Presentación de resultados
4.3 Análisis de las estrategias productivas y comerciales
Selection of the transformer version
Requirements of the installation site in accordance with DIN VDE 0101 (water protection, fire protection and func-tional endurance) suggest the use of cast-resin dry-type transformers (e.g. GEAFOL). Compared to oil-immersed transformers using mineral oil or silicone oil or diester oil, dry-type transformers place the lowest demands on the installation site while fulfilling the highest requirements in terms of personal protection and low fire load. Cast-resin dry-type transformers should at least meet the require-ments C2 (Climate Category), E2 (Environment Category) and F1 (Fire Safety Category) as defined in IEC 60076-11.
How many transformers are required?
Depending on the application, the use of several formers operated in parallel may be useful. GEAFOL trans-former require almost no maintenance. For this reason, a back-up transformer for maintenance work needn’t be considered.
Caution! Make sure that the two transformers to be operated in parallel have the same technical characteristics (including their rated short-circuit voltages). Reference value for dimensioning of two transformers operated in parallel: Rated power of each transformer = (power demand / 0.8) / 2.
Additional transformer ventilation for more power The output of GEAFOL transformers up to 2,500 kVA, in degree of protection IP00, can be increased to 140 % or 150 % when cross-flow fans are installed. Efficient blowing can, for example, raise the continuous output of a
1,000 kVA transformer to 1,400 kVA or 1,500 kVA. How-ever, the short-circuit losses are also twice or 2.3 times the value of the power loss for 100 % nominal load. Additional ventilation is a proven means for covering peak loads as well as compensating a transformer failure, when trans-formers are operated in parallel.
Guideline: The price for efficient additional ventilation is about 15 % of the transformer price.
Rated short-circuit transformer voltage
Normally, 6 % should be selected as a rated short-circuit voltage (uzr) for a rated power above 630 kVA in order to keep short-circuit currents as low as possible in the event of a fault. The switchgear installed at the secondary side of the transformer must be designed to withstand such short-circuit currents.
* also see the section “Transformer casing“, page 71 outwards, in fire resistance rating F 30A DIN 4102
Fire resistance rating
Fig. 53/2: GEAFOL cast-resin transformers installed in an electric
H
E E
A B
2U 2V 2W 2N
Fig. 53/1: Transformer truck rollers can be swung around in two directions. The roller-to-roller center spacing (E) applies to lengthways and sideways travel accordingly
5
Example:
A 1,000 kVA transformer with a rated short-circuit voltage of 4 % supplies the 0.4 kV secondary network with approx.
36 kA in case of a short circuit.
The same transformer with a rated short-circuit voltage of 6 % only supplies the 0.4 kV secondary network with approx. 24 kA in case of a short circuit.
Vector group
DYN5 (standard vector group in Germany)
DYN11 (frequently used vector group in Asia as well as in Europe)
Note: Vector groups Dyn5 and Dyn11 have the same price.
No-load losses – reduced losses
Following the guidelines for sustainable construction of the German Ministry for Traffic, Building and Residential Development and with regard to the energy passport, transformers with reduced losses should be preferred.
The economic efficiency of such a transformer can be verified by means of a loss evaluation.
Guideline: If the cost factor for a kilowatt hour exceeds 2,000 EUR per annum, the increased cost for a transformer with reduced losses pays off within five years.
Noise – acoustic power level
Noise caused by transformers can be reduced as follows:
.
Use of transformers with reduced no-load losses; this reduces the acoustic power level by approx. 8 dB..
Reduction of structure-borne noise by using metal-rubber rails and special transformer bedding. (Note: The transformer noise itself is not changed by this)..
Decoupling of connected busbars to minimize structure-borne noise (e.g. by using elastic tapes).Temperature monitoring
Transformers are equipped with a temperature monitoring system. For a three-phase transformer, this system consists of three series-connected PTC sensors – one per phase – and a tripping unit.
It is useful to provide for an additional temperature sensor loop for an alarm, which can be wired to the same tripping unit.
Transformer casing
The transformer casing serves as contact protection in electrical operating areas which are freely accessible. With IP23 or higher, it is possible to reduce the acoustic power level by up to 3 dB.
Conditions for installation – room layout
GEAFOL cast-resin transformers can be installed in the same room as medium- and low-voltage switchgear with-out any extra precautions. For switchgear that come within the scope of Elt Bau VO, the electric utilities room must be enclosed by fireproof walls and doors (walls in fire resis-tance rating F90A, doors in F30A).
5
1) Power increase through extra ventilation 2) Without extra ventilation
Rated power Sr [kVA]
Primary rated voltage Ur OS [kV]
Secondary rated voltage Ur US [kV]
Impedance voltage uzr [ %]
No-load losses Po [W]
Short-circuit losses at 120 °C Pk 120 [W]
Power loss at rated transformer power Pv (rated) [W]
Air flow rate required for cooling at rated transformer power (approx. values for 25 °C air temperature) [m3 / min]
Power loss at maximum transformer power (150 %)1) Pv (max) [W]
Air flow rate re- quired for cooling at maximum transformer power (approx. values for 25°C air temperature)1) [m3 / min]
Acoustic power level2) LWA [dB]
Total weight [kg]
Length (A) [mm]
Width (B) [mm]
Height (H) [mm]
Roller-to-roller center spacing (E) [mm] 100100.444401,9002,53085,14016596001,210670840without wheels 0.443201,9002,41085,02015517201,230675845without wheels 0.463602,0002,56085,31016595701,200680810without wheels 0.462902,0002,49085,24016517201,280685890without wheels 200.446001,7502,53084,93015596201,220740925without wheels 0.444001,7502,33074,73015517401,260745945without wheels 0.464602,0502,72095,53017596101,250750920without wheels 0.463402,0502,60085,41017517301,280750940without wheels 160100.446102,6003,470117,05022628201,2706901,025520 0.444402,6003,300106,88021549601,2606851,100520 0.465002,7503,530117,31022626901,220690990520 0.464002,7503,430117,21022548501,2907001,010520 200.448702,5003,620117,06022627901,2807451,060520 0.445802,5003,330106,77021549201,3207551,060520 0.466502,7003,620117,33022627801,3207601,040520 0.464802,7003,450117,16022548601,3507701,050520 250100.448203,2004,340138,74027651,0101,3307001,055520 0.446003,2004,120138,52026571,2501,3407001,190520 0.467003,3004,330138,87027659601,3407101,060520 0.465603,3004,190138,73027571,1301,3907201,070520 200.441,1003,2004,620149,02027651,0701,3707301,115520 0.448003,2004,320138,72027571,2301,4207401,130520 0.468803,4004,620149,30028651,0201,3907401,110520 0.466503,4004,390149,07028571,1901,4307451,130520 300.461,3004,0005,7001811,20034671,1901,4508251,365520 315100.449803,8005,1601610,39032671,1201,3408201,130670 0.447203,8004,9001510,13031591,4001,4008201,195670 0.468503,9005,1401610,50032671,1301,3608201,160670 0.466803,9004,9701510,33031591,2601,4008201,170670 200.441,2503,9005,5401710,90033671,3701,4908351,145670 0.449303,9005,2201610,58032591,5901,5208351,205670 0.461,0004,1005,5101711,15034671,3501,4908351,180670 0.467804,1005,2901610,93033591,4501,5208401,205670 300.461,4505,1707,1402214,25043691,4601,4109151,445670 400100.441,1504,4005,9901812,04037681,2901,3708201,230670 0.448804,4005,7201811,77036601,5001,3908201,330670 0.461,0004,9006,3902013,13040681,2301,4008201,220670 0.468004,9006,1901912,93039601,3901,4308201,230670 200.441,4503,8005,6301710,86033681,4701,4608301,285670 0.441,1003,8005,2801610,51032601,7101,5208351,305670 0.461,2004,3005,9301811,84036681,3801,4908401,260670 0.469404,3005,6701711,58035601,4601,5008401,260670 300.461,7005,5007,7502415,31046691,5901,5609251,500670 500100.441,3005,9007,7902415,90048691,4901,4108201,315670 0.441,0005,3006,8302114,12043611,6201,4208201,340670 0.461,2006,4008,2402517,04052691,4201,4508201,245670 0.469606,4008,0002416,80051611,5401,4908201,265670 200.441,7004,9007,0902213,83042691,5501,4608401,365670 0.441,3004,9006,6902013,43041611,7001,4908451,370670 0.461,4005,1007,0102114,02042691,5001,5308551,275670 0.461,1005,1006,7102113,72042611,6701,5608601,290670 300.461,9006,0008,5002616,75051701,8101,5609251,615670
5
ease through extra ventilation2) Without extra ventilation
Primary rated voltage Ur OS [kV]
Secondary rated voltage Ur US [kV]
Impedance voltage uzr [ %]
No-load losses Po [W]
Short-circuit losses at 120 °C Pk 120 [W]
Power loss at rated transformer power Pv (rated) [W]
Air flow rate required for cooling at rated transformer power (approx. values for 25 °C air temperature) [m3 / min]
Power loss at maximum transformer power (150 %)1) Pv (max) [W]
Air flow rate re- quired for cooling at maximum transformer power (approx. values for 25°C air temperature)1) [m3 / min]
Acoustic power level2) LWA [dB]
Total weight [kg]
Length (A) [mm]
Width (B) [mm]
Height (H) [mm]
Roller-to-rolle center spacing (E) [mm] 100.441,5007,3009,5302919,57059701,6701,4108201,485670 0.441,1507,3009,1802819,22058621,8401,4408201,485670 0.461,3707,2009,2902819,19058701,5701,5108501,310670 0.461,1007,2009,0202718,92057621,7601,5508501,330670 200.441,9506,9009,5402919,03057701,7901,4708401,530670 0.441,5006,9009,0902818,58056621,9301,5208451,565670 0.461,6507,2009,5702919,47059701,5901,5408701,380670 0.461,2507,2009,1702819,07058621,7801,5808801,390670 300.462,2006,6009,4602918,54056712,0901,6209401,640670 100.441,8007,80010,3803221,11064721,9701,5008201,535670 0.441,4007,8009,9803020,71063642,2101,5308251,535670 0.461,7008,30010,8303322,24067721,8401,5608601,390670 0.461,3008,30010,4303221,84066642,0901,6108701,410670 200.442,4008,50011,7503623,44071722,0201,5508501,595670 0.441,9008,50011,2503422,94069642,2201,5708551,595670 0.461,9508,20010,9703322,25067721,8801,6108901,470670 0.461,5008,20010,5203221,80066642,0701,6208901,460670 300.462,6507,90011,3403422,20067722,6201,7409651,695670 100.442,10010,00013,1004026,85081732,4401,5509901,730820 0.441,60010,00012,6003826,35079652,8501,6209901,795820 0.462,0009,50012,4503825,51077732,2601,6409901,510820 0.461,5009,50011,9503625,01075652,5901,6809901,530820 200.442,8009,50013,2504026,31079732,4201,5709901,790820 0.442,3008,70011,8703623,83072652,7401,6809901,665820 0.462,3009,40012,6403825,57077732,2501,6309901,630820 0.461,8009,40012,1403725,07076652,4301,6409901,650820 300.463,10010,00014,1004327,85084732,9901,8001,0601,795820 100.462,40011,00014,5004429,63089752,5701,7209901,590820 0.461,80011,00013,9004229,03087672,9201,7409901,630820 200.462,70012,00015,9004832,40098752,5901,7601,0001,640820 0.462,10012,00015,3004631,80096672,8101,7901,0001,650820 300.463,60011,50016,2504932,06097753,5801,8701,0651,895820 100.462,80012,60016,6605033,990102763,3601,8109901,740820 0.462,10012,60015,9604833,290100683,8501,8409901,780820 200.463,10012,80017,1805234,780105763,5101,8401,0101,840820 0.462,40012,80016,4805034,080103683,8901,8701,0201,850820 300.464,10013,50018,9505737,510113764,3501,9701,0901,995820 120.463,50016,20021,3206443,600131783,8601,9201,2801,9101,070 0.462,60016,20020,4206242,700129704,3901,9501,2801,9401,070 240.464,00015,50021,0506442,360127783,9301,9601,2801,9401,070 0.462,90015,50019,9506041,260124704,4302,0001,2801,9801,070 300.465,00015,00021,5006542,130127785,0902,1001,2802,1351,070 120.464,30019,00025,2007651,330154814,5502,0801,2802,0301,070 0.463,00019,00023,9007250,030150715,2302,1101,2802,0601,070 240.465,00018,50025,3507650,790153814,8702,1501,2802,0301,070 0.463,60018,50023,9507249,390149715,5202,1901,2802,0501,070 300.465,80020,00027,8008455,300166815,9202,2801,2802,2151,070