阅读说明：本技术 一种电感电流采样校准方法、系统和计算机可读存储介质 (Inductive current sampling calibration method, system and computer readable storage medium ) 是由 胡咸兵 任祖德 柏建国 于 2020-12-24 设计创作，主要内容包括：本发明涉及一种电感电流采样校准方法、系统和计算机可读存储介质。该方法包括在一个开关周期内,分析开关管通断与电感电流的关系,记录电感电流上升时间；根据所述开关周期与所述电感电流上升时间以及电感两侧输入电压与输出电压的关系,计算电感电流下降时间；将所述电感电流上升时间与所述电感电流下降时间相加,再除以所述开关周期,作为电感电流自动校准比例系数；将当前电感电流采样值乘以所述电感电流自动校准比例系数作为电感电流采样校准值。本发明校准范围宽、可以对电感电流断续情况进行补偿且精度高。(The invention relates to an inductive current sampling calibration method, a system and a computer readable storage medium. Analyzing the relation between the on-off of a switching tube and the inductive current in a switching period, and recording the rise time of the inductive current; calculating the falling time of the inductive current according to the relationship between the switching period and the rising time of the inductive current and the relationship between the input voltage and the output voltage at two sides of the inductor; adding the rising time of the inductive current and the falling time of the inductive current, and dividing the sum by the switching period to be used as an automatic calibration proportionality coefficient of the inductive current; and multiplying the current inductance current sampling value by the inductance current automatic calibration proportionality coefficient to serve as an inductance current sampling calibration value. The invention has wide calibration range, can compensate the discontinuous condition of the inductive current and has high precision.)

1. An inductor current sampling calibration method, comprising:

s1, in a switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise；

S2, according to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce；

S3, increasing the inductor current for a time T_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_auto；

S4, sampling the current inductance current value I_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample。

2. The inductor current sampling calibration method of claim 1, wherein the inductor current rise time T is_riseEqual to the conduction time T of the switch tube_on。

3. The inductor current sampling calibration method according to claim 1, wherein the inductor current falling time T is determined when the inductor current is continuous_reduceEqual to the turn-off time T of the switching tube_off(ii) a When the inductor current is interrupted, the inductor current falls for a time T_reduceLess than the turn-off time T of the switching tube_off。

4. The inductor current sampling calibration method according to any one of claims 1 to 3, further comprising:

s5, acquiring n groups of inductive current sampling calibration values and inductive current actual measurement values (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1;

s6, fitting the curve by using a least square method, and calculating a proportion coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB；

S7, based on the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleCalculating the manual calibration sampling value I of the inductive current_real。

5. The inductor current sampling calibration method according to claim 4, wherein said step S6 further comprises:

s61, respectively calculating n inductive current sampling calibration values I_autosample1、I_autosample2、...、I_autosamplenAnd n inductor currentsActual measured value I_measure1、I_measure2、...、I_measurenIs sampled by the calibration average I_{autosampleAvg}And the actual measured average value I_measureAvg：

I_{autosampleAvg}＝(I_autosample1+I_autosample2+…+I_autosamplen)/n；

I_measureAvg＝(I_measure1+I_measure2+…+I_measuren)/n；

S62, fitting a curve according to a least square method, and sampling a calibration value I based on the n inductive currents_autosample1、I_autosample2、...、I_autosamplenN actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenThe sample calibration average value I_{autosampleAvg}And the actual measured average value I_measureAvgThe proportionality coefficient K is calculated according to the following formula_manualA：

K_{manualA_Sum1}＝(I_autosample1-I_{autosampleAvg})*(I_measure1-I_measureAvg)+(I_autosample2-IautosampleAvg*Imeasure2--ImeasureAvg+...+Iautosamplen-IautosampleAvg*(Imeasuren-ImeasureAvg)；

K_{manualA_Sum2}＝(I_autosample1-I_{autosampleAvg})*(I_autosample1-IautosampleAvg+Iautosample2-IautosampleAvg*Iautosample2-IautosampleAvg+...+Iautosamplen-IautosampleAvg*Iautosamplen-IautosampleAvg；

K_manualA＝K_{manualA_Sum1}/K_{manualA_Sum2}；

S63 calibrating the average value I based on the samples_{autosampleAvg}The actual measurement mean value I_measureAvgAnd the proportionality coefficient K_manualAThe offset coefficient K is calculated according to the following formula_manualB：

K_manualB＝I_measureAvg-K_manualA*I_{autosampleAvg}。

6. The inductor current sampling calibration method according to claim 5, wherein in the step S7, I_real＝K_manualA*I_autosample+K_manualB。

7. An inductor current sampling calibration system, comprising:

the inductor current rise time recording module is used for recording the rise time of the inductor current in a switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise；

An inductive current fall time calculation module for calculating the inductive current fall time according to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce；

An auto-calibration proportionality coefficient calculation module for calculating the rise time T of the inductor current_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_auto；

An automatic calibration module for sampling the current inductor current_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample。

8. The inductor current sampling calibration system of claim 7, further comprising:

a manual calibration module for obtaining n groups of inductive current sampling calibration values and inductive current actual measurement values (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1; utilizing a least square method to fit a curve and calculating a proportional coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB(ii) a Base ofAt the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleAnd obtaining an inductor current manual calibration sampling value Ireal.

9. The inductor current sampling calibration system of claim 8, wherein the manual calibration module is further configured to:

respectively calculating n inductive current sampling calibration values I_autosample1、I_autosample2、...、I_autosamplenAnd n actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenIs sampled by the calibration average I_{autosampleAvg}And the actual measured average value I_measureAvg：

I_{autosampleAvg}＝(I_autosample1+I_autosample2+…+I_autosamplen)/n；

I_measureAvg＝(I_measure1+I_measure2+…+I_measuren)/n；

Fitting a curve according to a least square method, and sampling a calibration value I based on the n inductive currents_autosample1、I_autosample2、...、I_autosamplenN actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenThe sample calibration average value I_{autosampleAvg}And the actual measured average value I_measureAvgThe proportionality coefficient K is calculated according to the following formula_manualA：

K_{manualA_Sum1}＝(I_autosample1-I_{autosampleAvg})*(I_measure1-I_measureAvg)+(I_autosample2-I_{autosampleAvg})*(I_measure2-I_measureAvg)+…+(I_autosamplen-I_{autosampleAvg})*(I_measuren-I_measureAvg)；

K_{manualA_Sum2}＝(I_autosample1-I_{autosampleAvg})*(I_autosample1-IautosampleAvg+Iautosample2-IautosampleAvg*Iautosample2-IautosampleAvg+...+Iautosamplen-IautosampleAvg*Iautosamplen-IautosampleAvg；

K_manualA＝K_{manualA_Sum1}/K_{manualA_Sum2}；

Calibrating an average value I based on the samples_{autosampleAvg}The actual measurement mean value I_measureAvgAnd the proportionality coefficient K_manualAThe offset coefficient K is calculated according to the following formula_manualB：

K_manualB＝I_measureAvg-K_manualA*I_{autosampleAvg}。

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the inductor current sampling calibration method according to any one of claims 1 to 6.

Technical Field

The present invention relates to the field of power electronics technologies, and in particular, to a method and a system for calibrating inductor current sampling, and a computer-readable storage medium.

Background

Currently, in the field of power electronic control, in order to reduce the inductor current ripple and achieve power-limited operation, inner loop control of the inductor current is required, and the inductor current must be sampled to control the inductor current. In many engineering applications, the current value is sampled at the midpoint of the rising stage of the inductor current and used as the average current value of the switching cycle. Theoretically, if the inductor current is discontinuous, the sampling error is large. Because the equivalent calculated inductance current switching period average value is not added with the current interruption time, the sampling value is larger.

Disclosure of Invention

The present invention is directed to provide a method, a system, and a computer-readable storage medium for sampling and calibrating an inductor current, which have a wide calibration range, can compensate for an intermittent condition of the inductor current, and have high accuracy.

The technical scheme adopted by the invention for solving the technical problems is as follows: an inductor current sampling calibration method is constructed, and comprises the following steps:

s1, in a switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise；

S2, according to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce；

S3, increasing the inductor current for a time T_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_auto；

S4, sampling the current inductance current value I_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample。

In the inductor current sampling calibration system of the present invention, the inductor current rise time T_riseEqual to the conduction time T of the switch tube_on。

In the inductor current sampling calibration system, when the inductor current is continuous, the inductor current falls for a time T_reduceEqual to the turn-off time T of the switching tube_off(ii) a When the inductor current is interrupted, the inductor current falls for a time T_reduceLess than the turn-off time T of the switching tube_off。

In the inductor current sampling calibration system according to the present invention, the system further includes:

s5, acquiring n groups of inductive current sampling calibration values and inductive current actual measurement values (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1;

s6, fitting the curve by using a least square method, and calculating a proportion coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB；

S7, based on the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleCalculating the manual calibration sampling value I of the inductive current_real。

In the inductor current sampling calibration system according to the present invention, the step S6 further includes:

s61, respectively calculating n inductive current sampling calibration values I_autosample1、I_autosample2、...、I_autosamplenAnd n actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenIs sampled by the calibration average I_{autosampleAvg}And the actual measured average value I_measureAvg：

I_{autosampleAvg}＝(I_autosample1+I_autosample2+…+I_autosamplen)/n；

I_measureAvg＝(I_measure1+I_measure2+…+I_measuren)/n；

S62, fitting a curve according to a least square method, and sampling a calibration value I based on the n inductive currents_autosample1、I_autosample2、...、I_autosamplenN actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenThe sample calibration average value I_{autosampleAvg}And the actual measured average value I_measureAvgThe proportionality coefficient K is calculated according to the following formula_manualA：

K_{manualA_Sum1}＝(I_autosample1-I_{autosampleAvg})*(I_measure1-I_measureAvg)+(I_autosample2-I_{autosampleAvg})*(I_measure2-I_measureAvg)+…+

(I_autosamplen-I_{autosampleAvg})*(I_measuren-I_measureAvg)；

K_{manualA_Sum2}＝(I_autosample1-I_{autosampleAvg})*(I_autosample1-

IautosampleAvg+Iautosample2-IautosampleAvg*Iautosample2-Iautosa mpleAvg+...+Iautosamplen-IautosampleAvg*Iautosmplen-Iautosampl

eAvg；

K_manualA＝K_{manualA_Sum1}/K_{manualA_Sum2}；

S63 calibrating the average value I based on the samples_{autosampleAvg}The actual measurement mean value I_measureAvgAnd the proportionality coefficient K_manualAThe offset coefficient K is calculated according to the following formula_manualB：

K_manualB＝I_measureAvg-K_manualA*I_{autosampleAvg}。

In the inductor current sampling calibration system of the present invention, in the step S7, I_real＝K_manualA*I_autosample+K_manualB。

Another technical solution adopted by the present invention to solve the technical problem is to construct an inductive current sampling calibration system, including:

the inductor current rise time recording module is used for recording the rise time of the inductor current in a switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise；

Inductive currentA falling time calculation module for calculating the falling time according to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce；

An auto-calibration proportionality coefficient calculation module for calculating the rise time T of the inductor current_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_auto；

An automatic calibration module for sampling the current inductor current_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample。

In the inductor current sampling calibration system according to the present invention, the system further includes:

a manual calibration module for obtaining n groups of inductive current sampling calibration values and inductive current actual measurement values (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1; utilizing a least square method to fit a curve and calculating a proportional coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB(ii) a Based on the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleCalculating the manual calibration sampling value I of the inductive current_real。

In the inductor current sampling calibration system of the present invention, the manual calibration module is further configured to:

respectively calculating n inductive current sampling calibration values I_autosample1、I_autosample2、...、I_autosamplenAnd n actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenIs sampled by the calibration average I_{autosampleAvg}And the actual measured average value I_measureAvg：

I_{autosampleAvg}＝(I_autosample1+I_autosample2+…+I_autosamplen)/n；

I_measureAvg＝(I_measure1+I_measure2+…+I_measuren)/n；

Fitting a curve according to a least square method, and sampling a calibration value I based on the n inductive currents_autosample1、I_autosample2、...、I_autosamplenN actual measured values of the inductor current I_measure1、I_measure2、...、I_measurenThe sample calibration average value I_{autosampleAvg}And the actual measured average value I_measureAvgThe proportionality coefficient K is calculated according to the following formula_manualA：

K_{manualA_Sum1}＝

(I_autosample1-I_{autosampleAvg})*(I_measure1-I_measureAvg)+(I_autosample2-IautosampleAvg*Imeasure2-ImeasureAvg+...+Iautosamplen-IautosampleAvg*(Imeasuren-ImeasureAvg)；

K_{manualA_Sum2}＝(I_autosample1-I_{autosampleAvg})*(I_autosample1-

IautosampleAvg+Iautosample2-IautosampleAvg*Iautosample2-Iautosa mpleAvg+...+Iautosamplen-IautosampleAvg*Iautosamplen-Iautosampl

eAvg；

K_manualA＝K_{manualA_Sum1}/K_{manualA_Sum2}；

Calibrating an average value I based on the samples_{autosampleAvg}The actual measurement mean value I_measureAvgAnd the proportionality coefficient K_manualAThe offset coefficient K is calculated according to the following formula_manualB：

K_manualB＝I_measureAvg-K_manualA*I_{autosampleAvg}。

In order to solve the technical problem, another technical solution of the present invention is to configure a computer-readable storage medium, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the inductor current sampling calibration method.

By implementing the inductive current sampling calibration method, the inductive current sampling calibration system and the computer readable storage medium, the inductive current sampling calibration method, the inductive current sampling calibration system and the computer readable storage medium have wide calibration range, can compensate the inductive current discontinuous condition and have high precision. Furthermore, sampling errors caused by circuit hardware differences are manually calibrated, so that the sampling precision of the inductive current can be improved in all directions.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic diagram of the current sampling auto-calibration of the inductor current sampling calibration method of the present invention;

FIG. 2 is a schematic flow chart diagram of a first preferred embodiment of the inductor current sampling calibration method of the present invention;

FIG. 3 shows a schematic circuit diagram of a Buck circuit to which the inductor current sampling calibration method of the present invention is applied;

FIG. 4 is a circuit schematic of a Boost circuit to which the inductor current sampling calibration method of the present invention is applied;

FIG. 5 illustrates a circuit schematic of an INV circuit to which the inductor current sampling calibration method of the present invention is applied;

FIG. 6 illustrates the inductor current auto-calibration coefficients of a common circuit topology;

FIG. 7 is a schematic flow chart diagram illustrating a second preferred embodiment of the inductor current sampling calibration method of the present invention;

fig. 8 is a schematic structural diagram of a first preferred embodiment of the inductor current sampling calibration system of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

One aspect of the invention relates to an inductor current sampling calibration method, which comprises the following steps: in a switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise(ii) a According to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce(ii) a Setting the rise time T of the inductor current_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_auto(ii) a Sampling the current inductance current value I_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample。

Fig. 1 is a schematic diagram of the current sampling automatic calibration of the inductor current sampling calibration method of the present invention. The principle of the present invention is explained below with reference to fig. 1.

When the inductor current is interrupted, as shown in fig. 1: t is_{rise_D}＝T_{on_D}，T_{reduce_D}＜T_{off_D}. At this time, the actual sampling value of the inductor current is:theoretically, in the switching period T_sThe average value of the inductor current is:

at this time, an inductor current automatic calibration coefficient is defined:

K_auto＝I_theory/I_actual＝(T_{rise_D}+T_{reduce_D})/T_s；

when the inductor current continues, as shown in fig. 1:

T_{rise_C}＝T_{on_C}，T_{reduce_C}＝T_{off_C}；

at this time, the coefficient K is automatically calibrated_autoThe sampled value of the inductor current is not affected (not automatically calibrated):

K_auto＝(T_{rise_C}+T_{reduce_C})/T_s＝1。

therefore, the automatic calibration step has wide calibration range, can compensate the discontinuous condition of the inductive current and has high precision.

Another aspect of the invention relates to sampling the calibration value I for the previously obtained inductor current by fitting a calibration curve using a least squares method_autosampleAnd manually calibrating, and estimating an optimal manual calibration coefficient, so that an inductive current manual calibration sampling value with higher progress and maximum approach to an actual value is obtained. The method further comprises obtaining n sets of inductor current sample calibration values and an inductor current actual measurement value (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1; utilizing a least square method to fit a curve and calculating a proportional coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB(ii) a Based on the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleCalculating the manual calibration sampling value I of the inductive current_real. By manual sampling, the sampling difference of hardware circuits of different machines can be overcome, and higher sampling precision is obtained.

The present invention will be further described with reference to the following specific examples. Fig. 2 is a schematic flow chart of a first preferred embodiment of the inductor current sampling calibration method of the present invention. As shown in fig. 2, in step S1, in one switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise. In a preferred embodiment of the present invention, the topology and operation principle of a circuit, such as the circuit belonging to fig. 3, may be analyzed firstA Buck circuit shown, or a Boost circuit shown in fig. 4, or an INV circuit shown in fig. 5, or other inductive circuits. The topology and operation principle of the conventional inductive circuit, such as the Buck circuit, the Boost circuit or the INV circuit, are well known in the art, and those skilled in the art will know the topology and operation principle, and will not be described again here. Then, the switching period of the switching tube is set to T_sThen in a switching period T_sAnd analyzing the relation between the on-off of the switching tube and the inductive current, and recording the rise time T of the inductive current_rise。

In step S2, according to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce。

In the present embodiment, the inductor current rise time T is normally_riseEqual to the conduction time T of the switch tube_on. Inductor current fall time T_reduceUsually of unknown quantity, said inductor current falling time T when the inductor current is continuous_reduceEqual to the turn-off time T of the switching tube_off(ii) a When the inductor current is interrupted, the inductor current falls for a time T_reduceLess than the turn-off time T of the switching tube_off。

In step S3, the inductor current is raised for a time T_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_autoI.e. K_auto＝(T_rise+T_reduce)/T_s。

The calculation process is described below with reference to the Buck circuit, the Boost circuit, or the INV circuit shown in fig. 3-5, respectively.

According to the BUCK circuit shown in FIG. 3, inSampling at any moment, and calculating the reduction time T of the inductive current_reduce。T_onSwitch for BUCK circuitThe tube being in an interruption period T_sThe on-time of the capacitor; t is_offSwitching tube for BUCK circuit in an interrupt period T_sThe off time in.

Further, when the inductor current of the BUCK circuit is continuous: t is_rise＝T_on、T_reduce＝T_offTherefore: k_auto＝(T_rise+T_reduce)/T_s1 is ═ 1; when the inductor current of the BUCK circuit is interrupted: t is_rise＝T_on、T_reduce＜T_offAccording to the inductance during an interruption period T_sIn turn, a volt-second balance must be followed, namely:

(V_in-V_out)*T_rise＝V_out*T_reducenamely:

T_reduce＝(V_in-V_out)*T_rise/V_out＝(V_in-V_out)*T_on/V_outtherefore:

K_auto＝(T_rise+T_reduce)/T_s＝(V_in*T_on)/(V_out*T_s)。

according to the BOOST circuit shown in FIG. 4, inSampling at any moment, and calculating the reduction time T of the inductive current_reduce。T_onFor the switching tube of the BOOST circuit in an interruption period T_sThe on-time of the capacitor; t is_offFor BOOST circuit switching tube in an interruption period T_sInternal turn-off time;

further, when the inductor current of the BOOST circuit is continuous: t is_rise＝T_on、T_reduce＝T_offTherefore: k_auto＝(T_rise+T_reduce)/T_s1 is ═ 1; when the inductor current of the BOOST circuit is interrupted: t is_rise＝T_on、T_reduce＜T_offAccording to the inductance during an interruption period T_sIn turn, a volt-second balance must be followed, namely:

V_in*T_rise＝(V_out-V_in)*T_reducenamely:

T_reduce＝V_in*T_rise/(V_out-V_in)＝V_in*T_on/(V_out-V_in) Therefore:

K_auto＝(T_rise+T_reduce)/T_s＝(V_out*T_on)/[(V_out-V_in)*T_s]。

according to the INV circuit shown in FIG. 5, the fall time T of the inductor current is calculated_reduce. Switch tube Q₁And Q₃Are driven the same and the switching tube Q₁、Q₃And Q₅Complementation; switch tube Q₂、Q₄Driving the same and the switching tube Q₂、Q₄And Q₆And (4) complementation. At an output voltage V_outOf the switching tube Q₁、Q₃、Q₅Performing PWM modulation; at an output voltage V_outNegative half-cycle switching tube Q₂、Q₄、Q₆Performing PWM modulation; t is_onFor INV circuit switching tube Q₁、Q₃Or Q₂、Q₄In an interrupt period T_sThe on-time of the capacitor; t is_offFor INV circuit switching tube Q₁、Q₃Or Q₂、Q₄In an interrupt period T_sThe off time in.

When the INV circuit works in an inversion state, the INV circuit is similar to the BUCK circuitSampling at all times; when the INV circuit works in an inversion state and the inductive current is continuous: t is_rise＝T_on、T_reduce＝T_offTherefore: k_auto＝(T_rise+T_reduce)/T_s1 is ═ 1; when the INV circuit works in an inversion state and the inductive current is interrupted: t is_rise＝T_on、T_reduce＜T_offIn a break according to inductancePeriod T_sIn turn, a volt-second balance must be followed, namely:

(V_in-V_out)*T_rise＝V_out*T_reducenamely:

T_reduce＝(V_in-V_out)*T_rise/V_out＝(V_in-V_out)*T_on/V_outtherefore:

K_auto＝(T_rise+T_reduce)/T_s＝(V_in*T_on)/(V_out*T_s)。

when the INV circuit operates in a rectifying state, the INV circuit is similar to an inverted BOOST circuitSampling at all times; when the INV circuit works in a rectification state and the inductive current is continuous: t is_rise＝T_off、T_reduce＝T_onTherefore: k_auto＝(T_rise+T_reduce)/T_s1. When the INV works in a rectification state and the inductive current is interrupted: t is_rise＝T_off、T_reduce＜T_onAccording to the inductance during an interruption period T_sIn turn, a volt-second balance must be followed, namely:

V_out*T_rise＝(V_in-V_out)*T_reducenamely:

T_reduce＝V_out*T_rise/(V_in-V_out)＝V_out*(T_s-T_on)/(V_in-V_out) Therefore:

K_auto＝(T_rise+T_reduce)/T_s＝[V_in*(T_s-T_on)]/[(V_in-V_out)*T_s]。

summarizing the above embodiments, the inductor current auto-calibration coefficients of a common circuit topology are shown in fig. 6. Of course, the inductor current sampling calibration method of the present invention can also be used for inductor current calibration of other inductor circuits, and those skilled in the art can apply the method to various inductor circuits according to the teachings of the present invention, and will not be described herein again.

In step S4, the present inductor current sample value I is sampled_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample. I.e. I_autosample＝I_sample*K_auto。

The method for sampling and calibrating the inductive current of the embodiment aims at the sampling error caused by the interruption of the inductive current; when the inductive current is continuous, the proportionality coefficient K is automatically calibrated_autoEqual to 1. The automatic calibration step is adopted, the calibration range is wide, the discontinuous condition of the inductive current can be compensated, and the precision is high.

Fig. 7 is a schematic flow chart illustrating a second preferred embodiment of the inductor current sampling calibration method according to the present invention. In the embodiment shown in fig. 7, the step of automatic calibration may refer to the preferred embodiment shown in fig. 2, and on the basis of automatic calibration, manual calibration is also performed for sampling errors caused by circuit hardware differences, so that it may improve the inductor current sampling accuracy in all directions.

In the preferred embodiment shown in fig. 7, after the inductor current sample calibration value is obtained, the following steps are performed.

Acquiring n groups of inductive current sampling calibration values and inductive current actual measurement values (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1.

Then, fitting a curve by using a least square method, and calculating a proportional coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB，

In particular, the proportionality coefficient K_manualAThe calculating steps are as follows:

respectively calculating n inductive current sampling calibration values I_autosample1、I_autosample2、...、I_autosamplenAnd n pieces of electricityActual measurement value of inductive current I_measure1、I_measure2、...、I_measurenIs sampled by the calibration average I_{autosampleAvg}And the actual measured average value I_measureAvg：

I_{autosampleAvg}＝(I_autosample1+I_autosample2+…+I_autosamplen)/n；

I_measureAvg＝(I_measure1+I_measure2+…+I_measuren)/n。

Fitting a curve according to a least square method, and sampling a calibration value I based on the n inductive currents_autosample1、I_autosample2、...、I_autosamplen, the n actual measured values of the inductive current I_measure1、I_measure2、...、I_measurenThe sample calibration average value I_{autosampleAvg}And the actual measured average value I_measureAvgThe proportionality coefficient K is calculated according to the following formula_manualA。

Suppose that:

K_{manualA_Sum1}＝

(I_autosample1-I_{autosampleAvg})*(I_measure1-I_measureAvg)+(I_autosample2-IautosampleAvg*Imeasure2-ImeasureAvg+...+Iautosamplen-IautosampleAv

g*(Imeasuren-ImeasureAvg)；

further assume that:

K_{manualA_Sum2}＝

(I_autosample1-I_{autosampleAvg})*(I_autosample1-I_{autosampleAvg})+(I_autosample2-I_{autosampleAvg})*(I_autosample2-I_{autosampleAvg})+…+(I_autosamplen-

I_{autosampleAvg})*(I_autosamplen-I_{autosampleAvg})；

thus obtaining K_manualA＝K_{manualA_Sum1}/K_{manualA_Sum2}。

In particular, the offset coefficient K_manualBThe calculating steps are as follows:

calibrating an average value I based on the samples_{autosampleAvg}The actual measurement mean value I_measureAvgAnd the proportionality coefficient K_manualAThe offset coefficient K is calculated according to the following formula_manualB：

K_manualB＝I_measureAvg-K_manualA*I_{autosampleAvg}。

Finally, based on the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleCalculating the manual calibration sampling value I of the inductive current_realI.e. I_real＝K_manualA*I_autosample+K_manualB。

In the preferred embodiment, sampling errors due to circuit hardware differences are addressed. The inductive current sampling calibration method can improve the inductive current sampling precision in all directions.

In a further preferred embodiment of the invention, the scaling factor K may be adjusted after the manual calibration has been completed_manualAThe bias coefficient K_manualBAnd the data is stored in an EEPROM or other memory chips, so that the data loss is avoided.

The inductive current sampling calibration method, the inductive current sampling calibration system and the computer readable storage medium have the advantages of wide calibration range, capability of compensating the intermittent condition of the inductive current and high precision. Furthermore, sampling errors caused by circuit hardware differences are manually calibrated, so that the sampling precision of the inductive current can be improved in all directions.

Fig. 8 is a schematic structural diagram of a first preferred embodiment of the inductor current sampling calibration system of the present invention. As shown in fig. 8, the inductor current sampling calibration system includes: the device comprises an inductive current rise time recording module 100, an inductive current fall time calculating module 200, an automatic calibration proportionality coefficient calculating module 300 and an automatic calibration module 400. The inductor current rise time recording module 100 is used for recording the rise time of the inductor current in a switching period T_sInternal, analysis switchThe relationship between the on-off of the tube and the inductive current, and the rise time T of the inductive current_rise. The inductor current falling time calculation module 200 is configured to calculate the inductor current falling time according to the switching period T_sAnd the rise time T of the inductor current_riseAnd input voltage V at two sides of the inductor_inAnd an output voltage V_outCalculating the inductor current fall time T_reduce. The auto-calibration scaling factor calculation module 300 is used to calculate the inductor current rise time T_riseAnd said inductor current fall time T_reduceAdding and dividing by said switching period T_sAutomatically calibrating the proportionality coefficient K as the inductor current_auto. The automatic calibration module 400 is used for sampling the current inductor current value I_sampleMultiplying the inductance current by an automatic calibration proportionality coefficient K_autoAs a sample calibration value I for the inductor current_autosample。

In a further preferred embodiment of the present invention, the inductor current sampling calibration system further comprises a manual calibration module for obtaining n sets of inductor current sampling calibration values and inductor current actual measurement values (I)_autosample1，I_measure1)、(I_autosample2，I_measure2)、...、(I_autosamplen，I_measuren) Wherein n is a positive integer greater than 1; utilizing a least square method to fit a curve and calculating a proportional coefficient K of the manually calibrated inductive current_manualAAnd a bias coefficient K_manualB(ii) a Based on the proportionality coefficient K_manualAThe bias coefficient K_manualBAnd the inductance current sampling calibration value I_autosampleCalculating the manual calibration sampling value I of the inductive current_real。

In the preferred embodiment of the present invention, the inductor current rise time recording module 100, the inductor current fall time calculating module 200, the automatic calibration scaling factor calculating module 300, the automatic calibration module 400, and the manual calibration module may be configured according to the method steps in any of the preferred embodiments described above, and thus will not be described in detail herein.

In a further preferred embodiment of the present invention, the inductor current rising time recording module 100, the inductor current falling time calculating module 200, the automatic calibration scaling factor calculating module 300, the automatic calibration module 400 and the manual calibration module may be disposed in a DSP or MCU chip.

The present invention can be realized in hardware, software, or a combination of hardware and software. The present invention can be realized in a centralized fashion in at least one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods of the present invention is suited. A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.

The invention also relates to a computer-readable storage medium on which a computer program is stored which contains all the features enabling the implementation of the method of the invention when it is installed on a processor, in particular a DSP or MCU or other digital control chip. The computer program in this document refers to: any expression, in any programming language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to other languages, codes or symbols; b) reproduced in a different format.

The invention has been described above with the aid of method steps illustrating specified functions and relationships. For convenience of description, the boundaries and sequence of these functional building blocks and method steps have been defined herein specifically. However, given the appropriate implementation of functions and relationships, changes in the limits and sequences are allowed. Any such boundaries or sequence of changes should be considered to be within the scope of the claims.

The invention has also been described above with the aid of functional blocks illustrating some important functions. For convenience of description, the boundaries of these functional building blocks have been defined specifically herein. When these important functions are implemented properly, varying their boundaries is permissible. Similarly, flow diagram blocks may be specifically defined herein to illustrate certain important functions, and the boundaries and sequence of the flow diagram blocks may be otherwise defined for general application so long as the important functions are still achieved. Variations in the boundaries and sequence of the above described functional blocks, flowchart functional blocks, and steps may be considered within the scope of the following claims.

While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.