Fitting algorithm for charge and discharge characteristic curves of RC charge and discharge circuit

Abstract

The invention provides a fitting algorithm for charge and discharge characteristic curves of an RC charge and discharge circuit. The fitting algorithm comprises the steps of assuming a charge characteristic curve and a discharge characteristic curve respectively according to an actual charge characteristic curve and an actual discharge characteristic curve; first, respectively determining, by acquiring sampling data, value ranges in which coefficients Vu2_a and E2_a of the charge and discharge characteristic curves are possibly distributed; defining the value ranges as assumed value intervalsrespectively; dividing each assumed value interval into N short intervals (N is an integer greater than or equal to 1) with the same length; taking intermediate values from the assumed short value intervals as current values of Vu2_a and E2_a; automatically adjusting coefficients B2_a or B'2_a by an algorithm to obtain a plurality of SUM values with the same number as that of the short intervals;then taking the short interval corresponding to the minimum SUM value as an actual value interval of the Vu2_a or E2_a value; and fitting the charge and discharge characteristic coefficients Vu2_a orE2_a respectively in the short interval to obtain characteristic values of the actual charge and discharge characteristic curves. The range of applications of fitting techniques is expanded, and meanwhile the efficient fitting speed and accuracy are achieved.

Description

technical field [0001] The invention relates to a research on a charging and discharging circuit, in particular to a charging and discharging characteristic curve fitting algorithm in an RC charging and discharging circuit. Background technique [0002] The root of analyzing the RC charging and discharging circuit is to find its corresponding physical characteristics, and the most important step is to find out its corresponding charging and discharging equation. Through curve fitting, the physical coefficients corresponding to the RC charging and discharging characteristic curves can be found to help the analysis. The existing high-efficiency and high-speed fitting technology for charging and discharging characteristic curves is realized on the PC side, especially the fitting technology based on MATLAB, which is based on the powerful hardware processing capability of the PC. However, the hardware processing capability of the embedded platform cannot reach that level, which ...

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Problems solved by technology

[0003] Secondly, at present, when electric vehicles use the pre-estimation method to solve the insulation resistance value, due to the existence of RC circuits, the AD samples collected by the chip are inaccurate.

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