CN220709285U - Insulation detection device - Google Patents

Abstract

The utility model discloses an insulation detection device for detecting insulation resistance value of an energy storage system, comprising: the device comprises an anode detection module, a cathode detection module and a control module; the positive electrode detection module comprises a first resistor, a first voltage dividing resistor and a first switch module; the negative electrode detection module comprises a second resistor, a second voltage-dividing resistor and a second switch module; the positive electrode detection module is used for outputting voltage values of two ends of the first voltage dividing resistor to the control module; the negative electrode detection module is used for outputting voltage values of two ends of the second voltage dividing resistor to the control module; the control module is used for calculating the resistance value of the positive resistance according to the first closing voltage, the second closing voltage and the first open-circuit voltage or calculating the resistance value of the negative resistance according to the first closing voltage, the second closing voltage and the second open-circuit voltage, so that the measurement accuracy of the positive resistance or the negative resistance is improved.

Description

Insulation detection device

Technical Field

The utility model relates to the technical field of insulation detection, in particular to an insulation detection device.

Background

The power battery is a main power source of the power system of the electric automobile, the power supply voltage of the power system is hundreds of volts high, and the rated working current can reach tens of amperes or even higher. Because the working environment of the electric automobile is complex, insulation aging or damp and the like of the high-voltage cable can cause insulation performance between the high-voltage circuit and the chassis of the automobile to be reduced, and under the action of high voltage, a high-voltage side loop of the electric automobile can generate extremely high instantaneous current, so that safety of the automobile and personnel on the automobile is threatened. It can be seen that the insulation performance of an electric vehicle has a very important effect on the safety of the vehicle, and the insulation performance of an electric vehicle can be described by the size of insulation resistance.

At present, the detection precision of the insulation detection device is not high enough, and especially at two extremes, the detection precision error is larger.

Disclosure of Invention

The utility model provides an insulation detection device which is used for improving the measurement accuracy of positive resistance or negative resistance.

According to an aspect of the present utility model, there is provided an insulation detection device for detecting an insulation resistance value of an energy storage system, the energy storage system including a power source, a positive resistance and a negative resistance, a positive electrode of the power source being electrically connected to a first end of the positive resistance, a negative electrode of the power source being electrically connected to a second end of the negative resistance, the second end of the positive resistance being electrically connected to a first end of the negative resistance, the second end of the positive resistance being connected to a reference ground; the power supply, the positive resistor and the negative resistor are sequentially connected in series, a first node is arranged between the positive resistor and the negative resistor, and the reference ground is connected with the first node;

the insulation detection device includes:

the device comprises an anode detection module, a cathode detection module and a control module;

the positive electrode detection module comprises a first resistor, a first voltage dividing resistor and a first switch module, and the first resistor, the first voltage dividing resistor and the first switch module are connected in series; the negative electrode detection module comprises a second resistor, a second voltage-dividing resistor and a second switch module, and the second resistor, the second voltage-dividing resistor and the second switch module are connected in series;

The positive electrode detection module is connected to two ends of the positive resistor, and the output end of the positive electrode detection module is electrically connected with the first input end of the control module and is used for outputting voltage values of two ends of the first divider resistor to the control module;

the negative electrode detection module is connected to two ends of the negative resistor, and the output end of the negative electrode detection module is electrically connected with the second input end of the control module and is used for outputting voltage values of two ends of the second voltage dividing resistor to the control module;

the control module is used for calculating the resistance value of the positive resistance according to the first closing voltage, the second closing voltage and the first open-circuit voltage, or calculating the resistance value of the negative resistance according to the first closing voltage, the second closing voltage and the second open-circuit voltage; the first closing voltage is a voltage value of two ends of the first voltage dividing resistor when the first switch module and the second switch module are closed simultaneously; the second closing voltage is a voltage value of two ends of the second voltage dividing resistor when the first switch module and the second switch module are closed simultaneously; the first open-circuit voltage is a voltage value at two ends of the first voltage dividing resistor when the first switch module is closed and the second switch module is opened; the second open-circuit voltage is a voltage value at two ends of the second voltage dividing resistor when the first switch module is opened and the second switch module is closed.

Optionally, the control module is further configured to determine, according to a comparison result of the first closing voltage and the second closing voltage, a resistance value of the calculated positive resistance or a resistance value of the negative resistance.

Optionally, the control module is configured to control the second switch module to be opened when it is determined that the resistance of the positive resistor is smaller than the resistance of the negative resistor according to the first closing voltage and the second closing voltage, control the first switch module to be closed, and obtain a first open-circuit voltage, and calculate the resistance of the positive resistor according to the first closing voltage, the second closing voltage and the first open-circuit voltage; or when the resistance value of the positive resistor is larger than the resistance value of the negative resistor according to the first closing voltage and the second closing voltage, controlling the first switching module to be opened, controlling the second switching module to be closed, acquiring the second open-circuit voltage, and calculating the resistance value of the negative resistor according to the first closing voltage, the second closing voltage and the second open-circuit voltage.

Optionally, the first switch module includes:

the device comprises a fourth resistor, a seventh resistor, a ninth resistor, a first transistor, a second transistor, a first optocoupler, a second optocoupler and magnetic beads;

the first end of the control module is electrically connected with the first end of the first transistor and the first end of the fourth resistor, the second end of the fourth resistor is electrically connected with the second end of the first transistor and the first grounding end, the third end of the first transistor is electrically connected with the second end of the first optocoupler, the first power end is electrically connected with the first end of the first optocoupler, the second power end is electrically connected with the fourth end of the first optocoupler, and the third end of the first optocoupler is electrically connected with the first end of the second transistor and the first end of the ninth resistor;

The first end of the second optical coupler and the first end of the seventh resistor are connected with a second power end, the second end of the sixth resistor is electrically connected with the first end of the second optical coupler, the second end of the seventh resistor is electrically connected with the second end of the second optical coupler, the second end of the ninth resistor is electrically connected with the second end of the second transistor, the second end of the second transistor is electrically connected with a second grounding end, the second end of the second transistor is electrically connected with the first end of the magnetic bead, and the second end of the magnetic bead is electrically connected with a reference; the third end of the second transistor is electrically connected with the second optical coupler; the third end of the second optocoupler is electrically connected with the second end of the first resistor, and the fourth end of the second optocoupler is electrically connected with the first end of the first voltage dividing resistor.

Optionally, the positive electrode detection module further includes:

the first filter amplification module and the first analog-to-digital conversion module;

the first end of the first switch module is electrically connected with the first end of the control module, the second end of the first switch module is electrically connected with the second end of the first resistor, the first end of the first resistor is electrically connected with the positive electrode of the power supply, the third end of the first switch module is electrically connected with the first end of the first voltage dividing resistor, the second end of the first voltage dividing resistor is electrically connected with the second grounding end, the first end of the first voltage dividing resistor is electrically connected with the first end of the first filter amplification module, the second end of the first filter amplification module is electrically connected with the first end of the first analog-to-digital conversion module, the second end of the first analog-to-digital conversion module is electrically connected with the second end of the control module, and the third end of the first analog-to-digital conversion module is electrically connected with the third end of the control module.

Optionally, the first filtering and amplifying module includes:

an eleventh resistor, a thirteenth resistor, a fourteenth resistor, a first capacitor, a second capacitor and a dual operational amplifier;

the first end of the first voltage dividing resistor is electrically connected with the first end of the eleventh resistor and the first end of the first capacitor, the second end of the first capacitor is electrically connected with the first end and the second end of the dual operational amplifier, the second end of the eleventh resistor is electrically connected with the third end of the dual operational amplifier, the second end of the eleventh resistor is electrically connected with the first end of the second capacitor, and the second end of the second capacitor is electrically connected with the fourth end and the second grounding end of the dual operational amplifier;

the fifth end of the double operational amplifier is electrically connected with the first end of the double operational amplifier, the sixth end of the double operational amplifier is electrically connected with the first end of the thirteenth resistor, the second end of the thirteenth resistor is electrically connected with the second grounding end, the seventh end of the double operational amplifier is electrically connected with the first end of the fourteenth resistor, the second end of the fourteenth resistor is electrically connected with the sixth end of the double operational amplifier, and the seventh end of the double operational amplifier is electrically connected with the second grounding end and the first end of the first analog-to-digital conversion module; the eighth terminal of the dual operational amplifier is electrically connected to the second power supply terminal.

Optionally, the first analog-to-digital conversion module includes:

a digital-to-analog conversion unit and a switch unit;

the first end of the digital-to-analog conversion unit is electrically connected with the second end of the first filtering and amplifying module, the second end of the digital-to-analog conversion unit is electrically connected with the second end of the control module, the third end of the digital-to-analog conversion unit is electrically connected with the first end of the switch unit, and the second end of the switch unit is electrically connected with the third end of the control module.

Optionally, the digital-to-analog conversion unit includes:

an a/D converter, a sixth capacitor, and a seventh capacitor;

the seventh end and the eighth end of the A/D converter are electrically connected with the second power supply end, the fifth end and the sixth end of the A/D converter are electrically connected with the second grounding end, the fourth end of the A/D converter is electrically connected with the first end of the sixth capacitor and the first end of the seventh capacitor, the fourth end of the A/D converter is electrically connected with the second end of the fifteenth resistor and the first end of the fifth capacitor, the second end of the sixth capacitor and the second end of the seventh capacitor are electrically connected with the second grounding end, the third end of the A/D converter is electrically connected with the second grounding end, the second end of the A/D converter is electrically connected with the first end of the switch unit, and the first end, the ninth end and the tenth end of the A/D converter are electrically connected with the second end of the control module.

Optionally, the switching unit includes:

a sixteenth resistor, a third transistor and a third optocoupler;

the third end of the control module is electrically connected with the first end of the sixteenth resistor and the first end of the third transistor, the second end of the sixteenth resistor is electrically connected with the second end of the third transistor and the first grounding end, the third end of the third transistor is electrically connected with the second end of the third optocoupler, the first power end is electrically connected with the first end of the third optocoupler, the second power end is electrically connected with the first end of the nineteenth resistor, the second end of the nineteenth resistor is electrically connected with the fourth end of the third optocoupler, the third end of the third optocoupler is electrically connected with the second grounding end, and the fourth end of the third optocoupler is electrically connected with the second end of the A/D converter.

Optionally, the negative electrode detection module further includes:

the second filtering and amplifying module and the second analog-to-digital conversion module;

the second switch module comprises a fourth optical coupler;

the first end of the second switch module is electrically connected with the fourth end of the control module, the first end of the fourth optical coupler in the second switch module is electrically connected with the second grounding end, the second end of the fourth optical coupler in the second switch module is electrically connected with the first end of the second resistor, the second end of the second resistor is electrically connected with the first end of the second voltage dividing resistor, the second end of the second voltage dividing resistor is electrically connected with the negative electrode of the power supply, the first end of the second voltage dividing resistor is electrically connected with the first end of the second filter amplification module, the second end of the second filter amplification module is electrically connected with the first end of the second analog-to-digital conversion module, and the second end of the second analog-to-digital conversion module is electrically connected with the fifth end of the control module.

According to the embodiment of the utility model, the positive electrode detection module is connected to the two ends of the positive resistor, the output end of the positive electrode detection module is electrically connected with the first input end of the control module, and the positive electrode detection module outputs the voltage values of the two ends of the first divider resistor to the control module; the negative electrode detection module is connected to two ends of the negative resistor, the output end of the negative electrode detection module is electrically connected with the second input end of the control module, and the negative electrode detection module outputs voltage values of two ends of the second voltage dividing resistor to the control module; the control module calculates the resistance value of the positive resistance according to the first closing voltage, the second closing voltage and the first open-circuit voltage, or calculates the resistance value of the negative resistance according to the first closing voltage, the second closing voltage and the second open-circuit voltage, so that the measurement accuracy of the positive resistance or the negative resistance is improved.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the utility model or to delineate the scope of the utility model. Other features of the present utility model will become apparent from the description that follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of an insulation detection device according to an embodiment of the present utility model;

fig. 2 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model;

fig. 3 is a schematic structural view of still another insulation detection device according to an embodiment of the present utility model;

fig. 4 is a schematic structural view of still another insulation detection device according to an embodiment of the present utility model;

fig. 5 is a schematic structural view of another insulation detection device according to an embodiment of the present utility model;

fig. 6 is a schematic structural view of still another insulation detection device according to an embodiment of the present utility model;

fig. 7 is a schematic circuit connection diagram of a first switch module of an insulation detection device according to an embodiment of the present utility model;

fig. 8 is a schematic structural view of another insulation detection device according to an embodiment of the present utility model;

fig. 9 is a schematic circuit connection diagram of a first filtering amplifying module of an insulation detection device according to an embodiment of the present utility model;

fig. 10 is a schematic structural view of still another insulation detection device according to an embodiment of the present utility model;

fig. 11 is a schematic structural view of still another insulation detection device according to an embodiment of the present utility model;

Fig. 12 is a schematic structural view of another insulation detection device according to an embodiment of the present utility model;

fig. 13 is a schematic structural diagram of a second analog-to-digital conversion module in an insulation detection device according to an embodiment of the present utility model.

Detailed Description

In order that those skilled in the art will better understand the present utility model, a technical solution in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, shall fall within the scope of the present utility model.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present utility model and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1, the insulation detection device is used for detecting insulation resistance values of an energy storage system, the energy storage system comprises a power supply Q, a positive resistor Rp and a negative resistor Rn, a positive electrode of the power supply Q is electrically connected with a first end of the positive resistor Rp, a negative electrode of the power supply Q is electrically connected with a second end of the negative resistor Rn, the second end of the positive resistor Rp is electrically connected with a first end of the negative resistor Rn, and a second end of the positive resistor Rp is connected with a ground GND 1; the power supply Q, the positive resistor Rp and the negative resistor Rn are sequentially connected in series, a first node is arranged between the positive resistor Rp and the negative resistor Rn, and the ground GND1 is connected with the first node;

the insulation detection device includes:

the positive electrode detection module J1, the negative electrode detection module J2 and the control module K;

the positive electrode detection module J1 comprises a first resistor Rp1, a first voltage dividing resistor Rps and a first switch module Sp, wherein the first resistor Rp1, the first voltage dividing resistor Rps and the first switch module Sp are connected in series; the negative electrode detection module J2 comprises a second resistor Rn1, a second voltage-dividing resistor Rns and a second switch module Sn, and the second resistor Rn1, the second voltage-dividing resistor Rns and the second switch module Sn are connected in series;

The positive electrode detection module J1 is connected to two ends of the positive resistor Rp, and the output end of the positive electrode detection module Rp is electrically connected with the first input end of the control module K and is used for outputting voltage values of two ends of the first divider resistor Rps to the control module K;

the negative electrode detection module J2 is connected to two ends of the negative resistor Rn, and the output end of the negative electrode detection module J2 is electrically connected with the second input end of the control module K and is used for outputting voltage values of two ends of the second voltage dividing resistor Rns to the control module K;

the control module K is used for calculating the resistance value of the positive resistance Rp according to the first closing voltage, the second closing voltage and the first open circuit voltage, or calculating the resistance value of the negative resistance Rn according to the first closing voltage, the second closing voltage and the second open circuit voltage; the first closing voltage is a voltage value of two ends of the first divider resistor Rps when the first switch module Sp and the second switch module Sn are closed at the same time; the second closing voltage is a voltage value of two ends of the second voltage dividing resistor Rns when the first switch module Sp and the second switch module Sn are simultaneously closed; the first open-circuit voltage is a voltage value at two ends of the first divider resistor Rps when the first switch module Sp is closed and the second switch module Sn is opened; the second open-circuit voltage is a voltage value across the second voltage dividing resistor Rns when the first switch module Sp is opened and the second switch module Sn is closed.

The leakage resistance is understood to be the resistance corresponding to the leakage current flowing through the insulating medium between the power bus and the ground GND1 by applying a dc voltage between the power bus and the ground GND 1.

Specifically, when the battery management system does not work, the first switch module Sp and the second switch module Sn in the insulation detection device are in an off state, at this time, the ground resistance of the detection loop in the insulation detection device is far greater than 2MΩ, and meanwhile, the ground voltage of the positive electrode of the power supply Q and the ground voltage of the negative electrode of the power supply Q are lower than the safety voltage of a human body by 36V, at this time, electric shock can be effectively prevented, and good safety guarantee is provided for maintenance operation of the battery management system. When the battery management system works, the insulation detection device is in a working state, and the control module K is used for controlling the first switch module Sp and the second switch module Sn to be closed simultaneously, so that the first closing voltage at two ends of the first divider resistor Rps and the second closing voltage at two ends of the second divider resistor Rns are determined; and comparing the first closing voltage with the second closing voltage through the control module K, and determining and calculating the resistance value of the positive resistor Rp or the resistance value of the negative resistor Rn according to the comparison result of the first closing voltage and the second closing voltage. If the resistance value of the positive resistor Rp is determined to be calculated, the first switch module Sp is required to be closed, the second switch module Sn is required to be opened, the first open-circuit voltage at two ends of the first divider resistor Rps at the moment is determined, and the resistance value of the positive resistor Rp is calculated according to the first closed-circuit voltage, the second closed-circuit voltage and the first open-circuit voltage; if the resistance value of the negative resistance Rn is determined to be calculated, the first switch module Sp is opened, the second switch module Sn is closed, the second open-circuit voltage at the two ends of the second voltage dividing resistor Rns is determined, and the resistance value of the negative resistance Rn is calculated according to the first closed-circuit voltage, the second closed-circuit voltage and the second open-circuit voltage.

According to the embodiment of the utility model, the positive electrode detection module J1 is connected to the two ends of the positive resistor Rp, the output end of the positive electrode detection module Rp is electrically connected with the first input end of the control module K, and the positive electrode detection module Rp outputs the voltage values of the two ends of the first divider resistor Rps to the control module K; the negative electrode detection module J2 is connected to two ends of the negative resistor Rn, the output end of the negative electrode detection module J2 is electrically connected with the second input end of the control module K, and the negative electrode detection module J2 outputs voltage values of two ends of the second voltage dividing resistor Rns to the control module K; the control module K calculates the resistance value of the positive resistance Rp according to the first closing voltage, the second closing voltage and the first open circuit voltage, or calculates the resistance value of the negative resistance Rn according to the first closing voltage, the second closing voltage and the second open circuit voltage, so that the measurement accuracy of the positive resistance Rp or the negative resistance Rn is improved.

Optionally, referring to fig. 1, the control module K is further configured to determine, according to a comparison result of the first closing voltage and the second closing voltage, to calculate a resistance value of the positive resistor Rp or a resistance value of the negative resistor Rn.

Specifically, the control module K determines, according to the comparison result of the first closing voltage and the second closing voltage, that the resistance value of the calculated positive resistor Rp is greater than the resistance value of the negative resistor Rn, and calculates the resistance value of the negative resistor Rn when determining that the resistance value of the calculated positive resistor Rp is less than the resistance value of the negative resistor Rn.

For example, under the condition that the resistance value of the first voltage dividing resistor Rps is equal to the resistance value of the second voltage dividing resistor Rns and the resistance value of the first resistor Rp1 is equal to the resistance value of the second resistor Rn1, if the first closing voltage is greater than the second closing voltage, it is indicated that when the first switch module Sp and the second switch module Sn are simultaneously closed, the voltage values at two ends of the first voltage dividing resistor Rps are greater than the voltage value of the second voltage dividing resistor Rns, at this time, it is indicated that the voltage values at two ends of the positive resistor Rp are greater than the voltage values at two ends of the negative resistor Rn, at this time, the resistance value of the positive resistor Rp is greater than the resistance value of the negative resistor Rn, and if the resistance value of the negative resistor Rn obtained by detection meets the detection requirement of the insulation resistor, the resistance value of the positive resistor Rp must meet the detection requirement of the insulation resistor, at this time, only the resistance value of the negative resistor Rn is calculated; if the first closing voltage is smaller than the second closing voltage, it is indicated that when the first switch module Sp and the second switch module Sn are simultaneously closed, the voltage values at two ends of the first voltage dividing resistor Rps are smaller than the voltage value of the second voltage dividing resistor Rns, and at this time, the voltage values at two ends of the positive resistor Rp are smaller than the voltage values at two ends of the negative resistor Rn, which is indicated that the resistance value of the positive resistor Rp at this time is smaller than the resistance value of the negative resistor Rn, and if the resistance value of the positive resistor Rp obtained through detection meets the detection requirement of the insulation resistor, the resistance value of the negative resistor Rn must meet the detection requirement of the insulation resistor, and only the resistance value of the positive resistor Rp is calculated at this time.

Optionally, referring to fig. 1, the control module K is configured to control the second switch module Sn to be opened, control the first switch module Sp to be closed, and obtain a first open-circuit voltage when it is determined that the resistance value of the positive resistor Rp is smaller than the resistance value of the negative resistor Rn according to the first closed voltage and the second closed voltage, and calculate the resistance value of the positive resistor Rp according to the first closed voltage, the second closed voltage, and the first open-circuit voltage; or when the resistance value of the positive resistor Rp is larger than the resistance value of the negative resistor Rn according to the first closing voltage and the second closing voltage, the first switch module Sp is controlled to be opened, the second switch module Sn is controlled to be closed, the second open circuit voltage is obtained, and the resistance value of the negative resistor is calculated according to the first closing voltage, the second closing voltage and the second open circuit voltage.

Specifically, let the first closed voltage be Up, the second closed voltage be Un, the first open voltage be Up ', the second open voltage be Un', and the voltage at both ends of the power supply Q be SumV.

Fig. 2 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model; as shown in fig. 2, when the first switch module Sp and the second switch module Sn are simultaneously closed, the first KCL equation is obtained as follows:

(Up/Rps*Rp1+Up)/Rp+Up/Rps＝(Un/Rns*Rn1+Un)/Rn+Un/Rns；

(1) Fig. 3 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model, as shown in fig. 3, when it is determined that the resistance value of the positive resistor Rp is smaller than the resistance value of the negative resistor Rn according to the first closing voltage Up and the second closing voltage Un, the second switch module Sn is controlled to be opened, the first switch module Sp is controlled to be closed, and a first open circuit voltage Up 'is obtained, and if the first open circuit voltage Up' is not zero, the obtained second KCL equation is:

(Up'/Rps*Rp1+Up')/Rp+Up'/Rps＝(SumV-Up'/Rps*Rp1-Up')/Rn；

calculating the resistance value of the positive resistor according to the first KCL equation and the second KCL equation:

Rp＝[(Rps+Rp1)Up*SumV-(Rps*Rp1+Rp1*Rp1+Rps*Rps+Rps*Rp1)Up*Up'/100Rps-(Rns*Rp1+Rn1*Rp1+Rns*Rps+Rps*Rn1)Un*Up'/100Rns]/[(Rps+Rp1)*Up*Up'/100Rps+Un*Up'/100-Un*Up'*Rps/100Rns+Un*Up'*Rn1/100Rns-Un*Up'*Rp1/100Rns+Rps*Un*SumV/Rns-Up*SumV]。

fig. 4 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model, as shown in fig. 4, if the first open circuit voltage Up' is zero, the negative resistance Rn is infinity or the negative resistance Rn is open, and at this time, the third KCL equation is obtained:

(Up/Rps*Rp1+Up)/Rp+Up/Rps＝Un/Rns；

calculating the resistance value of the positive resistor according to the first KCL equation and the third KCL equation:

Rp＝(Rps*Rns+Rns*Rp1)Up/(Un*Rps-Up*Rns)。

(2) Fig. 5 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model, as shown in fig. 5, when it is determined that the resistance value of the positive resistor Rp is greater than the resistance value of the negative resistor Rn according to the first closing voltage Up and the second closing voltage Un, the first switch module Sp is controlled to be opened, the second switch module Sn is controlled to be closed, and a second open circuit voltage Un 'is obtained, and if the second open circuit voltage Un' is not zero, a fourth KCL equation is obtained:

(Un'/Rns*Rn1+Un')/Rn+Un'/Rns＝(SumV-Un'/Rns*Rn1-Un')/Rp；

Calculating the resistance value of the negative resistance Rn according to the first KCL equation and the fourth KCL equation:

Rn＝[(Rps+Rp1)Un*SumV-(Rps*Rp1+Rp1*Rp1+Rps*Rps+Rps*Rp1)Un*Un'/100Rps-(Rns*Rp1+Rn1*Rp1+Rns*Rps+Rps*Rn1)Up*Un'/100Rns]/[(Rps+Rp1)Un*Un'/100Rps+Up*Un'/100-Up*Un'*Rps/100Rns+Up*Un'*Rn1/100Rns-Up*Un'*Rp1/100Rns+Rps*Up*SumV/Rns-Un*SumV]；

fig. 6 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model, as shown in fig. 6, if the second open circuit voltage Un' is zero, the positive resistance Rp is infinite or the positive resistance Rp is open, and at this time, the fifth KCL equation is obtained as follows:

(Un/Rns*Rn1+Un)/Rn+Un/Rns＝Up/Rps；

calculating the resistance value of the negative resistance according to the first KCL equation and the fifth KCL equation:

Rn＝(Rps*Rns+Rps*Rn1)Un/(Up*Rns-Un*Rps)。

fig. 7 is a schematic circuit connection diagram of a first switch module of an insulation detection device according to an embodiment of the present utility model, and optionally, referring to fig. 7, the first switch module Sp includes:

the third resistor R1, the fourth resistor R2, the fifth resistor R3, the sixth resistor R4, the seventh resistor R5, the eighth resistor R6, the ninth resistor R7, the first transistor Q1, the second transistor Q2, the first optocoupler U1, the second optocoupler U2 and the magnetic bead FB;

the first end of the control module is electrically connected with the first end of a third resistor R1 and the first end of a fourth resistor R2, the second end of the third resistor R1 is electrically connected with the first end of a first transistor Q1, the second end of the fourth resistor R2 is electrically connected with the second end of the first transistor Q1 and a first grounding end GND, the third end of the first transistor Q1 is electrically connected with the second end of a first optocoupler U1, a first power end VCC is electrically connected with the first end of a fifth resistor R3, the second end of the fifth resistor R3 is electrically connected with the first end of the first optocoupler U1, the second power end VCC1 is electrically connected with the fourth end of the first optocoupler U1, and the third end of the first optocoupler U1 is electrically connected with the first end of an eighth resistor R6 and the first end of a ninth resistor R7;

The first end of the sixth resistor R4 and the first end of the seventh resistor R5 are connected with the second power supply end VCC1, the second end of the sixth resistor R4 is electrically connected with the first end of the second optocoupler U2, the second end of the seventh resistor R5 is electrically connected with the second end of the second optocoupler U2, the second end of the eighth resistor R6 is electrically connected with the first end of the second transistor Q2, the second end of the ninth resistor R7 is electrically connected with the second end of the second transistor Q2, the second end of the second transistor Q2 is electrically connected with the second ground end GND2, the second end of the second transistor Q2 is electrically connected with the first end of the magnetic bead FB, and the second end of the magnetic bead FB is electrically connected with the reference ground GND 1; the third end of the second transistor Q2 is electrically connected with the second optocoupler U2; the third end of the second optocoupler U2 is electrically connected to the second end of the first resistor Rp1, and the fourth end of the second optocoupler U2 is electrically connected to the first end of the first divider resistor Rps.

Specifically, when the control module determines that the resistance value of the positive resistor is calculated, a high level signal needs to be sent to the first switch module Sp, after the first switch module Sp receives the high level signal sent by the control module, the first transistor Q1 is turned on electrically, so that the first power supply end VCC, the fifth resistor R3, the light emitting diode in the first optocoupler U1, the first transistor Q1 and the first ground end GND are turned on to form a closed loop, at this time, the light emitting diode in the first optocoupler U1 is turned on electrically, so that the second power supply end VCC1, the first optocoupler U1, the ninth resistor R7 and the second ground end GND2 are turned on to form a closed loop, the second transistor Q2 receives the high level signal, so that the second transistor Q2 is turned on, at this time, the second power supply end VCC1, the sixth resistor R4, the light emitting diode in the second optocoupler U2, the second transistor Q2 and the second ground end GND2 are turned on to form a closed loop, at this time, the light emitting diode in the second optocoupler U2 is turned on to cause the second power supply end VCC1, the first resistor Rp and the first resistor Rp to be connected in series to form a positive voltage detection module Rp.

Fig. 8 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model, and optionally, referring to fig. 8, the positive electrode detection module further includes:

a first filter amplification module 10 and a first analog-to-digital conversion module 20;

the first end of the first switch module Sp is electrically connected with the first end of the control module K, the second end of the first switch module Sp is electrically connected with the second end of the first resistor Rp1, the first end of the first resistor Rp1 is electrically connected with the positive electrode of the power supply, the third end of the first switch module Sp is electrically connected with the first end of the first voltage dividing resistor Rps, the second end of the first voltage dividing resistor Rps is electrically connected with the second ground end GND2, the first end of the first voltage dividing resistor Rps is electrically connected with the first end of the first filter amplification module 10, the second end of the first filter amplification module 10 is electrically connected with the first end of the first analog-to-digital conversion module 20, the second end of the first analog-to-digital conversion module 20 is electrically connected with the second end of the control module K, and the third end of the first analog-to-digital conversion module 20 is electrically connected with the third end of the control module K.

The first resistor Rp1 may be formed by a plurality of resistors connected in series, and the first resistor Rp1 may be formed by 4 resistors having the same resistance value connected in series.

Specifically, when the control module K determines to calculate the resistance value of the positive resistor, a high-level signal is sent to the first switch module Sp, and after the first switch module Sp receives the high-level signal sent by the control module, the positive electrode of the power supply, the first resistor Rp1, the first voltage dividing resistor Rps and the second ground end GND2 are conducted to form a closed loop, and meanwhile, an analog-digital conversion module opening signal is sent to the first analog-digital conversion module 20 to control the first analog-digital conversion module 20 to open. The first switch module Sp is closed to enable the voltages at two ends of the first voltage dividing resistor Rps to be transmitted to the first filtering and amplifying module 10, the first filtering and amplifying module 10 is used for carrying out filtering processing and amplifying processing on the analog signals of the voltages at two ends of the first voltage dividing resistor Rps, the processed analog signals are transmitted to the first analog-digital conversion module 20, the analog signals of the voltages at two ends of the first voltage dividing resistor Rps are converted into digital signals, the digital signals processed by the first analog-digital conversion module 20 are transmitted to the control module K to be subjected to calculation processing, and finally the resistance value of the positive resistor is calculated. Because the analog signal is processed by the first filtering and amplifying module 10, the interference signal in the analog signal can be effectively removed, so that the resistance value of the positive resistor calculated by the control module K is more accurate.

Fig. 9 is a schematic circuit connection diagram of a first filtering and amplifying module of an insulation detection device according to an embodiment of the present utility model, and optionally, referring to fig. 9, the first filtering and amplifying module includes:

a tenth resistor R8, an eleventh resistor R9, a twelfth resistor R10, a thirteenth resistor R11, a fourteenth resistor R12, a fifteenth resistor R13, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a dual operational amplifier U3;

the first end of the first voltage dividing resistor is electrically connected with the first end of a tenth resistor R8, the second end of the tenth resistor R8 is electrically connected with the first end of an eleventh resistor R9 and the first end of a first capacitor C1, the second end of the first capacitor C1 is electrically connected with the first end 1 and the second end 2 of a double operational amplifier U3, the second end of the eleventh resistor R9 is electrically connected with the third end 3 of the double operational amplifier U3, the second end 2 of the eleventh resistor R9 is electrically connected with the first end of a second capacitor C2, and the second end of the second capacitor C2 is electrically connected with the fourth end of the double operational amplifier U3 and a second grounding end GND 2;

the fifth end 5 of the double operational amplifier U3 is electrically connected with the first end of the twelfth resistor R10, the sixth end 6 of the double operational amplifier U3 is electrically connected with the first end of the thirteenth resistor R11, the second end of the twelfth resistor R10 is electrically connected with the first end 1 of the double operational amplifier U3, the second end of the thirteenth resistor R11 is electrically connected with the second grounding end GND2, the seventh end of the double operational amplifier U3 is electrically connected with the first end of the fourteenth resistor R12 and the first end of the fifteenth resistor R13, the second end of the fourteenth resistor R12 is electrically connected with the sixth end 6 of the double operational amplifier U3, the second end of the fifteenth resistor R13 is electrically connected with the first end of the fifth capacitor C5 and the first end of the first analog-to-digital conversion module, and the second end of the fifth capacitor C5 is electrically connected with the second grounding end GND 2;

The eighth terminal 8 of the dual operational amplifier U3 is electrically connected to the second power terminal VCC1, the first terminal of the third capacitor C3 and the first terminal of the fourth capacitor C4 are electrically connected to the second power terminal VCC1, and the second terminal of the third capacitor C3 and the second terminal of the fourth capacitor C4 are electrically connected to the second ground terminal GND 2.

Specifically, after the voltage signals at two ends of the first voltage dividing resistor Rps are transmitted to the first filtering amplifying module, the voltage signals enter the third end 3 of the dual operational amplifier U3 through a tenth resistor R8 and an eleventh resistor R9, the voltage signals are filtered to form voltage signals without interference signals, the voltage signals without interference signals are input to the fifth end 5 of the dual operational amplifier U3 through a twelfth resistor R10 from the first end 1 of the dual operational amplifier U3, and the voltage signals without interference signals are amplified and then transmitted to the first analog-digital conversion module through a fifteenth resistor R13.

Fig. 10 is a schematic structural diagram of still another insulation detection device according to an embodiment of the present utility model, and optionally, referring to fig. 10, the first analog-to-digital conversion module 20 includes:

a digital-to-analog conversion unit 21 and a switching unit 22;

the first end of the digital-to-analog conversion unit 21 is electrically connected with the second end of the first filtering and amplifying module 10, the second end of the digital-to-analog conversion unit 21 is electrically connected with the second end of the control module K, the third end of the digital-to-analog conversion unit 21 is electrically connected with the first end of the switch unit 22, and the second end of the switch unit 22 is electrically connected with the third end of the control module K.

Specifically, the control module K sends a high-level signal to the first switch module Sp, and at the same time, the control module K sends an analog-to-digital conversion module opening signal to the first analog-to-digital conversion module 20, and controls the switch unit 22 to be closed, so that the first analog-to-digital conversion unit 21 starts to work, converts an analog signal transmitted from the first filter amplification module 10 to the first analog-to-digital conversion unit 21 into a digital signal, and transmits the digital signal to the control module K for calculation processing, and finally calculates the resistance value of the positive resistor.

Fig. 11 is a schematic structural diagram of still another insulation detection device according to an embodiment of the present utility model, and optionally, referring to fig. 11, the digital-to-analog conversion unit 21 includes:

an a/D converter U4, a sixth capacitor C6, and a seventh capacitor C7;

the seventh end 7 and the eighth end 8 of the a/D converter U4 are electrically connected to the second power supply end VCC1, the fifth end 5 and the sixth end 6 of the a/D converter U4 are electrically connected to the second ground end GND2, the fourth end 4 of the a/D converter U4 is electrically connected to the first end of the sixth capacitor C6 and the first end of the seventh capacitor C7, the fourth end 4 of the a/D converter U4 is electrically connected to the second end of the fifteenth resistor and the first end of the fifth capacitor, the second end of the sixth capacitor C6 and the second end of the seventh capacitor C7 are electrically connected to the second ground end GND2, the third end 3 of the a/D converter U4 is electrically connected to the second ground end GND2, the second end 2 of the a/D converter U4 is electrically connected to the first end of the switching unit 22, and the first end 1, the ninth end 9 and the tenth end 10 of the a/D converter U4 are electrically connected to the second end of the control module.

Specifically, under the condition that the switch unit 22 is closed, the second end 2 of the a/D converter U4 receives a high-level signal, so as to trigger the a/D converter U4 to start to operate, the analog signal processed by the first filtering and amplifying module is transmitted from the fourth end of the a/D converter U4, and after analog-to-digital conversion in the a/D converter U4, the analog signal is transmitted to the control module through the first end 1, the ninth end 9 and the tenth end 10 of the a/D converter U4 to be calculated, and finally, the resistance of the positive resistor is calculated.

Optionally, with continued reference to fig. 11, the switching unit 22 includes:

a sixteenth resistor R14, a seventeenth resistor R15, an eighteenth resistor R16, a nineteenth resistor R17, a third transistor Q3, and a third optocoupler U5;

the third end of the control module is electrically connected to the first end of the sixteenth resistor R14 and the first end of the seventeenth resistor R15, the second end of the seventeenth resistor R15 is electrically connected to the first end of the third transistor Q3, the second end of the sixteenth resistor R14 is electrically connected to the second end of the third transistor Q3 and the first ground GND, the third end of the third transistor Q3 is electrically connected to the second end of the third optocoupler U5, the first power supply end VCC is electrically connected to the first end of the eighteenth resistor R16, the second end of the eighteenth resistor R16 is electrically connected to the first end of the third optocoupler U5, the second power supply end VCC1 is electrically connected to the first end of the nineteenth resistor R17, the second end of the nineteenth resistor R17 is electrically connected to the fourth end of the third optocoupler U5, the third end of the third optocoupler U5 is electrically connected to the second ground GND2, and the fourth end of the third optocoupler U5 is electrically connected to the second end 2 of the a/D converter U4.

Specifically, the control module sends a high-level signal to the first switch module, and at the same time, the control module sends an analog-to-digital conversion module opening signal to the switch unit 22, after the switch unit 22 receives the analog-to-digital conversion module opening signal, the third transistor Q3 is electrically conducted, so that the first power supply end VCC, the eighteenth resistor R16, the light emitting diode in the third optocoupler U5, the third transistor Q3 and the first ground end GND are conducted to form a closed loop, and at the moment, the light emitting diode in the third optocoupler U5 is electrically lighted, so that the second power supply end VCC1, the third optocoupler U5, the nineteenth resistor R17 and the second ground end GND2 are conducted to form a closed loop, and further, the starting of the a/D converter U4 is triggered to open.

Fig. 12 is a schematic structural diagram of another insulation detection device according to an embodiment of the present utility model, and optionally, referring to fig. 12, the negative electrode detection module further includes:

a second filter amplification module 100 and a second analog-to-digital conversion module 200;

the second switch module Sn comprises a fourth optocoupler U6;

the first end of the second switch module Sn is electrically connected to the fourth end of the control module K, the first end of the fourth optocoupler U6 in the second switch module Sn is electrically connected to the second ground end GND2, the second end of the fourth optocoupler U6 in the second switch module Sn is electrically connected to the first end of the second resistor Rn1, the second end of the second resistor Rn1 is electrically connected to the first end of the second voltage dividing resistor Rns, the second end of the second voltage dividing resistor Rns is electrically connected to the negative electrode O of the power supply, the first end of the second voltage dividing resistor Rns is electrically connected to the first end of the second filter amplifier module 100, the second end of the second filter amplifier module 100 is electrically connected to the first end of the second analog-to-digital converter module 200, and the second end of the second analog-to-digital converter module 200 is electrically connected to the fifth end of the control module K.

The second resistor Rn1 may be formed by connecting a plurality of resistors in series, and for example, the second resistor Rn1 may be formed by connecting 4 resistors having the same resistance value in series. The second switch module Sn is identical to the circuit of the first switch module.

Specifically, when determining to calculate the resistance value of the negative resistance, the control module K sends a high-level signal to the first switch module Sn, and after receiving the high-level signal sent by the control module K, the first switch module Sp makes the negative electrode O of the power supply, the second resistor Rn1, the second voltage dividing resistor Rns and the second ground GND2 conductive to form a closed loop. The first switch module Sn is closed so that the voltages at two ends of the second voltage dividing resistor Rns are transmitted to the second filtering and amplifying module 100, the second filtering and amplifying module 100 performs filtering processing and amplifying processing on the analog signals of the voltages at two ends of the second voltage dividing resistor Rns, the processed analog signals are transmitted to the second analog-to-digital conversion module 200, the analog signals of the voltages at two ends of the second voltage dividing resistor Rns are converted into digital signals, and the digital signals processed by the second analog-to-digital conversion module 200 are transmitted to the control module K for calculation processing, so that the resistance value of the negative resistor is finally calculated. Because the analog signal is processed by the first filtering and amplifying module 100, the interference signal in the analog signal can be effectively removed, so that the resistance value of the positive resistor calculated by the control module K is more accurate.

Fig. 13 is a schematic structural diagram of a second analog-to-digital conversion module in an insulation detection device according to an embodiment of the present utility model, referring to fig. 13, a processed analog signal is transmitted to the second analog-to-digital conversion module through a pin a, an analog signal of voltages at two ends of a second voltage dividing resistor is converted into a digital signal, the digital signal processed by the second analog-to-digital conversion module is transmitted to a control module through a pin b for calculation, and finally, a resistance value of a negative resistor is calculated.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present utility model may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present utility model are achieved, and the present utility model is not limited herein.

The above embodiments do not limit the scope of the present utility model. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included in the scope of the present utility model.

Claims (10)

1. An insulation detection device is used for detecting an insulation resistance value of an energy storage system, wherein the energy storage system comprises a power supply, a positive resistor and a negative resistor, the power supply, the positive resistor and the negative resistor are sequentially connected in series, a first node is arranged between the positive resistor and the negative resistor, and the first node is connected with reference ground;

the insulation detection device is characterized by comprising:

the device comprises an anode detection module, a cathode detection module and a control module;

the positive electrode detection module comprises a first resistor, a first voltage dividing resistor and a first switch module, and the first resistor, the first voltage dividing resistor and the first switch module are connected in series; the negative electrode detection module comprises a second resistor, a second voltage-dividing resistor and a second switch module, and the second resistor, the second voltage-dividing resistor and the second switch module are connected in series;

the positive electrode detection module is connected to two ends of the positive resistor and is used for outputting voltage values of two ends of the first divider resistor to the control module;

the negative electrode detection module is connected to two ends of the negative resistor and is used for outputting voltage values of two ends of the second voltage dividing resistor to the control module;

The control module is used for calculating the resistance value of the positive resistor according to a first closed voltage, a second closed voltage and a first open circuit voltage or calculating the resistance value of the negative resistor according to the first closed voltage, the second closed voltage and the second open circuit voltage; the first closing voltage is a voltage value of two ends of the first voltage dividing resistor when the first switch module and the second switch module are closed simultaneously; the second closing voltage is a voltage value of two ends of the second voltage dividing resistor when the first switch module and the second switch module are closed simultaneously; the first open-circuit voltage is a voltage value at two ends of the first voltage dividing resistor when the first switch module is closed and the second switch module is opened; the second open-circuit voltage is a voltage value of two ends of the second voltage dividing resistor when the first switch module is opened and the second switch module is closed.

2. The insulation detection device according to claim 1, wherein the control module is further configured to determine to calculate a resistance value of the positive resistance or a resistance value of the negative resistance according to a comparison result of the first closing voltage and the second closing voltage.

3. The insulation detection apparatus according to claim 2, wherein the control module is configured to control the second switch module to be opened, control the first switch module to be closed, and acquire the first open circuit voltage when it is determined that the resistance value of the positive resistor is smaller than the resistance value of the negative resistor according to the first closing voltage and the second closing voltage, and calculate the resistance value of the positive resistor according to the first closing voltage, the second closing voltage, and the first open circuit voltage; or when the resistance value of the positive resistor is determined to be larger than the resistance value of the negative resistor according to the first closing voltage and the second closing voltage, controlling the first switch module to be opened, controlling the second switch module to be closed, acquiring the second open-circuit voltage, and calculating the resistance value of the negative resistor according to the first closing voltage, the second closing voltage and the second open-circuit voltage.

4. The insulation detection device of claim 1, wherein the first switch module comprises:

the device comprises a fourth resistor, a seventh resistor, a ninth resistor, a first transistor, a second transistor, a first optocoupler, a second optocoupler and magnetic beads;

The first end of the control module is electrically connected with the first end of the first transistor and the first end of the fourth resistor, the second end of the fourth resistor is electrically connected with the second end of the first transistor and the first grounding end, the third end of the first transistor is electrically connected with the second end of the first optocoupler, the first power end is electrically connected with the first end of the first optocoupler, the second power end is electrically connected with the fourth end of the first optocoupler, and the third end of the first optocoupler is electrically connected with the first end of the second transistor and the first end of the ninth resistor;

the first end of the second optocoupler and the first end of the seventh resistor are connected with the second power supply end, the second end of the seventh resistor is electrically connected with the second end of the second optocoupler, the second end of the ninth resistor is electrically connected with the second end of the second transistor, the second end of the second transistor is electrically connected with the second grounding end, the second end of the second transistor is electrically connected with the first end of the magnetic bead, and the second end of the magnetic bead is electrically connected with the reference; the third end of the second transistor is electrically connected with the second optical coupler; the third end of the second optocoupler is electrically connected with the second end of the first resistor, and the fourth end of the second optocoupler is electrically connected with the first end of the first voltage dividing resistor.

5. The insulation detection device according to claim 4, wherein the positive electrode detection module further comprises:

the first filter amplification module and the first analog-to-digital conversion module;

the first end of the first switch module is electrically connected with the first end of the control module, the second end of the first switch module is electrically connected with the second end of the first resistor, the first end of the first resistor is electrically connected with the positive electrode of the power supply, the third end of the first switch module is electrically connected with the first end of the first voltage dividing resistor, the second end of the first voltage dividing resistor is electrically connected with the second grounding end, the first end of the first voltage dividing resistor is electrically connected with the first end of the first filter amplification module, the second end of the first filter amplification module is electrically connected with the first end of the first analog-to-digital conversion module, the second end of the first analog-to-digital conversion module is electrically connected with the second end of the control module, and the third end of the first analog-to-digital conversion module is electrically connected with the third end of the control module.

6. The insulation detection device of claim 5, wherein the first filter amplification module comprises:

an eleventh resistor, a thirteenth resistor, a fourteenth resistor, a first capacitor, a second capacitor and a dual operational amplifier;

The first end of the first voltage dividing resistor is electrically connected with the first end of the eleventh resistor and the first end of the first capacitor, the second end of the first capacitor is electrically connected with the first end and the second end of the dual operational amplifier, the second end of the eleventh resistor is electrically connected with the third end of the dual operational amplifier, the second end of the eleventh resistor is electrically connected with the first end of the second capacitor, and the second end of the second capacitor is electrically connected with the fourth end of the dual operational amplifier and the second grounding end;

the fifth end of the dual operational amplifier is electrically connected with the first end of the dual operational amplifier, the sixth end of the dual operational amplifier is electrically connected with the first end of the thirteenth resistor, the second end of the thirteenth resistor is electrically connected with the second grounding end, the seventh end of the dual operational amplifier is electrically connected with the first end of the fourteenth resistor, the second end of the fourteenth resistor is electrically connected with the sixth end of the dual operational amplifier, and the seventh end of the dual operational amplifier is electrically connected with the second grounding end and the first end of the first analog-to-digital conversion module; the eighth end of the dual operational amplifier is electrically connected with the second power supply end.

7. The insulation detection device of claim 5, wherein the first analog-to-digital conversion module comprises:

a digital-to-analog conversion unit and a switch unit;

the first end of the digital-to-analog conversion unit is electrically connected with the second end of the first filtering and amplifying module, the second end of the digital-to-analog conversion unit is electrically connected with the second end of the control module, the third end of the digital-to-analog conversion unit is electrically connected with the first end of the switch unit, and the second end of the switch unit is electrically connected with the third end of the control module.

8. The insulation detection apparatus according to claim 7, wherein the digital-to-analog conversion unit includes:

an a/D converter, a sixth capacitor, and a seventh capacitor;

the seventh end and the eighth end of the A/D converter are electrically connected with a second power supply end, the fifth end and the sixth end of the A/D converter are electrically connected with a second grounding end, the fourth end of the A/D converter is electrically connected with the first end of the sixth capacitor and the first end of the seventh capacitor, the fourth end of the A/D converter is electrically connected with the second end of the fifteenth resistor and the first end of the fifth capacitor, the second end of the sixth capacitor and the second end of the seventh capacitor are electrically connected with the second grounding end, the third end of the A/D converter is electrically connected with the second grounding end, the second end of the A/D converter is electrically connected with the first end of the switch unit, and the first end, the ninth end and the tenth end of the A/D converter are electrically connected with the second end of the control module.

9. The insulation detection apparatus according to claim 7, wherein the switching unit includes:

a sixteenth resistor, a third transistor and a third optocoupler;

the third end of the control module is electrically connected with the first end of the sixteenth resistor and the first end of the third transistor, the second end of the sixteenth resistor is electrically connected with the second end of the third transistor and the first grounding end, the third end of the third transistor is electrically connected with the second end of the third optocoupler, the first power end is electrically connected with the first end of the third optocoupler, the second power end is electrically connected with the fourth end of the third optocoupler, the third end of the third optocoupler is electrically connected with the second grounding end, and the fourth end of the third optocoupler is electrically connected with the second end of the A/D converter.

10. The insulation detection device according to claim 1, wherein the negative electrode detection module further comprises:

the second filtering and amplifying module and the second analog-to-digital conversion module;

the second switch module comprises a fourth optical coupler;

the first end of the second switch module is electrically connected with the fourth end of the control module, the first end of the fourth optical coupler in the second switch module is electrically connected with the second grounding end, the second end of the fourth optical coupler in the second switch module is electrically connected with the first end of the second resistor, the second end of the second resistor is electrically connected with the first end of the second voltage dividing resistor, the second end of the second voltage dividing resistor is electrically connected with the negative electrode of the power supply, the first end of the second voltage dividing resistor is electrically connected with the first end of the second filter amplification module, the second end of the second filter amplification module is electrically connected with the first end of the second analog-to-digital conversion module, and the second end of the second analog-to-digital conversion module is electrically connected with the fifth end of the control module.