九、雷擊(Lightning Strike)對電容器之影響

在配電系統中常裝置電力電容器用於改善負載功率因數，因一般負載均屬電感性，對異常電壓及諧波(Harmonic)電壓，具有高阻抗性，而電容器則對異常電壓及諧波電壓具有低容抗性。因此當系統受雷電波擊(lightning strike)時，其發生之異常電壓及電流常由電容器吸收，而使電容器受到嚴重損傷﹕
一、 異常電壓損害(abnormal voltage damage)﹕異常電壓超出電容器額定時，破壞電容器絕緣。當電容器絕緣被破壞時，常造成電容器內部元件短路，或瞬間破裂。
二、 突波電流損害(surge current damage)﹕雷擊時於異常電壓發生時常伴隨突波電流發生，電容器Q＝CV，Q﹕電荷量，C﹕靜電容量，V﹕電壓;當Q值甚大時，於瞬間電容器承受不了，容易造成電容器爆裂，而產生電弧(electric arc)。 欲防止上述電容器受雷擊之損害，通常於受電點裝置避雷器，並於受電盤高壓側裝置突波吸收電容器(Surge Absorbing Capacitors)。

HIGH VOLTAGE SURGE-ABSORBING CAPACITOR

The surge-absorbing capacitor is specifically designed to have much higher withstand voltage than generators, etc. in order to protect equipments against steep surge voltage.

1. ENVIRONMENTAL CONDITIONS
a. Location: Indoor/Outdoor
b. Ambient Temperature:
    -20°C to +40°C(Daily mean temperature: Below 35°C
c. Altitude: Below 1,000m

2. CHARACTERISTICS
a. Capacitance Tolerance:
    -5% to +10% of the rated capacitance
    (Deflection within ±3% for each phase)
b. Temperature Rise: Below 25°C at 35°C
c. Insulation Resistance: Terminals to Case - More than 1,000 megohm
d. Oil-tight sealing: No oil leakage at 80°C
e. Residual Inductance: Below

Line Voltage	Test Voltage
	AC (50Hz or 60Hz)	DC
3300V 6600V 11000V 22000V	16kV (1 min.) 22kV (1 min.) 28kV (1 min.) 50kV (1 min.)	45kV (10sec.) 60kV (10sec.) 90kV (10sec.) 150kV (10sec.)

3. CASE COLOR:MUNSELL 7.5Y 7/2

4. STANDARD:Referred to JIS C4902 (No standard in the world available for the surge-absorbing capacitor.

5. INTERNAL CONNECTION
  

6.PRINCIPLE AND EFFECTIVENESS OF SURGE-ABSORBING CAPACITOR
When the surger-absorbing capacitor is connected in parallel with a rotary machine, etc., it is well known that the traveling wave is absorbed by the surge-absorbing capacitor resulting in reduction of the travelling wave voltage.
The effect is shown Fig. 1 and Fig. 2