of the R3 after S1 is closed to obtain a voltage value V2; if V1 is equal to V2, at least one of K1 and K2 is disconnected, and an alarm prompts a user that one grounding wire is abnormal. The voltage values across R3 in each state are shown in the table below.
First table, table for voltage change at two ends of R3 during ground fault detection
From the above table, it can be seen that only when both K1, K2 are normally connected, does the voltage across R3 decrease after S1 is closed. The magnitude of the voltage change across R3 depends on the magnitude of the R1 resistance. In general, R1 can be made as small as possible, and R3 is made as large as 2 to 3 times R1, so as to ensure reliable detection of voltage variation.
Compared with the traditional direct current power supply insulation detection device, the detection grounding wire K2 is added, and the detection grounding wire K2 is the same as the grounding wire K1 inherent in the traditional direct current power supply insulation detection device in wire diameter material, installation mode and wiring mode. The detection of the disconnection of the grounding wire does not affect the normal realization of the insulation detection function, but due to the fact that the abnormal damage mechanisms of the grounding of the two wires are consistent, such as aging of wire diameters, stress existing in the wiring, looseness of a wiring terminal and the like, when the grounding wire K2 is disconnected, the grounding wire K1 also has the risk of disconnection. Therefore, when any one grounding wire is disconnected, fault removal should be carried out in time.
FIG. 3 is an insulation detection schematic diagram of the present invention, wherein R1+, R1-, R2+, R2-,..... multidot.Rn +, Rn-are respectively the positive and negative ground insulation resistances of the branch 1, the branch 2, and the branch n; l1, L2, l.a., Ln are intelligent leakage current sensors respectively installed on the branches 1, 2, l.a., n.n loop, and are used for detecting the earth leakage current of each branch, so as to calculate the earth insulation resistance of each branch.
Fig. 4 is a block diagram of an overall structure of the dc power insulation detection device according to an embodiment of the present invention, and as shown in the figure, the dc power insulation detection device mainly includes a resistance switching network, an AD sampling processing circuit, a branch leakage current collecting network, a CPU, a sampling information and alarm information display, a background communication, and the like. The resistance switching network comprises an insulation detection circuit and a grounding abnormity detection circuit.
Fig. 5 is a flowchart of the insulation detection method of the present invention, as shown in the figure, before the insulation detection is performed, it is necessary to determine whether the grounding is abnormal, and when the insulation detection is started, the default grounding abnormality detection cycle time is up, and the grounding abnormality detection process is performed. When the operation time reaches the set cycle time, the grounding abnormality detection is started again.
And if the grounding abnormity is found, sending a grounding abnormity alarm, and detecting the insulation resistance after the grounding abnormity fault is relieved. And during insulation detection, detecting the insulation resistance of the bus to the ground, and if the insulation resistance of the bus is smaller than a preset alarm resistance value, performing branch insulation detection. And determining whether the branch insulation detection adopts single-side detection or double-side detection according to the detection result of the bus insulation resistance. And in the branch monitoring process, an alarm is sent out after the branch insulation is found to be reduced, and meanwhile, the alarm is sent out through background communication. And circularly detecting the grounding abnormity and the bus insulation resistance again after all the branches are inspected.
An embodiment is given below to describe in detail an insulation detection method using the insulation detection device for a dc power supply of the present invention:
when the insulation resistance is detected, the bus insulation resistance is detected first, and for convenience of calculation, the insulation detection resistance R1 is set to R2. When detecting the bus insulation resistance, S3 needs to be kept in an off state. Firstly controlling S1 to be closed and S2 to be opened, and obtaining the voltage-to-ground voltage U of the positive and negative buses through sampling1+，U1-(ii) a Then controlling S1 to be opened and S2 to be closed, sampling the ground voltage U of the positive bus and the negative bus2+，U2-(ii) a Then according to the formula:
and calculating the bus insulation resistance.
If the bus insulation resistance is found to have the condition that only one side of the positive bus and the negative bus drops, starting a unilateral branch detection method; and if the insulation resistance of the positive bus bar and the negative bus bar to the ground is reduced, starting the bilateral branch circuit detection method. The unilateral branch detection method only needs to close the detection change-over switch for the bus with the reduced insulation resistance value, and the bilateral branch detection method needs to close the positive and negative bus detection change-over switches respectively. The specific method comprises the following steps:
comparing the insulation resistance with the set alarm resistance Rs when R is+≤Rs，R-And when the signal is greater than Rs, starting a single-side branch detection method. And S2 is closed, S1 and S3 are opened, leakage current of each branch is detected respectively, and the ground voltage U + of the positive bus is detected, and the insulation resistance of the positive end of each branch to the ground is obtained by dividing the U + by the leakage current of each branch. In thatIn this embodiment, the alarm resistance is set to 20K Ω.
If R is+≤Rs，R-And starting the bilateral branch detection method when the Rs is less than or equal to. Closing S1, disconnecting S2 and S3, and measuring the voltage U of the positive and negative buses to the ground1+，U1-And leakage current I of branch nn1. Then S2 is closed, S1 and S3 are opened, and the voltage U of the positive and negative buses to the ground is measured2+，U2-And leakage current I of branch nn2. Then, the insulation resistance of each branch is calculated according to the following formula:
wherein R isn+Positive insulation resistance for branch n, Rn-Is the negative insulation resistance of branch n.
The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be noted that the above-mentioned embodiments are only examples of the present invention, and those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations of the present invention fall within the technical scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A direct-current power supply insulation detection device comprises an insulation detection circuit, wherein the insulation detection circuit comprises a first detection branch circuit, a second detection branch circuit and a first grounding wire K1, one end of the first detection branch circuit is connected with a positive bus, the other end of the first detection branch circuit is connected with one end of a first grounding wire K1, one end of the second detection branch circuit is connected with a negative bus, the other end of the second detection branch circuit is connected with the end of a first grounding wire K1, and the other end of the first grounding wire K1 is grounded; the method is characterized in that:
the grounding abnormity detection circuit is also included;
the grounding abnormity detection circuit comprises a third detection resistor R3, a fourth detection resistor R4, a third switch S3 and a second grounding wire K2; one end of the third detection resistor R3 is connected with a positive bus, and the other end is connected with one end of the third switch S3; one end of the fourth detection resistor R4 is connected with a negative bus, and the other end is connected with the end of the third switch S3; the other end of the third switch S3 is connected with one end of the second grounding wire K2; the other end of the second grounding line K2 is grounded.
2. The dc power insulation detecting apparatus of claim 1, wherein the first detecting branch comprises a first switch S1 and a first detecting resistor R1 connected in series; the second detection branch comprises a second switch S2 and a second detection resistor R2 which are connected in series.
3. The apparatus according to claim 2, wherein the first detecting resistor R1 has a resistance equal to the second detecting resistor R2.
4. The apparatus according to claim 1, 2 or 3, further comprising a voltage sampling circuit for measuring a voltage across the third detecting resistor R3 or the fourth detecting resistor R4.
5. The direct-current power supply insulation detection device according to claim 1, 2 or 3, further comprising a leakage current sensor for detecting the magnitude of the leakage current of each branch of the direct-current power supply to the ground.
6. The method for detecting the ground fault using the dc power insulation detecting apparatus according to claim 1, comprising the steps of:
closing the third switch S3, opening the first detection branch, determining whether the voltage across the fourth detection resistor R4 changes when the second detection branch is opened and closed, and if not, at least one of the first ground line K1 and the second ground line K2 is abnormal; or,
and closing the third switch S3, opening the second detection branch, and determining whether the voltage across the third detection resistor R3 changes when the first detection branch is opened and closed, and if not, at least one of the first ground line K1 and the second ground line K2 is abnormal.
7. An insulation detecting method using the insulation detecting device for a direct current power supply according to claim 1, comprising the steps of:
firstly, detecting equivalent insulation resistances of a positive bus and a negative bus, comparing the detected equivalent insulation resistances of the positive bus and the negative bus with a preset alarm resistance value, and if only one of the equivalent insulation resistances of the positive bus and the negative bus is lower than the alarm resistance value, then only detecting the corresponding positive insulation resistance or negative insulation resistance of each branch circuit; and if the equivalent insulation resistance of the positive bus and the equivalent insulation resistance of the negative bus are lower than the alarm resistance value, detecting the positive insulation resistance and the negative insulation resistance of each branch circuit.
8. The insulation detection method according to claim 7, wherein the positive and negative bus equivalent insulation resistance is detected by a method comprising:
making the first sensing resistor R1 of the first sensing branch equal to the second sensing resistor R2 of the second sensing branch;
opening the third switch S3;
switching on the first detection circuit, switching off the second detection circuit, and sampling to obtain the voltage U of the positive bus to the earth1+And the voltage U of the negative bus to the earth1-；
Switching off the first detection circuit, switching on the second detection circuit, and sampling to obtain a positive bus-to-ground voltage U2+And the voltage U of the negative bus to earth2-；
Calculating the equivalent insulation resistance R + of the positive bus and the equivalent insulation resistance R of the negative bus according to the following formulas:
9. an insulation detection method as claimed in claim 7 or 8, wherein said subsequent detection of only the positive or negative insulation resistance of each branch is performed by a method comprising:
if only the equivalent insulation resistance of the positive bus is lower than the alarm resistance value in the equivalent insulation resistances of the positive bus and the negative bus, the third switch is switched off S3, the first detection branch is switched off, the second detection branch is switched on, the leakage current of each branch is respectively detected, and the voltage U + of the positive bus to the ground is detected at the same time, and the leakage current of each branch is divided by the U + to obtain the positive insulation resistance of each branch to the ground;
if only the equivalent insulation resistance of the negative bus is lower than the alarm resistance value in the equivalent insulation resistances of the positive bus and the negative bus, the third switch S3 is switched off, the first detection branch is switched on, the second detection branch is switched off, the leakage current of each branch is respectively detected, the voltage U-to-ground of the negative bus is detected, and the leakage current of each branch is divided by the U-to-ground voltage of each branch to obtain the insulation resistance of the negative end of each branch to the ground.
10. The insulation detection method according to claim 7 or 8, wherein the following detection of the positive insulation resistance and the negative insulation resistance of each branch is performed by a method comprising:
opening the third switch S3, closing the first detection branch, opening the second detection branch, and measuring the voltage U of the positive bus to the ground1+And the voltage U of the negative bus to earth1-And leakage current I of branch nn1；
Opening the third switch S3, opening the first detection branch, closing the second detection branch, and measuring the voltage U of the positive bus to the ground2+And the voltage U of the negative bus to earth2-And leakage current I of branch nn2；
Calculating the insulation resistance of each branch according to the following formula:
wherein R isn+Positive insulation resistance for branch n, Rn-Is the negative insulation resistance of branch n.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101576310A CN102830283A (en) | 2011-06-13 | 2011-06-13 | Insulating detection device and detection method for direct-current power supply |
| PCT/CN2012/076654 WO2012171444A1 (en) | 2011-06-13 | 2012-06-08 | Direct current power supply insulation detection device and detection method therefor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101576310A CN102830283A (en) | 2011-06-13 | 2011-06-13 | Insulating detection device and detection method for direct-current power supply |
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| CN102830283A true CN102830283A (en) | 2012-12-19 |
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| CN2011101576310A Pending CN102830283A (en) | 2011-06-13 | 2011-06-13 | Insulating detection device and detection method for direct-current power supply |
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| CN (1) | CN102830283A (en) |
| WO (1) | WO2012171444A1 (en) |
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| CN105938175B (en) * | 2016-05-31 | 2019-03-12 | 贵阳英纳瑞电气有限公司 | Direct current system instant earthing on-line monitoring method and device manufacturing based on DSP |
| CN106353695A (en) * | 2016-10-24 | 2017-01-25 | 郑州云海信息技术有限公司 | Device and method for detecting insulation against ground fault of direct-current power source |
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| CN107843813A (en) * | 2017-09-28 | 2018-03-27 | 河南汇纳科技有限公司 | A kind of insulation detection device based on LoRa |
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| WO2021043173A1 (en) * | 2019-09-06 | 2021-03-11 | 中兴通讯股份有限公司 | Distributed insulation detection device for multi-stage dc system |
| US11585867B2 (en) * | 2020-02-13 | 2023-02-21 | Hl Mando Corporation | Multi ground line disconnection inspection device and method and electronic control device including the same |
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| CN111948504A (en) * | 2020-08-25 | 2020-11-17 | 的卢技术有限公司 | 800V energy storage system insulation detection circuit and method |
| CN113777452A (en) * | 2021-09-17 | 2021-12-10 | 广东电网有限责任公司 | Direct current system grounding test device and method for voltage self-adaptive station |
| CN113777452B (en) * | 2021-09-17 | 2024-01-16 | 广东电网有限责任公司 | DC system grounding test device and method for voltage self-adaptive station |
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