CN106249044A - A kind of replacing based on root mean square transformator saves the monolateral measuring method of quantity of electricity - Google Patents

Abstract

The invention discloses a kind of replacing based on root mean square transformator and save the monolateral measuring method of quantity of electricity, comprise the following steps: 1, determine energy-conservation replacing item boundaries, project base period, statistical report phase and representative calculating time；2, voltage transformer, current transformer are installed in transformator side and the special table meter of parameter and calculated savings quantity of electricity can be set；3, transformator is changed before the project implementation, measures in representative calculating time in base period the parameters such as transformer current voltage, open circuit loss, load loss, rated capacity, maximum load power；4, transformer current voltage, open circuit loss, load loss, rated capacity, maximum load power parameter in representative calculating time statistical report phase is measured；5, persistently calculate rms voltage affects coefficient, rms current affects coefficient；6, calculated savings quantity of electricity.The present invention has and simplifies measurement procedure, saved measurement cost and the measurement result advantage such as accurately.

Description

A kind of replacing based on root mean square transformator saves the monolateral measuring method of quantity of electricity

Technical field

The present invention relates to transformator quantity measuring method, be specifically related to a kind of replacing based on root mean square transformator and save electricity The monolateral measuring method of power electricity, this measuring method belongs to transformator field of measuring techniques.

Background technology

In power system, distribution transformer is as undertaking voltage, electric current and the capital equipment of power conversion, its quantity ten Divide huge, and in ascendant trend year by year.Although the loss of every transformator is less, but due to its huge radix and long-time It is in running status, so the total losses that distribution transformer causes every year are the most surprising.Meanwhile, some areas still use model Older transformator, its loss is apparently higher than novel transformer, therefore, improves electrical network by replacing new distribution transformator whole Physical ability effect level, reduction energy loss become inevitable choice.And in order in order, reasonably carry out transformator replacing, analyze The economic benefit of replacing project, the planning and designing simultaneously instructing power transformer to change, need the joint before and after transformator is changed About electricity measures, calculates.

Transformator is changed the measurement of saving quantity of electricity and be there is no unified reference standard at present.Application publication number is The Chinese invention patent application of CN103018584A discloses a kind of for electric power boosting and transformation saving electric power and the measurement of electricity With verification method, this patent of invention by installing metering device in transformator both sides, and the operation before and after measuring transformer transformation is joined Number, calculated savings quantity of electricity.Application publication number is that the Chinese invention patent application of CN104698269A discloses a kind of transformation Saving quantity of electricity measuring and calculating device and measuring method before and after device transformation, this patent of invention measures dress by installing in transformator one side Put, carry out calculated savings quantity of electricity by calculating transformer replacing forward backward averaging electric current, voltage.

Owing to electrical network commonly using single-ended metering system, use the method that two ends are measured, need to install at opposite side to survey Amount device, due to the measurement error meeting superposition of two ends measurement apparatus, therefore requires high to certainty of measurement, poor practicability.Use The method of single-ended measurement, is conducive to simplifying measurement procedure, saves and measures cost.But while using single-ended measuring method, need to examine Consider the accuracy of result, from the angle analysis of Energy Equivalent, use parameter based on meansigma methods to calculate quantity of electricity, at transformator It is likely to result in bigger error when peak-valley difference is bigger, is not suitable for needing energy-conservation as clearing foundation of amount of energy saving assessed value accurately Transformation project.

Summary of the invention

It is an object of the invention to the shortcoming overcoming prior art and deficiency, propose one based on root mean square transformator more Changing the saving monolateral measuring method of quantity of electricity, this measuring method has only to just can be real at transformator side installing metering device Existing.

The purpose of the present invention is achieved through the following technical solutions: a kind of replacing based on root mean square transformator saves electric power electricity Measure monolateral measuring method, comprise the following steps:

S1. energy-conservation replacing item boundaries, project base period, statistical report phase and T representative calculating time are determined；

S2., voltage transformer, current transformer are installed in transformator side and parameter and calculated savings electric power can be set The special table meter of electricity；

S3., before the project implementation changed by transformator, transformer current voltage, open circuit loss in representative calculating time in base period is measured P₀, load loss P_k, rated capacity S_N, maximum load power S_IMEtc. parameter；

S4., after the project implementation changed by transformator, transformer current voltage, sky in representative calculating time statistical report phase is measured Load-loss P '₀, load loss P '_k, rated capacity S '_N, maximum load power S '_IMEtc. parameter；

S5. special table meter starts and continues computing module, affects COEFFICIENT K according to measuring the data obtained calculating rms voltage_u And rms current affects COEFFICIENT K_i；

S6. special table meter is according to measuring the data obtained and calculating parameters obtained calculated savings quantity of electricity.

Boundary condition described in step S1 only refers to transformer body, and after i.e. changing, transformer body loss reduces and saves Quantity of electricity, including open circuit loss and load loss, ignore coupled electrical network and decrement be lost accordingly.The described base period Before referring to that the project implementation changed by transformator, for determining the time period of replacing project energy consumption benchmark.The described statistical report phase refers to use In determining that transformator is changed project and saved the time period of quantity of electricity.Refer to described representative calculating time reflect that transformator is true Positive activity situation and the time period of calculating transformer operational factor.

The instruments such as the voltage transformer summation current transformer described in step S2, should meet JJG 313-2010 and measure electricity consumption Current transformer vertification regulation and JJG 314-2010 measure by the relevant regulations of voltage ct calibrating code.Become at conservative control On the premise of Ben, improve certainty of measurement as far as possible.Use condition is relevant in should meeting GB " current transformer ", " voltage transformer " Regulation, daily maximum temperature is less than 40 DEG C, and Daily minimum temperature is not less than-25 DEG C, and daily mean temperature is less than 30 DEG C；Place to use Height above sea level is less than 1000m；Should be without severe contamination in air.

Special table meter described in step S2 should possess the computing capability of root-mean-square value.Simultaneously comprise reception voltage transformer, Current transformer measurement data function, base period, statistical report phase, the set-up function of representative calculating time, save quantity of electricity Computing function, wherein and data storage function.

In step S3, S4, before and after transformator is changed, special ammeter is by receiving voltage transformer, current transformer survey Transformer voltage, current data, carry out open circuit loss, load loss, rated capacity and maximum load power isoparametric Calculate, and store.

Rms voltage described in step S5 affects COEFFICIENT K_uRefer to rms voltage and voltage in T representative calculating time The ratio of rated value, characterizes the degree of voltage deviation rated voltage in actual motion, can be according to formulaCalculate and ?；Described rms current affects COEFFICIENT K_iRefer to RMS current and the ratio of current rating, table in T representative calculating time Levy the degree of electric current deviation rated current in actual motion, can be according to formulaCalculate and obtain；Special table meter has Ask for root mean square function, it is possible to the data recorded according to transformer calculate above-mentioned parameter, and can be according to the time of measurement Passage, persistently calculates parameter.

Transformator described in step S6 is changed body dissipation before and after saving quantity of electricity refers to transformator replacing and is reduced and save Quantity of electricity about, only considers open circuit loss P_FeWith load loss P_Cu, other stray losses, such as lead-in wire, shell, fan etc. Caused loss ratio is relatively small, does not therefore consider.Economize on electricity power after described saving electric power refers to transformator replacing refers to Before and after replacing, during transformer load maximum, transformer efficiency loss difference.Described saving electricity refers in the case of comparable, economize on electricity After measure enforcement compared with before enforcement, consume the quantity that electric energy reduces.

Described special table meter can calculate maximum load power S according to the current and voltage data that transformer records_IM, volume Constant volume S_N, rated no-load loss power P₀, nominal load loss power P_kIf not possessing on-the-spot test condition, P₀、 P_k、S_NParameter also can obtain on transformator nameplate.Saving electric power changed by described transformator can be according to formulaCalculate and obtain.

Described transformator is changed saving electricity and is included open circuit loss electricity Δ E_FeAnd load loss electricity Δ E_CuTwo Point, open circuit loss electricity can be according to formulaCalculate and obtain, load loss of electricity Can be according to formulaCalculating and obtain, saving electricity changed by transformator can be according to formulaCalculate and obtain.

Substantially fluctuate near rated voltage in view of transformator working voltage, therefore can be approximately considered rms voltage shadow Ring COEFFICIENT K_u=1, open circuit loss electricity can be reduced to Δ E_Fe=P₀T.In this case, transformator replacing saving electricity can table It is shown as

Specifically including that based on the root mean square transformator replacing saving monolateral measuring method of quantity of electricity of the present invention determines item Mesh border, base period, statistical report phase, representative calculating time；Voltage transformer, current transformer are installed in transformator side, with And special table meter；Specialty table meter possesses the senior computing function asking for root-mean-square value, operational factor, quantity of electricity；Pass through mutual inductance Device is measured, and the open circuit loss before and after the calculating acquisition transformator replacing of special table meter, load loss, rated capacity, maximum meet merit The operational factors such as rate, and store；By the data collected, special table meter persistently calculate rms voltage affect coefficient, Rms current affects the operational factors such as coefficient；According to every operational factor, the replacing of special table meter calculating transformer is saved Quantity of electricity.The method of the present invention only need to install measurement apparatus in transformator side, simplifies measurement procedure, saves and measure cost； Affecting coefficient calculations quantity of electricity by voltage rms current, measurement result is accurate, it is adaptable to need amount of energy saving accurately to comment Valuation is as the reducing energy consumption project of clearing foundation.

The present invention has such advantages as relative to prior art and beneficial effect:

(1) present invention proposes a kind of based on the root mean square transformator replacing saving monolateral measuring method of quantity of electricity, it is only necessary to Measurement apparatus is installed, it is adaptable to single-ended metering method universal in electrical network in the side of transformator, the most cost-effective, simplify Measurement procedure, has good economic benefit and practical value.

(2) one that the present invention proposes is changed based on root mean square transformator and is saved the monolateral measuring method of quantity of electricity, logical Cross rms voltage and affect COEFFICIENT K_u, rms current affect COEFFICIENT K_iCalculated savings quantity of electricity, divides from the angle of Energy Equivalent Analysis, uses based on root mean square method relative to method based on meansigma methods, and theoretical derivation is rigorous, and measuring accuracy is higher, is suitable for In the occasion needing accurate calculating transformer energy consumption.

Accompanying drawing explanation

Fig. 1 is the flow chart changed based on root mean square transformator and save the monolateral measuring method of quantity of electricity.

Fig. 2 is that item boundaries schematic diagram changed by the power transformer of the present invention.

Fig. 3 is the wiring schematic diagram of the present invention.

Detailed description of the invention

Below in conjunction with the accompanying drawings and embodiment the present invention is described in detail:

Embodiment one

(1) embodiment overview；

In the present embodiment, transformator replacing project is divided into the capacity such as highly effective transformer to change and highly effective transformer increase-volume is changed, To solve the loss of transformator height and the problem of transformer capacity deficiency.Become to wait S15, S13 type transformator of capacity to change S7 type As a example by depressor, the quantity of electricity that the capacity such as calculating transformer is saved after changing, its Central Plains S7 type transformator is transported with 0.5 load factor OK, it is constant that afterload changed by transformator, and transformator important technological parameters is shown in Table 1.

Table 1

(2) power system calculation is saved；

Step is as it is shown in figure 1, border (as shown in Figure 2) of first identifying project, and base period, project add up phase, exemplary operation week Phase all takes 720 hours.The equipment such as transformer, special ammeter of installation (as shown in Figure 3).In view of working voltage typically at specified electricity Near Ya, therefore rms voltage affects COEFFICIENT K_uApproximation is taken as 1, utilizes the transformer loss computing formula to be:

$\mathrm{\Δ}E=P_{0}T+P_k{K}_i^{2}T,$

In formula, rated no-load loss power P₀With load loss P_kCan obtain from transformator nameplate data or in-site measurement. According to the load condition of transformator, count rms current to affect coefficient be 0.6.Owing to being appearance replacing such as grade, it is assumed that before and after replacing Apparent energy S under peak load_IM=189kW, calculates according to monolateral measurement economize on electricity power formula:

$\mathrm{\Δ}\left(\mathrm{\Δ}P\right)=\mathrm{\Δ}P-{\mathrm{\ΔP}}^{\′}=(P_0+P_k\frac{S_{IM}^2}{S_N^2})-(P_0^{\′}+P_k^{\′}\frac{S_{IM}^{\′2}}{S_N^{\′2}}).$

After calculating, obtain the S7 type transformator of 315kVA capacity and the S13 type transformator of capacity, the electric power of saving such as be replaced by For:

$\mathrm{\Δ}\left(\mathrm{\Δ}P\right)=(\frac{862}{1000}+\frac{4970}{1000}\×\frac{{189}^2}{{315}^2})-(\frac{340}{1000}+\frac{3650}{1000}\×\frac{{189}^2}{{315}^2})=0.997kW,$

Equally, the S7 type transformator of 315kVA capacity such as is replaced by the S15 type transformator of capacity, and the electric power of saving is:

$\mathrm{\Δ}\left(\mathrm{\Δ}P\right)=(\frac{862}{1000}+\frac{4970}{1000}\×\frac{{189}^2}{{315}^2})-(\frac{170}{1000}+\frac{3650}{1000}\×\frac{{189}^2}{{315}^2})=1.167kW,$

(3) save electricity to calculate；

According to amount of electricity saving computing formula:

$\mathrm{\Δ}\left(\mathrm{\Δ}E\right)=\mathrm{\Δ}E-{\mathrm{\ΔE}}^{\′}=(P_{0}T+P_k{K}_i^{2}T)-(P_0^{\′}\×T+P_k^{\′}{K}_i^{2}T),$

After calculating, obtain the S7 type transformator of 315kVA capacity and the S13 type transformator of capacity, the electricity of saving such as be replaced by For:

$\begin{array}{c}\mathrm{\Δ}\left(\mathrm{\Δ}E\right)=(\frac{862}{1000}\×720+\frac{4970}{1000}\×{0.6}^2\×720)-(\frac{340}{1000}\×720+\frac{3650}{1000}\×{0.6}^2\×720)\\ =718kWh\end{array},$

Equally, the S7 type transformator of 315kVA capacity such as is replaced by the S15 transformator of capacity, and the electricity of saving is:

$\begin{array}{c}\mathrm{\Δ}\left(\mathrm{\Δ}E\right)=(\frac{862}{1000}\×720+\frac{4970}{1000}\×{0.6}^2\×720)-(\frac{170}{1000}\×720+\frac{3650}{1000}\×{0.6}^2\×720)\\ 841kWh\end{array},$

(4) save quantity of electricity to collect；

The present embodiment is saved quantity of electricity and is collected as shown in table 2, and table 2 is that 315KVA S7 type transformator such as is replaced by the capacity The quantity of electricity table that S13 or S15 transformator is saved.

Table 2

Embodiment two

(1) embodiment overview；

In the present embodiment, project changed by transformator is that the capacity such as highly effective transformer are changed, to wait S13 type transformator of capacity Change S7 type transformator, to solve transformator height loss problem.Transformator important technological parameters is shown in Table 1.Use respectively based on flat The method of equal electric current and the present invention calculate based on root mean square method and after changing, saves electricity.Transformator working voltage is at volume Determining near voltage, in one day, electric current perunit value is as shown in table 3, and table 3 is one day 24h electric current perunit value table of transformator.

Time/h	0	1	2	3	4	5	6	7
									Electric current/p.u.	0.35	0.2	0.15	0.14	0.15	0.18	0.25	0.5
Time/h	8	9	10	11	12	13	14	15
									Electric current/p.u.	0.59	0.68	0.71	0.61	0.6	0.65	0.68	0.68
Time/h	16	17	18	19	20	21	22	23
									Electric current/p.u.	0.63	0.53	0.52	0.5	0.49	0.49	0.45	0.4

Table 3

(2) save electricity to calculate；

Taking the statistical report phase is 720 hours, and according to method based on average current, the value obtaining average current is

$\stackrel{\‾}{I}=\frac{\mathrm{\Σ}I}{T}=0.46,$

According to saving electricity computing formula based on average current

$\mathrm{\Δ}\left(\mathrm{\Δ}E\right)=\mathrm{\Δ}E-{\mathrm{\ΔE}}^{\′}=(P_0-P_0^{\′})T+(P_k-P_k^{\′})\frac{I^2{U}^2}{S_N^2}T,$

Being calculated saving electricity is:

Δ (Δ E)=(0.862-0.34) × 720+ (4.97-3.65) × 0.46²× 720=576.94kWh,

According in the present invention based on root-mean-square method, obtaining rms current affects COEFFICIENT K_iFor

$K_i=\frac{\sqrt{\frac{{\∫}_0^T{i}^{2}dt}{T}}}{I_N}=0.50,$

Being calculated saving electricity is:

Δ (Δ E)=(0.862-0.34) × 720+ (4.97-3.65) × 0.50²× 720=613.71kWh,

It is the basis at Energy Equivalent owing to the present invention changing saving quantity of electricity method based on root mean square transformator On, obtain according to the formula direct derivation of transformer noload losses electricity and load loss electricity, ignore the measurement of measurement apparatus During error, it is believed that result of calculation is exact value, and result of calculation based on average current 36.77kWh on the low side.By above-mentioned point Analysis is it can be seen that certain error can be there is in computational methods based on average current, when transformator peak-valley difference increases further, Error also can increase therewith.

The above, patent preferred embodiment the most of the present invention, but the protection domain of patent of the present invention is not limited to This, any those familiar with the art is in the scope disclosed in patent of the present invention, according to the skill of patent of the present invention Art scheme and inventive concept equivalent or change in addition thereof, broadly fall into the protection domain of patent of the present invention.

Claims (5)

1. change the saving monolateral measuring method of quantity of electricity based on root mean square transformator for one kind, it is characterised in that include following Step:

1) energy-conservation replacing item boundaries, project base period, statistical report phase and representative calculating time are determined；

2) voltage transformer, current transformer are installed in transformator side and parameter and calculated savings quantity of electricity can be set Special table meter；

3), before the project implementation changed by transformator, transformer current voltage, open circuit loss, load in representative calculating time in base period is measured Loss, rated capacity, maximum load power parameter；

4), after the project implementation changed by transformator, transformer current voltage, unloaded damage in representative calculating time statistical report phase is measured Consumption, load loss, rated capacity, maximum load power parameter；

5) special table meter is according to measuring the data obtained, and persistently rms voltage affects coefficient, rms current affects coefficient in calculating；

6) special table meter is according to measuring the data obtained and calculating parameters obtained calculated savings quantity of electricity.

The most according to claim 1 replacing based on root mean square transformator saves the monolateral measuring method of quantity of electricity, and it is special Levy and be, in step 2, it is only necessary to install transformer and special table meter in transformator side, Measured Boundary only comprises transformator Open circuit loss and load loss.

The most according to claim 2 replacing based on root mean square transformator saves the monolateral measuring method of quantity of electricity, and it is special Levy and be, described special table meter be used for asking for root-mean-square, for receive voltage transformer, current transformer measurement data, for Base period, the statistical report phase, the setting of representative calculating time, for saving the calculating of quantity of electricity and for every result of calculation Storage.

The most according to claim 3 replacing based on root mean square transformator saves the monolateral measuring method of quantity of electricity, and it is special Levying and be, described special table meter is according to formulaIn formula, K_uFor rms voltage coefficient, u is to measure in real time Transformer voltage, T is transformator representative calculating time, U_NFor transformator rated voltage, t is the time, is calculated root-mean-square electricity Pressure affects COEFFICIENT K_u；According to formulaIn formula, K_iFor rms voltage coefficient, i is the transformator measured in real time Electric current, T is transformator representative calculating time, I_NFor transformator rated current, t is the time, is calculated rms voltage coefficient K_i；Do according to the passage of the time of measurement simultaneously and persistently calculate.

The most according to claim 4 replacing based on root mean square transformator saves the monolateral measuring method of quantity of electricity, and it is special Levying and be, described special table meter can be according to formula:

$\mathrm{\Δ}\left(\mathrm{\Δ}P\right)=(P_0+P_k\frac{S_{IM}^2}{S_N^2})-(P_0^{\′}+P_k^{\′}\frac{S_{IM}^{\′2}}{S_N^{\′2}}),$

In formula, Δ (Δ P) represents saves electric power, P₀、P_k、S_IM、S_NRefer to respectively change front transformator rated no-load loss power, volume Fixed load loss power, maximum load power, rated capacity, P '₀、P′_k、S′_IM、S′_NTransformator rated no-load after referring to respectively change Loss power, nominal load loss power, maximum load power, rated capacity, be calculated transformator and change saving electric power；Root According to formula:

$\mathrm{\Δ}\left(\mathrm{\Δ}E\right)=(P_0-P_0^{\′}){K_u}^{2}T+(P_k-P_k^{\′})K_i^{2}T,$

In formula, Δ (Δ E) represents saves electricity, P₀、P_kRefer to respectively change front transformator rated no-load loss power, specified complexity Loss power, K_u、K_iRefer to that rms voltage affects coefficient, rms current affects coefficient, P ' respectively₀、P′_kAfter referring to respectively change Transformator rated no-load loss power, specified complicated loss power, T refers to transformator representative calculating time, be calculated transformator Change and save electricity；Furthermore, it is contemplated that transformator working voltage fluctuates substantially near rated voltage, it is believed that rms voltage shadow Ring COEFFICIENT K_u=1, according to formula:

$\mathrm{\Δ}\left(\mathrm{\Δ}E\right)=(P_0-P_0^{\′})T+(P_k-P_k^{\′})K_i^{2}T,$

In formula, Δ (Δ E) represents saves electricity, P₀、P_kRefer to respectively change front transformator rated no-load loss power, specified complexity Loss power, K_iRefer to that rms current affects coefficient, P '₀、P′_kTransformator rated no-load loss power, specified after referring to respectively change Complicated loss power, T refers to transformator representative calculating time, calculate saving electricity.