Efficient insulation electric leakage detection circuit and insulation electric leakage detection method

[0093] Such as figure 1 , figure 2 Shown: the insulation leakage detection method adopting the above technical scheme, the specific method is as follows:

[0094] Step S01: Insulation testing starts

[0095] Step S02: Confirm that the switches J1~J5 are all off. At this time, the voltage collected by the A / D conversion module and the internal AD of the microcontroller should be about 0V; if not, it means that the switches J1~J5 cannot guarantee that they are all Completely disconnected, requiring re-inspection and maintenance;

[0096] Step S03: Only close the switch J2 and the switch J3, and keep the other switches in the off state;

[0097] Step S04: At this time, the voltage measured by the A / D conversion module is U; after U is detected, all the switches can be disconnected again according to the situation;

[0098] Step S05: Substitute U into the following formula:

[0099]

[0100] Calculate the total voltage UT;

[0101] Step S06: only switch J1 and switch J2

[0119] Step S19: After step S09 is completed, step S09 can start simultaneously with step S10, switch off switches J1-J3, and only close switch J4; jump to step 20;

[0120] Step S20: when the switch J4 is closed, the measured voltage is U3; jump to step S21

[0121] Step S21: Turn off the switches J1~J4, only close the switch J5, and jump to step S22

[0122] Step S22: When only the switch J5 is closed, the measured voltage is U4, and jump to step S23;

[0123] Step S23: Turn off the switches J1~J3, close the switches J4 and J5, and go to step S26

[0124] Step S24: According to the calculated values ​​of Rp2 and Rn2, according to the national standard GB18384, judge whether <100Ω / V or <500Ω / V is satisfied, and if so, jump to step S16

[0125] Step S25: end of insulation;

[0126] Step S26: In step S024, when the values ​​of Rp2 and Rn2 do not satisfy <100 Ω / V or <500 Ω / V, when the switch J4 and switch J5 are closed, the measured voltage is U5, and jump to step S27;

[0133] according to figure 1 , figure 2 Shown:

[0134] (1) In the present invention, before the detection of the entire new energy high-voltage system, when J1-J5 is disconnected, the voltages collected by the A / D conversion module and the internal AD of the single-chip microcomputer should be about 0V; if not, it means that the switch J1 ~J5 cannot guarantee that they are completely disconnected, and need to be re-inspected and maintained; this design ensures safety before testing;

[0135] In addition, the inherent insulation resistance Rp1 between the positive bus bar 2 of the battery pack 1 terminal and the shell earth, the inherent insulation resistance Rn1 between the negative bus bar 4 of the battery pack 1 terminal and the shell earth, and the inherent insulation resistance Rp2 between the load terminal positive bus bar 2 and the shell earth , The inherent insulation resistance Rn2 between the total negative busbar 4 at the load end and the earth of the shell; this