1

PS3-1

High Voltage Hybrid & Compact Relocable Switchgear: New Design of

Equipment for Multiple Use in Construction, Maintenance and Emergency

EBP ENÉAS BITTENCOUNT PINTO, GF GLAUCO FALCÃO, DR DOUGLAS

RODRIGUES, PU PABLO UMETSU

CPFL ENERGIA, ABB LTDA.

BRAZIL

SUMMARY This work presents the result of the joint development of the engineering areas of CPFL Energia

and ABB Ltda., to design an equipment that would gather a minimum of functionalities required

in conventional Air Insulated Substations, for transmission line bays, Power transformers

connections, capacitor bank connections and bus bar interconnections, operating up to 145 kV

voltage.

In addition, the equipment was designed to be transported between different points of the electrical

system, because CPFL's idea was to use it as a temporary bay for switching and protection at a

substation expansion site, where a second power transformer would be installed. Then, after

completion of the work, the equipment would be sent to a similar one, or applied in a different

place in scheduled maintenance tasks of the conventional equipment of these bays or, also, in

emergency situations, when there were defects or failures in such equipment.

For transportation to different locations, using the roads, highways and even the streets within the

cities, it is expected that the solution would consider the use of a trailer, or semi-trailer, drawn by

mechanical horses commonly found on the market. However, it is also important to properly

position the new equipment in the correct spaces next to it bays at the substation where the

functionalities will be replaced, as indicated above.

Besides, it was also considered the possibility of allocating the new equipment under transmission

line bays, in the servitude passage range of the line, predictably next to towers or support posts or

anchorage, in points where the line can be sectioned to provisionally implement operation

functionalities, protection, sectioning and even current measurement, even in variants of lines

under construction or emergency situations.

As there are many solutions built in terms of electromechanical arrangements in substations and

lines that will be objects of the use herein conceived, this does not make small the challenge of

proper and safe positioning of the new equipment, since its installation will require the

implantation of a variant of bus bars phases not less safer, so that interim connections can be made

for each use.

However, considering that the technological evolution has allowed to design and build electrical

equipment increasingly compact, robust and functional, as well as associated in unique armoured

modules with dimensions and weights allied to the improvement in the reliability and availability

of its functions, the concept adopted was one of hybrid switchgear module with SF6 gas

insulation attached to a rigid skid platform that could be simultaneously hoisted for a trailer or

semi-trailer by road and dragged, when on the substation ground or line, for the best position

2

between gantry and supporting structures of the existing equipment, because it has a smooth and

ready-made lower surface for that.

Then, from a technical specification of CPFL with the above requirements, ABB designed the new

equipment based on its already successful compact hybrid module PASS M0, with rated voltage

145 kV, nominal current 2500 A and containing the Circuit breaker functions (including a fast

reclosing cycle, typical for transmission lines), a disconnector with integrated earthling switch and

bushing type current transformers (for protection and measurement services), with the whole set

meeting the requirements of technical standardization IEC 62271-205: 2008 - Compact switchgear

assemblies for rated voltages above 52 kV - and the requirements of IEEE 693-2005 -

Recommended Practice for Seismic Design of Substations.

KEYWORDS

High Voltage Switchgear & Apparatus

Engineering solutions

Electrical System Expansion Plan

Enéas Bittencourt Pinto <ebpinto@cpfl.com.br>

3

INTRODUÇÃO Utilities and licensees of public electricity generation, transmission and distribution services have

been in existence for many decades, even over a century, since the general use of electricity was

conceived for the various activities of human societies in all their aspects, around the world.

The continuity of these services has long been maximized, given the enormous scientific and

technological advance in all areas of knowledge and its application, which allowed and

accompanied the great population growth, which, in turn, has demanded the expansion of

electrical systems, permanently.

However, technical solutions in all areas depend on their physical components being constantly

supervised, controlled, maintained and even replaced, so that no unacceptable interruptions occur,

or that severely compromise the proper functioning of these various activities and tasks performed

by the For companies.

It is not a small challenge, then, the procedures, staffing, and tooling that energy companies need

to use to keep electrical systems in proper operation, even when it needs to be expanded and

interfered with to solve failures, defects and occurrences that usually arise, given the age, state of

conservation and the conditions to which they are exposed, especially climatic, environmental and

interaction with the human population itself.

Power distributors are the link between the companies that generate and transmit almost all

electricity and the consumers who use it. However, in terms of physical and geographical

coverage, in order to bring energy to users spread throughout the territory, the former usually have

unique challenges in order to have an infrastructure that is efficient and cost-effective. Moreover,

in this, trained teams, standardized tasks and available tooling make a lot of difference in results.

The object of this article is inserted in this last premise, since it shows the innovation that can be

achieved, and apply, in the continuous improvement of the activities, with gains in productivity

and value added to the company. In this, it is fundamental the partnership with the market

developers manufactures and commercialize its new products that also aim at this aggregation,

including making the necessary adaptations to the specifics of the client.

CONTEXTUALIZATION CPFL Energia is, today, one of the largest companies of the Electric Sector in Brazil, highlighting

among its actions the distribution of electricity. There are already nine distributors that serve about

14% of the total national consumers, located in the Southeast and South regions of the country.

The demand for energy in these companies goes through a sub-transmission system that has

almost all transmission lines and substations that operate in three voltage classes of: 72.5 - 92.4 -

145 kV.

As already pointed out, these companies have been established for a long time. Not only that,

many of them have varied constructive solutions in terms of civil, electrical and electromechanical

projects, depending on their origins, as well as the evolution of the technology they have chosen or

could access throughout their life, including Control, protection, measurement and

communication. In common, such installations are virtually all at the time, with substations and

conventional lines, isolated in the air.

The substations themselves are composed of high-voltage spans of incoming transmission lines,

spans between busbars (double or main plus transfer), connection of power transformers and

connection of capacitor banks, as well as means gaps Output voltages of primary distribution

4

network feeders (these are also mostly aerial). Typically, the composition of electrical equipment

in these spans is very similar, given the similarity of functional needs, in terms of acquiring the

values of the electrical parameters necessary for the correct operation (which includes energy

measurement) and, in the event of failures, faults And defects, to the appropriate maneuver of

topological modification of circuits to overcome the difficulties and to maintain, as much as

possible, the continuity of the services, through the connection or disconnection of alternative

sources and transfer of loads.

In terms of high voltage, usually up to 145 kV, line input and power transformer connection spans

are the most common in conventional overhead distribution substations. The main electrical

equipment found in these locations are lightning rods, disconnectors, earthing switches, circuit

breakers, current transformers (CT) and potential transformers (TP). In older substations, there are

still tank-type circuit breakers that use mineral insulating oil, while in more recent installations,

the trend has been to use more modern and efficient, live tank type circuit breakers, initially with a

small volume of Oil and even with compressed air, and then with SF6 gas (sulfur hexafluoride).

With live tank type circuit breakers, however, there is a need for the use of a pedestal-type TC,

which is dispensable in case of dead tank type circuit breakers (which have bushing type TC).

The evident advantages of using SF6 as an insulating medium and of the interruption of the

electric arc in the high voltages, when compared in terms of operation and maintenance to the

previous technologies, allowed the return of the tank type circuit breakers with this gas, because

the use of Bushing has better reliability and lower cost than the pedestal type.

Furthermore, the SF6 allowed the development of compact modular solutions for the substations,

with respect to the aforementioned functionalities with the listed equipment, in sheltered and

weathered armor arrangements. Although of a high initial cost, gas-shielded substations confer

extremely high operational reliability with enormous maintenance reduction and space used for

installations compared to conventional isolated air solutions. And, they greatly reduce field

assembly time and power-up release, since they come pre-tested and pre-commissioned from the

factory.

Finally, in the most recent movement, with the accumulated experience, the main manufacturers

have developed the compact hybrid solutions, so named because they combine in a single

equipment the use of conventional insulation in the air with armored parts in SF6. With this, it is

possible to confer a reasonable degree of compaction to the facilities of a substation without

incurring the high cost of the exclusively gas-shielded.

CPFL does not have gas-shielded substations, but has already incorporated the technology of

compact hybrid maneuvering modules in a few cases, precisely where the limitation of available

space was decisive for its adoption.

MAINTENANCE IN ELECTRICAL SYSTEMS

It is not necessary here to discuss the importance and the details that involve the need to keep

operating the electrical installations of the substations and transmission lines that compose the

electrical systems, since they were implanted and enormously expanded, passing through the great

evolution in terms of the materials , Prospecting techniques, tooling and instrumentation, as well

as applied methodologies and personnel training.

When it comes directly to the subject, CPFL has for some time sought to resolve the impact on its

indicators of the limitation of preventive and corrective maintenance in equipment, especially the

entry gaps of transmission lines, Of transformers. Shutdowns are inevitable and the operating area

is always reluctant to release. Sometimes the time spent on tasks is long, largely due to the length

5

of time and obsolescence of components and parts of the equipment in the span, with difficulty in

replacing them, as well as to ensure the work safety of the teams employed, with activities

performed alongside Sectors kept energized in the substation.

The use of mobile substations and transformers (see Figure 1) is traditional in releasing the

transformation spans they replace, but this cannot be counted on when it comes to other

equipment, given the prioritization of the former. However, the quantity of these solutions

available to the needs of the distributors has always provoked a "queue" of use, not to mention that

in many cases its use is impeditive due to access and secure positioning. In addition, there are

often operational constraints, such as the ability to handle prospective shipments on site. Finally,

we must not forget the costs of licenses and traffic releases.

Figure 1 – Mobile Substation

MOBILE, TRANSPORTABLE AND RELOCABLE EQUIPMENT

At the beginning of the year 2000, CPFL was able to obtain a satisfactory cost-benefit from a

manufacturer who developed equipment to replace the power circuit breakers of 138 kV power

transformers, Assumptions in this application. Among these, maximum nominal current up to 420

A (powers up to 100 MVA), maximum symmetrical interruption capacity of 31.5 kA, no reclosing

(only one opening maneuver, with "fast" closing by special built-in Slow closing of the switch

unit) and, above all, be a set that could be assembled and disassembled for transport.

Such a solution was very successful and CPFL uses it to date, having bought another unit this

year. However, it is not possible to relinquish relays, including the initial start-up, in line circuit

breakers, not to mention the nominal current requirement of at least 1250 A (ideal minimum

carrying capacity of 300 MVA). At that time, attempts to make a mobile circuit breaker cost

prohibitive costs.

With such experience, a new concept emerged as an innovation for CPFL. Until then, the idea was

that equipment designed to temporarily replace another, in typical maintenance or emergency

situations, after which it would be moved to another location and to another similar service, would

normally be built on the platform of a trailer, or Semi-trailer, to be drawn by mechanical horses

and transported to the concessionaire's facilities along the geographical service area. This is the

case for substations and mobile transformers, by far the most important ones for use. But

equipment that is mountable and can be dismantled with each use can dispense with the rolling

part, being transported in trucks that the concessionaire already has for other tasks, or eventually

rented in the market. This provides an appreciable reduction in the cost of manufacturing and even

of maintenance, also dispensing licenses to travel. Of course, there should be resources for lifting

in the loading and unloading operations, which are usually already part of the concessionaire's

plant.

6

Then, with the expansion of CPFL's electrical systems, substantiated in consolidated works plans,

synchronized with the regulator's tariff revisions, and, to some extent, the pressure to execute a

growing equipment maintenance program in 2015 The opportunity to budget and seek again a

solution to the gaps of transmission line inputs, once again thinking of a mobile circuit breaker.

Considering that technological evolution has allowed the design and construction of increasingly

compact, robust and functional electrical equipment, in addition to being associated in single

armored modules with dimensions and weights combined with the improvement in the reliability

and availability of their functions, offered by a favorable market. Concept was a compact hybrid

module with SF6 gas insulation attached to a rigid platform that could be simultaneously hoisted

for a trailer or semi-trailer by road, and dragged, when on the subsoil or line Position between

frames and supports structures of the existing equipment, by having a smooth lower surface and

made for it.

Then, from a technical specification of CPFL with the above requirements, ABB designed the new

equipment based on its already successful three pole operation compact hybrid module type PASS

M0, nominal voltage 145 kV, current 2500 A and containing the functions of a circuit breaker

(including a quick-reclosing cycle, typical for transmission lines), a disconnector with integrated

grounding blade and bushing type current transformers (for protection and measuring IEC 62271-

205: 2008 - Compact switchgear assemblies for rated voltages above 52 kV - and the requirements

of IEEE 693-2005 - Recommended Practice for Seismic Design of Substations.

And the modifications that ABB had to introduce in order to meet the necessary characteristics led

to different solutions for the maximum dimensions, in particular the height, while at the same time

ensuring the minimization of the total weight for lifting and transport, to fit the Traffic legislation

allowing free traffic, without limitation of schedule, issuance of special licenses and scheduled

transportation routes, according to Resolution No. 210/2006 of the National Traffic Council. And

also to securely allow embarkation and disembarkation actions, from the road and ground trailers

platforms, through CPFL's standardized guinea-pigs for their works and maintenance tasks. With

this, the relocability of the equipment is standardized.

GENERAL DETAILS OF THE RELOCABLE COMPACT HYBRID MODULE

The single line diagram specified for the equipment is shown in Figure 2. In the spans to which it

will be installed, the breaker housing should be facing the side of the power source, usually a

transmission line. The features that the compact hybrid module embeds allow similar conventional

equipment to be temporarily replaced, maintained, unitarily or all at once.

Figure 2 – Single line diagram

In order to guide the manufacturer, CPFL has included in its specification a semi-trailer

dimensional design of the market, as a minimum condition in the design of the project, aiming the

shipment and transportation of the relocatable compact module (Figure 3).

7

Figure 3 - Example of Road Semi-trailer

Thus, ABB submitted its design to CPFL and final design approval is illustrated in the set of

drawings in Figures 4 to 7 below. Further on, they follow Figures 8 through 33, with photographs

of what was actually manufactured and delivered, showing various details.

The total weight of the assembly, considering the compact hybrid module and its platform, was at

4056 kgf. The central control cubicle weighs 350 kgf. The crosshead and lifting cables weigh

almost 405 kgf. Thus, the total transport weight is almost 4810 kgf

Figure 4 – Profile View

Figure 5 – Top View

8

Figure 6 – Lifting Mounting

Figure 7 – Positioning and risk zone

Fig. 8: Lift cradle

Fig. 9: Suspended lifting cradle, with cables

9

Fig. 10: Assembly lift for common truck

boarding

Fig. 11: Detail of the hoist, showing the

dedicated crosshead and its cables

Fig.12: Set of steel suspension cables and

washers for attachment to lifting eyelets

Fig.13: Circuit Breaker Drive

Fig. 14: Disconnector and earthing switch

chamber with viewport window

Fig. 15: Disconnector and earthing switch

drive

10

Fig. 16: SF6 Gas Density Monitor and

Pressure Gauge

Fig. 17: Secondary bushing CT terminals

Fig. 18: Local Control Cubicle

Fig. 19: LV Cables

Figura 33 – High Voltage Hybrid & Compact Relocable Switchgear

11

CONCLUSION

This work aimed to present a synthesis of the development of a "tool" for use in field activities in

distribution substations, and even in spans along transmission lines, aimed at the implantation and

expansion works, as well as maintenance services (programmed And emergency), typically carried out

on high voltage electrical equipment up to 145 kV.

The tool, the compact hybrid module of relocatable maneuver, was conceived from the consolidation

of the last technological developments of the manufacturers of electrical equipment of high tension,

aiming at reliability, robustness, reduction of the need of maintenance and reduction of the cost of the

electrical installations where they are applied, both at implantation and throughout the useful life. In

addition, the practical requirements of the user, that is, the electricity distribution companies.

It should also be noted that in CPFL, the concept of relocability, coupled with that of modularity, has

already been extended to other components of an energy substation, some of which already exist, such

as mobile substations and mobile transformers, and others Also of recent design and acquisition and

concurrent with that of this relocatable hybrid module, i.e. relocatable medium voltage reclosers and

mobile voltage regulators. With this, it is even possible to set up temporary substations, albeit with

some restrictions.

Thus, with the contribution of the manufacturers and suppliers of equipment, there was a significant

leap for distributors to face, at an acceptable cost-benefit, the constructive, operational and

maintenance challenges of their electrical systems, which have a huge variety Of technical solutions,

stemming from a legacy that merges with the incessant technological evolution in search of present

efficiency.

BIBLIOGRAPHY

Type here your bibliography in the order they are mention in the text. Times New Roman, 11. Follow

the examples.

[1] Norma Técnica IEC nº 62271-205/2008 (Compact switchgear assemblies for rated voltages

above 52 kV).

[2] Norma Técnica IEEE Std. 693-2005 – Recommended Practice for Seismic Design of

Substations. [3]Prospectiva del Sector Eléctrico 2002-2011. (Secretaría de Energía. Mexico,

2002).

[3] Especificação Técnica CPFL GED nº 16665, versão 1.0, de 06/11/2015.

[4] Resolução CONTRAN nº 210/2006, de 13/11/2006.