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High Voltage Surge Arrester
Applications:
 
(Polymer housed MOA for 110kv) (The polymer housed MOA for 10kv)
 
(Porcelain housed MOA for 220kv) (35kv MOA without gaps for middle phase)
(110kv MOA without gaps for suspension tower) (110kv MOA with gap for dead-end tower)
Pictures:
(0.22KV-10KV Surge Arrester with Polymer housing)
6KV-10KV Surge Arrester with porcelain housing
 
6-36KV Surge Arrester with polymer housing, disconnector and bracket
 (Base mounting Type, 35KV)  (Base mounting Type, 110KV)
  
(110KV-220KV)
Transmission line MOA for 10~220kV
 
Surge Arrester Core
General Description
Metal oxide surge arrester of rated voltage 3.8-750kV are protective apparatus used for protecting AC transmission and transformation equipment against damage from atmospheric overvoltage and switching overvoltage. The products are manufactured according to manufacturing technology transferred from HITACHI Ltd. of Japan. Compared with silicon carbide surge arrester, metal oxide surge arrester has superior protective characteristics, good reliability, high discharge capacity, and simple construction etc. thus, assuring the best overall protection for transmission and transformation equipment.
Usually, the arrester is connected between system and ground in parallel with protected equipment. At continuous operating voltage, zinc oxide resistors appear to be an extremely high resistance, the resistive current through the arrester is of the order of microamperes. In appearance of a lightning stroke or switching surge on the system, the residual voltage across the terminals of the surge arrester will be limited to a certain permissible value because of the excellent non-linearity of resistors, and high surge energy of the line will be absorbed, thus the insulation of electrical equipment is protected.
The zinc oxide surge arrester can be used in the following conditions: ambient temperature -40¡æ to +40¡æ; altitude above sea level up to 1000m; withstanding 8º earthquake intensity (horizontal acceleration 0.2g).
Anti-vibration type, anti-pollution type and plateau type arrester are available for special application. Anti-vibration type arresters are adaptable for using in an area with 9º earthquake intensity (horizontal acceleration 0.4g); anti-pollution type arresters for light or heavy polluted condition; and plateau type arresters for relative high altitude area.
Performance
The zinc oxide surge arrester show an excellent protective performance, high capability to withstand lightning and switching surge, good response characteristics to steep lightning impulse and superior anti-pollution property. The performance of the arresters meets the requirement of IEC 60099-4(2000), IEEEC62.11 and JEC (Japan standard),and other standards are available.
Superior protective characteristics
Owing to the high non-linearity and excellent steep response characteristics of zinc oxide resistors, both the steep wave front residual voltage and switching residual voltage of the zinc oxide surge arrester have been reduced. Thus the corresponding protective margins have been increased, and the protective margins for steep wave front surge, standard lightning and switching surge are approximately the same. Therefore, the best overall protection for electrical apparatus is provided.
The zinc oxide arresters are especially suitable for application to low surge impedance system, such as multiple lines, capacitor banks or cable, where conventional SiC arresters can hardly be applied satisfactorily.
Perfect overvoltage energy absorption capability
The non-linearity coefficient of zinc oxide resistors is about 30-50. In fact no following current can be observed during lightning surge operating duty test. Hence the energy absorbed by the arrester is very small. Capability against multiple lightning is greatly improved.
High overvoltage energy absorption capability
The zinc oxide arresters can absorb all kinds of energy of lightning and switching surge. The overvoltage energy absorption capability of our zinc oxide surge arrester is as follows:
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Nominal system voltage (kV) |
110-220 |
330 |
500 |
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Discharge capacity 2ms, rectangular wave (A) |
800 |
1000 |
1500 |
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Long duration discharge class (IEC standard) |
Class2 |
Class3 |
Class5 |
|
Energy absorption capability (kJ/kV) |
3 |
5 |
8 |
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Energy absorption capability limit (kJ/kV) |
9.2 |
11.2 |
15 |
Both nominal current operating duty test for 20 times and combined operating duty stability test have been passed successfully according to standard IEC.
High temporary overvoltage withstanding capability
Temporary power frequency overvoltage may be caused by single line-to-ground faults, capacitive charging effects for long transmission line and load rejection effect, etc. After an initial energy of 3kJ/kV rating, 5kJ/kV rating and 8kJ/kV rating has been respectively injected into the arresters of 110-220kV, 330kV and 500kV, the zinc oxide surge arresters still possess capability to withstand a temporary power frequency overvoltage 1.1UR ¡Ý10s, 1.15UR ¡Ý2.5s, as shown in Figure 1.
Reliable long term operating stability
Since the zinc oxide surge arresters have no gaps, the zinc oxide resistors are exposed to a long-term load of normal operating voltage and all kinds of overvoltage. Therefore operating stability is of critical importance for zinc oxide arresters. Zinc oxide resistors of different size have passed accelerated aging test under 115¡æ for 1000 hours according to IEC standard. A service life of more than 100 years may be expected at an ambient temperature of 40¡æ.
Excellent anti-pollution performance
Because the zinc oxide arresters have no series gaps, the influence of contaminants on porcelain surface upon the performance of arresters is greatly reduced, eliminating all the problems caused by series gaps, such as the reduction of spark-over voltage and degradation of the performance of interrupting following current.
About Disconnector
The polymer housed MOA with disconnector for 3-10kV
The polymer housed MOA with disconnector for 3-10kV is equipped with the insulation base and bracked. The top bolt of disconnector is directly connected with the bottom of MOA. The below bolt is connected with ground lead.Fig7 shows the product's full assemblage.
 The disconnector shall operate at the power frequency short circuit while MOA's failure under the abnormal conditions. As the dotted line showed in Fig2,the grounding end of the disconnector breaks away automatically, and the failed MOA is separated from the system, that means the MOA needs to be replaced. To do so, the disconnector should has the rapidly operation characteristic, withstand current impulse and operating duty without working.
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-------------------------The polymer housed MOA with disconnector for 3-10kV------------------------------------------ |
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1:Time versus current operation characteristic of disconnector |
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The disconnector must operate at the
fault current. Disconnector operation
test has been performanced on high
power test centre of Electrical
Power Research
lnstitute, P.R.China for values of
current 800A,200A,20A,5A according
to IEC Standard.Result of test is given
in the right table | |
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Current |
800A |
200A |
|
Sample NO. |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
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Operation time(s) |
0.016 |
0.012 |
0.018 |
0.012 |
0.019 |
0.026 |
0.076 |
0.018 |
0.068 |
0.066 |
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Current |
20A |
5A& |
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Sample NO. |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
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Operation time(s) |
50 |
35 |
2 |
1.5 |
24 |
46 |
529 |
595 |
98 |
316 | | |
| 2:The disconnector's ability for the current impulse and operating duty without working |
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The disconnector is in series with the MOA. The disconnector shall has no operating
while MOA is under the normal conditions, to guarantee the MOA can show its fine functions. The disconnctor shall withstand the following item according to GB11032:
(1):Long duration current impulse test without operating.
(2):Operating duty test without operating.
(3):Type test made by Power lndustry Ministry Electric Power Appearance
Quality lnspection & Test Centre, shows the superior performance of withstanding
2ms 150A,and operating duty with 4/10  s 65kA. | | |
| 3:The installation of MOA with disconnector |
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The bellow shows the connection of polymer housed MOA with disconnector for 3-10kV.dotted line shows the situation of the grounding part's disconnection while the disconnector operation.
Note :Distribution MOA, station MOA and MOA for capacitors is connected directly
with disconnector by insulation base | |
DISCONNECTOR INSTALLATION
 
1. MOA
2. INSULATION BASE
3. DISCNNECTOR
4. 30CM SOFT GROUNDING
5. INSTALATION BRACKET
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