1. A method for monitoring electric quantity metering error of AC charging station is characterized in that,

the method comprises the following steps:

the method comprises the steps of firstly, acquiring electric quantity metering data of each charging gun in a charging station in a charging process and electric quantity metering data of an alternating current general meter of the charging station;

the data includes: the charging station exchange summary table is used for measuring the electric quantity data in the past P measuring periods and the measuring data in the corresponding time period of each charging gun;

secondly, establishing a charging pile energy conservation equation set model comprising charging pile metering error parameters based on an energy conservation law and a charging station circuit topological structure;

thirdly, calculating each unknown physical quantity corresponding to the charging pile energy conservation equation set model by using a linear regression method;

step four, substituting the physical quantities calculated in the step three into a charging pile energy conservation equation set model according to the metering data in the step one, and then solving the charging pile energy conservation equation set model to obtain the metering error of the electric quantity of each charging gun;

and fifthly, judging whether the electric quantity metering error of each charging gun is smaller than a threshold value, and determining the metering function state of the charging gun according to the electric quantity metering error.

2. The method of claim 1, wherein the step of monitoring the error in the metering of electricity at the AC charging station,

in the first step, the power supply of the AC side general meter of the charging pile in the metering period j is metered to phi_{General assembly}(j) The electric quantity of a plurality of charging guns at the side of the charging pile is measured to be phi_{Gun i}(j)，i＝1，2，…M；

φ_{General assembly}(j) The electricity metering value of the metering point of the summary table in the same time interval,

φ_{gun i}(j) And metering the electric quantity metering value of each charging gun metering point.

3. The method of claim 2, wherein the step of monitoring the error of the electric quantity measurement of the AC charging station,

in the second step, the error parameter k of the charging pile is measured_iThe calculation formula of (2) is as follows:

wherein: epsilon_iAnd metering errors for the electric quantity of each charging gun.

4. The method of claim 3, wherein the step of monitoring the error of the electric quantity measurement of the AC charging station,

the calculation formula of the charging pile energy conservation equation set model is as follows:

the above formula is deformed, and the calculation formula of the difference between the total table of the metering period j and the sum of the electric quantity at the charging gun side is obtained as follows:

wherein

Wherein epsilon₀And the parameters of loss in the charging station comprise the energy loss and the line loss of each pile function module and each communication module.

5. The method of claim 4, wherein the step of monitoring the error of the electric quantity measurement of the AC charging station,

in the third step, calculating the physical quantities corresponding to the charging pile energy conservation equation set model:

charging gun metering error parameter kappa in charging pile energy conservation equation set model_iAnd a loss parameter epsilon in the charging station₀Is a parameter to be solved;

substituting the alternating current total meter and the electric quantity metering data of each charging gun to construct a plurality of charging pile energy conservation equation sets.

6. The method of claim 5, wherein the step of monitoring the error in the metering of electricity at the AC charging station,

solving the parameters to be solved by using a least square method to obtain the exact physical quantities;

substituting each physical quantity intoObtaining the metering error epsilon of each charging pile in the electric pile energy conservation equation set_i，

The calculation formula is as follows:

7. the method of claim 6, wherein the step of monitoring the error in the metering of electricity at the AC charging station,

the energy conservation equations of the charging piles are constructed as follows:

step one, a calculation formula of the sum of the electric quantity of the summary table and the charging gun side is rewritten into the following form:

step two, bringing the metering data into the formula in the step one, and establishing an equation set comprising the metering error parameters of the charging pile;

solving the equation set by using a least square method to obtain a metering error parameter kappa of each charging gun_iAnd the intra-site loss parameter epsilon₀；

Step four, solving according to the step three to obtain the metering error parameter kappa of each charging gun_iAnd the intra-site loss parameter epsilon₀And calculating to obtain the electric quantity metering error epsilon of each alternating current charging gun by using a calculation formula of the metering error parameters of the charging pile_i。

8. The method of claim 7, wherein the step of monitoring the error in the metering of electricity at the AC charging station,

the concrete form of the equation set of the charging pile metering error parameters is as follows:

9. the method for monitoring errors in metering of electricity at an AC charging station as recited in any of claims 1-8,

further comprising: sixthly, if the electric quantity metering error is larger than a threshold value, judging that the charging gun is abnormal in metering;

if the electric quantity metering error is smaller than the threshold value, judging that the charging gun is in normal metering;

the threshold value is error precision, and the value range of the threshold value is 1% -5%.

10. A charging station with a device for monitoring the metering error of electric quantity,

the system comprises at least one charging pile and electric quantity metering error monitoring equipment;

the charging pile is provided with at least one charging gun;

the electric quantity metering error monitoring equipment is provided with one or more processors and a storage device;

the storage device to store one or more programs;

the one or more programs, when executed by the one or more processors, cause the one or more processors to implement a method of coulomb error monitoring of an alternating current charging station according to any of claims 1-9.

Background

In the actual field operation of the field verification method for the electric quantity metering error of the charging pile metering point, special equipment based on real load detection is required for monitoring the charging pile, and most of the special equipment is integrated with a field monitoring vehicle, so that the cost is high, and the detection time of a single metering point is long. Overall, the scheme of monitoring the charging pile metering points through the on-site verification mode tends to increase the geometric multiple of workload along with the continuous increase of the number of the charging piles, and the research on a new, on-line and high-cost-performance charging pile metering point state monitoring technology and a management mode tends to be necessary.

Simultaneously, the measurement and detection of the charging pile are carried out by a tester carrying a load box to a field, the real load detection device is heavy, the energy consumption and time consumption of the detection process are low, the automation degree is low, and the demand on the tester is large. And trade detects with filling electric pile relates to the user many, and the use amount is big, and the area of involvement is wide, and the long-term good operation of filling electric pile can not be guaranteed to annual once the period measuring, needs state monitoring to guarantee that the measurement is accurate reliable.

Further, Chinese patent (publication number: CN109307852A) discloses a method and a system for determining the metering error of an electric automobile charging pile electric energy metering device, the invention provides the method and the system for determining the metering error of the electric automobile charging pile electric energy metering device, the method and the system comprehensively utilize a plurality of factors influencing the electric energy metering error, data mining is carried out by a cluster analysis method to generate samples, a fuzzy neural network method formed by combining a fuzzy system and an artificial neural network is utilized, the advantages of the two methods for processing a multi-coupling system are fully utilized, and an intelligent electric energy metering error evaluation model is built.

However, according to the scheme, the electric quantity metering value of the charging pile is predicted according to the first detection error and the charging pile states of the same type, and metering deviation exists; meanwhile, the method also needs to be carried out on site to carry out verification, belongs to the category of the traditional verification method, and has high verification cost; in the scheme, the electricity consumption prediction based on the clustering algorithm is further carried out, the result uncertainty is large, and a large error exists.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the electric quantity metering error monitoring method of the alternating current charging station and the charging station, which are characterized in that a charging pile energy conservation equation group model is constructed, and the charging pile comprehensive metering error is obtained by utilizing the charging pile metering table and the metering data in the charging station, so that the electric quantity metering error of the charging pile metering equipment can be remotely monitored on line, suspected abnormal charging piles can be effectively screened out, the workload of field verification is greatly reduced, the timeliness of field verification of the abnormal charging piles is improved, the detection cost is low, the accuracy is high, and the error is small.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a method for monitoring electric quantity metering error of AC charging station,

the method comprises the following steps:

the method comprises the steps of firstly, acquiring electric quantity metering data of each charging gun in a charging station in a charging process and electric quantity metering data of an alternating current general meter of the charging station;

the data includes: the charging station exchange summary table is used for measuring the electric quantity data in the past P measuring periods and the measuring data in the corresponding time period of each charging gun;

secondly, establishing a charging pile energy conservation equation set model comprising charging pile metering error parameters based on an energy conservation law and a charging station circuit topological structure;

thirdly, calculating each unknown physical quantity corresponding to the charging pile energy conservation equation set model by using a linear regression method;

step four, substituting the physical quantities calculated in the step three into a charging pile energy conservation equation set model according to the metering data in the step one, and then solving the charging pile energy conservation equation set model to obtain the metering error of the electric quantity of each charging gun;

and fifthly, judging whether the electric quantity metering error of each charging gun is smaller than a threshold value, and determining the metering function state of the charging gun according to the electric quantity metering error.

The alternating current charging station and the charging pile directly input the alternating current electric quantity of a power grid into the electric vehicle, an alternating current-direct current conversion module is arranged in the electric vehicle, and each charging gun has a corresponding electric quantity metering function.

Through continuous exploration and tests, the energy conservation equation set model comprising the charging pile metering error parameters is constructed, the energy conservation equation set and a corresponding solving method are constructed by utilizing the charging gun and the station total meter electricity metering data, and the charging gun electricity metering error is calculated.

According to the method, the electric quantity metering error of the charging pile is obtained through metering data analysis, so that the charging pile with the over-tolerance electric quantity metering error can be effectively screened out, and the metering deviation is reduced; meanwhile, the method can be used as a pre-screening step for field verification of the charging pile, so that the workload of field verification of the charging pile is greatly reduced, and the timeliness is high; further, the online real-time analysis can be realized, and the comprehensive cost is lower than that of field full inspection; compared with the prior art, the method has high accuracy and small error.

The linear regression method is least square method or Theil regression or Siegel regression or least median two times (LMS) regression.

As a preferable technical measure:

in the first step, the power supply of the AC side general meter of the charging pile in the metering period j is metered to phi_{General assembly}(j) The electric quantity of a plurality of charging guns at the side of the charging pile is measured to be phi_{Gun i}(j)，i＝1,2,…M；

φ_{General assembly}(j) The electricity metering value of the metering point of the summary table in the same time interval,

φ_{gun i}(j) And metering the electric quantity metering value of each charging gun metering point.

As a preferable technical measure:

in the second step, the error parameter k of the charging pile is measured_iThe calculation formula of (2) is as follows:

wherein: epsilon_iAnd metering errors for the electric quantity of each charging gun.

As a preferable technical measure:

the calculation formula of the charging pile energy conservation equation set model is as follows:

the above formula is deformed, and the calculation formula of the difference between the total table of the metering period j and the sum of the electric quantity at the charging gun side is obtained as follows:

wherein

And epsilon 0 is a loss parameter in the charging station, and comprises energy loss and line loss of each pile function module and each communication module.

As a preferable technical measure:

in the third step, calculating the physical quantities corresponding to the charging pile energy conservation equation set model:

charging gun metering error parameter kappa in charging pile energy conservation equation set model_iAnd a loss parameter epsilon in the charging station₀Is a parameter to be solved;

substituting the alternating current total meter and the electric quantity metering data of each charging gun to construct a plurality of charging pile energy conservation equation sets.

As a preferable technical measure:

solving the parameters to be solved by using a least square method to obtain the exact physical quantities;

substituting the physical quantities into a charging pile energy conservation equation set to obtain the metering error epsilon of each charging pile_i，

The calculation formula is as follows:

as a preferable technical measure:

the energy conservation equations of the charging piles are constructed as follows:

step one, a calculation formula of the sum of the electric quantity of the summary table and the charging gun side is rewritten into the following form:

step two, bringing the metering data into the formula in the step one, and establishing an equation set comprising the metering error parameters of the charging pile;

solving the equation set by using a least square method to obtain a metering error parameter kappa of each charging gun_iAnd the intra-site loss parameter epsilon₀；

Step four, solving according to the step three to obtain the metering error parameter kappa of each charging gun_iAnd the intra-site loss parameter epsilon₀And calculating to obtain the electric quantity metering error epsilon of each alternating current charging gun by using a calculation formula of the metering error parameters of the charging pile_i。

As a preferable technical measure:

the concrete form of the equation set of the charging pile metering error parameters is as follows:

as a preferable technical measure:

further comprising: if the electric quantity metering error is larger than the threshold value, judging that the charging gun is abnormal in metering;

if the electric quantity metering error is smaller than the threshold value, judging that the charging gun is in normal metering;

the threshold value is error precision, and the value range of the threshold value is 1% -5%.

As a preferable technical measure:

a charging station with a device for monitoring the metering error of electric quantity,

the system comprises at least one charging pile and electric quantity metering error monitoring equipment;

the charging pile is provided with at least one charging gun;

the electric quantity metering error monitoring equipment is provided with one or more processors and a storage device;

the storage device to store one or more programs;

when executed by the one or more processors, the one or more programs cause the one or more processors to implement a method of metering error monitoring for an ac charging station as described above.

Compared with the existing method for verifying the metering error of the charging gun on site through the virtual load and the real load, the method has the following advantages:

1. the overall time cost is low. The charging pile energy conservation equation set model disclosed by the invention is low in solving complexity, and can be used for calculating the metering errors of charging guns in a large number of charging stations in a short time.

2. Saving a large amount of manpower and material resources.

3. The charging gun charging system does not need to be additionally provided with equipment and modified by other devices in the station, and only needs to utilize the existing charging gun metering data and the total power consumption data of the charging station.

4. The required data accumulation time is shorter, the charging pile with problems can be found in time, and the timeliness is higher.

5. The invention can be realized on various computing platforms, and is convenient to be fused with other computing platforms.

Compared with the prior art, the invention has the following beneficial effects:

through continuous exploration and tests, the energy conservation equation set model comprising the charging pile metering error parameters is constructed, the energy conservation equation set and a corresponding solving method are constructed by utilizing the charging gun and the station total meter electricity metering data, and the charging gun electricity metering error is calculated. According to the method, the charging pile with the over-poor electric quantity metering error can be effectively screened out by analyzing the metering data, and the charging pile can be used as a pre-screening step for field verification of the charging pile, so that the workload of field verification of the charging pile is greatly reduced, the timeliness is high, online real-time analysis can be realized, the comprehensive cost is lower than that of field full-inspection, and compared with the prior art, the method has the advantages of high accuracy and small error.

Further, compared with the existing method for verifying the metering error of the charging gun on site through the virtual load and the real load, the method has the following advantages that:

1. the overall time cost is low. The charging pile energy conservation equation set model disclosed by the invention is low in solving complexity, and can be used for calculating the metering errors of charging guns in a large number of charging stations in a short time.

2. Saving a large amount of manpower and material resources.

3. The charging gun charging system does not need to be additionally provided with equipment and modified by other devices in the station, and only needs to utilize the existing charging gun metering data and the total power consumption data of the charging station.

4. The required data accumulation time is shorter, the charging pile with problems can be found in time, and the timeliness is higher.

5. The invention can be realized on various computing platforms, and is convenient to be fused with other computing platforms.

Drawings

FIG. 1 is a diagram of an AC charging station circuit topology to which the present invention is applicable;

FIG. 2 is a block diagram of the process of the present invention.

Detailed Description

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

On the contrary, the invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.

As shown in fig. 1-2, a method for monitoring metering error of electricity in an ac charging station,

the method comprises the following steps:

the method comprises the steps of firstly, acquiring electric quantity metering data of each charging gun in a charging station in a charging process and electric quantity metering data of an alternating current general meter of the charging station;

the data includes: the charging station exchange summary table is used for measuring the electric quantity data in the past P measuring periods and the measuring data in the corresponding time period of each charging gun;

secondly, establishing a charging pile energy conservation equation set model comprising charging pile metering error parameters based on an energy conservation law and a charging station circuit topological structure;

thirdly, calculating each unknown physical quantity corresponding to the charging pile energy conservation equation set model by using a linear regression method;

and fourthly, substituting the physical quantities calculated in the third step into the charging pile energy conservation equation set model according to the metering data in the first step, and then solving the charging pile energy conservation equation set model to obtain the metering error of the electric quantity of each charging gun.

And fifthly, judging whether the electric quantity metering error of each charging gun is smaller than a threshold value, and determining the metering function state of the charging gun according to the electric quantity metering error.

The alternating current charging station and the charging pile directly input the alternating current electric quantity of a power grid into the electric vehicle, an alternating current-direct current conversion module is arranged in the electric vehicle, and each charging gun has a corresponding electric quantity metering function.

Through continuous exploration and tests, the energy conservation equation set model comprising the charging pile metering error parameters is constructed, the energy conservation equation set and a corresponding solving method are constructed by utilizing the charging gun and the station total meter electricity metering data, and the charging gun electricity metering error is calculated. According to the method, the charging pile with the over-poor electric quantity metering error can be effectively screened out by analyzing the metering data, and the charging pile can be used as a pre-screening step for field verification of the charging pile, so that the workload of field verification of the charging pile is greatly reduced, the timeliness is high, online real-time analysis can be realized, the comprehensive cost is lower than that of field full-inspection, and compared with the prior art, the method has the advantages of high accuracy and small error.

The method mainly comprises the steps of obtaining data, establishing an energy conservation equation set model in the charging station based on an energy conservation law, wherein the energy conservation equation set model comprises charging gun metering error parameters, solving equations, converting results into metering errors, and determining the metering function state of the charging gun according to an error threshold value.

The data used by the invention are all the data automatically generated in the operation process of each metering device in the charging station, are all the existing data in the operation of the existing charging station, and do not need to additionally install data acquisition equipment and other auxiliary equipment.

The invention has the advantages that the data volume (the number of metering cycles) required for determining the metering error of the charging gun is low, and the time required for accumulating a sufficient number of effective metering cycles is short for the metering cycles which are less than or equal to 15 minutes and commonly adopted by the existing charging station and the in-station alternating current meter.

The invention can simultaneously calculate the electric quantity metering errors of a plurality of charging piles (guns) in one AC charging station, and is suitable for different charging station scales and charging station types (one pile for one gun or one pile for a plurality of guns).

A specific application embodiment of the invention is as follows:

the invention is suitable for monitoring the electric quantity metering error of the charging gun of the alternating current charging station. Suitable charging station types include:

1. there are a plurality of electric pile that fill, and every fills electric pile rifle that charges.

2. There are a plurality of electric pile that fill, and every fills a plurality of rifle that charge of electric pile.

3. Only one fills electric pile, fills electric pile and has a plurality of rifle that charges.

That is, the present invention is applicable to a charging station having a plurality of charging guns.

For a charging pile with only one charging gun, the electric quantity metering error of the charging gun is the electric quantity metering error of the charging pile; to the electric pile that fills that has a plurality of guns that charge, each gun that charges has independent ammeter measurement, and the error is different, fills electric pile electric quantity measurement error and indicates the electric quantity measurement error of each gun that charges in the stake. The invention directly calculates the electric quantity metering error of each charging gun.

The charging station applicable to the invention requires that each charging gun in the station has an electric quantity metering function and is a charging gun side metering point, and the station requires that a metering point for metering the total power supply quantity of an alternating current side is a total meter metering point.

According to the energy conservation method, through the energy conservation relation and the topological structure in the charging station, the established energy conservation equation set model of the charging pile is substituted into the electric quantity metering data and the electric quantity metering data of the alternating current total meter in the charging process of each charging gun in the charging station, and the electric quantity metering error of the charging gun is obtained through solving.

The topological structure is shown in figure 1, according to the topology, electric quantity flows out from the general table and finally flows onto the vehicle through the charging gun, and the electric quantity is conserved in the whole process.

A preferred embodiment of the present invention:

a metering cycle refers to a period of electricity usage.

For example, taking 15-minute intervals as a metering cycle, the power consumption of each charging gun in each 15 minutes is calculated according to the charging process data of the charging gun.

Recording the electric quantity of the alternating current side of P metering periods (data points) as phi_{General assembly}(j) J is 1, 2,.. P, M charging guns have electric quantity phi_{Gun i}(j) J is 1, 2, P, i is 1, 2, M, which means the totalized metering point electric quantity metering value and the metering point electric quantity metering value of each charging gun in the same time interval, and the real electric quantity used by each charging gun at the charging gun side is X_{Gun i}(j) The metering error of the charging gun is epsilon_iThen, there are:

is obtained by the above formula

The invention is also suitable for the electric quantity data of other metering periods.

According to the law of conservation of energy, there are

The total meter side power supply electric quantity is equal to the charging gun side charging electric quantity plus the station internal fixed loss epsilon₀

Wherein the station internal fixation loss comprises the loss of a charging pile display and communication equipment and a power transmission line.

The energy conservation relation is as follows:

substituting (2) into the formula:

namely:

note the book

In order to measure the error parameter(s),

the difference between the total table of the metering period j and the sum of the electric quantity on the charging gun side is shown.

The above equation is rewritten as follows

By the above formula, substitute electric quantity measurement data, can establish including filling electric pile energy conservation equation set model that fills electric pile measurement error parameter, its concrete form is as follows:

when the number of valid metering cycles P satisfies P>When M +1, the above equation can be solved by the least square method. The effective metering period means that the charging pile in the charging state in the metering period is different from other metering periods. In the equation set, each charging gun measures the error parameter kappa_iAnd a loss parameter epsilon in the charging station₀Are parameters to be solved.

Solving the equation set by using a least square method to obtain the metering error of each charging gunParameter k_iAnd the intra-site loss parameter epsilon₀According to the formula (1), the electric quantity metering error epsilon of each AC charging gun can be calculated_i。

And further, whether the electric quantity metering error of each charging gun is smaller than a threshold value is judged, the threshold value corresponds to the specified accuracy of the electric meter, if the electric meter is 0.5S, the error is not more than 0.5%, and the error threshold value is 0.5%. The charging gun is generally 1S table, namely, the error precision is 1 percent, and the threshold value is 1 percent.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.