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Streamer AG INMR World Congress 2017
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EASYQUENCH TECHNOLOGY: 20 YEARS OF INNOVATION IN LIGHTNING PROTECTION
Authors: Jens Bothe, Etienne Cuisinier
SUMMARY:
For now more than 20 years, Streamer has dedicated its work to Overhead Lines protection. The main products developed by Streamer are Line Lightning Protection Devices (LLPD), meant to protect medium voltage lines against direct lightning and lightning induced overvoltages. After local successes, Streamer technology is now spreading worldwide. LLPDs met the challenge of bringing high protection for Overhead Line by means of reliable and compact devices. By working internationally, Streamer faced more and more challenges of types of line designs and lightning threats. Building on this experience, the product range had been extended and processes strengthened in order to provide the best custom made solutions available.
STREAMER INTERNATIONAL AG
Streamer is a Group of companies, founded in 1996 in in St. Petersburg, Russia. The aim of the first setup was the development of a Line Lightning Protection Device based (LLPD) on first research by Georgij Podporkin from St. Petersburg State Polytechnical University.
Since then, major steps in the development of the company have been taken and are summarized below:
o 1996: Streamer incorporation is founded. New type of lighting protection technology is developed and the first patent obtained
o 1998-‐1999: Strategic investors join the company. A manufacturing facility is set up and a first distribution network in Russia is developed
o 1999-‐2007: A product Range for different application and network voltages is getting developed. Streamer establish a strong distribution network in GUS and obtain further patents to protect the technology
o 2008: Innovative EasyQuench technology is developed. Streamer opens a sales office in Moscow and enters a strategic partnership with Russian Grids. The company wins the first prize in XI Annual Competition “Russian Innovations” and enters international markets
o 2012: Streamer International AG is founded in Chur/Switzerland. Streamer has 650.000 installed LLPDs on networks
o 2013: Streamer opens an office in Bangkok/Thailand for business development of the Asian market. First pilot projects are implemented in south-‐east Asia and China.
o 2014: 1 Million LLPDs are installed. 27 patents are registered under Streamers brand and R&D cooperation is established with Universities in China and Switzerland. Streamer reaches 87% market share in Russia.
o 2015-‐2016: Streamer establishes a sales office in Beijing and penetrates new markets in Asia, Europe, Africa and South America. Strategic partnerships are established with Companies in UK and Russia. Streamer enlarges its Product Range in Fault Indication Systems and Transformer Online Drying solution.
Today Streamer employs more than 130 people in 6 different countries. More than 1.3 Million LLPDs are already installed in 15 countries all over the world (see Figures 1 and 2).
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Figure 1: streamer LLPD installations by country worldwide (status 2017)
Figure 2: Installed llpds from 1996 to 2016, in Kpcs
STREAMER LLPDS OVERVIEW
Lightning Line Protection Devices developed by Streamer provide efficient protection for MV lines, including many advantages:
ü Ability to prevent hazards from direct lightning and induced overvoltages
ü Withstand direct lightning and induced overvoltages ü High reliability and life span, self-‐protected device ü High discharge capabilities, truly adapted to line
requirements ü Easy to install, no maintenance required ü Ability to operate with a high level of footing resistance
Figure 3 shows a LLPD equipped on a cross arm.
Figure 3: LLPD equipped on a cross arm
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OPERATION PRINCIPLE
Streamer’s EasyQuench system consists of a large number of electrodes mounted onto the silicon rubber enclosure. There are holes between the electrodes leading to outside the enclosure. These holes form miniature gas-‐discharge chambers. See the operation principle in Figure 3:
Step 1: Lightning impulse or lightning induced overvoltage encounters the LLPD. Instead of having flashover of insulator, the LLPD sparks over. The gaps between the electrodes break down, thus providing an ionised preset path (discharge channel) for fault current establishment inside the chambers.
Step 2: The discharge channel expands with increasing holdover value, creating high pressure in the chambers. As well as power arcs occurring between the intermediate electrodes inside the low volume chambers, the sparks between the electrodes move to the surface of the insulation body due to the high pressure.
Step 3: …and farther blow outside around the LLPD. Under the blowing impact and elongation of channels between the electrodes, their intensive cooling takes place with increasing electrical resistance. Total resistance of the product is increased, enabling quenching of the fault current before its first passage through zero. Such type of fault current quenching is conditionally called zero quenching. Neither the wire nor the insulator is damaged and no trip occurs.
Figure 4: LLPD operation principle
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LLPD RANGE OF PRODUCTS
LLPDs are available in 2 main ranges of products. The first range of products is designed to protect OHL against induced overvoltages (caused by indirect lightning): indirect Lightning Line Protection Device (i-‐LLPD). The second range of products is designed to protect OHL against a direct lightning: direct lightning line protection devices (d-‐LLPD).
• i-‐LLPDs provide efficient protection against induced overvoltages and limited protection against direct lighting • d-‐LLPDs provide efficient protection against both induced overvoltages & direct lighting
Different types of LLPDs were developed to provide suitable protection for lines up to 40.5 kV (maximum operating voltage). Examples are given here below.
LLPD PARAMETERS & PERFORMANCES
Table 1 gives the main parameters and performances for i-‐LLPDs and d-‐LLPDs. Terms are defined below.
Highest Voltage for Equipment (HVE): root-‐mean-‐square value of the highest phase to phase voltage for which the equipment is designed with reference to its insulation and other characteristics.
Maximum prospective fault current: maximum fault current that can establish on a line, at LLPD’s location, without any protection device for which an LLPD can be equipped.
Maximum Prospective Follow Current: maximum follow current that an LLPD can quench and withstand, according to type tests.
Maximum fault quenching lightning current: maximum lightning current flowing through an LLPD at which it can quench the resulting fault current.
The maximum fault breaking lightning current explains why i-‐LLPDs cannot quench the fault current systematically from DLSs and d-‐LLPDs can: the lightning current from a DLS is much higher than that from a LIO.
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Table 1: LLPDs characteristics
Characteristics d-‐LLPDs i-‐LLPDs
LLPDs and Line Parameters
Highest Voltage for Equipment (HVE) From 6 to 40.5kV From 6 to 24kV
Line maximum prospective fault current 5kA Up to 1.5kA
Maximum prospective follow current 3.5kA NA
Footing resistance necessary From 1 to 130 Ω
Rated Frequency 50Hz
Frequency tolerance ±12Hz
LLPDs and Lightning
Nominal discharge current: 8/20μs 20kA peak current Up to 20kA peak current
Housing Impulse Withstand: 1,2/50μs 70kV peak voltage
High Current Impulse Withstand: 4/10μs * 65kA peak current
Lightning Discharge Capability: 200μs * 2.4C 1.2C
Minimum withstand operation 10
Maximum fault quenching lightning current 20kA 3kA
Power Losses 0%
Reliability
Yearly Product Failure Rate 0% (in areas with 10 flashes cloud to ground per km² per year)
Average Life Expectancy 20 to 30 years
Installation
Time to install/pole 10 to 100 minutes (depending on the protection solution implemented) 10 to 20 minutes
Additional Equipment Needed Cross Arm Fitting and Piercing Clamp
Ground Lead Ground lead may be needed (depending on the protection solution implemented)
No ground lead needed
Maintenance 1 visual verification per year
Weight 2.5kg to 3.5kg 1.0kg to 2.6kg
Maximum Altitude for Normal Operation 1000m (consult us if above)
*According to standards IEC 60099-‐8 paragraphs 8.5 and 8.6
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FULL IMPLEMENTATION METHODOLOGY
LLPDs can be implemented in different ways, depending on the type of threat and on the line characteristics. With its experience of more than 20 years in Overhead Lines protection, Streamer built its own process for analyzing lightning threats and implementing lightning protection solutions in the most efficient way.
LINE ANALYSIS & DEPLOYMENT OF LLPDS
The following process is used to estimate the lightning threat on the line and to suggest the most suitable protection solutions for it:
1) Site visit, gathering all line’s parameters and lightning parameters on the line’s area
2) Estimation of the lightning threat (number of trips per year due to direct lightning and due to induced overvoltages). The estimation is based on a line modelling (using EMTPR software) and calculations are based on [1]
3) Estimations of line performances are made for a set of different suitable and cost-‐effective LLPD deployment solutions
4) Results are provided to customers: with and without different LLPD deployment solutions, including costs and expected line performances (see Table 2)
5) Streamer provides blue prints (see Figure 5) and potentially custom made hardware mounting solutions fitting the line design for the chosen protection solution. LLPDs are then ready to be installed.
[1] IEEE, Guide for Improving the Lightning Performance of Electric Power Overhead Distribution Lines, 2004
Table 2: Example of summarized performances provided, more detailed results are available
Number of trips on the line per year
Without LLPDs From induced overvoltages 3,8
From direct lightning 24,5
With LLPDs (first solution) From induced overvoltages 0,4
From direct lightning 8,0
With LLPDs (second solution)
From induced overvoltages 0,9 From direct lightning 2,7
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Figure 5: Example of blue prints provided
TESTING METHODOLOGY OF LLPDS
Installing new and innovative solutions on Overhead Lines requires a testing methodology to evaluate the efficiency of LLPDs to prevent trips on line. For this, in the past years, Streamer developed the testing process summarized in the following paragraph (see also Figure 6).
Figure 6: Testing methodology
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ü In order to perform the field test, an appropriated line segment should be chosen. We usually focus on strategic segments with high number of potential trips and easy to isolate (it should be easy to determine whether the trip comes from this segment or another).
ü To lead the analysis, data concerning the line itself is needed. The collection of segment data includes line parameters, switchgear fault logger data and lightning data.
ü LLPDs are then implemented on the line segment, fault logs are also required in order to isolate the segment.
ü Once the segment is equipped, LLPDs should be observed for one lightning season, periodic checks can be carried out on LLPDs (using one-‐time-‐operation-‐indicators) and fault loggers.
ü At the end of the lightning season, fault log data, substation switchgear records, lightning data and LLPD operation data should be collected.
Finally, an analysis is performed, answering the following questions:
o Are the LLPDs installed correctly? o Are the LLPDs operating properly? o Is the application of LLPDs relevant? o Is the application of LLPDs efficient?
CONCLUSION:
Streamers history started in 1996 by an innovation for a Line Lightning Protection Device (LLPD) made by Georgij Podporkin from St. Petersburg State Polytechnical University. For a period of almost 10 years, Streamer was focused on developing the patent technology into a product solution for Medium Voltage Networks. After great commercial success on Russia, in 2012 Streamer started its international Market development. A wide range of products was developed to fit market requests from today more 15 different countries in the world. While Streamer is cooperating with different suppliers for other Product Ranges, its main focus of development always last on Lightning Protection. In order to offer the most suitable protection solutions for Overhead Lines, Streamer worked out a methodology to qualify lightning threats and to find the best way for the system integration of LLPDs. The company works in a network of scientific institutes, universities and distributors worldwide which is today the fundament of its worldwide growth. Today in 2017 Streamer is recognized as one of the leading companies for Lighting Protection on Overhead lines and has an international Team of 130 employees on offices in 6 different countries to better feed costumer requirements.