CN111122964A - Electric energy metering method and system - Google Patents

Abstract

The embodiment of the application discloses an electric energy metering method and system, which measure U in a three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal; when U is turned_ABAccess terminal or U_CBWhen the terminal is accessed, a first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBIncluded angles with the first phase current Ia and the second phase current Ic respectively to calculate electric energy; when a double PT access terminal is accessed, the first phase voltage U is obtained_ABSecond phase voltage U_CBThe first phase current Ia,The second phase current Ic and the power factor angle to calculate the electrical energy. Under the condition of single and double PT access, the accuracy of electric quantity metering during double PT access can be maintained.

Description

Electric energy metering method and system

Technical Field

The embodiment of the application relates to the technical field of electric energy metering, in particular to an electric energy metering method and system.

Background

The electric energy metering is a very important technology in an electric power system, is generally used for measuring line loss in the power transmission and distribution process and settling the electric charge in the power utilization field, and in recent years, along with the rapid development of distribution network automation and the requirement of primary and secondary integration of distribution networks provided by national network companies, the call for lean management of the distribution networks is increasingly improved. The line loss in the transmission and distribution network is used as important data, special equipment is required to complete measurement, and a station terminal line loss module and a feeder line terminal line loss module are planned in a primary and secondary fusion scheme of a national network company. Wherein the feeder terminal line loss module is required to provide voltage, current and power measurement values with the precision of 0.5s and electric energy metering values with the precision of 0.5 s.

In the application of electric quantity metering, a common wiring mode is a three-phase three-wire wiring mode. In the case of single PT access, the measurement and metering accuracy is insufficient.

Disclosure of Invention

Therefore, the embodiment of the application provides an electric quantity metering method and system, which can keep the electric quantity metering precision during double PT access no matter single or double PT access.

In order to achieve the above object, the embodiments of the present application provide the following technical solutions:

according to a first aspect of embodiments of the present application, there is provided an electricity metering method, the method comprising:

measuring U in three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal;

when U is turned_ABAccess terminal or U_CBWhen the terminal is accessed, a first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBIncluded angles with the first phase current Ia and the second phase current Ic respectively to calculate electric energy;

when a double PT access terminal is accessed, the first phase voltage U is obtained_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy.

Alternatively, when U_ABWhen the terminal is accessed, the first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBThe angles with the first phase current Ia and the second phase current Ic respectively include:

obtaining a first phase voltage U_ABA first phase current Ia and a second phase current Ic;

according to the first phase voltage U_ABObtaining a virtual second phase voltage U by the first phase current Ia and the second phase current Ic_CBAngle α, Ia and U of_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caThe α is the first phase voltage U_ABIs a reference voltage, U_CBCalculated by rotating clockwise; theta is described_aIs the first phase voltage U_ABIs calculated for the reference voltage, Ia is rotated clockwise; theta is described_caIs the first phase voltage U_ABIc is calculated for the reference voltage, rotating clockwise;

according to the α and the theta_caObtaining the second phase current Ic and the virtual second phase voltage U_CBAngle of (theta)_cTheta of_cIs said theta_caThe difference from said α.

Alternatively, when U_CBWhen the terminal is accessed, the first phase voltage U is obtained_ABOr second phase voltageU_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBThe angles with the first phase current Ia and the second phase current Ic respectively include:

obtaining the voltage U of the second phase_CBA first phase current Ia and a second phase current Ic;

according to the second phase voltage U_CBThe first phase current Ia and the second phase current Ic obtain a virtual first phase voltage U_ABAngle β, Ia and U of_CBIncluded angle theta'_acIc and U_CBIncluded angle theta'_cThe β is the second phase voltage U_CBIs a reference voltage, U_ABCalculated by rotating clockwise; theta'_acIs the second phase voltage U_CBIs calculated for the reference voltage, Ia is rotated clockwise; theta'_cWith the second phase voltage U_CBIc is calculated for the reference voltage, rotating clockwise;

according to said β and said θ'_acObtaining the first phase current Ia and the virtual first phase voltage U_ABAngle of (d)'_aOf θ'_aIs the theta'_acThe difference from said β.

Optionally, the theta_cIs theta_caThe difference from α, comprising:

if said theta_caIf the difference value with the α is negative, the difference value is increased by 360 degrees to obtain a positive difference value, and the positive difference value is taken as the theta_caThe difference from said α;

theta'_aIs the theta'_acThe difference from said β, comprising:

if theta'_aIs the theta'_acIf the difference value with the β is negative, increasing the difference value by 360 degrees to obtain a positive difference value, and taking the positive difference value as the theta'_aIs the theta'_acThe difference from said β.

Optionally, the electric energy calculation method includes:

calculating electric energy according to the total active power and time;

the total active power is calculated according to the split-phase active power and the split-phase reactive power;

the phase-splitting active power and the phase-splitting reactive power are based on the first phase voltage U_ABThe second phase voltage U_CBThe first phase current Ia, the second phase current Ic and a factor angle group, the factor angle group being a first factor angle group or a second factor angle group, the first factor angle group comprising theta_aAnd theta_cAnd the second set of divisor angles comprises θ'_aAnd θ'_c。

According to a second aspect of embodiments of the present application, there is provided a system for metering electrical quantity, the system comprising:

a judging module for measuring U in three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal;

single phase PT metering module, as U_ABAccess terminal or U_CBWhen accessing the terminal, it is used to obtain the first phase voltage U_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBIncluded angles with the first phase current Ia and the second phase current Ic respectively to calculate electric energy;

a two-phase PT metering module for acquiring the first phase voltage U when the two PT access terminals_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy.

Alternatively, when U_ABWhen the terminal is accessed, the single-phase PT metering module is specifically used for:

obtaining a first phase voltage U_ABA first phase current Ia and a second phase current Ic;

according to the first phase voltage U_ABThe first phase current Ia and the second phase current Ic are obtained as virtualPseudo second phase voltage U_CBAngle α, Ia and U of_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caThe α is the first phase voltage U_ABIs a reference voltage, U_CBCalculated by rotating clockwise; theta is described_aIs the first phase voltage U_ABIs calculated for the reference voltage, Ia is rotated clockwise; theta is described_caIs the first phase voltage U_ABIc is calculated for the reference voltage, rotating clockwise;

according to the α and the theta_caObtaining the second phase current Ic and the virtual second phase voltage U_CBAngle of (theta)_cTheta of_cIs said theta_caThe difference from said α.

Alternatively, when U_CBWhen the terminal is accessed, the single-phase PT metering module is specifically used for:

obtaining the voltage U of the second phase_CBA first phase current Ia and a second phase current Ic;

according to the second phase voltage U_CBThe first phase current Ia and the second phase current Ic obtain a virtual first phase voltage U_ABAngle β, Ia and U of_CBIncluded angle theta'_acIc and U_CBIncluded angle theta'_cThe β is the second phase voltage U_CBIs a reference voltage, U_ABCalculated by rotating clockwise; theta'_acIs the second phase voltage U_CBIs calculated for the reference voltage, Ia is rotated clockwise; theta'_cWith the second phase voltage U_CBIc is calculated for the reference voltage, rotating clockwise;

according to said β and said θ'_acObtaining the first phase current Ia and the virtual first phase voltage U_ABAngle of (d)'_aOf θ'_aIs the theta'_acThe difference from said β.

Optionally, the theta_cIs theta_caThe difference from α, comprising:

if said theta_caA negative difference from α, increasing the differenceObtaining a forward difference value by 360 degrees, and taking the forward difference value as theta_caThe difference from said α;

theta'_aIs the theta'_acThe difference from said β, comprising:

if theta'_aIs the theta'_acIf the difference value with the β is negative, increasing the difference value by 360 degrees to obtain a positive difference value, and taking the positive difference value as the theta'_aIs the theta'_acThe difference from said β.

Optionally, the system further comprises: the electric energy metering module is specifically used for:

calculating electric energy according to the total active power and time;

the total active power is calculated according to the split-phase active power and the split-phase reactive power;

the phase-splitting active power and the phase-splitting reactive power are based on the first phase voltage U_ABThe second phase voltage U_CBThe first phase current Ia, the second phase current Ic and a factor angle group, the factor angle group being a first factor angle group or a second factor angle group, the first factor angle group comprising theta_aAnd theta_cAnd the second set of divisor angles comprises θ'_aAnd θ'_c。

In summary, the embodiments of the present application provide an electric energy metering method and system, which measure U in a three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal; when U is turned_ABAccess terminal or U_CBWhen the terminal is accessed, a first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBIncluded angles with the first phase current Ia and the second phase current Ic respectively to calculate electric energy; when a double PT access terminal is accessed, the first phase voltage U is obtained_ABSecond phase voltage U_CBFirst, aPhase current Ia, second phase current Ic and power factor angle to calculate electrical energy. The accuracy of electric quantity metering during double PT access can be kept no matter under the condition of single or double PT access.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so that those skilled in the art can understand and read the present invention, and do not limit the conditions for implementing the present invention, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the functions and purposes of the present invention, should still fall within the scope of the present invention.

Fig. 1 is a schematic flow chart of an electric energy metering method according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram of an embodiment of an electric energy meter provided in an embodiment of the present application;

fig. 3 is a schematic diagram of an embodiment of an electric energy meter according to the present application;

fig. 4 is a block diagram of an electric energy metering system according to an embodiment of the present application.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A Potential Transformer (PT) is an instrument for transforming the voltage on a line, similar to a transformer. However, the purpose of transforming voltage by the transformer is to transmit electric energy, so the capacity is large, and is generally calculated by kilovolt-ampere or mega volt-ampere. The purpose of voltage transformer transformation is mainly to supply power to measuring instruments and relay protection devices, to measure the voltage, power and electric energy of lines, or to protect valuable equipment, motors and transformers in lines in case of line faults.

Because the voltage of the power grid is relatively stable in normal use, the voltage can be basically considered as U_ABAnd U_CBThe amplitude values are equal, and the electric energy metering method and the electric energy metering system provided by the embodiment of the application can still obtain the same measurement and metering precision as that of double PT access under the condition of single PT access. Only the internal part of the metering terminal needs to be adjusted on a software algorithm, the access signals of the other 1 PT are simulated by using software, and the measurement and metering data are calculated.

As shown in fig. 1, in the electric energy metering method provided in the embodiments of the present application, if only a single PT is accessed to a field voltage signal, a metering terminal virtualizes an input signal of another 1 PT channel according to the accessed single PT signal, and calculates measurement data such as voltage, current, and power and electric energy metering data. The virtual algorithm can be started and closed through the communication interface, and the actual requirements of a user on various field application scenes are met. The electric energy metering method comprises the following steps:

step 101: measuring U in three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal.

Step 102: when U is turned_ABAccess terminal or U_CBWhen the terminal is accessed, a first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the saidSecond phase voltage U_CBRespectively forming included angles with the first phase current Ia and the second phase current Ic to calculate electric energy.

Step 103: when a double PT access terminal is accessed, the first phase voltage U is obtained_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy.

In step 101, when the terminal parameter is configured as a three-phase three-wire access mode and the virtual computation is started, the judgment is started, and the judgment condition is as follows: when U is turned_ABGreater than a set threshold and U_CBWhen the value is less than the set threshold value, virtualizing a U_CBSo that U is_CB＝U_AB(ii) a When U is turned_CBGreater than a set threshold and U_ABWhen the value is less than the set threshold value, virtualizing a U_ABSo that U is_AB＝U_CB(ii) a Otherwise, normal calculation is carried out according to the double PT access.

The voltage of the power grid is relatively stable and can be basically considered as U_ABAnd U_CBEqual in amplitude, can be considered as U_CBAmplitude equal to U_ABAnd the angle between the two is considered to be different by 60 °

In step 102, when U is in operation_ABWhen the terminal is accessed, a first phase voltage U is obtained_ABA first phase current Ia and a second phase current Ic; according to the first phase voltage U_ABObtaining a virtual second phase voltage U by the first phase current Ia and the second phase current Ic_CBAngle α, Ia and U of_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caThe α is the first phase voltage U_ABIs a reference voltage, U_CBCalculated by rotating clockwise; theta is described_aIs the first phase voltage U_ABIs calculated for the reference voltage, Ia is rotated clockwise; theta is described_caIs the first phase voltage U_ABCalculated for reference voltage, Ic clockwise rotation, based on said α and said θ_caObtaining the second phase current Ic and the virtual second phase voltage U_CBAngle of (theta)_cTheta of_cIs said theta_caThe difference from said α.

In step 102, when U is in operation_CBWhen accessing the terminal, obtaining the voltage U of the second phase_CBA first phase current Ia and a second phase current Ic; according to the second phase voltage U_CBThe first phase current Ia and the second phase current Ic obtain a virtual first phase voltage U_ABAngle β, Ia and U of_CBIncluded angle theta'_acIc and U_CBIncluded angle theta'_cThe β is the second phase voltage U_CBIs a reference voltage, U_ABCalculated by rotating clockwise; theta'_acIs the second phase voltage U_CBIs calculated for the reference voltage, Ia is rotated clockwise; theta'_cWith the second phase voltage U_CBCalculated for reference voltage, Ic clockwise rotation from said β and said θ'_acObtaining the first phase current Ia and the virtual first phase voltage U_ABAngle of (d)'_aOf θ'_aIs the theta'_acThe difference from said β.

In one possible embodiment, if θ is greater than θ_caIf the difference value with the α is negative, the difference value is increased by 360 degrees to obtain a positive difference value, and the positive difference value is taken as the theta_caDifference with the α if theta'_aIs the theta'_acIf the difference value with the β is negative, increasing the difference value by 360 degrees to obtain a positive difference value, and taking the positive difference value as the theta'_aIs the theta'_acFor example, a difference of minus 60 degrees, then a positive difference of 300 degrees.

In one possible embodiment, the electric energy calculation method includes: calculating electric energy according to the total active power and time; the total active power is calculated according to the split-phase active power and the split-phase reactive power; the phase-splitting active power and the phase-splitting reactive power are based on the first phase voltage U_ABThe second phase voltage U_CBThe first phase current Ia, the second phase current Ic and a factor angle group, the factor angle group being a first factor angle group or a second factor angle group, the first factor angle group comprising theta_aAnd theta_cWhat is, what isThe second set of factor angles comprises θ'_aAnd θ'_c。

In one possible embodiment, the formula for the split-phase active power calculation may be Pa ═ U_AB×Ia×cosθ_a，Pc＝U_CB×Ic×cosθ_c(ii) a The formula of the split-phase reactive power calculation can be Qa ═ U_AB×Ia×sinθ_a，Qc＝U_CB×Ic×sinθ_c(ii) a The formula for the split phase apparent power calculation may be: sa is equal to U_AB×Ia，Sc＝U_CBX Ic; the formula for the total active power may be: pa + Pc, Qa + Qc, S²＝P²+Q²(ii) a Further, the electric energy value is accumulated and calculated according to the calculated power.

In order to more clearly illustrate the electric energy metering method provided by the embodiment of the present application, the following description is made by way of example with reference to the accompanying drawings. In order to meet the requirements of various application scenes of a client site, the virtual algorithm function is not started under the default condition, the virtual algorithm function can be configured through software and a communication interface, and after the virtual calculation function is started, the terminal can still automatically judge that the terminal is U according to the actual wiring effect_ABAccess terminal, U_CBAnd the access terminal or the dual PT access terminal automatically switches the normal calculation mode or the virtual calculation mode according to the actual wiring condition. When detecting single PT access, the terminal automatically virtualizes another 1 PT access signal by using a virtual computing mode, and starts to compute measurement and metering data.

When the terminal parameters are configured in a three-phase three-wire access mode and virtual calculation is started, starting judgment is carried out, the set threshold value can be 20V, and the judgment condition is as follows: when U is turned_AB>20V and U_CB<Virtualizing U at 20V_CBI.e. U_CB＝U_AB(ii) a When U is turned_CB>20V and U_AB<Virtualizing U at 20V_ABI.e. U_AB＝U_CB(ii) a Otherwise, normal calculation is carried out according to the double PT access.

In a conventional three-phase three-wire wiring system, as shown in fig. 2, U_ABAnd U_CBThe voltage signals have basically equal amplitude and 60 degrees of angle difference, and the current has different amplitude and angle according to the load characteristicsThe degrees are different, and in the wiring mode system, the voltage access signal is stable and unchangeable.

As shown in FIG. 3, upon loss of access to a PT, e.g., loss of U_CBUnder the condition of access, the voltage of the power grid is relatively stable, and basically, the voltage can be considered as U_ABAnd U_CBEqual in amplitude, can be considered as U_CBAmplitude equal to U_ABAnd the angle between the two is considered to differ by 60. Obtaining the current I by CT access signal_AAnd I_CSum of amplitudes relative to U_ABThe angle of (c). Thus, the virtual U can be obtained_CBAnd other values obtained by sampling, further calculating a measured value, and accumulating the electric energy value according to the calculated power value. The accuracy requirement of 0.5s is met.

Virtual U_CBAnd (3) calculating: u shape_ABSetting the angle of the reference voltage as 0 degree, rotating the angle clockwise for calculation, sampling the amplitude of the current sampling signal to obtain Ia and Ic directly, and calculating the angle by U_ABIa and U for reference_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caConsider U as_CB＝U_ABAnd the angle is 300 deg., so Ic and U can be derived from the vector diagram analysis of FIG. 2_CBIncluded angle theta_c＝θ_ca300 (the calculation needs to be adjusted to be within 0-360 degrees, namely, if the calculation is negative, the calculation is + 360), and then the calculation is carried out according to a formula.

Virtual U_ABAnd (3) calculating: u shape_CBRegarding the reference voltage as a reference voltage, the angle of the reference voltage is 0 degrees, the angle is calculated according to clockwise rotation, the amplitude of the current sampling signal can be sampled to directly obtain Ia and Ic, and the angles are U_CBIa and U for reference_CBIncluded angle theta_caIc and U_CBIncluded angle theta_cConsider U as_AB＝U_CBAnd the angle is +60 deg., so Ia and U can be obtained by the vector diagram analysis of FIG. 2_ABIncluded angle theta_a＝θ_ca60 (the calculation needs to set the result to be within 0-360 degrees, namely +360 treatment if the result is a negative value), and then the calculation is carried out according to a formula.

In order to meet the requirements of various application scenes of a client on site, the embodiment of the application providesThe electric energy metering method is not started under the condition of function default, can be configured through software and a communication interface, and can still automatically judge that the terminal is U according to the actual wiring effect after the virtual computing function is started_ABAccess terminal, U_CBThe access terminal is also a dual PT both access terminal. The normal calculation mode or the virtual calculation mode can be automatically switched according to the actual wiring condition. When detecting single PT access, the terminal automatically virtualizes 1 other PT access signal by using a virtual computing mode, and computes measurement and metering data.

In summary, the method and system for measuring electric energy provided by the embodiment of the present application measure U in a three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal; when U is turned_ABAccess terminal or U_CBWhen the terminal is accessed, a first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBIncluded angles with the first phase current Ia and the second phase current Ic respectively to calculate electric energy; when a double PT access terminal is accessed, the first phase voltage U is obtained_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy. The accuracy of electric quantity metering during double PT access can be kept no matter under the condition of single or double PT access.

Based on the same technical concept, an embodiment of the present application further provides an electric energy metering system, as shown in fig. 4, the system includes:

a judging module 401 for measuring U in the three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal.

Single phase PT metering module 402, as U_ABAccess terminal or U_CBAccess terminalIs used for acquiring a first phase voltage U_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBRespectively forming included angles with the first phase current Ia and the second phase current Ic to calculate electric energy.

A two-phase PT metering module 403 for acquiring the first phase voltage U when a dual PT access terminal is connected to_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy.

In one possible embodiment, when U_ABWhen accessing the terminal, the single-phase PT metering module 402 is specifically configured to:

obtaining a first phase voltage U_ABA first phase current Ia and a second phase current Ic; according to the first phase voltage U_ABObtaining a virtual second phase voltage U by the first phase current Ia and the second phase current Ic_CBAngle α, Ia and U of_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caThe α is the first phase voltage U_ABIs a reference voltage, U_CBCalculated by rotating clockwise; theta is described_aIs the first phase voltage U_ABIs calculated for the reference voltage, Ia is rotated clockwise; theta is described_caIs the first phase voltage U_ABCalculated for reference voltage, Ic clockwise rotation, based on said α and said θ_caObtaining the second phase current Ic and the virtual second phase voltage U_CBAngle of (theta)_cTheta of_cIs said theta_caThe difference from said α.

In one possible embodiment, when U_CBWhen accessing the terminal, the single-phase PT metering module 402 is specifically configured to:

obtaining the voltage U of the second phase_CBA first phase current Ia and a second phase current Ic; according to the second phase voltage U_CBThe first phase current Ia and the second phase current Ic obtain a virtual first phase voltage U_ABAngle β, Ia and U of_CBIncluded angle theta'_acIc andU_CBincluded angle theta'_cThe β is the second phase voltage U_CBIs a reference voltage, U_ABCalculated by rotating clockwise; theta'_acIs the second phase voltage U_CBIs calculated for the reference voltage, Ia is rotated clockwise; theta'_cWith the second phase voltage U_CBCalculated for reference voltage, Ic clockwise rotation from said β and said θ'_acObtaining the first phase current Ia and the virtual first phase voltage U_ABAngle of (d)'_aOf θ'_aIs the theta'_acThe difference from said β.

In one possible embodiment, if θ is greater than θ_caIf the difference value with the α is negative, the difference value is increased by 360 degrees to obtain a positive difference value, and the positive difference value is taken as the theta_caDifference with the α if theta'_aIs the theta'_acIf the difference value with the β is negative, increasing the difference value by 360 degrees to obtain a positive difference value, and taking the positive difference value as the theta'_aIs the theta'_acThe difference from said β.

In one possible embodiment, the electric energy metering system further includes: the electric energy metering module is specifically used for:

calculating electric energy according to the total active power and time; the total active power is calculated according to the split-phase active power and the split-phase reactive power; the phase-splitting active power and the phase-splitting reactive power are based on the first phase voltage U_ABThe second phase voltage U_CBThe first phase current Ia, the second phase current Ic and a factor angle group, the factor angle group being a first factor angle group or a second factor angle group, the first factor angle group comprising theta_aAnd theta_cAnd the second set of divisor angles comprises θ'_aAnd θ'_c。

In the present specification, each embodiment of the method is described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. Reference is made to the description of the method embodiments.

It is noted that while the operations of the methods of the present invention are depicted in the drawings in a particular order, this is not a requirement or suggestion that the operations must be performed in this particular order or that all of the illustrated operations must be performed to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions.

Although the present application provides method steps as in embodiments or flowcharts, additional or fewer steps may be included based on conventional or non-inventive approaches. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution. When an apparatus or client product in practice executes, it may execute sequentially or in parallel (e.g., in a parallel processor or multithreaded processing environment, or even in a distributed data processing environment) according to the embodiments or methods shown in the figures. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the presence of additional identical or equivalent elements in a process, method, article, or apparatus that comprises the recited elements is not excluded.

The units, devices, modules, etc. set forth in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. For convenience of description, the above devices are described as being divided into various modules by functions, and are described separately. Of course, in implementing the present application, the functions of each module may be implemented in one or more software and/or hardware, or a module implementing the same function may be implemented by a combination of a plurality of sub-modules or sub-units, and the like. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

Those skilled in the art will also appreciate that, in addition to implementing the controller as pure computer readable program code, the same functionality can be implemented by logically programming method steps such that the controller is in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Such a controller may therefore be considered as a hardware component, and the means included therein for performing the various functions may also be considered as a structure within the hardware component. Or even means for performing the functions may be regarded as being both a software module for performing the method and a structure within a hardware component.

The application may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform particular tasks or implement particular abstract data types. The application may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

From the above description of the embodiments, it is clear to those skilled in the art that the present application can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, or the like, and includes several instructions for enabling a computer device (which may be a personal computer, a mobile terminal, a server, or a network device) to execute the method according to the embodiments or some parts of the embodiments of the present application.

The embodiments in the present specification are described in a progressive manner, and the same or similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. The application is operational with numerous general purpose or special purpose computing system environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet-type devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.

The above-mentioned embodiments are further described in detail for the purpose of illustrating the invention, and it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (10)

1. An electric energy metering method, characterized in that the method comprises:

measuring U in three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal;

when U is turned_ABAccess terminal or U_CBWhen the terminal is accessed, a first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBRespectively associated with the first phase current Ia and the second phase current IaThe included angle of the phase current Ic is used for calculating electric energy;

when a double PT access terminal is accessed, the first phase voltage U is obtained_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy.

2. The method of claim 1, wherein when U is present_ABWhen the terminal is accessed, the first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBThe angles with the first phase current Ia and the second phase current Ic respectively include:

obtaining a first phase voltage U_ABA first phase current Ia and a second phase current Ic;

according to the first phase voltage U_ABObtaining a virtual second phase voltage U by the first phase current Ia and the second phase current Ic_CBAngle α, Ia and U of_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caThe α is the first phase voltage U_ABIs a reference voltage, U_CBCalculated by rotating clockwise; theta is described_aIs the first phase voltage U_ABIs calculated for the reference voltage, Ia is rotated clockwise; theta is described_caIs the first phase voltage U_ABIc is calculated for the reference voltage, rotating clockwise;

according to the α and the theta_caObtaining the second phase current Ic and the virtual second phase voltage U_CBAngle of (theta)_cTheta of_cIs said theta_caThe difference from said α.

3. The method of claim 1, wherein when U is present_CBWhen the terminal is accessed, the first phase voltage U is obtained_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBAre respectively provided withThe angle between the first phase current Ia and the second phase current Ic includes:

obtaining the voltage U of the second phase_CBA first phase current Ia and a second phase current Ic;

according to the second phase voltage U_CBThe first phase current Ia and the second phase current Ic obtain a virtual first phase voltage U_ABAngle β, Ia and U of_CBIncluded angle theta'_acIc and U_CBIncluded angle theta'_cThe β is the second phase voltage U_CBIs a reference voltage, U_ABCalculated by rotating clockwise; theta'_acIs the second phase voltage U_CBIs calculated for the reference voltage, Ia is rotated clockwise; theta'_cWith the second phase voltage U_CBIc is calculated for the reference voltage, rotating clockwise;

according to said β and said θ'_acObtaining the first phase current Ia and the virtual first phase voltage U_ABAngle of (d)'_aOf θ'_aIs the theta'_acThe difference from said β.

4. The method of any of claims 2 or 3, wherein θ is θ_cIs theta_caThe difference from α, comprising:

if said theta_caIf the difference value with the α is negative, the difference value is increased by 360 degrees to obtain a positive difference value, and the positive difference value is taken as the theta_caThe difference from said α;

theta'_aIs the theta'_acThe difference from said β, comprising:

if theta'_aIs the theta'_acIf the difference value with the β is negative, increasing the difference value by 360 degrees to obtain a positive difference value, and taking the positive difference value as the theta'_aIs the theta'_acThe difference from said β.

5. The method according to any one of claims 1 to 3, wherein the electric energy calculation method comprises:

calculating electric energy according to the total active power and time;

the total active power is calculated according to the split-phase active power and the split-phase reactive power;

the phase-splitting active power and the phase-splitting reactive power are based on the first phase voltage U_ABThe second phase voltage U_CBThe first phase current Ia, the second phase current Ic and a factor angle group, the factor angle group being a first factor angle group or a second factor angle group, the first factor angle group comprising theta_aAnd theta_cAnd the second set of divisor angles comprises θ'_aAnd θ'_c。

6. An electrical energy metering system, the system comprising:

a judging module for measuring U in three-phase three-wire system_ABAnd U_CBVoltage according to U_ABAnd U_CBJudging whether the wiring state belongs to U by voltage and set threshold value_ABAccess terminal or U_CBAn access terminal or a dual PT access terminal;

single phase PT metering module, as U_ABAccess terminal or U_CBWhen accessing the terminal, it is used to obtain the first phase voltage U_ABOr a second phase voltage U_CBA first phase current Ia and a second phase current Ic, and said first phase voltage U_ABOr the second phase voltage U_CBIncluded angles with the first phase current Ia and the second phase current Ic respectively to calculate electric energy;

a two-phase PT metering module for acquiring the first phase voltage U when the two PT access terminals_ABSecond phase voltage U_CBA first phase current Ia, a second phase current Ic and a power factor angle to calculate the electrical energy.

7. The system of claim 6, wherein when U is_ABWhen the terminal is accessed, the single-phase PT metering module is specifically used for:

obtaining a first phase voltage U_ABA first phase current Ia and a second phase current IaPhase current Ic;

according to the first phase voltage U_ABObtaining a virtual second phase voltage U by the first phase current Ia and the second phase current Ic_CBAngle α, Ia and U of_ABIncluded angle theta_aIc and U_ABIncluded angle theta_caThe α is the first phase voltage U_ABIs a reference voltage, U_CBCalculated by rotating clockwise; theta is described_aIs the first phase voltage U_ABIs calculated for the reference voltage, Ia is rotated clockwise; theta is described_caIs the first phase voltage U_ABIc is calculated for the reference voltage, rotating clockwise;

according to the α and the theta_caObtaining the second phase current Ic and the virtual second phase voltage U_CBAngle of (theta)_cTheta of_cIs said theta_caThe difference from said α.

8. The system of claim 6, wherein when U is_CBWhen the terminal is accessed, the single-phase PT metering module is specifically used for:

obtaining the voltage U of the second phase_CBA first phase current Ia and a second phase current Ic;

according to the second phase voltage U_CBThe first phase current Ia and the second phase current Ic obtain a virtual first phase voltage U_ABAngle β, Ia and U of_CBIncluded angle theta'_acIc and U_CBIncluded angle theta'_cThe β is the second phase voltage U_CBIs a reference voltage, U_ABCalculated by rotating clockwise; theta'_acIs the second phase voltage U_CBIs calculated for the reference voltage, Ia is rotated clockwise; theta'_cWith the second phase voltage U_CBIc is calculated for the reference voltage, rotating clockwise;

according to said β and said θ'_acObtaining the first phase current Ia and the virtual first phase voltage U_ABAngle of (d)'_aOf θ'_aIs the theta'_acWith said βThe difference value.

9. The system of any of claims 7 or 8, wherein θ is θ_cIs theta_caThe difference from α, comprising:

if said theta_caIf the difference value with the α is negative, the difference value is increased by 360 degrees to obtain a positive difference value, and the positive difference value is taken as the theta_caThe difference from said α;

theta'_aIs the theta'_acThe difference from said β, comprising:

if theta'_aIs the theta'_acIf the difference value with the β is negative, increasing the difference value by 360 degrees to obtain a positive difference value, and taking the positive difference value as the theta'_aIs the theta'_acThe difference from said β.

10. The system of any one of claims 6 to 8, further comprising: the electric energy metering module is specifically used for:

calculating electric energy according to the total active power and time;

the total active power is calculated according to the split-phase active power and the split-phase reactive power;

the phase-splitting active power and the phase-splitting reactive power are based on the first phase voltage U_ABThe second phase voltage U_CBThe first phase current Ia, the second phase current Ic and a factor angle group, the factor angle group being a first factor angle group or a second factor angle group, the first factor angle group comprising theta_aAnd theta_cAnd the second set of divisor angles comprises θ'_aAnd θ'_c。

Images