Automatic correction
setting system (САНК 4.2 УХЛ4).
System purpose is the determination of capacity
currents in 6-35 kV networks and setting of biasing-controlled arc-suppression
coils (ASCs) (РУОМ type).
There exist certain issues in the course of ASC
operation in 6-35 kV networks:
- The network configuration is changing constantly.
Those changes must be monitored and corresponding adjustment of ASC setting
must be made. It has been an impossible to implement until now, since the
network analysis and ASC setting adjustment are the tasks requiring
highly-qualified personnel. In case of incorrect setting, there occurs electric
arc with the line-to-ground short circuit (LGSC) and cable destruction which
all leads to the consumer disconnection for the whole period of tracing the
damaged area and repairing.
- Controlled arc-suppression coils (CASCs) of common
types cannot be operated in automatic mode in case of integrated sections,
while the network configuration is changing.
This means inaccurate setting.
- As a rule, controlled ASCs are more expensive than
uncontrolled; besides, many networks contain older types of ASCs that are still
in service. However, those do not meet modern needs of power grids for the
accurate compensation of capacity currents in case of LGSC. Replacement of
those older ASCs with CASCs is a measure requiring high expenditures.
- In case of LGSC, it is desirable to monitor the
indications of instruments for subsequent analysis and elimination of the
insulation damage causes. It is an impossible task if LGSC occurs at an
unattended substation.
All these issues can be resolved through the use of
САНК-5.1 system in combination with plunger-type CASC. In such a case:
- Complete automation of capacity currents correction
can be implemented. Each 5-10 minutes, САНК analyses network parameters,
determines the current in case of LGSC and sets CASC to the current, so no
personnel interference is required.
- When a correction of LGSC capacity currents is
required on adjacent sections of a network with probable integration of the
latter, САНК use makes it possible to analyze both separate and integrated
networks and set the correction with the accuracy independent from the current
circuit configuration. When sections are integrated, CASC load in case of LGSC
becomes proportional to their power.
- In case of significant capacity currents, it is
possible to use САНК for setting CASC+ASC system (where ASC is and uncontrolled
reactor) for the purposes of economy (it is possible to use less powerful
CASC); in this case, ASC corrects the main part of the current while CASC
allows САНК system to adjust the correction setting in case of the network
configuration change. At that, there is an opportunity of integrating sections
keeping the automated operation mode active.
- САНК stores information about all short circuits that
occurred: date, duration, CASC current and neutral-to-ground voltage, which
makes it possible to analyze the network condition. This information can be
accessed both directly from САНК display and remotely - through Ethernet-based
LAN.
Brief
technical overview:
- Patented
innovative method of capacity currents measuring ensuring error not exceeding
2%.
- Setting
of any biasing-controlled arc-suppression coils.
- Parallel
operation of several systems in combined sections.
- Operation
in the presence of uncontrolled ASCs in the section.
- Line-to-ground
short circuit statistics collection.
- Data
transmission using Ethernet-protocol.
- Dimensions
(HxWxD): 170x230x110 mm, weight 2.5 kg.
- Russian
Federation utility patent No 88221.
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