Switching type insulation monitoring error self-adapting method based on voltage prediction

Abstract

The invention provides a switching type insulation monitoring error self-adapting method based on voltage prediction. The method comprises the steps as follows: a self-calibration circuit comprising a calibration switch and a calibration resistor connected in series mutually is connected between the ground and a positive pole as well as between the ground and a negative pole of a bus in a switching type insulation monitoring device respectively; after the calibration switch is switched off, an error self-calibration mode is entered; bus voltage is measured and voltage to ground of the positive pole (negative pole) of the bus is collected for 3 times at a first preset time interval of (delta t1) minutes, and accordingly, the voltage to ground of the positive pole (negative pole) of the bus is calculated; insulation resistance to ground is calculated according to obtained parameters; after the calculating time of the insulation resistor reaches a preset time, whether the error between equivalence insulation resistance to ground of the positive pole and the negative pole of the bus with a preset number group and the known calibration resistance is in a reasonable range is analyzed; if the error is not in the reasonable range, a time definite value is added and taken as a new delta t1, and the steps are repeated; and if the error is in the reasonable range, the delta t1 is stored, and the calibration switch is switched off, so that the stored delta t1 enters a normal insulation resistance monitoring mode.

Description

technical field [0001] The present invention relates to an insulation monitoring error self-adaptive method, in particular to an application in communication high-voltage direct current (hereinafter referred to as HVDC) systems, electric vehicle charging systems and other occasions that require online real-time insulation monitoring and An error adaptive method for switching insulation monitoring based on voltage prediction in intelligent insulation monitoring instruments. Background technique [0002] In occasions such as HVDC systems and electric vehicle charging systems that require online real-time monitoring of insulation and intelligent insulation monitoring instruments, how to quickly measure insulation resistance with the smallest error has always been the goal that the industry is constantly seeking. [0003] The current practice is to use the DC system switching monitoring method, which can fully calculate and identify the equivalent insulation resistance to ground...

AI Technical Summary

Problems solved by technology

[0013] Use formulas (6) and (7) for voltage prediction. In practical applications, a fixed Δt is used to collect the voltage at both ends of the C+ and C- capacitors. However, in different occasions and periods, the switching insulation monitoring response speed and The measurement results of the equivalent insulation resistance of the positive and negative poles to the ground are not the best design. The larger the Δt, the more accurate the voltage prediction will be, but the measurement time will also increase.

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