Important information and explain the technical theory concepts
Why our products can suppress varieties of surges such as Lightning
Flash Surges (LFS), Power Switching Surges (PSS), Switching Inrush Current
(SIC), Electric Magnetic Pulse (EMP) and Series Spark Surge (SSS) under
ungrounded condition? Explain the technical theory and idea as following:
The people who have some electrical knowledge, will think about Ohm’s
Law when they talk about Voltage (V) and Current (I), the relationship between
V and I are R=(V/I). Therefore, surge suppression device ask low grounding
resistance is inevitable. If we can think Joule’s Law, the relationship between V
and I is E=(VXI), then will think over energy transferred into voltage or current.
If you have such concept, low grounding resistance or ungrounded are not
important.
Due idea of energy transferred into voltage, so “Surge energy transfer
circuit” acquired Invent patent of USA (No.:US8295024B2), Japan (No.:特許第
5192002), China (No.:ZL201010111239.8), Taiwan (No.: I 390816) etc.
Surge energy absorbed and transferred (SEAT) into voltage explained by
waveform picture of figure1.In figure1, a product of SEAT is powered and
under ungrounded condition, and 1,000Joule bi_wave surge which parameters
are 1.2X50 μSec 10kV, 8X20 μSec 5kA coupled directly into input port. Due
surge energy was absorbed and transferred into voltage, so output port
showed AC top waveforms are approximately up 6% higher compare the top of
waveform of prior surge coupling (noted: top waveforms up 6% are over
horizontal line). Surge energy transfer time is approximately 7 cycle period and
AC waveforms will decrease to original value after surge transferred
completely.
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Under powered and ungrounded condition, we coupled a 1.2X50 μSec 10kV、8X20 μSec
5kA，1,000J surge into SEAT, which absorbed surge energy and transferred it into AC
waveform of loads. We can see that the peaks of the AC waveform are approximately up 6%
higher, compare the top of waveform of prior surge coupling.
Figure1: Surge energy transferred into AC waveform.
A remnant surge voltage of the output terminal, Vr, is expressed by:
Vr = V c l a m p i n g －V( △ L )
= V c l a m p i n g － (1- k) × L ( d I r / d t )
(1)
where k is in a range of 0.1-0.9.
As known from equation (1), the magnitude of the inductor is reversely
proportional to the remnant surge voltage Vr. The less the remnant surge
voltage decreases when the value of the inductor increases, and increases
when the value of the inductor decreases. By varying the magnitude of the
inductor, the value of the remnant surge voltage Vr can be precisely controlled.
Such approach has a more definite and substantial suppression effect than
conventional surge voltage suppression approaches.
The voltage increment of the output terminal V(△), is expressed by:
2
V(△ ) =(1/C)∫(1-2k) Ir dt
(2)
where k is in a range of 0.1-0.9.
where C is a value of the high voltage capacitor. As indicated by Equation (2), the
voltage increment V ( △ ) is reversely proportional to the value C of the high voltage
capacitor.
The V ( △ ) decreases when the value C of the high voltage capacitor
increases, and increases when the V ( △ ) decreases.
A lasting time duration time of the voltage increment V ( △ ) is t
t＝
1
CV
(1  2k ) Ir
(3)
(△ )
where k is in a range of 0.1-0.9.
As indicated by Equation (3), the lasting time duration t time of the voltage
increment V ( △ ) is proportional to the value C of the high voltage capacitor. The
lasting time duration t of the voltage increment V ( △ ) is longer when the value C of the
high voltage capacitor is larger, and is shorter when the value C of the high voltage
capacitor is smaller.
From Equations (1), (2) and (3), the remnant surge voltage Vr of the output
terminal of the surge energy transfer circuit, the inductance of the inductor, the value
of the high voltage capacitor, and low voltage increment of the output terminal V ( △ )
and long lasting time duration t or high voltage increment of the output terminal V ( △ )
and short lasting time duration t can be effectively and precisely planned and
designed to meet different customized demand and raise surge immunity of power
facilities.
A large product, three-phase 5 wires AC 510V/360A Surge Energy
Absorbed Transferred into Voltage Systems, which using Invent patent “Surge
energy transfer circuit” and been produced and applied to facilities of power
station and board station, as figure2.
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Fig.2-1 ： Three-phase 5wires AC 510V/360A Surge
Energy Absorbed Transferred into Voltage
Systems.
Fig.2-2：Net weight is 500 kg of three-phases 5wires AC
510V/360A
Surge
Energy
Absorbed
Transferred into Voltage Systems.
Figure 2: Large product, three-phase 5wires AC 510V/360A Surge Energy Absorbed
Transferred into Voltage Systems, which applied to facilities of power station and
broadcasting station.
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