Dual current sensors realize wide-range high-precision current detection circuit and detection method

Abstract

A dual current sensor disclosed in the present invention realizes a wide-range high-precision current detection circuit, including: large and small range current sensors; first and second RC filter circuits, and filter input terminals of the first and second RC filter circuits Respectively connected with the voltage signal output terminals of the large and small range current sensors; and an analog-to-digital converter, the analog-to-digital converter has first and second signal input terminals, the first and second signal input terminals of the analog-to-digital converter The second signal input terminal is respectively connected to the filter output terminals of the first and second RC filter circuits. Also disclosed is a method for realizing wide-range and high-precision current detection by dual current sensors. The invention dynamically selects the current values ​​collected by the current sensors with two large and small ranges, performs smooth transition for the switching point of the ranges, and realizes high-precision current detection within a large range.

Description

technical field [0001] The invention relates to the technical field of a current detection method system for a power battery system of an electric vehicle, in particular to a dual current sensor realizing a wide-range high-precision current detection circuit and a detection method thereof. Background technique [0002] Hall current sensors are generally used to sample the charge and discharge current isolation of the power battery system of electric vehicles. The current of electric vehicles varies in a large range. The current may only be 1-2 amps, and using a wide-range current sensor of several hundred amps is difficult to accurately sample at low currents. At present, the mainstream battery SOC algorithm uses ampere-hour integration, and the measurement error of small current obviously affects the accuracy of SOC. If a current sensor with a small range is used, the measurement accuracy for small currents is high, but it cannot measure large currents. [0003] In respon...

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Problems solved by technology

[0004] However, this solution uses hardware to switch the range, and the circuit is more complicated, which undoubtedly greatly increases the hardware cost.

At the same time, since the function of smooth transition is not used, if the current is switching accessories in the range at this time, it will cause frequent switching of different sensors, and different sensors often have differences in the current collected and converted under the same current, resulting in increased current collection jitter

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