en
English
+
Anti-lighting and Anti-icing Insulators
Transmission lines pass through a wide range of areas, complex terrain, and inevitably lightning-prone areas. Lightning strikes usually cause transmission line trips and power outages. According to statistics, in 2012 and 2013, there were 1321 lightning strikes on transmission lines with voltage levels of 110kV and above in the state Grid, and lightning strikes accounted for about 40% of the total number of line trips. Conventional insulators can only play the role of insulation support and have no lightning protection or ice protection capabilities. At present, Japan and most other countries adopt the parallel installation of insulators and arresters to improve lightning protection capability. But conventional lightning protection measures have problems, such as complicated installation, limited lightning protection capabilities, frequent failures, and damages, and the lightning strikes caused external insulation flashover and disconnections still exist. In response to the problems mentioned above, the SKL has developed large-current surge arresters and lightning protection insulators of different voltage levels.
1. Technical Advantages
The through-current capability is increased to 100 kA, and the damage rate of the surge arrester is greatly reduced (from 19% to 0.3% per year in Hunan). The probability of bursting is greatly reduced when suffering from great amplitude lightning strokes, and the surge arrester can stand multiple lightning strikes, thus effectively protecting electrical equipment such as transformers and ring main units (RMU).
2. Technical Parameters
Rated voltage: 17kV
Nominal discharge current: 10kA2ms square wave current: 400A
1mA reference voltage: 25kv
4/10us large current impact: up to 120kA
AC wet withstand voltage: no less than 13kv
1. Technical Advantages
a. A new integrated structure of surge arrester and an insulator is adopted. The product has the functions of insulation support and lightning protection.
b. Using large-current ZnO (zinc oxide) resistors, the through-current performance is improved to 100 kA.
c. Using the large-and-small umbrella arrangement and adding the creepage distance of the umbrella skirt, the voltage of ice flashover, rain flashover, and pollution flashover under grade D pollution conditions are respectively increased by 30%，50%, and 27%.
d. The product is light in weight, and easy to install on-site. There's no need for special grounding treatment, natural grounding for the tower is enough.
2. Technical Parameters
Rated voltage: 51kV
4/10us large current impact: up to 120kA2ms square wave current: 400A
Nominal discharge current: 10kA
Lightning impulse voltage: no more than 100kVAC wet withstand voltage: no less than 26kV20mm icing voltage: z15kV
250mm / 24h Rain Flashover Voltage: ≥15kV
Anti-bending load of column anti-lightning and anti-icing composite insulator: 8 kNTensile Load of Suspension anti-lightning and anti-icing composite insulator: 70 kN
3. Application
Since 2017, nearly 280,000 10kv anti-lightning and anti-icing
composite insulators and 80,000 10kV gapless surge arresters have been applied in 235 10kV lines in China. In Hunan only, the annual lighting trip rate of the line decreased from 5.29 times/100km to 0.31 times/100km, and the decrease rate was up to 94 %. The wire breakage and equipment damage caused by lightning are greatly reduced, which effectively improved the lightning protection level of the line.
1. Technical Advantages
a. With the gap structure, the insulation gap bears the operating voltage under normal operation, the ZnOresistors do not bear the voltage, and there is no aging problem.
b.Installed in parallel with the insulator, the current performance is improved to 120 kA, and the lightning protection level of the line is significantly improved.(taking the Hunan area as an example, the annual lightning trip-out rate of 35kV lines before lightning protection transformation is 8-12 times/100km. After the application of 35 kV large-current gap surge arrester, the lightning trip-out rate is reduced to 0.45 times /100 km-a).
2. Technical Parameters
Rated voltage: 51kV
Nominal discharge current: 10kA2ms square wave current: 400A1mA reference voltage: 73kV
4/10us large current impact: up to 120kA
Figure335kV large-current
AC wet withstand voltage: no less than 70kV
1. Technical Advantages
a.The new structure of surge arrester and insulator integration is adopted, and the product has the functions of insulation support and lightning protection.
b.With large current ZnO resistors, the current performance is improved to 130 kA, which is 50% higher than that of general surge arresters, and the lightning trip-out rate is significantly decreased. In Hunan, only, the lightning trip-out rate of the protected 35kV line(without overhead ground wire) is lower than 0.36 times/(100km-a), compared with the lightning trip rate of 8.0 times/(100km-a) before application.
c.The lightning protection section is equipped with protection devices. When the lightning current exceeds the design value, the protection device can effectively prevent the resistor from damage caused by lightning current and product damage.
d.Easy to install on site. There's no need for special grounding treatment, natural grounding for the tower is enough.
2. Technical Parameters
Rated voltage: 51kV
4/10us large current impact: up to 150kA2ms square wave current: 400A
Nominal discharge current: 10kA
Lightning impulse voltage: no more than 100kV
AC wet withstand voltage: no less than 26kV
Tensile load: 100 kN
3. Application
In 2020, the 35kV anti-lightning and anti-icing composite insulator and 35kv large current gap surge arrester are applied in nearly 90 lines in Hunan. There is no lightning and anti一icing composite trip accident so far. The economic and social benefits are insulator remarkable.
a.The series structure of composite insulator and surge arrester is adopted, which integrates the support and lighting protection functions of both insulator and surge arrester.110kV anti-lightning and anti-icing-composite insulators have the functions of improving ice flashover and pollution flashover voltage levels of transmission lines.
b.The 150kA through- current capability design is used to meet the operation requirements of 110kV lines located in thunderous regions or without ground wire.
c.Ordinary line insulators and line surge arresters can be directly replaced by a 110kV anti-lightning and anti-icing composite insulator. There's no need for special grounding treatment, natural grounding for the tower is enough.
2. Technical Parameters
Structural height: 1314 ± 5mm
4/10us large current impact: up to 150kAClimbing distance: ≥ 4340mm
2ms square wave withstand current: ≥ 900ADC 1mA reference voltage: ≥ 130kV
Tensile load: 120kN
AC wet withstand voltage: no less than 170kV
3. Application
In 2019, the 110kv anti-lightning and anti-icing composite insulators were applied in the Banshan branch line of 110 kV Mubanta Line inLanshan County, and the 110 kV Fuhui Line in Anhua County, Hunanwithout ground wire. After several rounds of thunderstorms and icing weather, the headache of ground wire breakage, lightning trip outage, and anti-icing composite failure for operation caused by icing and lightning is proved to be totally insulator eliminated, which provides strong technical support for improving the safe and stable operation of wind power lines in repetitive icing areas.
1. Product Introduction
The series structure of composite insulator and surge arrester is adopted, and 220kV anti-lightning and anti-icing composite insulator are composed of a lightning protection section, insulation section, and connecting fittings, which integrates the support and lightning protection functions of both insulator and surge arrester. The lightning protection section is composed of high-performance ZnO resistors covered by an epoxy cylinder that absorbs and discharges lightning energy. There is a parallel protection gap to prevent damage to the resistors when the lightning current is too high, the insulation section adopts an enlarged umbrella diameter and umbrella skirts structure with spacing to prevent bridging of icing, improving the lightning resistance level of the line and the flashover voltage of icing and pollution.
2. Technical Advantages
a. It has the functions of lightning protection, icing prevention of transmission lines, and improving pollution flashover voltage.
b.The ordinary line insulators and line surge arresters can be replaced by 220kV anti-Jlightning and anti-icing composite insulators with easy installation.
c.175kA through- current capability design is adopted to meet the requirements of 220kV lines operation without a ground line.
3. Technical Parameters
Structural height: 2269 ± 15mm
Climbing distance: ≥ 8200mmDC 1mA reference voltage: 2 280kV
AC wet withstand voltage: 2340kV
4/10us large current impact: up to 175kA
2ms square wave withstand current: ≥ 1200A
Tensile load: 150kN
4. Application
The 220 kv anti-lightning and anti-icing composite insulator were put into operation on the 220kV Xinning-Fuyi line in Hunan in May 2017. The line successfully stood several rounds of thunderstorms and icing anti-lightning weather, the lightning trip and icing flashover outage failures have not anti一icing composite insu later
occurred so far.
1. Product Introduction
The anti-icing insulator is connected in series with the lightning protection component with tensile strength. Under normal conditions, the anti-icing insulator bears the operating voltage of the line. When lightning strikes, the lightning protection component is used to limit overvoltage and AC continuation current, it can prevent lightning trips and has the functions of insulation support, anti-lightning, and anti-icing flashover.
2. Technical Advantages
a. It has the functions of lightning protection, icing prevention of transmission lines, and improving the pollution flashover voltage.
b.The ordinary line insulators and line surge arresters can be replaced by 220kV anti-lightning and anti-icing-composite insulators with easy installation.
c.175kA through- current capability design is adopted to meet the requirements of 220kV lines operation without a ground line.
3. Technical Parameters
Structural height: 4500~4950mm
50 % lightning impulse discharge voltage: 1760 ~1780kVAc wet withstand voltage: ≥640kV
2ms square wave withstand current: ≥ 1500A (320J / cm3 )
lce flashover voltage (grade IV pollution, 271mm ice thickness): > 510kvTensile load: 210kN
4. Application
In September 2018, 500kV anti-lightning and anti-icing insulators were put into operation in thunderous and heavy ice regions(Shaoyang-Loudi,30km line section) of Hunan 500kv Changmin Line. This section of the 500 KV Changmin Line had experienced 7 times lightning trips in the previous years before the upgrade was carried out in 2018.After the application of the new insulators, the transmission line successfully withstood several rounds of thunderstorms and icing weather, icing, and lightning-induced ground wire breakage and lightning trip outage are eliminated.
