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...

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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 sp

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