CN116699505A - Electric energy meter wrong wiring judging method based on electricity utilization inspection instrument - Google Patents

Abstract

The invention relates to the technical field of power distribution and utilization, and particularly discloses an electric energy meter fault wiring judgment method based on a power utilization inspection instrument, which comprises the following steps: the voltage and current were collected with an electrical tester. And determining the phase sequence and the phase of the voltage according to the phase angle difference of the power frequency component. And calculating the power factor angle of the collected current and the positive and negative three-phase voltage to obtain a matrix 1. Index matrix 2 is derived from matrix 1. The absolute value sum of the corresponding 3 values of each element in the matrix 2 in the matrix 1 is calculated to obtain a matrix 3. The current phase and phase sequence are determined in combination with the load type and each matrix. Judging the wrong wiring condition: and if miswiring occurs, the electric quantity is supplemented according to the difference value and the ratio of the target power to the current power. According to the invention, the wiring modes are reflected through the index matrix, the power factor angle sum under each wiring mode is calculated, the most probable wiring mode which accords with the load characteristic is selected, the misconnection condition can be confirmed when the load power factor angle is large, the difference value and the ratio of the target power and the current power are calculated, the electric quantity is supplemented, and the engineering practicability is strong.

Description

Electric energy meter wrong wiring judging method based on electricity utilization inspection instrument

Technical Field

The invention relates to the technical field of power distribution and utilization, in particular to an electric energy meter wrong wiring judging method based on a power utilization inspection instrument.

Background

The power consumption inspection instrument product assists power supply personnel to clean the topology distribution of the line through six functions of platform area identification, power quality analysis, transformer transformation ratio analysis, power grid noise analysis, wrong wiring analysis, ammeter error analysis and the like, and analyzes power quality and power grid noise and line loss conditions in an all-around aspect. Because the field condition is complex, the situation of the line misconnection of the electric energy meter often occurs, and the line misconnection is easy to identify under the situation that the power factor angle of the load in the line is smaller, however, when the power factor angle of the load in the line is more than 30 degrees, multiple solutions exist, and at the moment, the misconnection situation is often difficult to directly confirm. Furthermore, in case of miswiring, there may be a corresponding deviation between the power calculated by the device and the actual power, which may cause a final power calculation error, affecting the related rights of the power supply company and the user.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides an electric energy meter wrong connection judging method based on an electric energy inspection instrument, which is characterized in that all possible connection modes are reflected through an index matrix, the sum of three-phase power factor angles under different connection modes is calculated, the most possible connection mode is calculated by selecting the minimum value which accords with load characteristics, the wrong connection condition can be confirmed when the power factor angle of the load in the line is larger than 30 degrees, and meanwhile, the difference value and the ratio of target power and current power are calculated to carry out electric quantity pursuit.

The aim of the invention can be achieved by the following technical scheme:

a method for judging wrong wiring of an electric energy meter based on an electricity consumption tester comprises the following steps.

Step 1: three-phase voltage U is gathered to electricity inspection appearance device ₁ 、U ₂ 、U ₃ And three-phase current I ₁ 、I ₂ 、I ₃ Is a waveform of (a).

Calculation U ₃ And U ₁ Is less than U of the phase angle difference of the power frequency component ₃ U ₁ Determining the phase sequence of the voltage according to the calculation result, and further determining the phase according to the phase sequence, namely U ₁ 、U ₂ 、U ₃ And A, B, C three-phase voltage U _a 、U _b 、U _c Corresponding relation of (3).

Step 2: respectively calculate I _n And U _m 、-U _m Angle of power factor I _n U _m 、∠I _n -U _m A matrix 1 of 3 x 6 is obtained.

Wherein n is 1, 2 or 3; m is a, b and c.

Step 3: from the matrix 1, a 6 x 8 index matrix 2 is formed.

Each element in matrix 2 consists of 3 values, which in turn are column indices in rows 1, 2, 3 in matrix 1.

Step 4: the sum of the absolute values of the corresponding 3 values of each element in the matrix 1 is calculated through traversal to form a matrix 3.

Step 5: the current phase and phase sequence are determined in combination with the load type and the matrices 1, 2, 3.

Step 6: comparing the phase sequence and the phase difference of the voltage and the current, and judging whether the electric energy meter is miswired or not: if miswiring occurs, respectively calculating the difference and the ratio of the target power and the current power, and finishing electric quantity additional compensation according to the calculation result.

Preferably, the calculating method of the power frequency component phase angle difference specifically comprises the following steps: and extracting two variable power frequency phases by using discrete Fourier transformation, converting the two variable power frequency phases into angle values, and calculating the difference value of the two angle values to obtain a power frequency component phase angle difference.

Determining a voltage phase sequence according to the calculation result, and further determining a three-phase voltage U corresponding to the phase sequence _a 、U _b 、U _c The method of (1) is as follows: if you are less than U ₃ U ₁ Greater than 115 degrees and less than 125 degrees, the voltage is a positive phase sequence, and the voltage phase can be determined as follows: u (U) ₁ 、U ₂ 、U ₃ Respectively correspond to U _a 、U _b 、U _c The method comprises the steps of carrying out a first treatment on the surface of the If you are less than U ₃ U ₁ Greater than-125 degrees and less than-115 degrees, the voltages are in reverse order, and the voltages can be determined to be the same as each other: u (U) ₁ 、U ₂ 、U ₃ Respectively correspond to U _a 、U _c 、U _b 。

Preferably, in the step 2, I is calculated first ₁ 、I ₂ 、I ₃ And U _a Respectively calculating I by combining the power factor angles of the (E) and the hexagonal graphs ₁ 、I ₂ 、I ₃ and-U _a 、U _b 、-U _b 、U _c 、-U _c To obtain a matrix 1.

。

The currents represented by each column from left to right in the matrix are A, -A, B, -B, C, -C in that order.

Preferably, when an element in matrix 1 is not at [ -90 °, when the range is 90 DEG, the element value is set to +.

Preferably, the matrix 2 in the step 3 is as follows.

。

Preferably, the specific flow of step 5 is as follows.

S1, selecting elements with three-phase corresponding values meeting load characteristics from the matrix 2.

The load characteristic, namely the capacitive load power factor angle, is at [ -90 degrees, 0 degrees), and the inductive load power factor angle is at (0 degrees, 90 degrees ].

S2, further selecting one or more elements with minimum corresponding values from the selected elements, and obtaining the current phase and the phase sequence according to the index of the elements.

Preferably, the current power W in the step 6 ₁ The calculation method is as follows.

If the voltage is positive phase sequence, then。

If the voltage is in the reverse phase sequence, then。

Wherein +.I ₁ U ₁ 、∠I ₂ U ₁ 、∠I ₃ U ₁ Respectively is I ₁ 、I ₂ 、I ₃ And U ₁ Is a power factor angle of (c).

Target power W ₀ The calculation method is as follows.

。

Wherein +.I _a U _a 、∠I _b U _b 、∠I _c U _c Respectively is I _a And U _a 、I _b And U _b 、I _c And U _c Power factor angle, I _a 、I _b 、I _c The three-phase current values correspond to the phase sequence and the phase respectively.

The beneficial effects of the invention are as follows: the index matrix is used for reflecting all possible connection modes, the sum of three-phase power factor angles under different connection modes is calculated, the minimum value which accords with load characteristics is selected to calculate the most possible connection mode, when the power factor angle of a load in a circuit is larger than 30 degrees, the clear misconnection condition can be confirmed, meanwhile, the difference value and the ratio of target power and current power are calculated to carry out electric quantity compensation, and the method has strong engineering practicability.

Drawings

Fig. 1 is a general flow chart of the present invention.

Fig. 2 is a hexagonal diagram corresponding to embodiment 1 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Example 1: referring to fig. 1, the method for judging the wrong wiring of the electric energy meter based on the electricity consumption tester comprises the following steps.

Three-phase voltage U is gathered to electricity inspection appearance device ₁ 、U ₂ 、U ₃ And three-phase current I ₁ 、I ₂ 、I ₃ Extracting U with discrete Fourier transform (Discrete Fourier Transform, DFT) ₁ The power frequency phase of (2) is converted into an angle value of 10 DEG, and U is extracted ₃ The power frequency phase of (2) is converted into an angle value of 110 DEG to calculate U ₃ And U ₁ Is less than U of the phase angle difference of the power frequency component ₃ U ₁ -110 ° -10 ° = -120 °, determining a voltage phase sequence, -125 ° < U according to the calculation result ₃ U ₁ And (3) < -115 degrees, determining that the voltages are in reverse order, and determining that the voltages are respectively: u (U) ₁ 、U ₂ 、U ₃ Respectively correspond to U _a 、U _c 、U _b 。

Step 2: as shown in FIG. 2, extracting I with DFT ₁ 、I ₂ 、I ₃ The power frequency phase of (2) is converted into angle values of 55 degrees, 85 degrees and 135 degrees respectively, and I is calculated ₁ 、I ₂ 、I ₃ And U _a The power factor angles of (a) are respectively 45 degrees, 75 degrees and 125 degrees, and U is known by combining a hexagonal graph _a 、-U _a 、U _b 、-Ub、U _c 、-U _c The angles of (1) are respectively 0 DEG, 180 DEG, 120 DEG, -60 DEG, -120 DEG and 60 DEG, and I is calculated respectively ₁ 、I ₂ 、I ₃ and-U _a 、U _b 、-U _b 、U _c 、-U _c To obtain a matrix 1, if the angle value in the matrix 1 is not within the range of-90 DEG, 90 DEG]Within the range directly set it asThe final result of matrix 1 is as follows.

。

Step 3: all possible wiring cases are listed, resulting in a 6 x 8 matrix 2 as follows.

。

The index matrix enumerates all possible current wiring patterns, with row 1, column 1 elements [1,3,5 ]]For example, represent I ₁ 、I ₂ 、I ₃ The wiring modes of (a) are respectively I _a 、I _b 、I _c Similarly, row 3, column 3 elements [3,2,5]Represents I ₁ 、I ₂ 、I ₃ The wiring modes of (a) are respectively I _b 、-I _a 、I _c Calculating elements [ x, y, z ] of a certain row and a certain column by using the matrix]When the corresponding power factor angles are summed, the sum of absolute values of the 1 st row and the x column elements, the 2 nd row and the y column elements and the 3 rd row and the z column elements in the matrix 1 is only needed to be calculated.

Step 4: and selecting elements with three-phase corresponding values meeting load characteristics from the matrix 2, and calculating the sum of absolute values of 3 angles in the matrix 1 corresponding to each item to obtain a matrix 3 as follows.

。

One or more elements with the minimum corresponding value in the matrix 3 are further selected from the selected elements, and the minimum value of the elements in the matrix 3 is 65 degrees.

Step 5: determining the phase and phase sequence of the current by combining the load type and the matrixes 1, 2 and 3, wherein the matrix 3 has the unique minimum value of 65 degrees, the known A, B two-phase load is a inductive load, and the 65-degree corresponding element [1,4 and 5 ]]The angle values of the 1 st row, 1 st column, 2 nd row and 4 th column of the matrix 1 are in the range of (0 DEG, 90 DEG)]Within the range, the load capacitive characteristics are satisfied, so that the corresponding elements [1,4,5 ] in the matrix 2]Namely a current connection mode, namely the representative current is I ₁ 、I ₂ 、I ₃ Respectively correspond to I _a 、-I _b 、I _c For the case that the minimum value in the matrix 3 does not meet the load capacity sensing characteristic, the next minimum value of the elements in the matrix 3 is required to be solved, whether the corresponding wiring mode meets the load capacity sensing characteristic is checked, and the like.

Step 6: comparing the phase sequence and the phase of the voltage and the current, judging whether the electric energy meter is miswired, wherein in the embodiment, the voltage phase is U ₁ 、U ₂ 、U ₃ Respectively correspond to U _a 、U _c 、U _b The current phase is I ₁ 、I ₂ 、I ₃ Respectively correspond to I _a 、-I _b 、I _c And the wiring is wrong, so that the electric quantity is needed to be supplemented. Respectively calculating the current power W ₁ And target power W ₀ U is known to ₁ 、U ₂ 、U ₃ The effective values of (1) are 210V, 220V, 230V and I respectively ₁ 、I ₂ 、I ₃ The effective values of (a) are 13.5A, 15.7A and 18.6A respectively, the voltage is in reverse phase sequence, and the current power is the same as the current power=2639W。

According to the hexagonal diagram shown in fig. 2, the angle IaU is calculated respectively _a =45°、∠I _b U _b =15°、∠I _c U _c =5°, target power=9569W。

Finally, the difference value and the ratio of the target power to the current power are given: w (W) ₀ -W ₁ =6930W；W ₀ /W ₁ =3.63。

The above embodiments are illustrative of the specific embodiments of the present invention, and not restrictive, and various changes and modifications may be made by those skilled in the relevant art without departing from the spirit and scope of the invention, so that all such equivalent embodiments are intended to be within the scope of the invention.

Claims (7)

1. The utility model provides a wrong wiring judgment method of electric energy meter based on electricity consumption inspection appearance which characterized in that includes the following steps:

step 1: three-phase voltage U is gathered to electricity inspection appearance device ₁ 、U ₂ 、U ₃ And three-phase current I ₁ 、I ₂ 、I ₃ Is a waveform of (a);

calculation U ₃ And U ₁ Is less than U of the phase angle difference of the power frequency component ₃ U ₁ Determining the phase sequence of the voltage according to the calculation result, and further determining the phase according to the phase sequence, namely U ₁ 、U ₂ 、U ₃ And A, B, C three-phase voltage U _a 、U _b 、U _c Corresponding relation of (3);

step 2: respectively calculate I _n And U _m 、-U _m Angle of power factor I _n U _m 、∠I _n -U _m Obtaining a matrix 1 of 3×6;

wherein n is 1, 2 or 3; m is a, b and c;

step 3: forming a 6 x 8 index matrix 2 from the matrix 1;

each element in the matrix 2 consists of 3 values, and the 3 values are column indexes in the 1 st, 2 nd and 3 rd rows in the matrix 1 in sequence;

step 4: traversing and calculating the sum of absolute values of 3 corresponding values of each element in the matrix 2 in the matrix 1 to form a matrix 3;

step 5: determining the phase and phase sequence of the current by combining the load type and the matrixes 1, 2 and 3;

step 6: comparing the phase sequence and the phase difference of the voltage and the current, and judging whether the electric energy meter is miswired or not: if miswiring occurs, respectively calculating the difference and the ratio of the target power and the current power, and finishing electric quantity additional compensation according to the calculation result.

2. The method for judging the wrong wiring of the electric energy meter based on the electricity consumption inspection instrument according to claim 1, wherein the method for calculating the phase angle difference of the power frequency component is specifically as follows: extracting two variable power frequency phases by using discrete Fourier transformation, converting the two variable power frequency phases into angle values, and calculating the difference value of the two angle values to obtain a power frequency component phase angle difference;

determining a voltage phase sequence according to the calculation result, and further determining a three-phase voltage U corresponding to the phase sequence _a 、U _b 、U _c The method of (1) is as follows: if you are less than U ₃ U ₁ Greater than 115 degrees and less than 125 degrees, the voltage is a positive phase sequence, and the voltage phase can be determined as follows: u (U) ₁ 、U ₂ 、U ₃ Respectively correspond to U _a 、U _b 、U _c The method comprises the steps of carrying out a first treatment on the surface of the If you are less than U ₃ U ₁ Greater than-125 degrees and less than-115 degrees, the voltages are in reverse order, and the voltages can be determined to be the same as each other: u (U) ₁ 、U ₂ 、U ₃ Respectively correspond to U _a 、U _c 、U _b 。

3. The method for determining the wrong wiring of the electric energy meter based on the electricity consumption tester according to claim 1, wherein in the step 2, I is calculated first ₁ 、I ₂ 、I ₃ And U _a Respectively calculating I by combining the power factor angles of the (E) and the hexagonal graphs ₁ 、I ₂ 、I ₃ and-U _a 、U _b 、-U _b 、U _c 、-U _c To obtain a matrix 1:

；

the currents represented by each column from left to right in the matrix are A, -A, B, -B, C, -C in that order.

4. The method for judging the wrong wiring of the electric energy meter based on the electricity consumption tester according to claim 1, wherein when the value of a certain element in the matrix 1 is not in the range of [ -90 degrees, 90 degrees ].

5. The method for determining the wrong wiring of the electric energy meter based on the electricity consumption tester according to claim 1, wherein the matrix 2 in the step 3 is specifically as follows:

。

6. the method for judging the wrong wiring of the electric energy meter based on the electricity consumption tester according to claim 1, wherein the specific flow of the step 5 is as follows:

s1, selecting elements with three-phase corresponding values meeting load characteristics in a matrix 1 from the matrix 2;

the load characteristic, namely the value of the capacitive load power factor angle is [ -90 degrees, 0 degrees), and the value of the inductive load power factor angle is (0 degrees, 90 degrees ];

s2, further selecting one or more elements with minimum corresponding values from the selected elements, and obtaining the current phase and the phase sequence according to the index of the elements.

7. The method for determining wrong wiring of an electric energy meter based on an electricity consumption tester according to claim 1, wherein the current power W in the step 6 ₁ The calculation method comprises the following steps:

if the voltage is positive phase sequence, then

；

If the voltage is in the reverse phase sequence, then

；

Wherein +.I ₁ U ₁ 、∠I ₂ U ₁ 、∠I ₃ U ₁ Respectively is I ₁ 、I ₂ 、I ₃ And U ₁ Is a power factor angle of (2);

target power W ₀ The calculation method comprises the following steps:

；

wherein +.I _a U _a 、∠I _b U _b 、∠I _c U _c Respectively is I _a And U _a 、I _b And U _b 、I _c And U _c Power factor angle, I _a 、I _b 、I _c The three-phase current values correspond to the phase sequence and the phase respectively.