Calculation method for three-phase four-wire meter voltage loss compensation electric quantity during three-phase current imbalance

Abstract

The invention relates to a method for calculating the loss-of-voltage compensation electric quantity of a three-phase four-wire meter during three-phase current imbalance. The method comprises the following steps: determining a loss-of-voltage phase and loss-of-voltage time; acquiring related power consumption data of the day before voltage loss and during the voltage loss period; calculating an electric quantity and a current summation value of a voltage loss phase, an average power factor of a normal phase and a product of the current summation value of the voltage loss phase and the average power factor of the normal phase one day before voltage loss; calculating a current summation value of a voltage loss phase, an average power factor of a normal phase and a product of the current summation value and the average power factor of the normal phase in each day during the voltage loss period; comparing the product of the voltage loss phase current summation value of each day in the voltage loss period and the normal phase average power factor with the product of the day before voltage loss to obtain an electric quantity correction coefficient of each day in the voltage loss period; multiplying the electricity consumption correction coefficient by the voltage loss phase electricity quantity of the day before voltage loss to obtain the correction electricity quantity of the voltage loss phase of each day during the voltage loss period; and adding the corrected electric quantity of the no-voltage phase and the metering electric quantity of the normal phase to obtain the total reduction electric quantity. According to the invention, the accuracy and practicability of compensation electric quantity calculation are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electric energy metering, and in particular relates to a method for calculating the amount of electric energy to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced. Background Art

[0002] When a three-phase four-wire meter loses voltage, it is necessary to make up the electricity. The commonly used electricity calculation method is the correction coefficient method. The correction coefficient method assumes that the power of each phase of the three-phase four-wire meter is the same, that is, if one phase voltage is lost, it is compensated at 1.5 times, and if two phases voltage are lost, it is compensated at 3 times. However, when the three-phase current is unbalanced, the power and electricity measured in each phase differ greatly, and a loss of voltage occurs at this time. If the correction coefficient method is used to calculate the make-up electricity, a large error will be generated, affecting the economic interests of both the power supply and the user. Therefore, it is necessary to study a new calculation method to calculate the make-up electricity when a three-phase four-wire meter loses voltage under the condition of three-phase current imbalance. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method for calculating the amount of electricity to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced.

[0004] The above-mentioned object of the present invention is achieved by the following technical solutions:

[0005] A method for calculating the amount of power required to compensate for voltage loss in a three-phase four-wire meter when the three-phase current is unbalanced comprises the following steps:

[0006] Step 1: After the voltage of the three-phase four-wire meter is restored to normal after on-site processing, determine the phase of the electric energy meter that lost voltage and the time of the voltage loss, where the time of the voltage loss includes the starting date of the voltage loss, the ending date of the voltage loss and the number of days of the voltage loss;

[0007] Step 2: Obtain relevant power consumption data from the power consumption information collection system one day before and during the voltage loss period. The relevant power consumption data include active and reactive power data of three metering elements, current data of the voltage loss phase, and electric energy meter readings on the start and end days of the voltage loss. The active and reactive power data of the three metering elements are: P a , Q a ;P b , Q b ;P c , Q c ;

[0008] Step 3: Calculate the power of the voltage-losing phase, the summed current value, the average power factor of the normal phase, and the product of the summed current value of the voltage-losing phase and the average power factor of the normal phase one day before the voltage loss, and use these data as the reference value for calculating the voltage loss compensation power;

[0009] Step 4, calculating the sum of the current of the voltage-loss phase, the average power factor of the normal phase, and the product of the two for each day during the voltage-loss period;

[0010] Step 5: Compare the product of the sum of the phase current under voltage on each day during the voltage loss period and the average power factor of the normal phase with the product of the day before the voltage loss to obtain the power correction coefficient for each day during the voltage loss period;

[0011] Step 6: Multiply the power consumption correction coefficient by the power consumption of the pressure loss phase on the day before the pressure loss to obtain the corrected power consumption of the pressure loss phase on each day during the pressure loss period.

[0012] Step 7, add the corrected electric quantity of the voltage-losing phase to the measured electric quantity of the normal phase to obtain the total restored electric quantity;

[0013] Step 8: Calculate the metered electricity of the three-phase four-wire meter during the voltage loss period according to the electricity meter readings on the start and end dates of the voltage loss. Then, subtract the metered electricity during the voltage loss period from the calculated restored electricity to obtain the replenished electricity during the voltage loss period.

[0014] Moreover, step 3 includes single-phase voltage loss and two-phase voltage loss calculations:

[0015] The calculation method for single-phase voltage loss is:

[0016] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0017] The electricity E of phase X one day before the voltage loss x,B and X-phase current sum SI x,B The calculation formula is:

[0018]

[0019]

[0020] Where, d-1 refers to the day before the pressure loss; P xi,d-1 I is the active power of phase X in a collection period of 15 minutes; xi,d-1 It is the current value of X phase in a collection period of every 15 minutes;

[0021] Average power factor of phase YZ one day before voltage loss pg yz,B , the product of the sum of the X-phase current and the average power factor of the YZ phases M x,B The calculation formula is:

[0022]

[0023] M x,B =SI x,B ×pg x,B (4)

[0024] Where P yi,d-1 , Q yi,d-1 , P zi,d-1 , Q zi,d-1 They are respectively the active power and reactive power of the Y and Z phases in a collection period of 15 minutes each; pg yz,B is the average power factor of phases Y and Z on day d-1, M x,B It is the product of the sum of the X-phase current and the average power factor of the YZ phases.

[0025] Calculation method when two phases lose pressure:

[0026] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0027] The electricity E of phases Y and Z one day before the voltage loss y,B 、E z,B The sum of the Y and Z phase currents SI y,B 、SI z,B The calculation formula is:

[0028]

[0029]

[0030] In the formula, I yi,d-1 ,I zi,d-1 It is the current value of phases Y and Z in a collection period of 15 minutes.

[0031] Average power factor of phase X one day before voltage loss pg x,B , the product of the sum of the Y and Z phase currents and the average power factor of the X phase is M y,B 、M z,B The calculation formula is:

[0032]

[0033]

[0034] In the formula, Q xi,d-1 It is the reactive power of phase X in a collection period of 15 minutes.

[0035] Furthermore, step 4 includes a single pressure loss calculation and a two-way pressure loss calculation:

[0036] Calculation method when single-phase voltage loss:

[0037] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0038] The sum of the current of phase X during the voltage loss period SI x,d , average power factor of phase YZ pg yz,d And the product of the two M x,dThe calculation formula for is:

[0039]

[0040]

[0041] M x,d =SI x,d ×pg x,d (11)

[0042] Where d refers to a day during the pressure loss period; I xi,d P is the current value of the X phase during a 15-minute sampling period during the voltage loss period; yi,d , Q yi,d , P zi,d , Q zi,d They are respectively the active power and reactive power of the Y and Z phases in a collection period of 15 minutes each during the voltage loss period.

[0043] Calculation method when two phases lose pressure:

[0044] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0045] The sum of the currents of the Y and Z phases during the voltage loss period SI y,d 、SI z,d , average power factor of phase X pg x,d And the product of the sum of current and the average power factor M y,d 、M z,d The calculation formula for is:

[0046]

[0047]

[0048]

[0049] In the formula, I yi,d ,I zi,d Q is the current value of the Y and Z phases during a 15-minute sampling period during the voltage loss period; xi,d It is the reactive power of phase X in a collection period of 15 minutes during the voltage loss period.

[0050] Moreover, step 5 includes single-phase voltage loss calculation and two-phase voltage loss calculation:

[0051] Calculation method when single-phase voltage loss:

[0052] Set the pressure-loss phase as X phase, and the normal phases as Y and Z phases;

[0053] The M of each day during the pressure loss period x,d Compared with M on the day before the pressure lossx,B The ratio obtained by comparison is the power correction coefficient r of phase X per day during the voltage loss period. x,d ;

[0054]

[0055] Calculation method when two phases lose pressure:

[0056] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0057] During the pressure loss period, the M of the two phases Y and Z for each day y,d 、M z,d Compared with M on the day before the pressure loss y,B 、M z,B The ratio obtained by comparison is the power correction coefficient r of the two phases Y and Z per day during the voltage loss period. y,d 、r z,d ;

[0058]

[0059] Furthermore, step 6 includes single-phase pressure loss calculation and dual-phase pressure loss calculation:

[0060] Calculation method when single-phase voltage loss:

[0061] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0062] Use the power correction factor r of phase X during voltage loss x,d Multiply by the power E of phase X the day before the voltage loss x,B The corrected power E of phase X per day during the voltage loss period can be obtained. x,d ;

[0063] E x,d =r x,d ×E x,B (17)

[0064] (2) Calculation method when two phases lose pressure:

[0065] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0066] The power correction coefficient r of phases Y and Z during the voltage loss period is used y,d 、r z,d Multiply by the electricity E of phases Y and Z the day before the voltage loss y,B 、E z,B The corrected electric quantity E of phases Y and Z per day during the voltage loss period can be obtained. y,d 、E z,d ;

[0067]

[0068] Moreover, in step 7, the total reduction amount is E h ,but:

[0069]

[0070] Moreover, in step 8, the measured power of the three-phase four-wire meter during the voltage loss period is E j , the compensation power ZE during the voltage loss period, then:

[0071] ZE=E h -E j (20)

[0072] The advantages and positive effects of the present invention are:

[0073] The present invention proposes a new method for calculating the voltage loss compensation power of a three-phase four-wire meter when the three-phase current is unbalanced. The method uses the summed current value of the voltage loss phase and the average power factor of the normal phase during the voltage loss period to obtain the power correction coefficient of the voltage loss phase, and then multiplies the power correction coefficient by the measured power of the voltage loss phase one day before the voltage loss to obtain the corrected power of the voltage loss phase during the voltage loss period. Finally, the voltage loss compensation power is obtained by subtracting the metered power from the calculated restored power. The method is simple to calculate, and effectively solves the problem of large errors in the voltage loss compensation power using the correction coefficient method of the three-phase four-wire meter when the three-phase current is unbalanced, and improves the accuracy and practicality of the compensation power calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a flow chart of the calculation method of the present invention. DETAILED DESCRIPTION

[0075] The structure of the present invention is further described below with reference to the accompanying drawings and by way of examples. It should be noted that the present examples are descriptive rather than restrictive.

[0076] A method for calculating the amount of power to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced. Figure 1 , including the following steps:

[0077] Step 1: Find the user whose three-phase four-wire meter loses voltage and handle it on site. When the voltage of the three-phase four-wire meter returns to normal, determine the phase of the electric energy meter that loses voltage and the time of the voltage loss, where the time of the voltage loss includes the start date of the voltage loss, the end date of the voltage loss and the number of days S of the voltage loss.

[0078] Step 2: Obtain relevant power consumption data from the power consumption information collection system one day before and during the voltage loss period. The relevant power consumption data include active and reactive power data of three metering elements, current data of the voltage loss phase, and electric energy meter readings on the start and end days of the voltage loss. The active and reactive power data of the three metering elements are: P a, Q a ;P b , Q b ;P c , Q c .

[0079] Step 3: Calculate the power of the voltage-losing phase, the summed current, the average power factor of the normal phase, and the product of the summed current of the voltage-losing phase and the average power factor of the normal phase one day before the voltage loss, and use these data as the reference value for calculating the voltage loss compensation power.

[0080] Because when a three-phase four-wire meter loses voltage, the current in the phase with the lost voltage will generate a negative current due to the voltage phase problem, so when summing the current, it should be calculated according to the absolute value. When calculating the average power factor, because the reactive power of the normal phase may be positive or negative, when calculating the average power factor, the reactive power is also calculated according to the absolute value.

[0081] (1) Calculation method when single-phase voltage is lost:

[0082] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0083] The electricity E of phase X one day before the voltage loss x,B and X-phase current sum SI x,B The calculation formula is:

[0084]

[0085]

[0086] Where, d-1 refers to the day before the pressure loss; P xi,d-1 I is the active power of phase X in a collection period of 15 minutes; xi,d-1 It is the current value of X phase in a collection period of 15 minutes.

[0087] Average power factor of phase YZ one day before voltage loss pg yz,B , the product of the sum of the X-phase current and the average power factor of the YZ phases M x,B The calculation formula is:

[0088]

[0089] M x,B =SI x,B ×pg x,B (4)

[0090] Where P yi,d-1 , Q yi,d-1 , P zi,d-1 , Q zi,d-1They are respectively the active power and reactive power of the Y and Z phases in a collection period of 15 minutes each; pg yz,B is the average power factor of phases Y and Z on day d-1, M x,B It is the product of the sum of the X-phase current and the average power factor of the YZ phases.

[0091] (2) Calculation method when two phases lose pressure:

[0092] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0093] The electricity E of phases Y and Z one day before the voltage loss y,B 、E z,B The sum of the Y and Z phase currents SI y,B 、SI z,B The calculation formula is:

[0094]

[0095]

[0096] In the formula, I yi,d-1 ,I zi,d-1 It is the current value of phases Y and Z in a collection period of 15 minutes.

[0097] Average power factor of phase X one day before voltage loss pg x,B , the product of the sum of the Y and Z phase currents and the average power factor of the X phase is M y,B 、M z,B The calculation formula is:

[0098]

[0099]

[0100] In the formula, Q xi,d-1 It is the reactive power of phase X in a collection period of 15 minutes.

[0101] Step 4: Calculate the sum of the currents of the voltage-loss phases, the average power factor of the normal phases, and the product of the two for each day during the voltage-loss period.

[0102] (1) Calculation method when single-phase voltage is lost:

[0103] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0104] The sum of the currents of the X phases during the voltage loss period SI x,d , average power factor of phase YZ pg yz,d And the product of the two M x,d The calculation formula for is:

[0105]

[0106]

[0107] M x,d =SI x,d ×pg x,d (11)

[0108] Where d refers to a day during the pressure loss period; I xi,d P is the current value of the X phase during a 15-minute sampling period during the voltage loss period; yi,d , Q yi,d , P zi,d , Q zi,d They are respectively the active power and reactive power of the Y and Z phases in a collection period of 15 minutes each during the voltage loss period.

[0109] (2) Calculation method when two phases lose pressure:

[0110] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0111] The sum of the currents of the Y and Z phases during the voltage loss period SI y,d 、SI z,d , average power factor of phase X pg x,d And the product of the sum of current and the average power factor M y,d 、M z,d The calculation formula for is:

[0112]

[0113]

[0114]

[0115] In the formula, I yi,d ,I zi,d Q is the current value of the Y and Z phases during a 15-minute sampling period during the voltage loss period; xi,d It is the reactive power of phase X in a collection period of 15 minutes during the voltage loss period.

[0116] Step 5: Compare the product of the sum of the phase current during the voltage loss period and the average power factor of the normal phase on each day with the product of the day before the voltage loss to obtain the power correction coefficient for each day during the voltage loss period.

[0117] (1) Calculation method when single-phase voltage loss occurs:

[0118] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0119] The M of each day during the pressure loss period x,dCompared with M on the day before the pressure loss x,B The ratio obtained by comparison is the power correction coefficient r of phase X per day during the voltage loss period. x,d .

[0120]

[0121] (2) Calculation method when two phases lose pressure:

[0122] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0123] During the pressure loss period, the M of the two phases Y and Z for each day y,d 、M z,d Compared with M on the day before the pressure loss y,B 、M z,B The ratio obtained by comparison is the power correction coefficient r of the two phases Y and Z per day during the voltage loss period. y,d 、r z,d .

[0124]

[0125] Step 6: Multiply the power consumption correction coefficient by the power consumption of the pressure loss phase on the day before the pressure loss to obtain the corrected power consumption of the pressure loss phase on each day during the pressure loss period.

[0126] (1) Calculation method when single-phase voltage is lost:

[0127] Set the de-voltage phase to X phase and the normal phases to Y and Z phases:

[0128] Use the power correction factor r of phase X during voltage loss x,d Multiply by the power E of phase X the day before the voltage loss x,B The corrected power E of phase X per day during the voltage loss period can be obtained. x,d ;

[0129]

[0130] (2) Calculation method when two phases lose pressure:

[0131] Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z:

[0132] The power correction coefficient r of phases Y and Z during the voltage loss period is used y,d 、r z,d Multiply by the electricity E of phases Y and Z the day before the voltage loss y,B 、E z,B The corrected electric quantity E of phases Y and Z per day during the voltage loss period can be obtained. y,d 、E z,d ;

[0133]

[0134] Step 7: Add the corrected power of the voltage-depleted phase to the measured power of the normal phase to obtain the total restored power E. h :

[0135]

[0136] Step 8: Calculate the metered electricity E of the three-phase four-wire meter during the voltage loss period based on the electricity meter readings on the start and end dates of the voltage loss. j (The normal method of calculating electricity is to subtract the electricity indication at the beginning of the month from the electricity indication at the end of the voltage loss to obtain the electricity. For example, the electricity indication at the end of each month is subtracted from the electricity indication at the beginning of each month to obtain the electricity for that month). Then, the calculated restored electricity is subtracted from the measured electricity during the voltage loss to obtain the compensatory electricity ZE during the voltage loss.

[0137]

[0138] For the convenience of calculation, the calculation can be performed one by one according to the format of Table 1 and Table 2, and the reduction amount of the pressure loss phase during the pressure loss period can be obtained.

[0139] Table 1 Calculation table for phase X voltage loss

[0140]

[0141] Table 2 Calculation table when YZ phase loses voltage

[0142]

[0143] The derivation process of the power calculation method is as follows:

[0144] The current electricity consumption information collection system will collect and upload the current data of the energy meter at a certain time interval (15 minutes). The collected data items include voltage, current, active power, reactive power, etc. The power load of general users is relatively stable. The power data collected every 15 minutes can basically reflect the actual situation of the power load. The power obtained by summing the power is basically the same as the power measured by the energy meter, and the error is very small. Therefore, the total power consumption E of the whole day can be obtained by summing the 96 active power data collected 24 hours a day. d , as shown below:

[0145]

[0146] Among them, E a,d 、E b,d 、E c,d are the metered power of phases A, B, and C on day d, respectively, ai,d , P bi,d , P ci,dThey represent the active power of each 15-minute acquisition period on the dth day; U ai,d , U bi,d , U ci,d They represent the voltage of each 15-minute sampling period on the dth day; I ai,d ,I bi,d ,I ci,d They represent the current in each 15-minute sampling period on the dth day; cosφ ai,d 、cosφ bi,d 、cosφ ci,d They represent the power factor of each 15-minute collection period on the dth day.

[0147] The three-phase voltage balance is an indicator of power quality. Its deviation is generally small and can be approximately considered as a fixed value U. The average power factor of each phase every day is used to replace the power factor of each 15-minute collection period, and the following formula can be obtained:

[0148]

[0149] in, are the average power factors of phases A, B, and C on day d.

[0150] Then the ratio of the electricity measured on day d to day d+1 is:

[0151]

[0152] Among them, SI a,d 、SI b,d 、SI c,d They represent the summed current of each phase on the dth day.

[0153] It can be seen from formula (23) that the ratio of the three-phase metered electricity of A, B, and C on different dates can be approximated as the ratio of the summed current value and the product of the average power factor. When a three-phase four-wire meter loses voltage, the current of the phase losing voltage can still be measured and collected normally; and there is a strong correlation between the three-phase power loads. Although their current magnitudes and phases are different, the ratio of the average power factors of each phase on different dates can be approximately considered to be roughly the same. Therefore, when calculating the electricity during the voltage loss period, the electricity measured by the voltage loss phase one day before the voltage loss can be selected as the electricity reference value, and the summed current value of the voltage loss phase and the average power factor of the normal phase during the voltage loss period are calculated respectively, and the two are multiplied to obtain the product of the current and the power factor. The product of that day is compared with the product of the day before the voltage loss. The ratio obtained is the electricity correction coefficient of the voltage loss phase on that day. Then, the electricity correction coefficient is multiplied by the electricity measured by the voltage loss phase one day before the voltage loss.

[0154] Example:

[0155] The power consumption capacity of a certain user is 200kVA, the installed meter is a three-phase four-wire meter, and the current transformer ratio is 300 / 5. The total power and phase power measured from November 23 to November 26, 2023 are shown in Table 3. Now simulate the voltage loss of phase C of the user's power meter from November 24 to November 26, and use the correction coefficient method and the new method proposed in this paper to calculate the voltage loss compensation power respectively, and compare them.

[0156] Table 3 Total power and phase power measured by actual users

[0157]

[0158] 1. Calculate using the correction coefficient method:

[0159] Add the A-phase power and B-phase power of each day from 11.24 to 11.26, and multiply by 1.5 to get the corrected power, which is 782.7kWh, and the supplementary power of D is 260.9kWh. Add the total power of each day from 11.24 to 11.26 to get the actual power, which is 653.4kWh. The deviation rate between the corrected power obtained by the correction coefficient method and the actual power is 19.8%, which is a large error.

[0160] 2. Use the power calculation method based on the current summation value and the average power factor:

[0161] (1) Confirm the phase, time and days of pressure loss.

[0162] Phase of pressure loss: Phase C;

[0163] Decompression time: November 24, 2023 - November 26, 2023

[0164] Days of decompression: 3 days.

[0165] (2) Obtain relevant electricity consumption data from November 23, 2023 to November 26, 2023 from the electricity consumption information collection system.

[0166] (3) Calculate according to Table 3.

[0167] (4) Calculate the power E of phase C one day before the voltage loss c,B , C phase current sum value SI c,B , the average power factor of phase AB pg ab,B , and the product of the sum of the power and the average power factor M c,B , as shown in Table 8.

[0168] (5) Calculate the sum of phase C current SI during voltage loss c,d , the average power factor of phase AB pg ab,d, and the product of the sum of the power and the average power factor M c,d , as shown in Table 4.

[0169] Table 4 Calculation table of power consumption when user phase C loses voltage

[0170]

[0171] (6) Change the M from 11.24 to 11.26 c,d With 11.23M c,B The ratio obtained is the power correction coefficient z c,d , as shown in Table 4.

[0172] (7) Change the z from 11.24 to 11.26 c,d With 11.23 E c,B Multiply them and get the corrected power of phase C during the period from November 24 to November 26.

[0173] (8) Add the corrected power of phase C to the measured power of phases AB to obtain the restored power of 648.12 kWh.

[0174] (9) Subtract the measured power of phases A and B during the period of 11.24-11.26 (521.8 kWh) from the restored power, and the voltage loss compensation power is 126.32 kWh.

[0175] During the period of 11.24-11.26, the actual power meter was 653.4kWh. The restored power obtained by the power calculation method based on the current summation value and the average power factor was 648.12kWh, with a deviation rate of -0.81%, a small error, and its accuracy and practicality were significantly better than the correction coefficient method to obtain the corrected power of the voltage loss phase during the voltage loss period.

[0176] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for calculating the amount of power required to compensate for a three-phase four-wire meter's voltage loss when the three-phase current is unbalanced, characterized in that: The steps include: Step 1: After the voltage of the three-phase four-wire meter is restored to normal after on-site processing, determine the phase of the electric energy meter that lost voltage and the time of the voltage loss, where the time of the voltage loss includes the starting date of the voltage loss, the ending date of the voltage loss and the number of days of the voltage loss; Step 2: Obtain relevant power consumption data from the power consumption information collection system one day before and during the voltage loss period. The relevant power consumption data include active and reactive power data of three metering elements, current data of the voltage loss phase, and electric energy meter readings on the start and end days of the voltage loss. The active and reactive power data of the three metering elements are: P a , Q a ;P b , Q b ;P c , Q c ; Step 3: Calculate the power of the voltage-losing phase, the summed current value, the average power factor of the normal phase, and the product of the summed current value of the voltage-losing phase and the average power factor of the normal phase one day before the voltage loss, and use these data as the reference value for calculating the voltage loss compensation power; Step 4, calculating the sum of the current of the voltage-loss phase, the average power factor of the normal phase, and the product of the two for each day during the voltage-loss period; Step 5: Compare the product of the sum of the phase current under voltage on each day during the voltage loss period and the average power factor of the normal phase with the product of the day before the voltage loss to obtain the power correction coefficient for each day during the voltage loss period; Step 6: Multiply the power consumption correction coefficient by the power consumption of the pressure loss phase on the day before the pressure loss to obtain the corrected power consumption of the pressure loss phase on each day during the pressure loss period. Step 7, add the corrected electric quantity of the pressure-loss phase to the measured electric quantity of the normal phase to obtain the total restored electric quantity; Step 8: Calculate the metered electricity of the three-phase four-wire meter during the voltage loss period according to the electricity meter readings on the start and end dates of the voltage loss. Then, subtract the metered electricity during the voltage loss period from the calculated restored electricity to obtain the replenished electricity during the voltage loss period.

2. The method for calculating the amount of electricity to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced according to claim 1 is characterized in that: Step 3 includes single-phase and two-phase voltage loss calculations: The calculation method for single-phase voltage loss is: Set the de-voltage phase to X phase and the normal phases to Y and Z phases: The electricity E of phase X one day before the voltage loss x,B and X-phase current sum SI x,B The calculation formula is: Where, d-1 refers to the day before the pressure loss; P xi,d-1 I is the active power of phase X in a collection period of 15 minutes; xi,d-1 It is the current value of X phase in a collection period of every 15 minutes; Average power factor of phase YZ one day before voltage loss pg yz,B , the product of the sum of the X-phase current and the average power factor of the YZ phases M x,B The calculation formula is: M x,B =SI x,B ×pg x,B (4) Where P yi,d-1 , Q yi,d-1 , P zi,d-1 , Q zi,d-1 They are respectively the active power and reactive power of the Y and Z phases in a collection period of 15 minutes each; pg yz,B is the average power factor of phases Y and Z on day d-1, M x,B It is the product of the sum of the X-phase current and the average power factor of the YZ phases. Calculation method when two phases lose pressure: Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z: The electricity E of phases Y and Z one day before the voltage loss y,B 、E z,B The sum of the Y and Z phase currents SI y,B 、SI z,B The calculation formula is: In the formula, I yi,d-1 ,I zi,d-1 It is the current value of the Y and Z phases in a collection period of 15 minutes; Average power factor of phase X one day before voltage loss pg x,B , the product of the sum of the Y and Z phase currents and the average power factor of the X phase is M y,B 、M z,B The calculation formula is: In the formula, Q xi,d-1 It is the reactive power of phase X in a collection period of 15 minutes.

3. The method for calculating the amount of electricity to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced according to claim 1 is characterized in that: Step 4 includes single-item pressure loss calculation and two-item pressure loss calculation: Calculation method when single-phase voltage loss: Set the de-voltage phase to X phase and the normal phases to Y and Z phases: The sum of the currents of the X phases during the voltage loss period SI x,d , average power factor of phase YZ pg yz,d And the product of the two M x,d The calculation formula for is: M x,d =SI x,d ×pg x,d (11) Where d refers to a day during the pressure loss period; I xi,d P is the current value of the X phase during a 15-minute sampling period during the voltage loss period; yi,d , Q yi,d , P zi,d , Q zi,d They are respectively the active power and reactive power of the Y and Z phases in a collection period of 15 minutes each during the voltage loss period. Calculation method when two phases lose pressure: Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z: The sum of the currents of the Y and Z phases during the voltage loss period SI y,d 、SI z,d , average power factor of phase X pg x,d And the product of the sum of current and the average power factor M y,d 、M z,d The calculation formula for is: In the formula, I yi,d ,I zi,d Q is the current value of the Y and Z phases during a 15-minute sampling period during the voltage loss period; xi,d It is the reactive power of phase X in a collection period of 15 minutes during the voltage loss period.

4. The method for calculating the amount of electricity to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced according to claim 1 is characterized in that: Step 5 includes single-phase voltage loss calculation and two-phase voltage loss calculation: Calculation method when single-phase voltage loss: Set the pressure-loss phase as X phase, and the normal phases as Y and Z phases; The M of each day during the pressure loss period x,d Compared with M on the day before the pressure loss x,B The ratio obtained by comparison is the power correction coefficient r of phase X per day during the voltage loss period. x,d ; Calculation method when two phases lose pressure: Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z: During the pressure loss period, the M of the two phases Y and Z for each day y,d 、M z,d Compared with M on the day before the pressure loss y,B 、M z,B The ratio obtained by comparison is the power correction coefficient r of the two phases Y and Z per day during the voltage loss period. y,d 、r z,d ; 5. The method for calculating the amount of electricity to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced according to claim 1 is characterized in that: Step 6 includes single-phase pressure loss calculation and dual-phase pressure loss calculation: Calculation method when single-phase voltage loss: Set the de-voltage phase to X phase and the normal phases to Y and Z phases: Use the power correction factor r of phase X during voltage loss x,d Multiply by the power E of phase X the day before the voltage loss x,B The corrected power E of phase X per day during the voltage loss period can be obtained. x,d ; E x,d =r x,d ×E x,B (17) Calculation method when two phases lose pressure: Set the normal phase as phase X and the voltage-depleted phases as phases Y and Z: The power correction coefficient r of phases Y and Z during the voltage loss period y,d 、r z,d Multiply by the electricity E of phases Y and Z the day before the voltage loss y,B 、E z,B The corrected electric quantity E of phases Y and Z per day during the voltage loss period can be obtained. y,d 、E z,d ; 6. The method for calculating the amount of electricity to be compensated for a three-phase four-wire meter when the three-phase current is unbalanced according to claim 1 is characterized in that: In step 7, the total reduction charge is E h ,but:

7. The method for calculating the amount of electricity to be compensated for a three-phase four-wire meter's voltage loss when the three-phase current is unbalanced according to claim 1, characterized in that: In step 8, the measured power of the three-phase four-wire meter during the voltage loss period is E j , the compensation power ZE during the voltage loss period, then: THEY=E h -E j (20)。

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