SLUAB06 January   2025 AMC131M02 , AMC3330 , ISO7731

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Topologies for Insulation Monitoring in ESS
    1. 2.1 Single Switch Topology
      1. 2.1.1 Test Steps
    2. 2.2 Dual Switch Floating Sampling Topology
      1. 2.2.1 Test Steps
    3. 2.3 Dual Switch Sampling in High Voltage Side Topology
    4. 2.4 AC Injection Topology
  6. 3Comparison of Designs
    1. 3.1 Injection Resistance Influence on Accuracy
  7. 4Capacitor Influence on Sampling Time
    1. 4.1 How to Choose Y Capacitor
    2. 4.2 Sampling Time
  8. 5Key Devices
    1. 5.1 BQ79731-Q1
    2. 5.2 UCC33421-Q1
    3. 5.3 AMC131M02
    4. 5.4 AMC3330
    5. 5.5 ISO773x
  9. 6Topos Simulation Result and Conclusion
  10. 7Summary
  11. 8References

3.1 Injection Resistance Influence on Accuracy

For the topologies of the bridge method, we change different injection resistors to calculate the final accuracy, and find that the insulation detection accuracy is proportional to the injection resistance accuracy.

Table 3-1 Influence of Injection Resistance to Insulation Detection Accuracy
Injection resistance value
4.5M 5.5M 6.5M
Injection resistance accuracy Insulation resistance detection accuracy
0.1% 0.31% 0.29% 0.30%
0.2% 0.63% 0.58% 0.54%
0.5% 1.59% 1.45% 1.36%
1.0% 3.22% 2.93% 2.74%