CN106783039A - Hybrid insulation systems oil-filled transformer and its structural optimization method - Google Patents

Abstract

Hybrid insulation systems oil-filled transformer, including oil-filled transformer main body, wherein, the insulating oil in oil-filled transformer main body uses mineral insulating oil, and the insulating paper in oil-filled transformer main body uses DPE insulating papers.The invention also discloses the structural optimization method of above-mentioned hybrid insulation systems oil-filled transformer.The present invention can lift oil-filled transformer overload capacity in the case where only solid insulating material is changed, can not only continue to continue to use the operation maintenance for mineral insulating oil and fault detection criteria, the development cost for exceeding loading capability transformer can also be greatly lowered, reliability gets both with economy, easy to utilize.

Description

Hybrid insulation systems oil-filled transformer and its structural optimization method

Technical field

The present invention relates to design of transformer and applied technical field, specifically hybrid insulation systems oil-filled transformer and its Structural optimization method.

Background technology

As national economy is fast-developing, network load grows continuously and fast, and power grid construction relatively lags behind, and causes electricity Power transformer load rate remains high, or even long term overloading operation.Transformers for Rural Networks is special due to its local environment Property, seasonal overload conditions are particularly acute.To solve overload problem, the development for exceeding loading capability transformer is extremely urgent.It is existing High overload transformer is generally replaced using new type high temperature liquid and solid insulating material to the insulating materials of traditional transformer, It is costly, and operation, the maintenance criterion of traditional oil-filled transformer cannot be applied.How oil-filled transformer liquid is being changed without The development cost of transformer is reduced while body insulating materials, this turns into current people's question of common concern.However, not having now There is corresponding equipment, also have no related report.

The content of the invention

It is an object of the invention to overcome the deficiencies in the prior art, there is provided a kind of to reduce the mixed of transformer development cost Close insulation system oil-filled transformer.The invention also discloses the structure optimization side of above-mentioned hybrid insulation systems oil-filled transformer Method, it can carry out reasonably optimizing, can further reduce oil immersed type transformation in the case where insulating materials changes to transformer device structure The manufacturing cost of device so that oil-filled transformer is more convenient for popularization and application.

The present invention solves the above problems and is achieved through the following technical solutions：Hybrid insulation systems oil-filled transformer, Including oil-filled transformer main body, the insulating oil in the oil-filled transformer main body uses mineral insulating oil, oil immersed type transformation Insulating paper in device main body uses DPE insulating papers.Wherein, the insulating paper in oil-filled transformer main body of the present invention is exhausted using DPE Edge paper, it has, and the wet-out rate in mineral insulating oil is fast, drying time is short, temperature resistant grade is high, good mechanical property, price are low Advantage.

Based on the structural optimization method of above-mentioned hybrid insulation systems oil-filled transformer, comprise the following steps：

Conventional insulation system oil-filled transformer allows overload magnification and mixes under step one, the long-term emergent overload of calculating Closing insulation system oil-filled transformer permission overload magnification, and calculate hybrid insulation systems oil-filled transformer allows overload times Number allows the ratio of overload magnification with Conventional insulation system oil-filled transformer；

Step 2, the hybrid insulation systems oil-filled transformer that will be calculated allow overload magnification and Conventional insulation system oil Immersion transformer allows the ratio of overload magnification to be equivalent to winding resistance in oil-filled transformer main body and ratio is lost, according to winding Resistance loss radiometer calculates winding conducting wire reduced radius ratio, and by winding conducting wire radius in oil-filled transformer main body based on The winding conducting wire reduced radius ratio for calculating is reduced；

Step 3, the box volume of oil-filled transformer main body, core volume, insulating oil consumption and insulating paper consumption are pressed The winding conducting wire reduced radius ratio for calculating is reduced, by the winding copper material consumption of oil-filled transformer main body by calculating Winding conducting wire reduced radius ratio square reduced.

Further, the permission overload magnification of oil-filled transformer is by overloading under the medium-term and long-term emergent overload of the step one When hot(test)-spot temperature limit value corresponding overload magnification determine, wherein, the computing formula of hot(test)-spot temperature is during overload：

Wherein, θ_hT () is hot(test)-spot temperature, θ_aIt is environment temperature, △ θ_oiIt is original state top-oil temperature liter,It is initial shape State focus is poor to top-oil temperature degree, △ θ_orIt is top-oil temperature liter under total losses,For under rated current focus to top-oil temperature degree Difference, R is load loss and open circuit loss ratio, and K is load factor, and x is top layer oil index, and y is around class index, function f₁(t) The function of time of ascending amount, f are risen for reflection top-oil temperature₂T () is the function of time for reflecting focus to the difference change of top-oil temperature degree.

The present invention is different from the solid insulating material that Conventional insulation system is used, but cooling medium uses mineral insulation Oil, therefore under identical heat condition, the two Temperature Distribution is identical, the hot(test)-spot temperature for being reached is also identical, therefore can use identical Hot(test)-spot temperature computing formula.

Further, the relation between the winding resistance and winding conducting wire radius is as follows：

Wherein, R is winding resistance, and ρ is winding conductor resistivity of material, and l is winding conductor length, and S cuts for winding conductor Area, r is winding conductor radius.Calculate that winding wire diameter reduces ratio based on the heating principle of equal effects during present invention application, ignore change Influence of the depressor open circuit loss for temperature rise, it is believed that load loss is to cause the elevated main cause of winding temperature, approximately by winding electricity Resistance loss is considered as transformer thermal source, is assessed by the overload capacity of transformer of the present invention and Conventional insulation system transformer, examines Consider the relation between winding resistance and winding conducting wire radius, calculate the reduction ratio of winding wire diameter.

In sum, the invention has the advantages that：(1) present invention is in the case where only solid insulating material is changed Oil-filled transformer overload capacity can be lifted, can not only continue to continue to use the operation maintenance for mineral insulating oil and fault detect mark It is accurate, moreover it is possible to the development cost for exceeding loading capability transformer to be greatly lowered, reliability gets both with economy.

(2) performance difference of the present invention based on novel solid insulating materials and conventional solid insulating materials, compares this hair The overload capacity of the bright transformer and traditional transformer, for transformer of the present invention propose reduction winding wire diameter, Reduce core volume, reduce box volume, reduce the structure optimizations such as insulating materials consumption suggestion, it is practical, it is mix insulation The structure design of system transformer provides theoretical foundation, and reduces its manufacturing cost, has using hybrid insulation systems transformation The popularization of device and use, with important theory value and realistic meaning.

Specific embodiment

To make the object, technical solutions and advantages of the present invention become more apparent, with reference to embodiment and accompanying drawing, to this Invention is described in further detail, and exemplary embodiment of the invention and its explanation are only used for explaining the present invention, do not make It is limitation of the invention.

Embodiment：

Hybrid insulation systems oil-filled transformer, including oil-filled transformer main body, wherein, in oil-filled transformer main body Insulating oil use mineral insulating oil, the insulating paper in oil-filled transformer main body use DPE insulating papers.

Wei De Man is according to IEEE C57.100-2011 directive/guides, and the heat for having carried out 2 years by a definite date for DPE insulating papers is old Change experiment, result of the test is as shown in table 1.From table 1：DPE insulating papers are resistance to the hybrid insulation systems that mineral insulating oil is constituted Hot grade is 130 DEG C, that is, the hybrid insulation systems class of insulation for using DPE insulating papers is B grades, and transformer insulated spoilage does not surpass Hot(test)-spot temperature limit value when crossing allowed band is 165 DEG C.

Because the flash-point of all kinds of mineral insulating oils is in 100 DEG C~170 DEG C intervals, therefore select particular kind of mineral Insulating oil can meet requirement of the flash-point higher than 165 DEG C, then the performance of mineral insulating oil will not turn into hybrid insulation systems transformer The limiting factor of overload capacity.

Table 1DPE insulation system thermal aging tests result is summarized

Based on the structural optimization method of above-mentioned hybrid insulation systems oil-filled transformer, comprise the following steps：Step one, meter Conventional insulation system oil-filled transformer allows overload magnification and hybrid insulation systems oil immersed type to become under calculating long-term emergent overload Depressor allows overload magnification, and calculates hybrid insulation systems oil-filled transformer permission overload magnification and Conventional insulation system oil Immersion transformer allows the ratio of overload magnification；Step 2, the hybrid insulation systems oil-filled transformer that will be calculated were allowed Carry multiple and Conventional insulation system oil-filled transformer allow the ratio of overload magnification be equivalent in oil-filled transformer main body around Group resistance loss ratio, is lost ratio and calculates winding conducting wire reduced radius ratio according to winding resistance, and by oil immersed type transformation Winding conducting wire radius is reduced in the winding conducting wire reduced radius ratio for calculating in device main body；Step 3, oil immersed type is become The box volume of depressor main body, core volume, insulating oil consumption and insulating paper consumption are by the winding conducting wire reduced radius for calculating Ratio is reduced, by the winding copper material consumption of oil-filled transformer main body in the winding conducting wire reduced radius ratio for calculating Square reduced.

The present embodiment in the specific implementation, the permission overload magnification of oil-filled transformer under the medium-term and long-term emergent overload of step one The corresponding overload magnification of hot(test)-spot temperature limit value determines when being by overloading, wherein, the computing formula of hot(test)-spot temperature is during overload：

Wherein, θ_hT () is hot(test)-spot temperature, θ_aIt is environment temperature, △ θ_oiIt is original state top-oil temperature liter,It is initial shape State focus is poor to top-oil temperature degree, △ θ_orIt is top-oil temperature liter under total losses,For under rated current focus to top-oil temperature degree Difference, R is load loss and open circuit loss ratio, and K is load factor, and x is top layer oil index, and y is around class index, function f₁(t) The function of time of ascending amount, f are risen for reflection top-oil temperature₂T () is the function of time for reflecting focus to the difference change of top-oil temperature degree.

In the specific implementation, the relation between winding resistance and winding conducting wire radius is as follows for the present embodiment：

Wherein, R is winding resistance, and ρ is winding conductor resistivity of material, and l is winding conductor length, and S cuts for winding conductor Area, r is winding conductor radius.

The liquid insulating material of Conventional insulation system generally uses mineral insulating oil, fixed insulation material generally to use fiber Plain insulating paper, liquid insulating material of the invention uses mineral insulating oil, fixed insulation material to use DPE insulating papers.

The present embodiment calculates hot(test)-spot temperature using formula (1), wherein, using recommendation the parameter value in formula (1) more.Table 2 oil-filled transformer thermal characteristic parameter recommendations when showing that cooling medium uses mineral insulating oil in insulation system.

The oil-filled transformer thermal characteristic parameter recommendation of table 2

Thermal characteristic parameter	Recommendation
		Oily index x	0.8
Around class index y	1.6
		Oily timeconstantτo	180
Winding timeconstantτw	4
		Constant k11	1.0
Constant k21	1.0
		Constant k22	2.0
Loss ratio R	5
		Focus coefficient H	1.1
Top-oil temperature rises Δ θ under total lossesor	55
		Focus is to top-oil temperature degree gradient Hg under rated currentr	23

Can be calculated：Permission overload magnification under the long-term emergent overload of Conventional insulation system oil immersion-type distribution transformer is 1.34 times, the permission overload magnification under the long-term emergent overload of transformer described in the present embodiment is 1.53 times, i.e., using resistant to elevated temperatures General fibre element paper changes DPE insulating papers, the overload capacity of oil immersion-type distribution transformer can be promoted into 1.53 times by 1.34 times, It is sufficient for rural power grids overload demand.

In oil immersion-type distribution transformer operation, ignore influence of the open circuit loss for temperature rise, it is believed that load loss is to make Into the elevated main cause of winding temperature.And winding resistance loss in load loss proportion more than 95%, then can approximately by around Group resistance loss is considered as the thermal source of oil-filled transformer heating.

Under identical overload magnification, the thermal source size that transformer described in the present embodiment can bear can reach Conventional insulation system 1.14 times of transformer.When transformer institute bringing onto load is constant, winding resistance loss is directly proportional to winding resistance, can using formula (4) , when winding conducting wire reduced radius are original 0.94 times, ignore winding wire diameter and reduce the winding copper cash total length and case for causing The reduction of body horizontal direction size, core volume can be reduced into original 0.94 times, and transformer-cabinet volume can be reduced into originally 0.94 times, insulating oil consumption can be reduced into original 0.94 times, and insulating paper consumption can be reduced into original 0.94 times, winding copper Timber-used amount can be reduced to original 0.88 times.In this way, reducing winding wire diameter can to a certain extent reduce transformer manufacturing cost, And it is suitable with Conventional insulation system transformer by the hybrid insulation systems transformer overload ability after line footpath adjustment, therefore the knot Structure Adjusted Option is only applicable to overload lighter area, it is possible to decrease hybrid insulation systems oil-filled transformer material cost.

Using the hybrid insulation systems oil-filled transformer temperature capacity of DPE insulating papers and mineral insulating oil relatively using common The Conventional insulation system oil-filled transformer of cellulose paper and mineral insulating oil is higher by about 15%, then compare Conventional insulation system oil Heat radiation oil duct, import and export oil footpath between immersion transformer, hybrid insulation systems oil-filled transformer winding can reduce about 10%, Corrugation radiator is such as used, then the ripple wing number of corrugation radiator also can be reduced accordingly.The structural adjustment scheme can overload in lifting Hybrid insulation systems oil-filled transformer material cost is reduced while ability, with wittrgreat utility.

Above-described specific embodiment, has been carried out further to the purpose of the present invention, technical scheme and beneficial effect Describe in detail, should be understood that and the foregoing is only specific embodiment of the invention, be not intended to limit the present invention Protection domain, all any modification, equivalent substitution and improvements within the spirit and principles in the present invention, done etc. all should include Within protection scope of the present invention.

Claims (4)

1. hybrid insulation systems oil-filled transformer, including oil-filled transformer main body, it is characterised in that the oil immersed type transformation Insulating oil in device main body uses mineral insulating oil, and the insulating paper in oil-filled transformer main body uses DPE insulating papers.

2. the structural optimization method based on the hybrid insulation systems oil-filled transformer described in claim 1, it is characterised in that bag Include following steps：

Conventional insulation system oil-filled transformer allows overload magnification and mixing exhausted under step one, the long-term emergent overload of calculating Edge system oil-filled transformer allow overload magnification, and calculate hybrid insulation systems oil-filled transformer allow overload magnification with Conventional insulation system oil-filled transformer allows the ratio of overload magnification；

Step 2, the hybrid insulation systems oil-filled transformer that will be calculated allow overload magnification and Conventional insulation system oil immersed type Transformer allows the ratio of overload magnification to be equivalent to winding resistance in oil-filled transformer main body and ratio is lost, according to winding resistance Loss ratio calculates winding conducting wire reduced radius ratio, and by winding conducting wire radius in oil-filled transformer main body by calculating Winding conducting wire reduced radius ratio reduced；

Step 3, by the box volume of oil-filled transformer main body, core volume, insulating oil consumption and insulating paper consumption by calculate The winding conducting wire reduced radius ratio for going out is reduced, by the winding copper material consumption of oil-filled transformer main body by calculate around Scaled down square of wire radius of group are reduced.

3. the structural optimization method of hybrid insulation systems oil-filled transformer according to claim 2, it is characterised in that institute Hot(test)-spot temperature limit value correspondence when the permission overload magnification for stating oil-filled transformer under the medium-term and long-term emergent overload of step one is by overloading Overload magnification determine, wherein, the computing formula of hot(test)-spot temperature is during overload：

${\mathrm{\θ}}_h\left(t\right)={\mathrm{\θ}}_a+{\mathrm{\Δ\θ}}_{oi}+\{{\mathrm{\Δ\θ}}_{or}\×{\[\frac{1+R\×K^2}{1+R}\]}^x-{\mathrm{\Δ\θ}}_{oi}\}\×f_1\left(t\right)+H_{g_i}+\{H_{g_r}{K}^y-H_{g_i}\}\×f_2\left(t\right)---\left(1\right)$

$f_1\left(t\right)=1-e^{(-t)/(k_{11}\×{\mathrm{\τ}}_0)}---\left(2\right)$

$f_2\left(t\right)=k_{21}\×(1-e^{(-t)/(k_{22}\×{\mathrm{\τ}}_w)})-(k_{21}-1)\×(1-e^{(-t)/({\mathrm{\τ}}_o/k_{22})})---\left(3\right)$

Wherein, θ_hT () is hot(test)-spot temperature, θ_aIt is environment temperature, △ θ_oiIt is original state top-oil temperature liter,It is original state heat Point, △ θ poor to top-oil temperature degree_orIt is top-oil temperature liter under total losses,For focus is poor to top-oil temperature degree under rated current, R It is load loss and open circuit loss ratio, K is load factor, and x is top layer oil index, and y is around class index, function f₁T () is anti- Reflect the function of time that top-oil temperature rises ascending amount, f₂T () is the function of time for reflecting focus to the difference change of top-oil temperature degree.

4. the structural optimization method of the hybrid insulation systems oil-filled transformer according to Claims 2 or 3, its feature exists In the relation between the winding resistance and winding conducting wire radius is as follows：

$R=\mathrm{\ρ}\frac{l}{S}=\mathrm{\ρ}\frac{l}{{\mathrm{\πr}}^2}---\left(4\right)$

Wherein, R is winding resistance, and ρ is winding conductor resistivity of material, and l is winding conductor length, and S is winding conductor sectional area, R is winding conductor radius.