SDAA253 January   2026 TPSI2240-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Insulation Monitor
  5. 2Detailed Description
    1. 2.1 Solving for the Unknown Isolation Resistances
    2. 2.2 Addressing Large Time Constant Cases
    3. 2.3 Prediction Algorithms
    4. 2.4 Understanding Error Sources
    5. 2.5 Test Results
  6. 3Summary
  7. 4References

2.5 Test Results

The key test results of TIDA-010985 are shown in Figure 2-10 and Figure 2-11. Each test condition includes ten IMD measurements for statistical analysis (mean and standard deviation). Fixed-point math error is significant in some cases. Overall, the measurement errors and response time were well below the UL 2231-2 requirements (±15%, 10 seconds). For Figure 2-10 below, for asymmetric faults, the error displayed is the Riso in the fault condition. The 1MΩ-1MΩ case requires a 3-s cycle to resolve due to a very large time constant.

IMD Riso Measurement Error, 1000VDC, 2s Cycle Figure 2-10 IMD Riso Measurement Error, 1000VDC, 2s Cycle
IMD Ciso Error, 1MΩ-100kΩ, 2s Cycle Figure 2-11 IMD Ciso Error, 1MΩ-100kΩ, 2s Cycle