General
Tkxh-z multi-turn arc suppression automatic tracking compensation
complete device can carry out real-time measure to grounding
capacitive current and track the changes of grid parameter
automatically. It can realize overcompensation and under
compensation according to parameter value. The run function is very
flexible. Arc suppression can enforce to compensate fast to signal
phase grounding break and output according to setting trip. It
mainly applies to overhead lines, cable line-based or hybrid line
distribution network system. Compensation device can real-time
monitor, has high reliability and low power consumption, and
improve the safety and quality of power supply of the power grid
operation.
The device has the following characteristics:
☆The speed of grounding compensation is fast. It can compensate to
signal phase ground break in millisecond, which lower the rate of
occurrence of the instantaneous grounding fault developing into a
permanent failure.
☆The device has the perfect safety mechanism. It can block to the
arc suppression coil load switchgear when the signal phase or the
system break (such as the break of CT, PT or power failure).
☆It can realize some sets arc suppression run together. It can
realize multi-control run or mutual backup run, which improve the
stability of device run.
☆Big screen LCD display, Menu graphical interface. Switchover by
the manual way or automatic method. It has time parameter, run
parameter, control parameter setting functions and check fault
information function and so on. Real-time measure and show the
following information: arc suppression gear, device run condition,
off tuning degree, capacity current, residual current, neutral
voltage, neutral current, times of signal grounding fault, begin
time of ground, stop time of ground and so on.
☆The device equips with RS-485 serial interface, connecting with
all kinds of complex automatic system, so that monitor and remote
control to realize the effect of nobody guard.
☆Store 200 information of ground fault so that analyze begin time
of ground, stop time of ground, ground neutral voltage, ground
capacitor current, ground residual current,Wireless voltage and so
on.
☆The main components of Tkxh-z multi-turn arc suppression automatic
tracking compensation complete device are import in U.S. and passes
the Anti-interference and electromagnetic compatibility test. The
controller uses the second power technology to Resist destructive
electromagnetic interference. The reset circuit can carry out the
automatic restoration. It can run 250 thousand hour without break
average that improves the reliability of the device.
☆Detect the change of system ground capacitive current real-time.
Adjust inductance in time to keep the grounding residual current in
the setting range.
☆When off-tuning-degree over the limit, single-phase ground can
send out sound and light alarm, and can display and remote
transmit.
Summary
The voltage level is 6Kv-66kV in the urban gird, rural grid and the
mine enterprise without neutral point ground. It can run with
accident in the short time when the grid take place the signal
ground (up to 2 hours), to ensure the reliability of power supply.
But with the fast development of urban grid, the proportion of
cable lines Increased, and the system have an increasing demand of
ground capacitive current and Current flowing through the point of
failure is large after single phase grounds.
To deal with the above problem, the grid system uses the style of
Resonance ground, namely after set arc suppression on the neutral
point. The capacitive current will be compensated by Perceptual
current brought by the arc suppression when the signal phase
grounds to make the residual current on the break point smaller,
the effect of natural arc extinction and then prevent the accident
from enlarging. The experience shows that arc suppression coil can
reduce Gap arc over-voltage and ferroresonance over-voltage, lessen
the rate of trip in the circle accident, lower the personal injury
and drop the damage of device.
On the basis of the standard of state power industry《Overvoltage
protection and insulation coordination of AC electrical
installations》(DL/T620-1997)),the arc suppression should be used if
the capacitive current of signal phase accident in the 3-10kV
overhead lines and 35kv, 66kv system exceeds 10As, or the
capacitive current of signal phase accident in the 3-10kV cable
circuit.
TKXII-Z arc suppression coil compensation device is multi-turn. The
controller can track the operational state. Real-time on line. It
can regulate the compensation stalls using the load switchgear. The
compensation can be quickly input and automatically exited by the
thyristor self-triggering way with high reliability and fast
operation if ground fault occurs. Automatic tune and fault line
detection complete installation micro-controller utilizes modular
design, every function is designed as Independent plug-in module so
as to adapt different users. According to the real demand, we can
match small current line detection device to choice ground outgoing
line and realize shunt operation of some arc suppression coil
device.
The Working Principle of installation
Arc suppression can make the signal-phase grounding arc automatic
instant extinguish on the basis of the following points:
1、Inductance current of arc suppression compensates grounding
capacitance current of grid, inhabits the destruction of earth
fault current and makes the grounding arc of residual current put
off easily.
2、Inductance current of arc suppression can reduce the recovery of
the initial velocity and amplitude of the fault phase voltage to
avoid the recovery of ground arc and make it extinct.
The decrease of ground fault current strongly inhibits the damaging
effect of electrodynamic force, thermal effects and free-air of the
ground current and electronic arc, decreases the probability of
residual current on the fault point and makes the recovery of
dielectric insulating strength of the fault point easily exceed the
recovery of the initial velocity of the faulted phase voltage. So,
the ground arc to be extinguished compensation grid will be
restored to normal operation in an instant.
When arc suppression coil grounding system is in normal operation,
inductive reactance of arc suppression has the cascade harmonic
relationship with capacitive reactance of the power grid-to-ground
and the voltage source is the unbalance voltage.
The use of cascade damping resistance and the method of thyristor
self-trigging can ensure arc suppression enter into best
compensation stall and fast be input and automatically be exited.
When the system happens to ground fault, the neutral point voltage
is boosted and there is shunt harmonic relationship between
inductive reactance of arc suppression and ground capacitive
reactance of system.
As is shown in the following picture-“zero order practical
equivalent circuits in the signal ground fault”, the reactive
compensation current flows back into the system by the fault point,
its direction lag neutral point voltage 90 °, and the current phase
is contrary between the compensation current and ground capacitive
current, that reduces the effect of ground residual current .