CN110672925A - High-precision insulation resistance detection circuit - Google Patents
High-precision insulation resistance detection circuit Download PDFInfo
- Publication number
- CN110672925A CN110672925A CN201911019096.5A CN201911019096A CN110672925A CN 110672925 A CN110672925 A CN 110672925A CN 201911019096 A CN201911019096 A CN 201911019096A CN 110672925 A CN110672925 A CN 110672925A
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- Prior art keywords
- insulation
- circuit
- resistor
- detection
- voltage division
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/025—Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/04—Voltage dividers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention relates to a high-precision insulation resistance detection circuit, which comprises an insulation detection module and a voltage division module which are connected in series; the insulation detection module comprises a plurality of groups of insulation resistance detection units which are connected in parallel; the insulation resistance detection unit comprises a battery, a detection circuit and a diode which are connected in series; the detection circuit comprises a first insulation resistor, a second insulation resistor, an inductance device and a button switch, wherein the first insulation resistor and the second insulation resistor form a series circuit, and the inductance device and the button switch are connected with the series circuit in parallel; the voltage division module comprises a voltage division circuit and a grounding circuit, wherein the voltage division circuit comprises a first switch, a first voltage division resistor, a second voltage division resistor and a third voltage division resistor which are sequentially connected in series. The application of the invention solves the problems of inaccurate resistance detection, large error in false alarm and detection and complex calculation of the insulation resistance detection circuit in the prior art.
Description
Technical Field
The invention relates to the field of insulation monitoring devices, in particular to a high-precision insulation resistance detection circuit.
Background
The direct current systems of the power plant and the transformer substation provide working power supplies for control and signal systems, relay protection, automatic devices and the like, are important for guaranteeing continuous and safe operation of the power plant and the power station, and require higher reliability and continuous power supply capacity of the direct current systems and power supply networks thereof. As one of measures for improving the continuous power supply capacity, the direct current system works in a 'floating ground' operation mode, which is characterized in that a primary ground fault occurs, the normal operation of the system is not influenced, but if a secondary ground fault occurs while the potential hazard exists, the continuous operation of the system is possibly endangered, the insulation level of the system needs to be continuously monitored, and when the insulation level is reduced to a certain degree, an alarm signal is sent out and the weak insulation link is positioned. Dc system insulation monitoring devices are provided to achieve this goal.
The insulation monitoring device monitors the insulation level of the direct current system by detecting the insulation resistance of the direct current system. The method mainly comprises a bridge method, a low-frequency signal injection method and a leakage current detection method.
The existing insulation resistance detection circuit has many problems, such as: the detection circuit is complex, the resistance value of the insulation resistor is inaccurate to detect, the result is misreported, the error of the detection result is large, the calculation formula is complex, and the occupied processor resource is overlarge.
And the existing insulation resistance detection circuit cannot judge whether the detection circuit works normally, so that the result is easily reported by mistake. These problems will affect the reliability of the insulation monitoring device, and the potential hazards cannot be solved, so that huge hidden dangers are buried for subsequent work.
Therefore, a new technical solution is needed to solve the above problems.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provide a high-precision insulation resistance detection circuit for an insulation monitoring device, and the specific technical scheme is as follows:
a high-precision insulation resistance detection circuit comprises an insulation detection module and a voltage division module which are connected in series;
furthermore, the insulation detection module comprises a plurality of groups of insulation resistance detection units which are connected in parallel;
further, the insulation resistance detection unit comprises a battery, a detection circuit and a diode which are connected in series;
further, the detection circuit comprises a first insulation resistor, a second insulation resistor, an inductance device and a button switch, the first insulation resistor and the second insulation resistor form a series circuit, and the inductance device and the button switch are connected in parallel with the series circuit;
further, the voltage division module comprises a voltage division circuit and a grounding circuit, wherein the voltage division circuit comprises a first switch, a first voltage division resistor, a second voltage division resistor and a third voltage division resistor which are sequentially connected in series; the grounding circuit is connected between the first voltage-dividing resistor and the second voltage-dividing resistor.
Further, the insulation detection module is connected in series with one end of the first switch.
Further, one end of the third voltage dividing resistor is connected in series with the negative electrode of the battery.
Further, the ground circuit includes a second switch.
Further, the detection line is grounded.
Further, the joint of the first insulation resistor and the second insulation resistor is connected with the ground.
Further, the voltage dividing circuit further comprises a voltmeter, and the voltmeter is connected with the third voltage dividing resistor in parallel.
The invention has the following beneficial effects:
1. the insulation resistance detection circuit has simple circuit, higher precision of calculating the resistance value of the insulation resistance and small calculation amount of a processor, so that less resources of the processor are occupied;
2. the insulation resistance detection circuit can perform circuit self-detection and judge the circuit so as to detect whether the circuit works normally;
3. compared with the prior art, the detection circuit and the calculation method are simpler, the error rate is reduced, and the accuracy of the detection result is guaranteed.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a circuit diagram of a detection circuit according to the present invention;
fig. 2 is an equivalent circuit diagram of the detection circuit of the present invention.
Wherein: 1-battery, 2-diode, 3-first insulation resistor, 4-second insulation resistor, 5-inductive device, 6-button switch, 7-first switch, 8-first voltage dividing resistor, 9-second voltage dividing resistor, 10-third voltage dividing resistor, 11-second switch, 12-voltmeter.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or may be connected through the interior of two elements or in interactive relation with one another. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
Examples
The existing insulation resistance detection circuit has the problems of complex detection circuit, inaccurate insulation resistance detection, error report of result, large error of detection result, complex calculation formula, overlarge occupied processor resource and the like. Therefore, the present invention provides a high-precision insulation resistance detection circuit to solve the above-mentioned problems.
FIG. 1 is a circuit diagram of a detection circuit according to the present invention; fig. 2 is an equivalent circuit diagram of the detection circuit of the present invention.
Referring to fig. 1-2, the present invention provides a high precision insulation resistance detection circuit, which includes an insulation detection module and a voltage division module connected in series;
the insulation detection module comprises a plurality of groups of insulation resistance detection units which are connected in parallel;
the insulation resistance detection unit comprises a battery 1(U1), a detection line and a diode 2(D1) which are connected in series;
the detection circuit comprises a first insulation resistor 3(Rp1), a second insulation resistor 4(Rn1), an inductance device 5(L1) and a button switch 6(Q1), wherein the first insulation resistor 3(Rp1) and the second insulation resistor 4(Rn1) form a series circuit, and the inductance device 5(L1) and the button switch 6(Q1) are connected with the series circuit in parallel;
the voltage division module comprises a voltage division circuit and a grounding circuit, wherein the voltage division circuit comprises a first switch 7(S0), a first voltage division resistor 8(Rs), a second voltage division resistor 9(Ra) and a third voltage division resistor 10(Rb) which are sequentially connected in series; the ground circuit is connected between the first voltage-dividing resistor 8(Rs) and the second voltage-dividing resistor 9 (Ra).
Further, the insulation detection module is connected in series with one end of the first switch 7 (S0).
Further, one end of the third voltage dividing resistor 10(Rb) is connected in series with the negative electrode of the battery 1 (U1).
Further, the ground circuit includes a second switch 11 (S1).
Further, the detection line is grounded.
Further, the junction of the first insulation resistor 3(Rp1) and the second insulation resistor 4(Rn1) is connected to ground.
Further, the voltage dividing circuit further includes a voltmeter 12(V0), and the voltmeter 12(V0) is connected in parallel with the third voltage dividing resistor 10 (Rb).
The invention relates to an insulation resistance detection circuit, wherein a detection method in a working state comprises the following steps:
1. a connection circuit which opens the first switch 7(S0), closes the second switch 11(S1) in the initial state, and the processor samples the voltage of the third voltage dividing resistor 10(Rb) at this time as V1;
2. turning off the first switch 7(S0), turning off the second switch 11(S1), waiting for a period of time, and the processor samples the voltage V2 of the third voltage dividing resistor 10(Rb) at that time;
3. calculating whether the value of V2-V1 is within a threshold value, thereby determining whether the second switch 11(S1) is closed or open;
4. closing the first switch 7(S0), opening the second switch 11(S1), and the processor samples the voltage V3 of the third voltage dividing resistor 10(Rb) at that time;
5. the first switch 7 is turned off (S0), the second switch 11 is turned off (S1), and the processor samples the voltage V4 of the resistor Rb at that time;
6. calculating whether the value of V4-V3 is within a threshold value, and judging whether the first switch 7(S0) is closed or opened;
7. boosting the voltage to a set voltage value Ubus through a front-stage inductance device 5 (L1-Lm) and a button switch 6 (Q1-Qm), and keeping the Ubus stable;
8. closing the first switch 7(S0), closing the second switch 11(S1), measuring the voltage V1_1 of the third voltage dividing resistor 10(Rb) of the sampling resistor at that time, and setting an equation listing V1_1 and the insulation resistor and PV voltage to equation 1 by applying the superposition principle;
9. opening the first switch 7(S0), closing the second switch 11(S1), measuring the voltage V1_0 of the third voltage dividing resistor 10(Rb) of the sampling resistor at that time, applying kirchhoff' S principle, and setting an equation between V1_0 and the insulation resistor and PV voltage as equation 2;
10. and (4) calculating the insulation resistance value by using the simultaneous equations of the equation 1 and the equation 2.
A circuit as shown in fig. 1 and 2 is constructed, in which the button switch 6(Q1 to Qm) and the diode 2(D1 to Dm) can be inverter power circuit components, and the first switch 7(S0) and the second switch 11(S1) are mechanical switch components that can be recycled or equivalent.
The circuit for detecting the insulation resistance is simple in circuit and concise in calculation method, and the precision and accuracy of the corresponding circuit for calculating the resistance value of the insulation resistance are improved;
the detection circuit of the present invention can perform circuit self-detection, such as detecting the open/close states of the first switch 7(S0) and the second switch 11(S1) in the above detection method, and thus, judging the circuit, it can detect whether the circuit is working normally.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example" or "some examples" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by one skilled in the art.
While embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications and variations may be made therein by those of ordinary skill in the art within the scope of the present invention.
Claims (7)
1. A high accuracy insulation resistance detection circuitry which characterized in that: the device comprises an insulation detection module and a voltage division module which are connected in series;
the insulation detection module comprises a plurality of groups of insulation resistance detection units which are connected in parallel;
the insulation resistance detection unit comprises a battery (1), a detection circuit and a diode (2) which are connected in series;
the detection circuit comprises a first insulation resistor (3), a second insulation resistor (4), an inductance device (5) and a button switch (6), the first insulation resistor (3) and the second insulation resistor (4) form a series circuit, and the inductance device (5) and the button switch (6) are connected with the series circuit in parallel;
the voltage division module comprises a voltage division circuit and a grounding circuit, wherein the voltage division circuit comprises a first switch (7), a first voltage division resistor (8), a second voltage division resistor (9) and a third voltage division resistor (10) which are sequentially connected in series; the grounding circuit is connected between the first voltage-dividing resistor (8) and the second voltage-dividing resistor (9).
2. The detection circuit of claim 1, wherein: the insulation detection module is connected in series with one end of the first switch (7).
3. The detection circuit of claim 1, wherein: one end of the third voltage dividing resistor (10) is connected in series with the negative electrode of the battery (1).
4. The detection circuit of claim 1, wherein: the grounding circuit comprises a second switch (11).
5. The detection circuit of claim 1, wherein: and carrying out grounding treatment on the detection line.
6. The detection circuit according to claim 1 or 5, wherein: and the joint of the first insulation resistor (3) and the second insulation resistor (4) is connected with the ground.
7. The detection circuit of claim 1, wherein: the voltage division circuit further comprises a voltmeter (12), and the voltmeter (12) is connected with the third voltage division resistor (10) in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911019096.5A CN110672925A (en) | 2019-10-24 | 2019-10-24 | High-precision insulation resistance detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911019096.5A CN110672925A (en) | 2019-10-24 | 2019-10-24 | High-precision insulation resistance detection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN110672925A true CN110672925A (en) | 2020-01-10 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911019096.5A Pending CN110672925A (en) | 2019-10-24 | 2019-10-24 | High-precision insulation resistance detection circuit |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112986809A (en) * | 2021-01-27 | 2021-06-18 | 苏州海鹏科技有限公司 | Relay detection circuit suitable for photovoltaic inverter and detection method thereof |
| CN113791278A (en) * | 2021-09-30 | 2021-12-14 | 蜂巢能源科技有限公司 | Battery pack insulation resistance detection method and device, battery pack and vehicle |
-
2019
- 2019-10-24 CN CN201911019096.5A patent/CN110672925A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112986809A (en) * | 2021-01-27 | 2021-06-18 | 苏州海鹏科技有限公司 | Relay detection circuit suitable for photovoltaic inverter and detection method thereof |
| CN112986809B (en) * | 2021-01-27 | 2022-11-18 | 苏州海鹏科技有限公司 | Relay detection circuit suitable for photovoltaic inverter and detection method thereof |
| CN113791278A (en) * | 2021-09-30 | 2021-12-14 | 蜂巢能源科技有限公司 | Battery pack insulation resistance detection method and device, battery pack and vehicle |
| CN113791278B (en) * | 2021-09-30 | 2023-06-30 | 蜂巢能源科技有限公司 | Battery pack insulation resistance detection method and device, battery pack and vehicle |
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