New DC switchgear concept

AFB® arc-free ultra high-speed circuit breaker with improved operational characteristics is applied in DC switchgear:

• no open arc;
• lowest maintenance;
• high wear resistance and long lifetime;
• high-speed contacts opening system;
• minimum tripping time;
• equipped with control and internal monitoring system;
• protection functions: Imax protection and di/dt protection.

EST, EDT disconnectors manufactured by Elpro (Germany) are applied for electric power circuit switching.

Applied disconnectors have a unique crimp-type contact system design with double gap and wiping contacts, geared by a small-sized servo drive.

Disconnectors are classified as maintenance-free components, with 30 000 cycles (or 20 years) before maintenance.

Disconnectors are equipped with noiseless low consumption electric drive, capacity 18 W. Application of electric drives controlled with automation system reduces risk of disconnectors and bearing insulation damage in case of false staff operation with undue exertion.

Switchgear is provided with microprocessor control and diagnostics system based on industrial controllers SOTA^® (Pluton), which include visualization panel with color LCD display.

Industrial controller SOTA^® has significant calculation performance, high productivity and compact size.

Main functions of SOTA^® industrial controller:

• displaying of necessary data in simple and convenient form;
• switching devices touch control;
• trolley rolling in and out control, trolley position visual checking;
• visualization on color LCD display of:
  - switching components and trolley condition;
  - current and voltage values;
  - messages history;
  - trends;
  - settings;
  - traction network monitoring system screens.
• control mode selection (manual, remote, program)
• compliance with the main IEC 61131 series international standards;
• support of multiple protocols, including IEC 61850.

Switchgear components are mounted in separate compartments:

• automatics and control compartment;
• compartment with high speed circuit breaker;
• power busbars and cables compartment.

High- and low-voltage circuits are separated from each other providing operational reliability, equipment maintenance and operation safety.

Safe access to cables
Safe access to cables with operating busbar under voltage is provided due to isolated separation of busbar compartment into three physically independent of each other compartments (auxiliary busbar compartment — main busbar compartment — feeder cables busbar compartment)

Maintainability
Withdrawable unit as a part of switchgear allows quick and safe inspection/maintenance of power switching device in maintenance position. Operation and control position allow visual remote monitoring of power circuit opening.

Uni- or bilateral maintenance provides easy access to all components of the cubicle and maintenance safety.