METHOD FOR MEASURING INSULATION RESISTANCE WITH ABSORPTION CURRENT EXTRAPOLATION Russian patent published in 2023 - IPC G01R31/12 G01R27/02 

FIELD: electrical measurements.

SUBSTANCE: invention is related to measurements of insulation resistance, especially in cases where the controlled object has a large electrical capacitance relative to the "earth" and large absorption currents. Two measuring half-cycles are performed with different applied measuring voltages U₁ and U₂. In each half-cycle, an estimate (prediction) of the steady-state current value i_e1 and i_e2 are calculated and the insulation resistance is calculated using the formula R_in =(U₁-U₂)/(i_e1 - i_e2). To calculate the estimate of the steady-state current value after applying the measuring voltage at times t₀, t₁, t₂, … t_N-1 N measurements of current i₀, i₁, i₂,… i_N-1 are performed and approximated with the following function f(t) = A₀ + A₁ · e^-t/B₀ + A₂ (t-B₁) ^-B₂ using a combination of direct and iterative methods for implementing the least-square method. As an estimate of the steady-state current value, the value A₀ is used.

EFFECT: reduced time and error in measuring insulation resistance.

1 cl, 3 dwg