CURRENT CALIBRATION METHOD AND SYSTEM BY COMPENSATING VOLTAGE OF CURRENT SENSOR

Abstract

Disclosed are a current calibration method and a system by compensating a voltage of a current sensor, the method comprises: obtaining a power supply sampling voltage V.sub.cc by performing ADC sampling on a power supply of the current sensor, and obtaining a ground plane sampling voltage V.sub.GND_sensor by performing analog-to-digital converter (ADC) sampling on a voltage of the ground plane; sampling a current of the current sensor to obtain a sensor sampling voltage V.sub.out, and compensating the voltage of the current sensor to calibrate the sensor sampling voltage V.sub.out, wherein the calibrated sensor sampling voltage V.sub.out_correct is:

[00001]$V_{\mathrm{out\_correct}}=\frac{\left(V_{\mathrm{out}}-V_{\mathrm{GND\_sensor}}\right).Math.V_{\mathrm{nom}}}{V_{\mathrm{cc}}-V_{\mathrm{GND\_sensor}}}$

wherein V.sub.nom is a rated voltage of the power supply of the current sensor; and obtaining a calibrated sensor sampling voltage according to the calibrated sensor current value and a conversion coefficient of sampling voltage-current.

Claims

1. A current calibration method by compensating a voltage of a current sensor, comprising: S1: obtaining a power supply sampling voltage V.sub.cc by performing analog-to-digital converter (ADC) sampling on a power supply of the current sensor, and obtaining a ground plane sampling voltage V.sub.GND_sensor by performing ADC sampling on a voltage of the ground plane; S2: sampling a current of the current sensor to obtain a sensor sampling voltage V.sub.out, and compensating the voltage of the current sensor to calibrate the sensor sampling voltage V.sub.out, wherein the calibrated sensor sampling voltage V.sub.out_correct is: $V_{\mathrm{out\_correct}}=\frac{\left(V_{\mathrm{out}}-V_{\mathrm{GND\_sensor}}\right).Math.V_{\mathrm{nom}}}{V_{\mathrm{cc}}-V_{\mathrm{GND\_sensor}}}$ V.sub.nom is a rated voltage of the power supply of the current sensor; and S3: obtaining a calibrated sensor sampling voltage according to the calibrated sensor current value and a conversion coefficient of sampling voltage-current.

2. A current calibration system by compensating a voltage of a current sensor, comprising: a sensor current sampling circuit configured for obtaining a sensor sampling voltage V.sub.out; a sensor power supply sampling circuit configured for obtaining a power supply sampling voltage V.sub.cc; a sensor ground plane sampling circuit configured for obtaining a ground plane sampling voltage V.sub.GND_sensor; a calibration module configured for calibrating the sensor sampling voltage V.sub.out according to the power supply sampling voltage V.sub.cc and the ground plane sampling voltage V.sub.GND_sensor, and obtaining a calibrated sensor current value according to the calibrated sensor sampling voltage V.sub.GND_correct.

3. The current calibration system according to claim 2, wherein the calibration module is a Microcontroller Unit (MCU).

4. The current calibration system according to claim 2, wherein the calibration module is a Digital Signal Processing (DSP).

5. The current calibration system according to claim 3, wherein the sensor current sampling circuit, the sensor power supply sampling circuit and the sensor ground plane sampling circuit adopt ADC sampling and are configured for outputting digital sampling signals to the calibration module.

6. The current calibration system according to claim 4, wherein the sensor current sampling circuit, the sensor power supply sampling circuit and the sensor ground plane sampling circuit adopt ADC sampling and are configured for outputting digital sampling signals to the calibration module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following is further described in combination with the accompanying drawings and the embodiments.

[0025] FIG. 1 is a schematic diagram of current calibration of a current sensor of related art 1.

[0026] FIG. 2 is a schematic diagram of current calibration through voltage compensation of a current sensor provided by an embodiment of the present application;

[0027] FIG. 3 is a flowchart diagram of a current calibration method by compensating a voltage of a current sensor provided by an embodiment of the present application.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] As shown in FIG. 2, an embodiment of the present application provides a current calibration system by compensating a voltage of a current sensor circuit 1, including:

[0029] a sensor current sampling circuit 2 configured for obtaining a sensor sampling voltage V.sub.out;

[0030] a sensor power supply sampling circuit 3 configured for obtaining a power supply sampling voltage V.sub.cc from a power supply;

[0031] a sensor ground plane sampling circuit 4 configured for obtaining a ground plane sampling voltage V.sub.GND_sensor from a ground plane;

[0032] a calibration module 5 configured for calibrating the sensor sampling voltage V.sub.out according to the power supply sampling voltage V.sub.cc and the ground plane sampling voltage V.sub.GND_sensor, and obtaining a calibrated sensor current value according to the calibrated sensor sampling voltage V.sub.GND_correct.

[0033] The calibration module 5 uses a Microcontroller Unit (MCU) or a Digital Signal Processing (DSP) or another sampling processor device to sample a current output by the current sensor.

[0034] As shown in FIG. 3, the current calibration method by compensating a voltage of a current sensor provided by another embodiment of the present application includes:

[0035] S1: obtaining a power supply sampling voltage V.sub.cc by performing analog-to-digital converter ADC sampling on a power supply of a current sensor, and obtaining a ground plane sampling voltage V.sub.GND_sensor by performing ADC sampling on a voltage of the ground plane;

[0036] S2: sampling a current of the current sensor to obtain a sensor sampling voltage V.sub.out, and compensating a voltage of the current sensor to calibrate the sensor sampling voltage V.sub.out, where the calibrated sensor sampling voltage V.sub.out_correct is :

[00003]$V_{\mathrm{out\_correct}}=\frac{\left(V_{\mathrm{out}}-V_{\mathrm{GND\_sensor}}\right).Math.V_{\mathrm{nom}}}{V_{\mathrm{cc}}-V_{\mathrm{GND\_sensor}}}$

[0037] where V.sub.nom is a rated voltage of the power supply of the current sensor;

[0038] S3: obtaining a calibrated sensor sampling voltage according to the calibrated sensor current value and a conversion coefficient of sampling voltage-current.

[0039] For example, the MCU samples the current output by the current sensor to obtain the sampling voltage 2.5V, and the rated voltage of the power supply of the current sensor is 5V. The MCU samples the power supply V.sub.cc and the ground plane V.sub.GND_sensor of the current sensor to obtain 5.1V and 0.2V respectively. Then the calibrated sensor sampling voltage obtained by compensating the voltage of the current sensor is:

[00004]$V_{\mathrm{out\_correct}}=\frac{\left(V_{\mathrm{out}}-V_{\mathrm{GND\_sensor}}\right).Math.V_{\mathrm{nom}}}{V_{\mathrm{cc}}-V_{\mathrm{GND\_sensor}}}=\frac{\left(2.5V-0.2V\right).Math.5V}{\left(5.1V-0.2V\right)}\approx 2.35V$

[0040] Finally, the actual current value is obtained by converting with the conversion coefficient of the sampling voltage-current.

[0041] The above embodiment is only to illustrate the technical concept and characteristics of the present application. Its purpose is to enable the person skilled with the technology to understand the content of the present application and implement the present application. It does not limit the protection scope of the present application. Any modification made according to the spiritual essence of the main technical scheme of the present application shall be covered by the protection scope of the present application.