Presentation is loading. Please wait.

Presentation is loading. Please wait.

HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation and a proposal of solution.

Similar presentations


Presentation on theme: "HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation and a proposal of solution."— Presentation transcript:

1 HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation and a proposal of solution.

2 HJ International Latin America, Inc. Presentation of the situation There is an excess of installed capacity of distribution transformers

3 HJ International Latin America, Inc. An interesting ratio Invoiced energy, Gwh per year Invoiced energy, Gwh per year Fi = Fi = CITD * fp * 24 * 360 CITD: Installed capacity in Distribution Transformers, GVA CITD: Installed capacity in Distribution Transformers, GVA fp: Global system power factor fp: Global system power factor

4 HJ International Latin America, Inc. Determining the magnitude of the Over-Capacity One indicator of the over-capacity is the ratio between the installed capacity of Power Transformers in the Substations at the end of the transmission lines and …..One indicator of the over-capacity is the ratio between the installed capacity of Power Transformers in the Substations at the end of the transmission lines and …..

5 HJ International Latin America, Inc. Determining the magnitude of the Over-Capacity …. the total installed capacity of distribution transformers reducing medium voltage to low voltage levels.…. the total installed capacity of distribution transformers reducing medium voltage to low voltage levels.

6 HJ International Latin America, Inc. Determining the magnitude of the Over-Capacity In most cases, the ratio R :In most cases, the ratio R : Installed Capacity of Distribution Transformers Installed Capacity of Distribution Transformers R = Installed Capacity of Power Transformers Installed Capacity of Power Transformers > 2.0> 2.0

7 HJ International Latin America, Inc. Something to think about…. Since the flow of energy in the system is the same for Power and Distribution Transformers…..Since the flow of energy in the system is the same for Power and Distribution Transformers….. AVERAGE LOADAVERAGE LOAD DISTRIBUTION POWER TRANSFORMERS TRANSFORMERSAVERAGE LOADAVERAGE LOAD DISTRIBUTION POWER TRANSFORMERS TRANSFORMERS = = R R

8 HJ International Latin America, Inc. Now, transformer size can be selected based on maximum load (Utilization Factor, Fu)... Max Load Fu = Transf. Size

9 HJ International Latin America, Inc. …or based on the rms equivalent load... TRANSFORMER AVERAGE LOAD : TRANSFORMER AVERAGE LOAD : rms equiv. load rms equiv. load La = La = Transf. size Transf. size TRANSFORMER OVERSIZE

10 HJ International Latin America, Inc. Then we realize that... If transformers are selected just thinking of maximum load… …this conduces to select capacities much higher than the actually needed. Transformer sizes should be selected as possible based on the average load taken from the actual load curve (projected)… It is important to take advantage of the transformer overload capacity.

11 HJ International Latin America, Inc. Oversize magnitude comes from... Ratio R, commented before, and A ratio K depending on the load curve and defined as... K = Fu / La = Maximum load / Average load Maximum oversize magnitude comes from the product given by……. OSmax = R * K

12 HJ International Latin America, Inc. Something more to think about…. Since the flow of energy in the system is the same for Power and Distribution Transformers…..Since the flow of energy in the system is the same for Power and Distribution Transformers….. AVERAGE LOAD Fu OF THE DISTRIBUTION POWER TRANSFORMERS TRANSFORMERSAVERAGE LOAD Fu OF THE DISTRIBUTION POWER TRANSFORMERS TRANSFORMERS = = R * K R * K

13 HJ International Latin America, Inc. A typical value for K is 1.6. This makes OSmax = 4.8 Thus, the average load of distribution transformers in the system can be so low as….

14 HJ International Latin America, Inc. Immediate goal is... ToTo increase the average load of Distribution Transformers in the System. TIP Importance of the load losses in this process

15 HJ International Latin America, Inc. Average Load of Distribution Transformers in the system (Instance) Average transformer ratings may be reduced in the system by factors from 2 up to 5 !!

16 HJ International Latin America, Inc. There are 2 aspects to be taken into account as increasing average load of distribution transformers TRANSFORMER LOSSES TRANSFORMER FAILURES H HH However….

17 HJ International Latin America, Inc. Increasing or reducing through higher La in the system?? LOSSES COST...

18 WHERE WE ARE TODAY INDICATES OUR COMPROMISE CURRENT SITUATION 20 % WHERE WE SHOULD BE 60 A 75 % 60 A 75 %

19 HJ International Latin America, Inc. It is experienced an increment of overload failures along with a higher “La” in the system UNLESS THE TRANSFORMER BE ADEQUATELY PROTECTED AGAINST OVERLOADS !! TRANSFORMER FAILURES

20 HJ International Latin America, Inc. Our proposal of solution is... THE SELF PROTECTED TRANSFORMER To increase the Average Load “La” without increasing overload failures To allow the reduction of the Over-Capacity factor “R” along with the losses in the system without increasing other related costs To reduce installation costs To get a significant reduction of the overall transformers failure rate in the distribution system

21 HJ International Latin America, Inc. P – A – U – S - E

22 SUMMARY OF THE SELF - PROTECTION PRINCIPLES A GUIDE THAT SHOWS THE MAIN CONCEPTS TO SUCCESSFULLY INTRODUCE THE SELF - PROTECTION PHILOSOPHY

23 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 1 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

24 HJ International Latin America, Inc. Using Self Protected Transformers is not only to add some components to the transformer…!! ARRESTER BREAKER FUSES SIGNAL LIGHT OPERATING HANDLE & EMERGENCY OVERLOAD

25 HJ International Latin America, Inc. …it is to use a COMPLETE philosophy to protect and handle with... THE TRANSFORMERS...

26 HJ International Latin America, Inc. …it is to use a COMPLETE philosophy to protect and handle with......THE DISTRIBUTION SYSTEM...

27 HJ International Latin America, Inc. …it is to use a complete philosophy to protect and handle with......AND THE CUSTOMERS !

28 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 2 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

29 HJ International Latin America, Inc. Main transformer protecting tasks, including selection and coordination… ARE TRANSFORMER MANUFACTURER ISSUES !! CONVENTIONAL SELF - PROTECTED BLACK BOX

30 HJ International Latin America, Inc. This causes... Simplification of the transformers installation Less warranty discussions between Utility and transformer manufacturer Longer warranty terms

31 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 3 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

32 HJ International Latin America, Inc. HV Fuse should be internally connected THIS TO AVOID:THIS TO AVOID: Fuse rating changedFuse rating changed Dangerous operation of damaged unitsDangerous operation of damaged units Miss-coordination of the transformer protecting devicesMiss-coordination of the transformer protecting devices

33 HJ International Latin America, Inc. This arises a question... IS IT NEEDED TO INSTALL THE FUSED CUT-OUT WITH EVERY TRANSFORMER ?

34 Some responses from self-protecting principles to this question are: The load-break operation is made in LV side by operating the breaker operating handle (this is a safer operation) Fuse has one main and one secondary function: MAIN FUNCTION of the fuse is to act like an over-current protection by isolating a failed transformer from the system. MAIN FUNCTION of the fuse is to act like an over-current protection by isolating a failed transformer from the system. SECONDARY FUNCTION is to act like a back-up protection SECONDARY FUNCTION is to act like a back-up protection To eliminate the use of fused Cut-out with every transformer it is important to have well trained people to handle with energized lines It is strongly recommended to use Wildlife Guards in those case fused Cut-out is not used

35 HJ International Latin America, Inc. Cut-outs continue to be an essential part of the distribution circuits for circuit maintenance proposals... SPECIALLY AT THE BEGINNING OF THE CIRCUIT BRANCHES

36 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 4 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

37 HJ International Latin America, Inc. Signal Light is an essential part of one integral self-protecting policy to get an effective load management OFF SHOWS A NORMAL LOAD OR CIRCUIT SITUATION SHOWS A NORMAL LOAD OR CIRCUIT SITUATION ON SHOWS AN ABNORMAL LOAD OR CIRCUIT SITUATION SHOWS AN ABNORMAL LOAD OR CIRCUIT SITUATION

38 HJ International Latin America, Inc. The signal light is an essential part of an integral self-protection policy It’s an easy and economical way to detect any thermal abnormal operating condition without the need of costly measuring and monitoring methods It operates like a PREVENTIVE ALARM without customer disconnection It can be factory calibrated to meet the actual load curve requirements and the desired trip conditions It’s a very effective way to detect energy robbery If attended, it’s a very effective way to reduce non-planned loadbreaks

39 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 5 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

40 HJ International Latin America, Inc. Arresters are to be installed at the transformer’s tank IN CONVENTIONAL TRANSFORMERS CUT-OUT FUSES WOULD BE INSTALLED UP- STREAM

41 HJ International Latin America, Inc. Arresters arranged far from transformer tank makes the transformer not right protected

42 THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 6 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

43 HJ International Latin America, Inc. Transformer Load Management (TLM) in service service is to be made Any overload, at peak hours, above the maximum allowed is to be detected and alarm is to be given by the transformer itself Any transformer giving reiterative alarm information is to be changed for a larger capacity unit. Before that, a load analysis is to be made According to above change policy a SELECTIVE transformers load analysis in the system is made. Signal light acts like a sample selector. Overload capacity of the transformers is to be actually used

44 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY PRINCIPLE # 7 IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

45 HJ International Latin America, Inc. Assets Management of the transformers in service is to be made LIKE ANY OTHER ASSET, TRANSFORMER’S LIFE AT THE INSTALLATION PLACE IS TO BE PLANNED ACCORDING TO THE LOAD AND TO A REPLACEMENT POLICY AN INVENTORY ROTATION POLICY SHOULD BE DEFINED !

46 HJ International Latin America, Inc. THE SELF - PROTECTION PHILOSOPHY OTHER PRINCIPLES & FINAL ISSUES IMPORTANT NOTE APPLICABILITY OF THESE PRINCIPLES MAY VARY DEPENDING ON THE PARTICULAR CIRCUMSTANCES OF THE UTILITY

47 HJ International Latin America, Inc. UNBALANCED LOADS UNBALANCED LOADS IN 3F BREAKERS CAN CAUSE PREMATURE SIGNAL LIGHT OR BREAKER TRIP. FOR THIS REASON OUR PRINCIPLE # 6 CALLS TO MAKE A LOAD ANALYSIS IN EACH CIRCUIT CAUSING SIGNAL LIGHT OR BREAKER TRIP. AGAIN SELF PROTECTION PHILOSOPHY APPLICATION ACTS LIKE PREVENTIVE WAY TO DETECT SYSTEM PROBLEMS WITHOUT HIGH COSTS INTERRUPTIONS. UNBALANCED LOADS ARE EASILY DETECTED IN A 3F BANK OF 1F SELF PROTECTED UNITS.

48 HJ International Latin America, Inc. Making an economical evaluation of a conventional transformers project vs. self-protected project TRANSFORMER SIZES COMPARED ARE DIFFERENT !! SELF - PROTECTED CONVENTIONAL kVA RATING = X kVA RATING = X/2

49 HJ International Latin America, Inc. Introducing Self Protecting Philosophy can help to simplify and to reduce costs of Distribution Circuits No use of cross arms for arrestersNo use of cross arms for arresters No use of cross arms for Cut-outsNo use of cross arms for Cut-outs Use of line spacers & wildlife guardsUse of line spacers & wildlife guards No LV fuse holdersNo LV fuse holders

50 HJ International Latin America, Inc. LOAD HARMONICS LOAD HARMONICS CAUSING OVER HEATING INSIDE THE TRANSFORMERS WILL ALSO CAUSE OVER HEATING OF THE BREAKER’S BIMETALIC, TRIPPING IT.

51 HJ International Latin America, Inc. Breaker Losses ANY COST ANALYSIS OF THE BREAKER LOSSES BASED ON THE ACTUAL LOAD CURVE WILL SHOW THAT IT IS TOO LOW PER YEAR MAKING THE LOW VOLTAGE BREAKER THE MOST ECONOMICAL AND FLEXIBLE ALTERNATIVE TO PROTECT THE TRANSFORMER

52 HJ International Latin America, Inc. Light & Breaker trip temperatures can be selected based on the kWh demand curve LOAD CURVE kWh DEMAND CURVE TEMPERATURE PROFIL TRIP TEMPERATURES DETERMINATION

53 HJ International Latin America, Inc. SELF PROTECTION APPLICATION COVERS SMALL DISTRIBUTION TRANSFORMERS (UP TO 500kVA) THAT NORMALLY DON’T USE THERMOMETERS OR LIQUID LEVEL GAUGES BREAKER’S BIMETALIC ACTS LIKE A TEMPERATURE DETECTOR WITH ALARM & TRIP FEATURES WHEN INTERNAL TRANSFORMER’S TEMPERATURES REACH DANGEROUS PREDETERMINED LEVELS BREAKER’S BIMETALIC ACTS ALSO LIKE A LOW OIL LEVEL DETECTOR WITH ALARM & TRIP FEATURES WHEN INTERNAL OIL REACHES LEVELS WHERE THE BIMETAL GET NOT OIL IMMERSED

54 HJ International Latin America, Inc. Expected life of the transformer oil DUE TO THE OPERATING TEMPERATURE CONTROL, SELF-PROTECTED TRANSFORMERS MAKE OIL LIFE LONGER THAN CONVENTIONAL POSSIBLE OIL DETERIORATION CAUSED BY UNDER-OIL ARCING IS FAR COMPENSATED BY THE LOW OIL OPERATING TEMPERATURE DURING THE LIFE OF SELF- PROTECTED TRANSFORMERS NUMBER OF BREAKER OPERATIONS DURING TRANSFORMER’S LIFE IS MINIMIZED BY MAKING A RIGHT USE OF THE SIGNAL LIGHT

55 HJ International Latin America, Inc. Customized thermal protection based on heat run test TEMPERATURE RANGE FOR TRIP CALIBRATION SIGNAL LIGHT BREAKER OTHER PROTECTING DEVICES LIKE FUSES OR COOPER MAGNEX ARE NOT SO FLEXIBLE THERE IS A DIFFERENT CALIBRATION AVAILABLE EVEN FOR THE SAME kVA RATING

56 HJ International Latin America, Inc. COMPARISON BETWEEN SECONDARY BREAKER VS PRIMARY MAGNEX INTERRUPTER

57 HJ International Latin America, Inc. COMPARISON BETWEEN SECONDARY BREAKER VS PRIMARY MAGNEX INTERRUPTER …CONTINUED...

58 HJ International Latin America, Inc. COMPARISON BETWEEN SECONDARY BREAKER VS PRIMARY MAGNEX INTERRUPTER …CONTINUED

59 HJ International Latin America, Inc. SUMMARY We have seen during this presentation:We have seen during this presentation: Over capacity problem of the Distribution Systems & causesOver capacity problem of the Distribution Systems & causes Our proposal of solutionOur proposal of solution Effect of the over capacity & its solution on losses and failuresEffect of the over capacity & its solution on losses and failures What is and how works the self protected transformers conceptWhat is and how works the self protected transformers concept Principles of Self Protection philosophy & performance of a self protected unit in the distribution circuitsPrinciples of Self Protection philosophy & performance of a self protected unit in the distribution circuits How to begin a change process to successfully introduce the Self Protection philosophy without mistakesHow to begin a change process to successfully introduce the Self Protection philosophy without mistakes

60 HJ International Latin America, Inc. E N D


Download ppt "HJ International Latin America, Inc. Installed capacity of Distribution Transformers. The situation and a proposal of solution."

Similar presentations


Ads by Google