CN-121978407-A - Accurate measuring method for voltage and current phase angle of sectional intelligent ammeter

CN121978407ACN 121978407 ACN121978407 ACN 121978407ACN-121978407-A

Abstract

The invention discloses a precise measurement method of a voltage and current phase angle of a sectional intelligent electric energy meter, which relates to the technical field of electric energy meter measurement and comprises the steps of S1, constructing a sectional load-transformer angle difference correlation model, dividing a plurality of load sections according to application scenes of the sectional intelligent electric energy meter and working characteristics of a transformer, collecting current transformer angle difference data and voltage transformer impedance drift related data in different load sections, establishing correlation relations between each load section and corresponding transformer angle difference compensation coefficients by combining inherent parameters of the transformer and storing the correlation relations.

Inventors

WU DEBAO
CAO YUWEI
Hu Maoyi
LI ZHUANG

Assignees

联桥科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (9)

1. The accurate measuring method of the voltage and current phase angle of the sectional intelligent electric energy meter is characterized by comprising the following steps of: S1, constructing a sectional load-transformer angular difference correlation model, dividing a plurality of load intervals according to application scenes of a sectional intelligent electric energy meter and working characteristics of a transformer, collecting current transformer angular difference data and voltage transformer impedance drift related data in different load intervals, and establishing and storing correlation relations between each load interval and corresponding transformer angular difference compensation coefficients by combining intrinsic parameters of the transformer; s2, acquiring electrical parameters of a load in real time, acquiring amplitude data of a voltage signal and a current signal through a built-in sampling module of the electric energy meter, and transmitting the amplitude data to a control module; s3, determining a current load interval, and judging a specific interval where the current load is located by the control module according to a preset load interval dividing standard; s4, matching the angle difference compensation coefficient of the transformer, and calling a stored association model by the control module, and automatically matching the corresponding compensation coefficient according to the current load interval; S5, dynamic self-adaptive compensation and phase angle calculation are carried out, the control module obtains an initial phase angle based on the collected voltage and current signals, and the matched compensation coefficient is utilized for dynamic self-adaptive compensation, so that a phase angle measurement result is output.
2. The method for accurately measuring the voltage and current phase angle of the sectional intelligent ammeter according to claim 1, wherein the step S1 comprises the following steps when constructing a sectional load-transformer angle difference correlation model: Dividing a no-load interval, a light-load interval, a medium-load interval and a heavy-load interval by combining a rated current range of the sectional intelligent electric energy meter, a load change rule in actual power grid operation and rated working parameters of a transformer, and setting a clear current amplitude dividing boundary in each interval; Simulating typical operation conditions of each load interval in a laboratory environment, synchronously acquiring actual angle difference data of a current transformer and impedance change data of a voltage transformer through a standard metering instrument, and continuously acquiring a plurality of groups of data under each condition; analyzing and processing the acquired multiple groups of data by adopting a data fitting algorithm, removing abnormal data, establishing a mapping relation between a load interval and the angle difference of the transformer, and determining a transformer angle difference compensation coefficient corresponding to each load interval; And sorting the corresponding relation among the load interval, the mutual inductor angle difference data and the compensation coefficient into a segmented load-mutual inductor angle difference correlation model according to a preset format, and storing the segmented load-mutual inductor angle difference correlation model into a nonvolatile storage module of the electric energy meter.
3. The method for precisely measuring the voltage and current phase angle of the segmented intelligent ammeter according to claim 1, wherein the step S3 comprises the following steps when determining the current load interval: the control module receives the voltage and current amplitude data transmitted by the sampling module, then carries out noise reduction treatment on the data, and eliminates abnormal amplitude data caused by instantaneous fluctuation of the power grid; Extracting the effective value of the processed amplitude data, comparing the effective value with preset amplitude thresholds of all load intervals one by one, and primarily judging the interval range where the current load is possibly located; The method comprises the steps of retrieving recent load operation data stored in the electric energy meter, analyzing a load change trend, and correcting a preliminary judgment result by combining trend characteristics; and (3) combining the comparison result and the trend correction result, determining a specific interval in which the current load is located, and transmitting interval information to the compensation coefficient matching unit.
4. The method for precisely measuring the voltage and current phase angle of the segmented intelligent ammeter according to claim 1, wherein the step S5 comprises the following steps when performing dynamic adaptive compensation and phase angle calculation: The control module performs Fourier transform processing on the acquired voltage signals and current signals, separates out fundamental components, and calculates an initial voltage current phase angle based on the fundamental components; Carrying out validity check on the matched mutual inductor angular difference compensation coefficient, and confirming that a load interval corresponding to the coefficient is consistent with a load interval which is currently judged, wherein the coefficient value is in a preset reasonable range; calculating to obtain a phase angle compensation quantity through a preset algorithm according to the value of the initial phase angle, the angle difference compensation coefficient of the transformer and the amplitude characteristic of the voltage and current signals; and performing superposition operation on the initial phase angle and the compensation quantity to complete dynamic self-adaptive correction on the initial phase angle, and finally outputting a compensated voltage and current phase angle measurement result.
5. The method for accurately measuring the voltage and current phase angle of the sectional intelligent ammeter according to claim 1, wherein the sampling module adopted in the step S2 is a high-precision synchronous sampling module, the module has a synchronous acquisition function of voltage signals and current signals, the sampling frequency is adaptively adjusted according to the rated frequency of a power grid, real-time verification is carried out on data in the sampling process, and the data is immediately collected again when abnormal data transmission is detected.
6. The method for accurately measuring the voltage and current phase angles of the sectional intelligent electric energy meter according to claim 1, wherein the number of the load sections divided in the step S1 can be adjusted according to the application scene of the sectional intelligent electric energy meter, the number of the load sections divided is increased in the industrial electricity scene with frequent load change, the number of the load sections divided is reduced in the resident electricity scene with gentle load change, and the amplitude threshold value of each load section can be adjusted on site through the communication interface of the electric energy meter.
7. The method for accurately measuring the voltage and current phase angles of the sectional intelligent ammeter according to claim 1, wherein when the control module calls a sectional load-transformer angle difference correlation model in the step S4, an index query mode is adopted to locate the transformer angle difference compensation coefficient corresponding to the current load interval, if the corresponding compensation coefficient is not found, the compensation coefficients of two adjacent load intervals are automatically called to calculate the temporary compensation coefficient through an interpolation algorithm, and meanwhile, the situation is recorded and fed back to a background system through a communication module.
8. The method for accurately measuring the voltage and current phase angles of the sectional intelligent electric energy meter according to claim 1, wherein the sectional load-transformer angle difference correlation model constructed in the step S1 has a periodic updating function, a model updating program is automatically started after each preset period of operation of the electric energy meter, the actual load data and the transformer operation data collected in the step S2 in the period of time are combined, the transformer angle difference compensation coefficient of each load section is optimized and adjusted, and the updated model covers the original model and is stored.
9. The method for accurately measuring the voltage and current phase angle of the sectional intelligent ammeter according to claim 1, wherein the method for obtaining the initial phase angle in the step S5 includes a fourier transform method, a zero crossing detection method or a phase locking loop method, the control module selects an initial phase angle calculation method according to the distortion degree of the voltage and current signal, and when the signal distortion rate exceeds a preset threshold, the control module switches to a calculation method with stronger distortion resistance.

Description

Accurate measuring method for voltage and current phase angle of sectional intelligent ammeter Technical Field The invention relates to the technical field of electric energy meter measurement, in particular to a precise measuring method for a voltage and current phase angle of a sectional intelligent electric energy meter. Background The intelligent electric energy meter is core equipment in a power grid metering system, can accurately collect, store and transmit electricity data, is a basic support for realizing power marketing trade, energy conservation and emission reduction monitoring and electricity consumption behavior analysis, has running stability and metering accuracy directly related to legal rights of power supply enterprises and electricity consumption users, has important significance in guaranteeing safe and economical running of a power grid and promoting optimal allocation of power resources, has voltage and current phase angle measurement as one of key core functions of the intelligent electric energy meter, reflects phase correspondence of voltage signals and current signals in the power grid, has measurement accuracy directly determining reliability of an electric energy metering result, and also has important basis for judging load electricity consumption characteristics, monitoring running state of the power grid and diagnosing line faults, and has irreplaceable effects in optimizing a power grid scheduling scheme, improving power supply quality and reducing power grid loss. However, the phase angle measurement technology of the existing sectional intelligent electric energy meter still has certain defects, the phase error compensation scheme of the existing electric energy meter is designed aiming at a fixed load interval, the characteristic that the internal angle difference of the current transformer in different load current intervals can show nonlinear change is ignored, meanwhile, the voltage transformer is easy to generate impedance drift in the long-term operation process, and then extra phase offset is caused. The intelligent electric energy meter has the advantages that the angle difference of the mutual inductor is difficult to keep consistent when the sectional intelligent electric energy meter is switched under different working conditions such as light load, heavy load and no load, the phase angle measurement error is obviously increased, the accuracy of electric energy metering is seriously affected, the requirement of the intelligent electric network on high-accuracy electric energy metering cannot be met, and therefore, the development of the accurate measuring method of the voltage and current phase angle of the sectional intelligent electric energy meter has important significance. Disclosure of Invention The invention aims to make up the defects of the prior art, provides a precise measurement method for the voltage and current phase angle of a sectional intelligent electric energy meter, and can collect load voltage and current amplitude data in real time to precisely judge the current load interval by constructing a sectional load-transformer angle difference correlation model in advance, automatically match corresponding transformer angle difference compensation coefficients to dynamically and adaptively compensate the initial phase angle, solve the problems of nonlinear change of the angle difference of the current transformer in different load intervals and phase offset caused by the impedance drift of the voltage transformer in the prior art, consider the measurement requirements under different working conditions such as light load, heavy load and no load, avoid phase measurement errors caused by inconsistent angle differences of the transformers under different loads, improve the precision of measuring the voltage and current phase angle of the sectional intelligent electric energy meter, and provide reliable guarantee for the accuracy of electric energy metering. The invention provides a method for accurately measuring the voltage and current phase angle of a sectional intelligent electric energy meter, which aims to solve the technical problems and comprises the following steps of: S1, constructing a sectional load-transformer angular difference correlation model, dividing a plurality of load intervals according to application scenes of a sectional intelligent electric energy meter and working characteristics of a transformer, collecting current transformer angular difference data and voltage transformer impedance drift related data in different load intervals, and establishing and storing correlation relations between each load interval and corresponding transformer angular difference compensation coefficients by combining intrinsic parameters of the transformer; s2, acquiring electrical parameters of a load in real time, acquiring amplitude data of a voltage signal and a current signal through a built-in sampling module of the electric energy meter, and