CN107907832B

CN107907832B - Metering instrument battery residual capacity calculation method

Info

Publication number: CN107907832B
Application number: CN201710907975.6A
Authority: CN
Inventors: 钭伟明; 李大伟; 章欢; 丁渊明; 盛成龙; 吴燕娟
Original assignee: Goldcard Smart Group Co Ltd
Current assignee: Jinka Water Technology Co ltd; Zhejiang Tancy Instrument Science & Technology Co ltd
Priority date: 2017-09-29
Filing date: 2017-09-29
Publication date: 2020-01-21
Anticipated expiration: 2037-09-29
Also published as: CN107907832A

Abstract

The invention aims to provide a method for calculating the residual electric quantity of a battery of a metering device, which aims to solve the technical problem that the prior technical scheme cannot give consideration to both energy consumption and precision. The method comprises the following steps: judging whether the first electric quantity interval grade conversion occurs or not according to the residual electric quantity C1; if the first electric quantity interval grade is changed, the current battery temperature and the current battery voltage are obtained; judging whether second electric quantity interval grade conversion occurs or not according to the current battery temperature and the current battery voltage, if the second electric quantity interval grade conversion occurs, obtaining the residual electric quantity C2 according to the current battery temperature and the current battery voltage, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; and repeating the steps after a preset time interval. The implementation of the invention can achieve the following beneficial technical effects: the detection frequency of the remaining power detection method is reduced, the energy consumption is reduced, and the accuracy of the remaining power of the invention is improved.

Description

Metering instrument battery residual capacity calculation method

Technical Field

The invention relates to the field of meters, in particular to a method for calculating the residual electric quantity of a battery of a metering device.

Background

The lithium primary battery has the advantages of small volume, large capacity, low self-discharge rate, environmental protection and the like. The application technology of the dry battery is developed rapidly, and the dry battery is gradually substituted for the traditional dry battery and is widely applied to metering instruments. With the wide application of the lithium primary battery, people put high demands on the safety and reliability of the application of the lithium primary battery, and the application technical problems of the lithium primary battery are gradually revealed.

On the one hand, some are applied for more than 5 years due to the longer life cycle of the lithium primary battery. Whether the actual service life can meet the design requirements or not is difficult to verify in a short time due to the influence of the use environment.

On the other hand, in order to ensure the safety of the product, part of the primary lithium battery is installed in a closed environment, and the primary lithium battery is not replaced in the whole life cycle of the product. When an abnormality occurs (such as fast power consumption), if the abnormality cannot be known in time, reasons can be checked and processed, and the abnormality can influence the normal operation of the whole system as a unique power supply.

The battery life cycle and abnormality judgment are premised on detection of the remaining capacity of the battery.

At present, the remaining power is mainly predicted by the following method:

1. the method for detecting the residual electric quantity on line comprises the following steps: the battery temperature and the battery voltage are detected, and the remaining capacity grade is obtained by inquiring a CCV-SOC data table (voltage-remaining capacity relation data table) which is measured in advance at different temperatures.

The battery voltage may be a voltage of the battery measured by an open circuit voltage method. The battery voltage can also be the voltage difference before and after discharging, namely, constant current or constant resistance is used for discharging, the voltage before discharging of the battery and the voltage after discharging of the battery (generally, within 5 seconds from the beginning of discharging, the voltage is consistent with a pre-measured CCV-SOC data table), the voltage difference before and after discharging is obtained and used as the battery voltage, the constant resistance discharging mode is simple, only the parallel sampling resistor is needed for discharging, and the voltage difference before and after the parallel sampling resistor is measured. The battery voltage may be other voltages having a corresponding relationship with the remaining capacity.

2. An ampere-hour integration method: on the basis of current detection, calculation prediction is carried out in combination with the use time.

Two electric quantity prediction modes in the prior art have the following problems:

1. the method for detecting the residual electric quantity on line has the following defects: the timing detection frequency is difficult to control. If the detection frequency is high, the current residual capacity is detected to be in the same grade section for many times, so that the energy loss of the battery is caused; if the detection frequency is slow, the detection cannot be carried out in time when the electric quantity grade is changed, and the measurement precision of the residual electric quantity is influenced.

2. The method of ampere-hour integration has the following defects: the accumulation of measurement errors and uncertain interference cannot be eliminated, and the calculation accuracy of the residual capacity is influenced.

The two detection methods cannot give consideration to both energy consumption and precision, and are difficult to meet the requirement of battery detection of the metering instrument, so that a metering instrument battery residual capacity calculation method which can give consideration to both precision and energy consumption needs to be designed.

Disclosure of Invention

The invention aims to provide a method for calculating the residual electric quantity of a battery of a metering device, which aims to solve the technical problem that the prior technical scheme cannot give consideration to both energy consumption and precision.

In order to achieve the purpose, the method for calculating the residual capacity of the battery of the metering device comprises the following steps:

step S0, dividing battery electric quantity grade interval;

step S1, acquiring the average current of the interval, the residual electric quantity when the interval from the upper electric quantity interval to the current-level electric quantity is changed and the battery service time of the current-level electric quantity interval;

step S2, obtaining the residual capacity C1 according to the interval average current, the residual capacity when the interval from the upper level electric capacity interval to the current level electric capacity is changed and the battery service time of the current level electric capacity interval;

step S3, judging whether the first electric quantity interval grade transformation occurs according to the residual electric quantity C1; if the first electric quantity interval grade conversion occurs, the step S4 is executed, if the first electric quantity interval grade conversion does not occur, the step is ended;

step S4, acquiring the current battery temperature and the current battery voltage;

step S5, judging whether second electric quantity interval grade conversion occurs according to the current battery temperature and the current battery voltage, if the second electric quantity interval grade conversion occurs, entering step S6, if the second electric quantity interval grade conversion does not occur, entering step S4 after a certain time;

step S6, acquiring residual electric quantity C2 according to the current battery temperature and the current battery voltage, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval;

and repeating the steps S1 to S6 after a preset time interval.

In the method for calculating the remaining battery capacity of the metering device, before the step S1 is executed for the first time, the method further includes an initialization step, where the initialization step includes: acquiring the battery temperature and the battery voltage at the moment, acquiring residual electric quantity C2 according to the battery temperature and the battery voltage at the moment, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; or, before the step S1 is executed for the first time, the method further includes an initialization step, where the initialization step includes: and acquiring the theoretical residual capacity of the battery, and taking the theoretical residual capacity as the residual capacity when the upper-level electric capacity interval is converted into the current-level electric capacity interval.

In the method for calculating the remaining battery capacity of the metering instrument, before the first second battery capacity interval grade is changed, the theoretical average current of the battery is used as the interval average current, and after the first second battery capacity interval grade is changed, the average current of the upper-grade battery capacity interval is used as the interval average current.

In the method for calculating the remaining battery power of the metering device, the average current of the upper power interval is calculated by a first formula:

the average current of the upper electric quantity interval is represented; c₀Representing the residual electric quantity when the upper electric quantity interval is converted into the upper electric quantity interval; c₁Representing the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; t is₀The time from the upper electric quantity interval to the upper electric quantity interval is represented; t is₁And the time from the upper electric quantity interval to the current electric quantity interval is represented.

In the method for calculating the remaining battery power of the metering instrument, the battery service time of the current-stage power interval is obtained by calculating according to the formula two:

ΔT＝T-T₁(II)

Wherein, Δ T represents the battery service time of the current-level electric quantity interval, T represents the current time₁And the time from the upper electric quantity interval to the current electric quantity interval is represented.

In the method for calculating the remaining battery capacity of the metering device, the obtaining the remaining battery capacity C1 according to the interval average current, the remaining battery capacity when the interval from the upper level electric capacity interval to the current level electric capacity is changed, and the battery service time of the current level electric capacity interval includes: the remaining capacity C1 is obtained by calculation of formula three,

wherein, C₂Represents the remaining capacity C1; c₁Representing the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; delta T represents the battery service time of the current-level electric quantity interval;

represents the interval average current.

In the above method for calculating remaining battery power of a metering device, the obtaining of remaining battery power C2 according to the current battery temperature and the current battery voltage includes: and acquiring the electric quantity corresponding to the current battery voltage as the residual electric quantity C2 according to the linear relation between the battery voltage and the electric quantity in the current electric quantity grade interval under the current battery temperature and the linear relation.

In the method for calculating the remaining battery power of the metering device, the method further includes a step of evaluating the remaining service life of the battery, and the step of evaluating the remaining service life of the battery includes: acquiring the average current of the residual electric quantity C1 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C1 and the average current of the upper-level electric quantity interval; or, the method further comprises a step of evaluating the remaining service life of the battery, wherein the step of evaluating the remaining service life of the battery comprises the following steps: and acquiring the average current of the residual electric quantity C2 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C2 and the average current of the upper-level electric quantity interval.

In the method for calculating the remaining battery capacity of the metering device, the method further includes a first early warning step, where the first early warning step includes: and acquiring the theoretical remaining service life of the battery, and judging whether the metering device gives an alarm or not according to the remaining service life of the battery and the theoretical remaining service life of the battery.

In the method for calculating the remaining battery capacity of the metering device, the method further includes a second early warning step, where the second early warning step includes:

step Y1: acquiring the current battery temperature and the current battery voltage; acquiring residual capacity C3 according to the current battery temperature and the current battery voltage;

step Y2: judging whether an alarm condition is met or not according to the residual electric quantity C3, and if the alarm condition is met, alarming;

repeating the step Y1 to the step Y2 after the interval is set for a time length;

the judgment of whether the alarm condition is met according to the remaining electric quantity C3 includes any one of the following judgment modes:

acquiring residual electric quantity C1, if the difference value between the residual electric quantity C1 and the residual electric quantity C3 exceeds a difference threshold value N1, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met;

acquiring residual electric quantity C1, if the ratio of the residual electric quantity C1 to the residual electric quantity C3 exceeds a ratio threshold value M1, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met;

acquiring the used time of a battery and the average current of a higher-level electric quantity interval; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; if the difference value between the used average current of the battery and the average current of the upper-level electric quantity interval exceeds a difference threshold value N2, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met;

acquiring the used time of a battery and the average current of a higher-level electric quantity interval; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; if the ratio of the used average current of the battery to the average current of the upper-level electric quantity interval exceeds a ratio threshold value M2, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met;

acquiring the used time and theoretical average current of the battery; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; and if the difference value of the used average current of the battery and the theoretical average current exceeds the difference threshold value N3, judging that the alarm condition is met, otherwise, not meeting the alarm condition.

Acquiring the used time and theoretical average current of the battery; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; if the ratio of the used average current of the battery to the theoretical average current exceeds a ratio threshold value M3, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met;

judging whether electric quantity interval grade conversion occurs or not according to the residual electric quantity C3, if so, obtaining the pre-judging time for the electric quantity interval grade conversion according to the interval average current and the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval, and if the time difference between the pre-judging time and the current time exceeds the time difference threshold value, judging that the alarm condition is met; otherwise, the alarm condition is not met.

The implementation of the invention can achieve the following beneficial technical effects:

1. the invention discloses a method for calculating the residual electric quantity of a battery of a metering device, which comprises the following steps: step S0, dividing battery electric quantity grade interval; step S1, acquiring the average current of the interval, the residual electric quantity when the interval from the upper electric quantity interval to the current-level electric quantity is changed and the battery service time of the current-level electric quantity interval; step S2, obtaining the residual capacity C1 according to the interval average current, the residual capacity when the interval from the upper level electric capacity interval to the current level electric capacity is changed and the battery service time of the current level electric capacity interval; step S3, judging whether the first electric quantity interval grade transformation occurs according to the residual electric quantity C1; if the first electric quantity interval grade conversion occurs, the step S4 is executed, if the first electric quantity interval grade conversion does not occur, the step is ended; step S4, acquiring the current battery temperature and the current battery voltage; step S5, judging whether second electric quantity interval grade conversion occurs according to the current battery temperature and the current battery voltage, if the second electric quantity interval grade conversion occurs, entering step S6, if the second electric quantity interval grade conversion does not occur, entering step S4 after a certain time; step S6, acquiring residual electric quantity C2 according to the current battery temperature and the current battery voltage, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; and repeating the steps S1 to S6 after a preset time interval. For convenience of description, the method for obtaining the residual electric quantity according to the average current of the interval, the residual electric quantity when the interval from the upper-level electric quantity interval to the current-level electric quantity is converted and the battery service time of the current-level electric quantity interval is called as a residual electric quantity ampere-hour meter algorithm; the method for acquiring the residual electric quantity or the residual electric quantity grade interval according to the battery temperature and the battery voltage is called as a residual electric quantity on-line detection method; according to the method, the level of the residual electric quantity is pre-judged according to the residual electric quantity C1, the level of the second electric quantity interval is judged only when the level of the first electric quantity interval is pre-judged to be changed, and the residual electric quantity C2 is obtained through the residual electric quantity online detection method after the level of the second residual electric quantity occurs, so that the detection frequency of the residual electric quantity online detection method is reduced, and the energy consumption is reduced; after the level of the second electric quantity interval is changed, the residual electric quantity C2 obtained according to the online residual electric quantity detection method becomes a calculation basis of the residual electric quantity C1, so that the residual electric quantity C1 can eliminate errors generated by a residual electric quantity ampere-hour meter algorithm after each time of changing of the level of the residual electric quantity, errors cannot be accumulated in the residual electric quantity C1 calculated by the residual electric quantity ampere-hour meter algorithm, and the accuracy of the residual electric quantity is improved.

2. Before the step S1 is executed for the first time, the method further includes an initialization step, where the initialization step includes: and acquiring the battery temperature and the battery voltage at the moment, acquiring the residual capacity C2 according to the battery temperature and the battery voltage at the moment, and taking the residual capacity C2 as the residual capacity when the upper-level capacity interval is converted into the current-level capacity interval. The residual capacity when the initial upper-level electric quantity interval is converted to the current-level electric quantity interval is obtained through the battery temperature and the battery voltage at the moment, so that the value of the residual capacity in the subsequent residual capacity calculation process is more accurate, and especially when the average current of the interval adopts the average current of the upper-level electric quantity interval, the interval average current can be close to the true value through the initialization method.

3. Before the step S1 is executed for the first time, the method further includes an initialization step, where the initialization step includes: and acquiring the theoretical residual capacity of the battery, and taking the theoretical residual capacity as the residual capacity when the upper-level electric capacity interval is converted into the current-level electric capacity interval. And the theoretical residual capacity is used as the initial residual capacity when the upper-level electric quantity interval is converted into the current-level electric quantity interval, so that the initial residual capacity can be conveniently obtained.

4. Before the first second electric quantity interval grade conversion, the theoretical average current of the battery is used as the interval average current, and after the first second electric quantity interval grade conversion, the average current of the upper-grade electric quantity interval is used as the interval average current. The average current of the upper-level electric quantity interval is used as the interval average current, dynamic update of the interval average current is achieved, the interval average current is close to an actual value, and the residual electric quantity of the instrument battery obtained through subsequent calculation is more accurate.

5. The average current of the upper electric quantity interval is calculated by a formula I:

the average current of the upper electric quantity interval is represented; c₀Representing the residual electric quantity when the upper electric quantity interval is converted into the upper electric quantity interval; c₁Representing the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; t is₀The time from the upper electric quantity interval to the upper electric quantity interval is represented; t is₁And the time from the upper electric quantity interval to the current electric quantity interval is represented. The average current of a higher-level electric quantity interval and the real average current close to the higher-level electric quantity interval are obtained through a formula I, so that the instrument obtained through subsequent calculationThe residual capacity of the battery is more accurate.

6. The battery service time of the current-level electric quantity interval is obtained by calculation according to a formula II:

ΔT＝T-T₁(II)

Wherein, Δ T represents the battery service time of the current-level electric quantity interval, T represents the current time₁And the time from the upper electric quantity interval to the current electric quantity interval is represented. The battery service time of the current-level electric quantity interval is obtained through calculation of a formula II, so that the residual electric quantity of the instrument battery obtained through subsequent calculation is more accurate.

7. The step of obtaining the remaining capacity C1 according to the interval average current, the remaining capacity when the interval from the upper level capacity interval to the current level capacity is changed, and the battery service time of the current level capacity interval includes: the remaining capacity C1 is obtained by calculation of formula three,

wherein, C₂Represents the remaining capacity C1; c₁Representing the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; delta T represents the battery service time of the current-level electric quantity interval;represents the interval average current. The remaining capacity C1 can be quickly calculated by formula three.

8. The obtaining of the remaining capacity C2 according to the current battery temperature and the current battery voltage includes: and acquiring the electric quantity corresponding to the current battery voltage as the residual electric quantity C2 according to the linear relation between the battery voltage and the electric quantity in the current electric quantity grade interval under the current battery temperature and the linear relation. And acquiring more accurate residual capacity C2 according to the current battery temperature and the current battery voltage by utilizing the linear relation between the battery voltage and the electric quantity in the current electric quantity grade interval.

9. The method further comprises a battery remaining useful life assessment step comprising: and acquiring the average current of the residual electric quantity C1 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C1 and the average current of the upper-level electric quantity interval. The remaining service life of the battery can be accurately obtained, whether the service life of the new battery can meet the design requirements or not is rapidly screened, and meanwhile, the remaining service life of the battery can reflect the instrument service life of the metering instrument and is used as the basis for maintaining and replacing the metering instrument.

10. The method further comprises a battery remaining useful life assessment step comprising: and acquiring the residual capacity C2 and the interval average current, and calculating the residual service life of the battery according to the residual capacity C2 and the interval average current. The remaining service life of the battery can be accurately obtained, whether the service life of the new battery can meet the design requirements or not is rapidly screened, and meanwhile, the remaining service life of the battery can reflect the instrument service life of the metering instrument and is used as the basis for maintaining and replacing the metering instrument.

11. And acquiring the theoretical remaining service life of the battery, and judging whether the metering device gives an alarm or not according to the remaining service life of the battery and the theoretical remaining service life of the battery. And judging whether the battery is abnormal or not according to the residual service life of the battery and the theoretical residual service life of the battery, and alarming when the battery is abnormal so as to inform workers to maintain in time and improve the efficiency.

12. The method further comprises a second early warning step, wherein the second early warning step comprises the following steps:

and executing a second early warning step once every set time interval, and judging whether to alarm or not according to the residual capacity C3 obtained by the residual capacity online detection method. It can prevent the battery from being abnormal because the electric quantity is too fast to judge the battery abnormality.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a flow chart of a second early warning step of the present invention.

Detailed Description

To facilitate understanding of those skilled in the art, the present invention will be further described with reference to specific examples:

example 1:

the invention provides a method for calculating the residual capacity of a battery of a metering device, which comprises the following steps as shown in figure 1:

step S0, dividing battery electric quantity grade interval;

and repeating the steps S1 to S6 after a preset time interval.

First, the present invention obtains the current remaining capacity C1 of the battery according to the remaining capacity ampere-hour meter algorithm, and at this time, the remaining capacity C1 can be used as the calculation result of the remaining capacity of the battery at this time.

Secondly, the invention judges whether the grade conversion of a first electric quantity interval occurs or not according to the obtained residual electric quantity C1, if the grade conversion of the first electric quantity interval occurs, the invention judges whether the grade conversion of a second electric quantity interval occurs or not according to the current battery temperature and the current battery voltage, when the grade conversion of the second electric quantity interval occurs, the residual electric quantity C2 is obtained according to an on-line residual electric quantity detection method, the residual electric quantity C2 is used as the residual electric quantity when the upper-level electric quantity interval is converted to the current-level electric quantity interval, and the residual electric quantity C2 becomes the calculation basis for calculating the residual electric quantity C1 next time. It is to be understood that the remaining capacity C2 may be calculated as the remaining capacity of the battery. It is worth noting that: the occurrence of the first power interval level transition is the basis for the process to proceed to step S4, and does not represent that the power interval level transition actually occurs; the second electric quantity interval grade conversion represents that electric quantity grade conversion actually occurs, namely, a higher-level electric quantity interval and a current-level electric quantity interval are changed.

The invention has the beneficial effects that: the method comprises the steps of pre-judging the level of the residual electric quantity according to the residual electric quantity C1, carrying out second electric quantity interval level conversion judgment when the first electric quantity interval level conversion is carried out, and obtaining the residual electric quantity C2 through a residual electric quantity online detection method after the second residual electric quantity level is carried out, so that the detection frequency of the residual electric quantity online detection method is reduced, and the energy consumption is reduced; after the grade of the residual electric quantity is changed, the residual electric quantity C2 obtained according to the online detection method of the residual electric quantity becomes the calculation basis of the residual electric quantity C1, so that the residual electric quantity C1 can eliminate the error generated by the residual electric quantity ampere-hour meter algorithm after each grade change of the residual electric quantity, further, the residual electric quantity C1 calculated by the residual electric quantity ampere-hour meter algorithm can not accumulate the error, and the precision of the residual electric quantity of the invention is improved.

It should be understood that the battery voltage in the present invention is a voltage corresponding to a CCV-SOC data table (voltage-remaining capacity relation data table), and if the detected voltage can obtain the remaining capacity by table lookup according to a pre-measured voltage-remaining capacity relation data table, the detected voltage can be referred to as the battery voltage; the battery voltage may be, but is not limited to, an open circuit voltage or a voltage difference before and after discharge as described in the background.

In the method for calculating the remaining battery power of the metering device, the step S1 to the step S6 are repeated after the preset time interval, and are used for indicating that the step S1 to the step S6 are executed for one round at intervals, and it can be known that the ending step in the step S3 only indicates the ending of the step S1 to the step S6. In the present invention, the preset interval duration may be set according to the actual condition of the battery, for example, set to 1 day.

In the method for calculating the remaining battery capacity of the metering device, the certain time may be preset time T1, and time T1 may be set as required, for example, set to 1 day. It should be noted that, in step S5, other operations may be performed during the period of time after the second power interval level is determined not to have changed and before the process proceeds to step S4.

In order to facilitate an understanding of the invention and of alternative embodiments of the invention, the invention is further explained and illustrated below:

dividing a battery electric quantity grade interval: dividing the battery electric quantity into n grades according to the battery condition, wherein n is a positive integer and is more than or equal to 2; the battery electric quantity grade interval division requirement is based on that the residual electric quantity online detection method can distinguish the electric quantity grade interval delta V value. For example: the 16Ah lithium primary battery was classified into 10 grades, each grade being 10% of the total charge, including [ 100%, 90%, [ 90%, 80%), … …, [ 20%, 10%, [ 10%, 0%); the electric quantity of each grade interval is 1.6 Ah. If the currently measured remaining capacity C2 is 85%, the current level capacity interval is [ 90%, 80%) and the upper level capacity interval is [ 100%, 90%).

The remaining electric quantity when the upper electric quantity interval is converted into the current electric quantity interval is as follows: before the step S6 is executed for the first time, the remaining power may be obtained through an initialization mode, specifically, the remaining power when the upper level power interval is converted into the current level power interval may be initialized before the step S1 is executed for the first time; it can be known that the time from initializing the upper level electric quantity interval to the residual electric quantity when the current level electric quantity interval is converted is the time from the upper level electric quantity interval corresponding to the residual electric quantity to the current level electric quantity interval.

As an optional initialization manner, the initialization step includes: acquiring the battery temperature and the battery voltage at the moment, acquiring residual electric quantity C2 according to the battery temperature and the battery voltage at the moment, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; the residual capacity when the initial upper-level electric quantity interval is converted into the current-level electric quantity interval is obtained through the battery temperature and the battery voltage at the moment, so that the value of the residual capacity in the subsequent residual capacity calculation process is more accurate, and particularly when the average current of the interval adopts the average current of the upper-level electric quantity interval, the interval average current can be close to the true value through the initialization method; it can be known that the time at the time of initialization is used as the time from the upper power interval to the current power interval, so as to obtain the battery service time of the current power interval. It is known that the discharge voltage is a voltage measured by an in-line remaining power detection method.

As another alternative initialization method, the initialization step includes: and acquiring the theoretical residual capacity of the battery, and taking the theoretical residual capacity as the residual capacity when the upper-level electric capacity interval is converted into the current-level electric capacity interval. The theoretical residual capacity is used as the residual capacity when the initial upper-level electric quantity interval is converted into the current-level electric quantity interval, so that the residual capacity is convenient to obtain; similarly, it can be known that the time at the time of initialization is used as the time from the upper power interval to the time of transition from the current power interval, so as to obtain the battery usage time of the current power interval.

After step S6 is executed, the remaining power C2 obtained in step S6 is used as the remaining power when the upper power interval is shifted to the current power interval, instead of the remaining power when the original upper power interval is shifted to the current power interval, and it can be known that the time when the remaining power C2 is obtained in step S6 is used as the time when the upper power interval is shifted to the current power interval, so as to obtain the battery usage time of the current power interval, and of course, after step S6 is executed, the time when the upper power interval is shifted to the current power interval and the remaining power when the upper power interval is shifted to the current power interval both change.

Taking the current remaining capacity as 85% as an example, at this time, the upper level electric capacity interval is [ 100%, 90%), the current level electric capacity interval is [ 90%, 80%), and the remaining capacity obtained by the present invention when the upper level electric capacity interval is converted to the current level electric capacity interval is equal to 90% or close to 90%, but not necessarily 90%. The reason is that: in the actual calculation process, after the grade conversion of the second electric quantity interval occurs, the residual electric quantity C2 is used as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; it should be noted that, due to the difference of the preset time intervals and the error between the remaining capacity C1 and the actual remaining capacity, it is determined that the actual time when the level transition of the second capacity interval occurs is not the time when the level transition of the second capacity interval occurs exactly, and the remaining capacity C2 itself has an error, so that the remaining capacity obtained by the present invention from the upper level capacity interval to the current level capacity interval is not necessarily equal to 90%.

The battery service time of the current-level electric quantity interval is as follows: namely the used time of the battery in the current-level electric quantity interval; the battery service time and the interval average current of the current-level electric quantity interval are used for calculating the used electric quantity of the current-level electric quantity interval. After the second electric quantity interval grade conversion is judged according to the current battery temperature and the current battery voltage, the residual electric quantity C2 is used as the residual electric quantity when the upper electric quantity interval is converted into the current electric quantity interval, so in order to reduce the calculation error, the battery service time of the current electric quantity interval is obtained by calculating according to a formula II:

ΔT＝T-T₁(II)

Wherein, Δ T represents the battery service time of the current-level electric quantity interval, T represents the current time₁And the time from the upper electric quantity interval to the current electric quantity interval is represented. The time from the upper electricity quantity interval to the current electricity quantity interval is the time when the level of the second electricity quantity interval is judged to be changed or the time when the residual electricity quantity from the upper electricity quantity interval to the current electricity quantity interval is initialized at the latest time according to the current battery temperature and the current battery voltage.

Interval average current: i.e. the average current of the current level electric quantity interval. As an alternative way of acquiring the interval average current, one of the following acquisition ways may be adopted. The first way to obtain the interval average current is: the theoretical average current is directly used as the interval average current, and the theoretical average current can be verified by means of instrument measurement, for example, a battery is connected with a product and is monitored for 1-72 hours or more, so that the average current of all functions of the product, which can normally and stably run, is obtained; the theoretical average current can also be the average current calculated by matching the parameters of the battery with the product connected with the battery; the method for obtaining the theoretical average current is taken as a conventional means in the technology in the field, and the invention is not described in detail; the advantages are that: repeated measurement or repeated calculation of the average current of the interval is not needed in the subsequent calculation process, and the defects are as follows: the obtained interval average current has low accuracy, and particularly has large error when abnormal conditions occur. The second way to obtain the interval average current is: before the first second electric quantity interval grade is changed, the theoretical average current of the battery is used as the interval average current, and after the first second electric quantity interval grade is changed, the average current of a higher-level electric quantity interval is used as the interval average current; the advantages are that: the interval average current can be obtained without measurement, the accuracy of the obtained interval average current is high, and dynamic update of the interval average current is achieved, so that the interval average current is close to an actual value, and the battery residual electric quantity of the metering instrument is calculated more accurately. It is understood that, in addition to the above three ways, other relevant ways can be adopted to obtain the interval average current.

In the above optional manners for obtaining the interval average current, the second manner for obtaining the interval average current is a preferable embodiment, and if the second manner for obtaining the interval average current is adopted, as an optional manner for calculating the average current of the upper electric quantity interval, the average current of the upper electric quantity interval may be calculated by the following formula: the average current of the upper electric quantity interval can be calculated by adopting a formula I:

wherein the content of the first and second substances,

the average current of the upper electric quantity interval is represented; c₀Representing the residual electric quantity when the upper electric quantity interval is converted into the upper electric quantity interval; c₁Representing the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; t is₀The time from the upper electric quantity interval to the upper electric quantity interval is represented; t is₁And the time from the upper electric quantity interval to the current electric quantity interval is represented. Taking the remaining power as 75% for example, the upper power interval is [ 100%, 90%), the remaining power when the upper power interval is shifted to the upper power interval is [ 100%, 90%) to [ 90%, 80%), and the time when the upper power interval is shifted to the upper power interval is [ 100%, 90%) to [ 90%, 80%). It can be known that the remaining power when the upper power interval to the upper power interval is shifted when the remaining power is 75% is the remaining power when the upper power interval to the current power interval is shifted when the remaining power is 85%; the time from the upper power level section when the remaining power is 75% to the transition of the upper power level section is the time from the upper power level section when the remaining power is 85% to the transition of the current power level section. The advantages are that: after the level of the second electric quantity interval is changed for the first time, the average current of the upper electric quantity interval is used as the interval average current, namely the average current is calculated according to the actual used electric quantity and the actual using time, and the interval average current in the previous period is dynamically updated according to the calculated average current, so that the calculation of the residual electric quantity of the battery is more accurate.

For example: measuring the average current of the initial period of the product by using a 16Ah lithium battery

The power is 200uA (theoretical average current, which can be verified by using an instrument), when the grade change of the residual power is detected for the first time, the residual power is measured to be 14Ah, and the service life is 1 year.

According to the residual electric quantity, the used electric quantity in the current-level electric quantity interval can be calculated to be 2 Ah.

Calculating interval average current:

finally 228uA was used instead of an average current of 200 uA.

And when the power level conversion is detected again, the residual power of the lithium battery is measured to be 12Ah, and the total service life is 0.9 year.

According to the residual electric quantity, the used electric quantity from the higher-level electric quantity grade to the current level can be calculated to be 2 Ah.

Calculating the average current:

finally 254uA was used instead of average current of 228 uA.

By analogy, the remaining capacity is calculated with the most recently calculated average current.

As an alternative embodiment of the foregoing method for calculating the remaining battery capacity of the gauge, the remaining capacity C1 may be obtained by calculation using the following formula three:

represents the interval average current.

As an optional implementation manner in the method for calculating the remaining battery capacity of the metering device, the current battery temperature and the current battery voltage are both obtained through detection, specifically, the current battery temperature may be measured by a temperature sensor, and the battery voltage may be obtained through sampling by a discharge voltage monitoring circuit.

As an optional implementation manner in the method for calculating remaining battery power of a metering device, the step of determining whether a second power interval level transformation occurs according to the current battery temperature and the current battery voltage may be: and acquiring an electric quantity interval corresponding to the current battery voltage according to the CCV-SOC data table at the current battery temperature, and judging whether second electric quantity interval grade conversion occurs or not according to the electric quantity interval.

As an optional implementation manner of the method for calculating remaining battery capacity of a metering device, the obtaining of remaining battery capacity C2 according to the current battery temperature and the current battery voltage includes: and acquiring the electric quantity corresponding to the current battery voltage as the residual electric quantity C2 according to the linear relation between the battery voltage and the electric quantity in the current electric quantity grade interval under the current battery temperature and the linear relation. And acquiring more accurate residual electric quantity according to the current battery temperature and the current battery voltage by utilizing the linear relation between the battery voltage and the electric quantity in the current electric quantity grade interval so as to obtain a more accurate residual electric quantity value. It can be known that the linear relationship between the battery voltage and the electric quantity in the current electric quantity grade interval at the current battery temperature can be directly embodied on a CCV-SOC data table, namely, the corresponding relationship between the battery voltage and the electric quantity in the electric quantity grade interval is refined; if the battery voltage V1 corresponds to 90% of the remaining electric quantity; battery voltage V2 corresponds to 89% remaining battery power; the battery voltage V3 corresponds to 88% of remaining power; v1, V2 and V3 indicate specific voltage value or values.

Example 2:

the difference from example 1 is that: the method for calculating the residual electric quantity of the battery of the metering instrument further comprises a step of evaluating the residual service life of the battery, and the step of evaluating the residual service life of the battery comprises the following steps: and acquiring the average current of the residual electric quantity C1 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C1 and the average current of the upper-level electric quantity interval. It can be known that the remaining service life of the battery can be obtained by dividing the remaining capacity C1 by the average current of the above-level capacity interval. The remaining service life of the battery can reflect the service life of the metering instrument and is used as the basis for maintenance and replacement of the metering instrument.

Example 3:

the difference from example 1 is that: the method for calculating the residual electric quantity of the battery of the metering device further comprises the following steps: the method comprises a step of evaluating the remaining service life of the battery, wherein the step of evaluating the remaining service life of the battery comprises the following steps: and acquiring the average current of the residual electric quantity C2 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C2 and the average current of the upper-level electric quantity interval. It can be known that the remaining service life of the battery can be obtained by dividing the remaining capacity C2 by the average current of the above-level capacity interval. The remaining service life of the battery can reflect the service life of the metering instrument and is used as the basis for maintenance and replacement of the metering instrument.

Example 4:

in the embodiment, a step of alarming by a meter is added on the basis of the embodiment 2 or the embodiment 3: and acquiring the theoretical remaining service life of the battery, and judging whether the metering device gives an alarm or not according to the remaining service life of the battery and the theoretical remaining service life of the battery. Specifically, whether the metering device gives an alarm or not according to the remaining service life of the battery and the theoretical remaining service life of the battery may be: and judging whether the difference value between the theoretical remaining service life of the battery and the remaining service life of the battery is greater than a preset set difference value or not, and if so, giving an alarm. Whether the metering device gives an alarm or not can be judged according to the remaining service life of the battery and the theoretical remaining service life of the battery as follows: and alarming when the ratio of the residual service life of the battery to the theoretical residual service life of the battery is smaller than a preset set ratio value. It should be understood that the alarm mode can be various, and the preferred alarm mode of the invention is remote alarm through wireless communication.

Example 5:

in this embodiment, a second warning step executed in parallel is added on the basis of embodiment 1, embodiment 2, embodiment 3 or embodiment 4. As shown in fig. 2, the second early warning step includes:

and executing a second early warning step once every set time interval, and judging whether to alarm or not according to the residual capacity C3 obtained by the residual capacity online detection method. The method can solve the problem that the battery is abnormal due to too fast electric quantity loss when the battery is abnormal.

The second early warning step is to give an alarm when the battery is abnormal, and simultaneously judge whether a residual capacity C3 needs to be obtained by adopting a residual capacity online monitoring method before the alarm; the interval setting time period may be set for a relatively long time, for example, one month. It can be known that the set duration can be different according to different current power level intervals, for example, the remaining power is in the interval of [ 100% to 90%), the detection times need to be increased appropriately, that is, the preset duration value is set to be decreased appropriately, so as to detect whether the lithium primary battery has a power consumption abnormal condition with large power consumption; for example, when the remaining power is in the range of [ 30% -20%), the battery power may soon fail to support the normal operation of the system, and the number of detections also needs to be increased appropriately, i.e., the set duration value is set to be decreased appropriately, so as to find out the abnormality in time.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may be: and acquiring residual electric quantity C1, if the difference value between the residual electric quantity C1 and the residual electric quantity C3 exceeds a difference threshold value N1, judging that the alarm condition is met, otherwise, judging that the alarm condition is not met. Whether the alarm is given is judged by judging whether the difference value between the residual electric quantity C1 calculated by the ampere-hour meter algorithm and the residual electric quantity C3 calculated by the residual electric quantity detection method exceeds a difference threshold value N1, and whether the alarm condition is met is judged by simple steps, wherein the difference threshold value N1 can be set according to actual requirements, such as 0.2 Ah.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may also be: acquiring residual electric quantity C1, if the ratio of the residual electric quantity C1 to the residual electric quantity C3 exceeds a ratio threshold value M1, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met; whether the ratio of the residual electric quantity C1 calculated by the ampere-hour meter algorithm to the residual electric quantity C3 calculated by the residual electric quantity detection method exceeds a ratio threshold value M1 is judged to judge whether an alarm is given or not, whether an alarm condition is met or not is judged by simple steps, and the ratio threshold value M1 can be set according to actual requirements, such as 1.1.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may also be: acquiring the used time of a battery and the average current of a higher-level electric quantity interval; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; and if the difference value between the used average current of the battery and the average current of the upper-level electric quantity interval exceeds the difference threshold value N2, judging that the alarm condition is met, otherwise, not meeting the alarm condition. The average current used by the battery is compared with the average current of the upper electricity quantity section to judge whether to alarm, when the current-level section is abnormal, the difference value between the average current used by the battery and the average current of the upper electricity quantity section is increased and exceeds a difference threshold value N2, so that whether the alarm condition is met can be judged by judging whether the difference value between the average current used by the battery and the average current of the upper electricity quantity section exceeds a difference threshold value N2. The difference threshold N2 may be set according to actual requirements, for example, 30 uA.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may also be: acquiring the used time of a battery and the average current of a higher-level electric quantity interval; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; and if the ratio of the used average current of the battery to the average current of the upper electricity quantity interval exceeds a ratio threshold value M2, judging that the alarm condition is met, otherwise, judging that the alarm condition is not met. The average current used by the battery is compared with the average current of the upper electricity quantity section to judge whether to alarm, when the current-level section is abnormal, the ratio of the average current used by the battery to the average current of the upper electricity quantity section is increased and exceeds a ratio threshold value M2, so that whether the alarm condition is met can be judged by judging whether the ratio of the average current used by the battery to the average current of the upper electricity quantity section exceeds a ratio threshold value M2. The value threshold N2 may be set according to actual requirements, for example, 1.1.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may also be: acquiring the used time and theoretical average current of the battery; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; and if the difference value of the used average current of the battery and the theoretical average current exceeds the difference threshold value N3, judging that the alarm condition is met, otherwise, not meeting the alarm condition. The used average current of the battery is compared with the theoretical average current to judge whether to alarm, when the interval at the current stage is abnormal, the difference value between the used average current of the battery and the theoretical average current is increased and exceeds a difference threshold value N3, so that whether the alarm condition is met can be judged by judging whether the difference value between the used average current of the battery and the theoretical average current exceeds a difference threshold value N3. The difference threshold N3 may be set according to actual requirements, for example, 30 uA.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may also be: acquiring the used time and theoretical average current of the battery; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; if the ratio of the used average current of the battery to the theoretical average current exceeds a ratio threshold value M3, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met; the average current used by the battery is compared with the theoretical average current to judge whether to alarm, when the current-level interval is abnormal, the ratio of the average current used by the battery to the theoretical average current is increased and exceeds a ratio threshold value M3, so that whether to meet the alarm condition can be judged by judging whether the ratio of the average current used by the battery to the theoretical average current exceeds a ratio threshold value M3. The value threshold N2 may be set according to actual requirements, for example, 1.1.

The judgment of whether the alarm condition is met according to the remaining electric quantity C3 may also be: judging whether electric quantity interval grade conversion occurs or not according to the residual electric quantity C3, if so, obtaining the pre-judging time for the electric quantity interval grade conversion according to the interval average current and the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval, and if the time difference between the pre-judging time and the current time exceeds the time difference threshold value, judging that the alarm condition is met; otherwise, the alarm condition is not met. And judging whether to alarm or not according to the time difference between the pre-judgment time and the current time only after judging whether the electricity quantity interval grade is changed or not according to the residual electricity quantity C3, so that the steps of judgment are reduced, and the judgment efficiency is judged.

The above description is only an embodiment of the present invention, but the technical features of the present invention are not limited thereto, and any changes or modifications within the technical field of the present invention by those skilled in the art are covered by the claims of the present invention.

Claims

1. The method for calculating the residual capacity of the battery of the metering device is characterized by comprising the following steps of:

step S0, dividing battery electric quantity grade interval;

and step S2, obtaining the residual capacity C1 according to the average current of the interval, the residual capacity when the interval from the upper level electric capacity interval to the current level electric capacity is changed and the battery service time of the current level electric capacity interval:

represents the interval average current;

step S6, acquiring the electric quantity corresponding to the current battery voltage as the residual electric quantity C2 according to the linear relation between the battery voltage and the electric quantity in the current electric quantity grade interval under the current battery temperature and according to the linear relation, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval;

and repeating the steps S1 to S6 after a preset time interval.

2. The method for calculating the remaining battery power of a metering device of claim 1, wherein before the step S1 is executed for the first time, the method further comprises an initialization step, and the initialization step comprises: acquiring the battery temperature and the battery voltage at the moment, acquiring residual electric quantity C2 according to the battery temperature and the battery voltage at the moment, and taking the residual electric quantity C2 as the residual electric quantity when the upper-level electric quantity interval is converted into the current-level electric quantity interval; or, before the step S1 is executed for the first time, the method further includes an initialization step, where the initialization step includes: and acquiring the theoretical residual capacity of the battery, and taking the theoretical residual capacity as the residual capacity when the upper-level electric capacity interval is converted into the current-level electric capacity interval.

3. The method for calculating the remaining battery power of a metering device according to claim 1, wherein a theoretical average current of the battery is used as a section average current before the first level-change of the second power section, and the average current of the upper level power section is used as the section average current after the first level-change of the second power section.

4. The method for calculating the remaining battery power of a metering device according to claim 3, wherein the average current of the upper power interval is calculated by a formula one:

5. The method for calculating the remaining battery power of the metering device according to claim 1, wherein the battery service time in the current-stage power interval is obtained by calculating according to a formula two:

ΔT＝T-T₁(II)

6. The method for calculating the remaining battery power of the metering device according to any one of claims 1 to 5, wherein: the method further comprises a battery remaining useful life evaluation step, the battery remaining useful life evaluation step comprising: acquiring the average current of the residual electric quantity C1 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C1 and the average current of the upper-level electric quantity interval; or, the method further comprises a step of evaluating the remaining service life of the battery, wherein the step of evaluating the remaining service life of the battery comprises the following steps: and acquiring the average current of the residual electric quantity C2 and the upper-level electric quantity interval, and calculating the residual service life of the battery according to the residual electric quantity C2 and the average current of the upper-level electric quantity interval.

7. The method for calculating the remaining battery power of a metering device according to claim 6, wherein: the method further comprises a first early warning step, wherein the first early warning step comprises the following steps: and acquiring the theoretical remaining service life of the battery, and judging whether the metering device gives an alarm or not according to the remaining service life of the battery and the theoretical remaining service life of the battery.

8. The method for calculating the remaining battery power of the metering device according to any one of claims 1 to 5, wherein: the method further comprises a second early warning step, wherein the second early warning step comprises the following steps:

acquiring the used time and theoretical average current of the battery; calculating the used electric quantity of the battery according to the residual electric quantity C3, and obtaining the used average current of the battery according to the used electric quantity and the used time of the battery; if the difference value between the used average current and the theoretical average current of the battery exceeds a difference threshold value N3, judging that an alarm condition is met, otherwise, judging that the alarm condition is not met;