Shunt type current measurement compensation method and device

文档序号:19103 发布日期:2021-09-21 浏览:17次 中文

阅读说明:本技术 一种分流器式的电流测量补偿方法、装置 (Shunt type current measurement compensation method and device ) 是由 高挺 于 2021-08-23 设计创作,主要内容包括:本发明公开了一种分流器式的电流测量补偿方法,包括以下步骤:在标准检验环境下,测量出分流器的输出回路与第一温度采样点间的热阻R-(th);设定分流器的初始参数;按照预设时间间隔采集第一温度采样点的温度T-a以及更新的分流器的电阻和电流;利用获取的电流和电阻计算分流器的耗散功率P;利用获取的耗散功率P以及采集的温度T-a得到分流器的实际温度T;利用分流器的线性拟合的公式计算漂移后的分流器的电阻;测量分流器电压U,利用测量得到的分流器电压U和获取的电阻根据欧姆定律计算,得到更新后的实时电流。本发明实现了通过利用上一时刻电流来补偿下一时刻电流,循环往复,实现减少电流本身对电流测量带来的影响,提高了电流测量精度。(The invention discloses a shunt type current measurement compensation method, which comprises the following steps: measuring the thermal resistance R between the output loop of the current divider and the first temperature sampling point under the standard test environment th (ii) a Setting initial parameters of the flow divider; collecting the temperature T of a first temperature sampling point according to a preset time interval a And updated shunt resistance and current; calculating the dissipation power P of the current divider by using the acquired current and the resistance; using the captured dissipated power P and the collected temperature T a Obtaining the actual temperature T of the current divider; calculating the resistance of the shunt after the drift by utilizing a linear fitting formula of the shunt; and measuring the voltage U of the shunt, and calculating according to ohm's law by using the measured voltage U of the shunt and the obtained resistance to obtain updated real-time current. The invention realizes current measurement by compensating current at the next moment by using current at the previous moment and realizing cyclic reciprocationThe influence brought by the quantity improves the current measurement precision.)

1. A shunt type current measurement compensation method is characterized by comprising the following steps:

s100, measuring thermal resistance R between an output loop of the current divider and a first temperature sampling point in a standard test environmentth

S200, setting initial parameters of the shunt;

s300, collecting the first time interval according to a preset time intervalTemperature T of temperature sampling pointaAnd updated shunt resistance and current;

s400, calculating the dissipation power P of the shunt by using the acquired current and the resistance;

s500, utilizing the acquired dissipation power P and the acquired temperature TaObtaining the actual temperature T of the current divider;

s600, calculating the resistance of the shunt after the drift by using a linear fitting formula of the shunt;

s700, measuring the voltage U of the shunt, calculating according to ohm' S law by using the measured voltage U of the shunt and the obtained resistance to obtain updated real-time current, and returning to the step S300.

2. The shunt-type current measurement compensation method according to claim 1, wherein in step S100, a thermal resistance R between an output loop of the shunt and the first temperature sampling point is measured under a standard test environmentthThe method specifically comprises the following steps:

s101, placing a shunt type current sensor comprising the shunt in a thermostat;

s102, electrically connecting the shunt type current sensor with a constant current source to form a power-on loop;

s103, connecting the shunt type current sensor with an upper computer through a CAN bus;

s104, selecting a position on the current divider as a second temperature sampling point, coating heat-conducting glue on the position, and placing a thermocouple to be connected to a temperature collector;

and S105, calculating the thermal resistance between the first temperature sampling point and the current divider according to the acquired temperature of the first temperature sampling point and the acquired temperature of the second temperature sampling point.

3. The shunt-type current measurement compensation method according to claim 2, wherein S104, the thermal resistance between the first temperature sampling point and the shunt is calculated by obtaining the temperature of the first temperature sampling point and the temperature of the second temperature sampling point, and the specific calculation steps are as follows:

s1041, setting the temperature in the temperature box to reach a constant state;

s1042, setting constant current flowing through the shunt in the constant current source loop, and calculating the dissipation power P = I of the shuntC 2R0In which ICFor a set constant current, R0Is the shunt resistance value;

s1043, obtaining the temperature T of the first temperature sampling point through the upper computer1Acquiring the temperature T of the second temperature sampling point through the temperature collector2;

S1044. calculating the thermal resistance Rth=(T2-T1)/P。

4. The shunt-type current measurement compensation method according to claim 1, wherein in step 500, obtaining the real-time temperature T of the shunt by using the obtained dissipated power P specifically comprises:

s501, multiplying the acquired dissipation power P by thermal resistance RthTo obtain a temperature difference, i.e.

Temperature difference Δ T = P × Rth;

S502, obtaining the temperature T of the first temperature sampling pointaAnd adding the obtained temperature difference delta T to obtain the real-time temperature T of the current divider.

5. The shunt-type current measurement compensation method of claim 1, wherein in step 600, the linear fitting of the shunt is formulated as

R1=K(I2RRth+Ta-T0)R0+R0

Where k is the shunt temperature coefficient, I is the updated real-time current, R is the updated shunt resistance, R is the current of the current shunt0For the shunt at T0Resistance at temperature, RthIs the thermal resistance, T, between the output loop of the shunt and the first temperature sampling pointaIs the first temperature sampling point temperature, T0Is the initial temperature, R1The resistance value of the shunt after drift.

6. The current divider type current measurement compensation device is characterized by comprising

A measuring module for measuring the thermal resistance R between the output loop of the shunt on the PCB circuit board and the first temperature sampling pointthAnd transmitting to a data acquisition module;

the initialization module (1) is used for setting initial parameters of the shunt;

a data acquisition module (3) for acquiring the temperature T of the first temperature sampling point according to a preset time intervalaAnd updated shunt resistance and current;

the first data calculation module (4) is used for calculating the dissipated power P of the current divider according to the acquired current and the resistance;

a second data calculation module (5) for multiplying the thermal resistance R by the dissipation power P obtainedthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRthThe temperature T of the first temperature sampling point is obtainedaAdding the obtained temperature difference delta T to obtain the real-time temperature T of the current divider;

the data processing module (6) is used for calculating the resistance after the drift by utilizing a formula of the temperature resistance of the linear fitting current divider;

and the data cycle updating module (7) is used for calculating according to ohm's law by using the measured voltage U of the current divider and the acquired resistance to obtain updated real-time current, and returning the updated real-time current to the data acquisition module.

7. The current-shunt-type current-measurement compensation device according to claim 6, wherein the data acquisition module (3) further comprises:

a temperature sampling unit for real-time collecting the temperature value T of the first temperature sampling point on the PCBaThe first temperature sampling point is arranged on an output loop of the current divider;

and the data acquisition unit is used for acquiring the drifted resistance fed back by the data processing module and the real-time current fed back by the data cycle updating module.

8. The current-shunt current-measurement compensation device according to claim 7, wherein the data acquisition module (3) further comprises:

and the voltage sampling unit is used for measuring the actual voltage of the output loop of the current divider and transmitting the actual voltage to the data cycle updating module.

9. The shunt current measurement compensation device of claim 6, wherein the linear fit of the shunt is formulated as R1=K(I2RRth+Ta-T0)R0+R0Where k is the shunt temperature coefficient, I is the updated real-time current, R is the updated shunt resistance, R is the current of the current shunt0For the shunt at T0Resistance at temperature, RthIs the thermal resistance, T, between the output loop of the shunt and the first temperature sampling pointaIs the first temperature sampling point temperature, T0Is the initial temperature, R1The resistance value of the shunt after drift.

10. A computer-readable storage medium, comprising a stored computer program, wherein the computer program, when executed, controls an apparatus in which the computer-readable storage medium is located to perform a shunt-type current measurement compensation method according to any one of claims 1 to 5.

Technical Field

The invention relates to the technical field of automobile shunts, in particular to a shunt type current measurement compensation method and device.

Background

The current shunt type current sensor for the electric automobile mainly comprises a power supply module, a CAN communication module, an MCU, an ADC analog-to-digital conversion module and a shunt. The voltage difference generated when the current flows through the shunt under the ideal state is collected by the ADC, the current value at the time is calculated in the MCU, but the shunt has a resistance thermal temperature coefficient, and the resistance can generate certain drift under different temperatures. The shift in resistance value can be expressed by the following equation:

R=R0+K(T-T0)

R0is an initial resistance value, k is a temperature coefficient, T0Is the initial temperature.

At present, in order to compensate for errors caused by temperature to current measurement, a common method is that a temperature detection point is added near a shunt, and then a table is looked up according to the environmental temperature to compensate for errors caused by resistance thermal temperature coefficients.

The existing method for compensating by looking up a table through the ambient temperature has the defects that the ambient temperature does not represent the temperature of the current divider, the temperature change has certain hysteresis, the self-heating of the current divider can bring errors, the larger the current is, the larger the error is, and the looking-up table cannot compensate the measurement influence caused by the self-heating in real time.

Disclosure of Invention

The present invention is directed to one or more of the above-mentioned conventional problems, and provides a shunt-type current measurement compensation method and a shunt-type current measurement compensation apparatus.

According to one aspect of the invention, a shunt-type current measurement for an electric vehicle is provided

The compensation method comprises the following steps:

s100, measuring the thermal resistance R between an output loop of the shunt and a first temperature sampling point by using a precision resistance measuring instrument in a standard test environmentth

S200, setting initial parameters of the shunt;

s300, collecting the temperature T of a first temperature sampling point according to a preset time intervalaAnd updated score

Resistance and current of the current device;

s400, calculating the dissipation power P of the shunt by using the acquired current and the resistance:

s500, utilizing the acquired dissipation power P and the acquired temperature TaThe actual temperature of the flow divider is obtained

Degree T;

s600, calculating the resistance value of the shunt after the drift by using a linear fitting formula of the shunt;

s700, measuring the current divider voltage U, and obtaining the current divider voltage U by using the measured current divider voltage U

The updated real-time current is obtained by calculating the resistance according to ohm' S law, and the step S300 is returned to.

In some embodiments, the step S100 is to measure the thermal resistance R between the output loop of the shunt and the first temperature sampling point under a standard test environmentthThe method specifically comprises the following steps:

s101, placing a shunt type current sensor comprising the shunt in a thermostat;

s102, electrically connecting the shunt type current sensor with a constant current source to form a power-on loop;

connecting the shunt type current sensor with an upper computer through a CAN bus;

s103, selecting a position on the current divider as a second temperature sampling point, coating heat-conducting glue on the position, and placing a thermocouple to be connected to a temperature collector;

and S104, calculating the thermal resistance between the first temperature sampling point and the current divider according to the acquired temperature of the first temperature sampling point and the acquired temperature of the second temperature sampling point.

In some embodiments, s104, calculating the thermal resistance between the first temperature sampling point and the shunt by obtaining the temperature of the first temperature sampling point and the temperature of the second temperature sampling point, where the specific calculation steps are as follows:

s1041, setting the temperature in the temperature box to reach a constant state;

s1042, setting constant current flowing through the shunt in the constant current source loop, and calculating the dissipation power P = I of the shuntC 2R0In which ICFor a set constant current, R0Is the shunt resistance value;

s1043, obtaining the temperature T of the first temperature sampling point through the upper computer1Acquiring the temperature T of the second temperature sampling point through the temperature collector2;

S1044. calculating the thermal resistance Rth=(T2-T1)/P 。

In some embodiments, in step 500, obtaining the real-time temperature T of the shunt by using the obtained dissipated power P specifically includes:

multiplying the obtained dissipation power P by the thermal resistance RthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRth;

The temperature T of the first temperature sampling point is obtainedaAnd adding the obtained temperature difference delta T to obtain the real-time temperature T of the current divider.

In certain embodiments, in step 600, the linear fit of the flow splitter is formulated as

R1=K(I2RRth+Ta-T0)R0+R0Where k is the shunt temperature coefficient, I is the updated real-time current, R is the updated shunt resistance, R is the current of the current shunt0For the shunt at T0Resistance at temperature, RthIs the thermal resistance, T, between the output loop of the shunt and the first temperature sampling pointaIs the first temperature sampling point temperature, T0Is the initial temperature, R1The resistance value of the shunt after drift.

According to a second aspect of the present invention, there is provided a shunt-type current measurement compensation apparatus comprising

A measuring module for measuring the thermal resistance R between the output loop of the shunt on the PCB circuit board and the first temperature sampling pointthAnd transmitting to a data acquisition module;

the initialization module is used for setting initial parameters of the shunt;

a data acquisition module for acquiring the temperature T of the first temperature sampling point at preset time intervalsaAnd updated shunt resistance and current;

the first data calculation module is used for calculating the dissipation power P of the current divider according to the acquired current and the resistance;

a second data calculation module for multiplying the obtained dissipation power P by the thermal resistance RthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRthThe temperature T of the first temperature sampling point is obtainedaAdding the obtained temperature difference delta T to obtain the real-time temperature T of the current divider;

the data processing module is used for calculating the resistance after the drift by utilizing a formula of the temperature resistance of the linear fitting shunt;

a data cycle update module for using the measured shunt voltage U and the obtained resistance

And calculating according to ohm's law to obtain updated real-time current, and returning to the data acquisition module.

In certain embodiments, the data acquisition module comprises:

a temperature sampling unit for real-time collecting the temperature T of the first temperature sampling point on the PCBaThe first temperature sampling point is arranged on an output loop of the current divider;

and the data acquisition unit is used for acquiring the drifted resistance fed back by the data processing module and the real-time current fed back by the data cycle updating module.

In some embodiments, the data acquisition module further comprises:

and the voltage sampling unit is used for measuring the actual voltage of the output loop of the current divider and transmitting the actual voltage to the data cycle updating module.

In some embodiments, the linear fit of the flow splitter is formulated as R1=K(I2RRth+Ta-T0)R0+R0Where k is the shunt temperature coefficient, I is the updated real-time current, R is the updated shunt resistance, R is the current of the current shunt0For the shunt at T0Resistance at temperature, RthIs the thermal resistance, T, between the output loop of the shunt and the first temperature sampling pointaIs the first temperature sampling point temperature, T0Is the initial temperature, R1The resistance value of the shunt after drift.

According to a third aspect of the present invention, there is provided a computer readable storage medium comprising a stored computer program, wherein the computer program when executed controls an apparatus in which the computer readable storage medium is located to perform a shunt-type current measurement compensation method as described above.

The invention has the beneficial effects that:

the invention measures the thermal resistance R between the output loop of the shunt positioned on the PCB and the first temperature sampling point by the precision resistance measuring instrumentthThe data acquisition module acquires the temperature T of the first temperature sampling point according to a preset time intervalaAnd the resistance and the current of the shunt are updated, the first data calculation module calculates the dissipation power P of the shunt according to the acquired current and the resistance, and the second data calculation module multiplies the dissipation power P acquired by the first data calculation module by the thermal resistance RthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRthThe temperature T of the first temperature sampling point is obtainedaAnd the real-time temperature T of the current divider is obtained by adding the obtained temperature difference delta T, the resistance after the drift is calculated by the data processing module by using a linear fitting formula of the temperature resistance of the current divider, and the updated real-time current is obtained by the data circulation updating module by using the measured voltage U of the current divider and the obtained resistance and calculating according to an ohm law. Therefore, in the current measurement compensation device provided by the invention, the data cyclic updating module can send the current to the data acquisition module according to the set time interval, and the data acquisition module performs cyclic acquisition and updating of the current, namely, the current at the next moment is compensated by using the current at the previous moment, and the current is cyclically repeated, so that the influence of the current on current measurement is reduced, and the current measurement precision is improved.

Drawings

FIG. 1 is a schematic flow chart of a shunt-type current measurement compensation method;

FIG. 2 is a schematic flow chart of another embodiment of a shunt-type current measurement compensation method;

FIG. 3 is a schematic flow chart of another embodiment of a shunt-type current measurement compensation method;

FIG. 4 is a schematic flow chart of another embodiment of a shunt-type current measurement compensation method;

FIG. 5 is a block schematic diagram of a current shunt current measurement compensation arrangement;

fig. 6 is a schematic structural diagram of the current divider type current measurement compensation device.

With the foregoing drawings in mind, certain embodiments of the disclosure have been shown and described in more detail below. These drawings and written description are not intended to limit the scope of the disclosed concepts in any way, but rather to illustrate the concepts of the disclosure to those skilled in the art by reference to specific embodiments.

Detailed Description

The technical scheme of the application is further explained in detail with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Some embodiments of the invention are described in detail below with reference to the accompanying drawings. In case of conflict, features of the following embodiments and embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Example one

Fig. 1 is a diagram illustrating a shunt-type current measurement compensation method according to an embodiment of the present invention, which includes the following steps:

s100, measuring the thermal resistance R between an output loop of the current divider and a first temperature sampling point in a standard test environmentth

S200, setting initial parameters of the flow divider, wherein the initial parameters specifically comprise a temperature coefficient k of the flow divider,

shunt at T0Resistance value R at temperature0Thermal resistance R between the shunt body and the temperature sampling pointthEtc.;

s300, collecting the temperature T of a first temperature sampling point according to a preset time intervalaAnd updated score

The resistance and the current of the current device are sampled according to the preset time interval;

s400, calculating the dissipation power P of the shunt by using the acquired current and the resistance;

s500, acquiring dissipation power P and acquisition temperature TaObtaining the actual temperature T of the current divider;

s600, calculating the resistance value of the shunt after the drift by using a linear fitting formula of the shunt;

s700, measuring the current divider voltage U, and obtaining the current divider voltage U by using the measured current divider voltage U

The updated real-time current is obtained by calculating the resistance according to ohm' S law, and the step S300 is returned to.

As shown in FIG. 2, in step S100, under a standard test environment, a thermal resistance R between an output loop of a shunt and a first temperature sampling point is measuredthThe shunt and the first temperature sampling point are both arranged on the PCB, the first temperature sampling point is arranged on an output loop of the shunt, the temperature of the first temperature sampling point can be measured by adopting a temperature detection component, and the shunt specifically comprises:

s101, placing a shunt type current sensor comprising a shunt in a thermostat, wherein the shunt type current sensor comprises components such as a shunt, a temperature sensor and the like;

s102, electrically connecting the shunt type current sensor with a constant current source to form a power-on loop;

connecting the current divider type current sensor with an upper computer through a CAN bus;

s103, selecting a position on the current divider as a second temperature sampling point, coating heat-conducting glue on the position, and placing a thermocouple to be connected to a temperature collector;

and S104, calculating the thermal resistance between the first temperature sampling point and the current divider according to the acquired temperature of the first temperature sampling point and the acquired temperature of the second temperature sampling point.

As shown in fig. 3, s104, calculating the thermal resistance between the first temperature sampling point and the shunt by obtaining the temperature of the first temperature sampling point and the temperature of the second temperature sampling point, specifically calculating steps are as follows:

s1041, setting the temperature in the temperature box to reach a constant state;

s1042, setting constant current flowing through the shunt in the constant current source loop, and calculating the dissipation power P = I of the shuntC 2R0In which ICFor a set constant current, R0Is the shunt resistance value;

s1043, obtaining the temperature T of the first temperature sampling point through the upper computer1Acquiring the temperature T of the second temperature sampling point through the temperature collector2;

S1044. calculating the thermal resistance Rth=(T2-T1)/P。

Specifically, in step 100, the standard test environment is a clean environment with a standard temperature T of 20 ± 5 ℃ and a relative humidity of 45-65%. Therefore, the ambient temperature and humidity in the process of measuring the thermal resistance are ensured, and the current measurement is more accurate.

As shown in fig. 4, in step 500, obtaining a real-time temperature T of the shunt by using the obtained dissipated power P includes: s501, multiplying the acquired dissipation power P by thermal resistance RthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRth;

S502, obtaining the temperature T of the first temperature sampling pointaAnd adding the obtained temperature difference delta T to obtain the real-time temperature T of the current divider.

Thermal resistance R of shunt on PCBthDenotes that its own consumed power P = I2R ,

Spontaneous heat generation of temperature difference Δ T = P × RthResistance drift R due to self-heating shunt1=KI2RRthR0 Measuring the offset Δ U = IR of the voltage generation generated by the shunt1=KI3RRthR0Thereby obtaining a shunt measurementThe error of the current is in direct proportion to the direction of the current flowing through the current, so that the influence of the current on the current measurement can be reduced by adopting the method.

In step 600, a linear fit of the splitter is formulated as R1=K(I2RRth+Ta-T0)R0+R0Where k is the shunt temperature coefficient, I is the updated real-time current, R is the updated shunt resistance, R is the current of the current shunt0For the shunt at T0Resistance at temperature, RthIs the thermal resistance, T, between the output loop of the shunt and the first temperature sampling pointaIs the first temperature sampling point temperature, T0Is the initial temperature, R1The resistance value of the shunt after drift. Therefore, the resistance value of the shunt after drift is measured through the linear fitting formula.

In this embodiment, the present invention measures the output loop of the shunt and the first temperature sample

Thermal resistance R between pointsthThe current at the previous moment is used for calculating the dissipation power and calculating to obtain the dissipation power P and the temperature difference of the current divider, the real-time temperature of the first temperature sampling point is collected through the temperature detection component, the real-time temperature and the obtained temperature difference are added to obtain the real-time temperature of the current divider, and therefore the drift resistance value is obtained through the obtained real-time temperature of the current divider.

Example two

Fig. 5 is a schematic diagram of a shunt-type current measurement compensation apparatus according to an embodiment of the present invention, including:

a measuring module for measuring the thermal resistance R between the output loop of the shunt on the PCB circuit board and the first temperature sampling pointthAnd transmitting to a data acquisition module; the initialization module 1 is used for setting initial parameters of the shunt; a data acquisition module 3 for acquiring the temperature T of the first temperature sampling point according to a preset time intervalaAnd updated shunt resistance and current; first data calculation module4, calculating the dissipation power P of the current divider according to the acquired current and the resistance; a second data calculation module 5 for multiplying the thermal resistance R by the dissipation power P obtainedthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRthThe temperature T of the first temperature sampling point is obtainedaAdding the obtained temperature difference delta T to obtain the real-time temperature T of the current divider; the data processing module 6 is used for calculating the resistance after the drift by utilizing a formula of the temperature resistance of the linear fitting current divider; and the data cycle updating module 7 is used for calculating according to ohm's law by using the measured voltage U of the current divider and the acquired resistance to obtain updated real-time current, and returning the updated real-time current to the data acquisition module.

In the embodiment, the invention measures the thermal resistance R between the output loop of the shunt positioned on the PCB and the first temperature sampling pointthThe data acquisition module acquires the temperature T of the first temperature sampling point according to a preset time intervalaAnd the resistance and the current of the shunt are updated, the first data calculation module calculates the dissipation power P of the shunt according to the acquired current and the resistance, and the second data calculation module multiplies the dissipation power P acquired by the first data calculation module by the thermal resistance RthA temperature difference is obtained, i.e. a temperature difference Δ T = PxRthThe temperature T of the first temperature sampling point is obtainedaAnd the real-time temperature T of the current divider is obtained by adding the obtained temperature difference delta T, the resistance after the drift is calculated by the data processing module by using a linear fitting formula of the temperature resistance of the current divider, and the updated real-time current is obtained by the data circulation updating module by using the measured voltage U of the current divider and the obtained resistance and calculating according to an ohm law. Therefore, in the current measurement compensation device provided by the invention, the data cyclic updating module can send the current to the data acquisition module according to the set time interval, and the data acquisition module performs cyclic acquisition and updating of the current, namely, the current at the next moment is compensated by using the current at the previous moment, and the current is cyclically repeated, so that the influence of the current on current measurement is reduced, and the current measurement precision is improved.

As shown in fig. 6, the measurement module is constructed in the following manner; the current divider type current sensor is placed in a constant temperature boxAnd connecting the constant current source to form a loop; shunt formula current sensor loops through ADC, MCU, CAN communication unit and host computer simultaneously and passes through CAN bus communication connection, selects a position on the shunt as second temperature sampling point, coats the heat conduction glue at this position and places a thermocouple and be connected to temperature collection ware, then calculates the thermal resistance between first temperature sampling point and the shunt through following step, specifically includes: setting the temperature in the temperature box to a constant state; setting constant current flowing through the shunt in the constant current source loop, and calculating the dissipation power P = I of the shuntC 2R0In which ICFor a set constant current, R0Obtaining the temperature T of the first temperature sampling point by an upper computer1Acquiring the temperature T of the second temperature sampling point through the temperature collector2Calculating the thermal resistance Rth=(T2-T1)/P。

As shown, the data acquisition module 3 further includes: a temperature sampling unit for real-time collecting the temperature value T of the first temperature sampling point on the PCBaThe first temperature sampling point is arranged on an output loop of the current divider; and the data acquisition unit is used for acquiring the drifted resistance fed back by the data processing module and the real-time current fed back by the data cycle updating module. The voltage sampling unit is used for measuring the actual voltage of the output loop of the current divider and transmitting the actual voltage to the data cycle updating module;

the linear fit of the shunt is formulated as R1=K(I2RRth+Ta-T0)R0+R0Where k is the shunt temperature coefficient, I is the updated real-time current, R is the updated shunt resistance, R is the current of the current shunt0For the shunt at T0Resistance at temperature, RthIs the thermal resistance, T, between the output loop of the shunt and the first temperature sampling pointaIs the first temperature sampling point temperature, T0Is the initial temperature, R1The resistance value of the shunt after drift.

The shunt-type current measurement compensation method shown in this embodiment can be implemented in a shunt-type current measurement compensation device in the embodiment shown in the drawings, and the implementation principle and the technical effect are the same, and are not described herein again.

The present invention also provides a computer readable storage medium including a stored computer program, wherein the computer program controls an apparatus in which the computer readable storage medium is located to execute the shunt-type current measurement compensation method described above when the computer program runs.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

What has been described above are merely some embodiments of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.

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