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Presentation About Company

JSC Pluton
5 Novostroyek st.
69076 Ukraine

+38 061 220 4811
+38 061 220 4813

+38 061 220 4812

E-mail: info@pluton.ua

DC Switchgears


Modern new generation DC Switchgears are made for operation at traction substations in power supply system of public electric transport traction network.

Main features:

  • high reliability;
  • protection level (acc. to IEC 60529): IP54 control section, IP43 other sections (except floor);
  • insufficient necessity in periodical maintenance and repair;
  • small overall dimensions, weight, materials consumption and as a result substation area saving;
  • provision of inspection convenience because of application of carriage-type element with circuit-breaker and linear disconnector;
  • equipment monitoring and self-diagnosis possibility, as a result reduction of time for maintenance, faults detection, repair-and-renewal operations;
  • built-in traction network monitoring system with set of traction network electronic protections;
  • high operation safety provided by design.

DC Switchgears comply with requirements of Electrical Installations Regulations (PUE), Operating Rules (PTE) and Electric Consumers Safety Rules (PTB EP), SNIP, and also technical specifications.

DC Switchgear


 Fig. 1
DC Switchgear

DC Switchgear manufactured by PrJSC PLUTON has successfully passed type tests for International Electrotechnical Commission standard  IEC 61992-6:2006 conformity in testing center IPH Institut (Berlin, Germany).

Concept solutions applied in Pluton DC Switchgears are based on human intrusion minimization in processes of switching, assembling and disassembling of circuit at substation. We proceed from the notion that the lesser the man interferes in switching process, interlocking process, the lesser he applies mechanical efforts to switching devices during switching the more reliable becomes operation of electric installation and the lesser the possibility of electric trauma for staff. This concept is realized by means of application of small-size, low-powered servodrives for disconnectors control, for rolling off/in of trolley with circuit-breaker, And also by means of application of electromagnetic interlockings controlled by industrial controllers.

Switchgear power part is made with application of maintenance-free contact joints technology. Special German compensating devices, which fix clamps on contact joints, irrespective of temperature and thermal diurnal and seasonal oscillation, are applied. Due to this fact, there is no need in periodical retorque, stripping of contact joints during DC Switchgear operation. Temperature stabilization of contact joint increases fire safety of switchgears and substation as a whole.

DC Switchgears consist of three main sections: section with high-speed circuit-breaker, power busbars and cables section, automation and control section. Power and low-voltage sections are divided. It provides maintenance and operation safety, and also makes impossible plasma penetration from section to section and from power sections into control section.

High-Speed Circuit Breaker installed on Trolley


 Fig. 2 
High-Speed Circuit Breaker
installed on Trolley

In high-speed circuit-breaker section there is carriage-type element trolley, where high-speed circuit-breaker, linear two-pole disconnector, carriage-type element servodrive, actuating mechanisms of electromagnetic interlockings are installed. Carriage-type element has three positions: operation, control and repair. Carriage-type element moves automatically from operation to control and back from control to operation by means of electric servodrive. At the same time the man makes no efforts by rolling of trolley out or in. The trolley moves to repair position and back to operation only after the main controller allows to roll it out having checked all interlockings involved in security system at substation (and not only in one particular cubicle).

Described algorithm means that the man only gives command to assemble or disassemble circuit by pressing this or that button on control desk. Everything else is done by electronics and mechanics. checks possibility of fulfillment of issued command for reasons of security, controls disconnestors, high-speed circuit-breakers, carriage-type trolley, mechanical interlockings. If its impossible to execute this or that command the system informs about command failure and about the reason of this failure.

High-Speed Circuit Breaker UR40-81


 Fig. 3 High-Speed
Circuit Breaker UR40-81


In DC Switchgears UR26-81 and UR40-81 high-speed circuit-breakers of Secheron company (Switzerland) production are applied. Application of these circuit-breakers allows to manufacture cubicle with following dimensions: 80020001200 mm (WxHxD). Weight and dimensions values of described switchgears 2.5 times less than similar parameters of switchgears, created on the basis of VAB high-speed circuit-breakers and VAT current-limiting circuit breakers. Reduced dimensions of switchgears sufficiently save place at substation and cuts down expenses for construction part.

Operational and electric characteristics of UR26-81 and UR40-81 sufficiently exceed similar characteristics of VAB and VAT circuit breakers.As a result of high mechanical and electrical strength application of UR26-81 and UR40-81 circuit-breakers leads to reduction of costs for its maintenance. Design of circuit-breaker allows to make necessary mechanical interlockings with linear disconnector.

Table 1. Technical characteristics of UR26-81, UR 40-81 high-speed circuit-breakers

Name of parameter 

UR26-81 (82)

UR40-81 (82)

1. Current type in main circuit


2. Rated operating current, installation in cabinet, A



3. Rated voltage in main circuit, V 

900 (1800)

4. Current settings limits, kA 



5. Rated breaking capacity in noninductive circuit, peak/rated, kA/kA 


6. Mechanical strength without maintenance, cleaning and greasing (non-emergency switching) 

8 25000

7. Out-of-turn inspection 

 Inspection after 250 overload trips

8. Weight, kg 



9. Test voltage, kV 


10. DC auxiliary voltage, V 

24, 36, 48, 72, 96, 110, 220


Main advantages of UR26-81 and UR40-81 high-speed circuit-breakers:

  • Mechanical simplicity;
  • Automatic adjustment of contact tightness;
  • Long operation life (3000 short-circuit currents breaking before contacts replacement);
  • Insulating material, self-cleaning under influence of arc;
  • Breaking setting is smoothly regulated;
  • All insulating materials conform to strict European ecological requirements;
  • There is no arcing contact. It provides minimal breaking time;
  • Current at short-circuit breaking of circuit-breaker doesnt reach big values;
  • There is no need in greasing, regulation and maintenance for a long period of time.


EDT Disconnector


 Fig.  4
EDT Disconnector

In DC Switchgears disconnectors EST and EDT are applied. They have unique design of contact system with double disconnection and self-stripping contacts started by small-size servodrive. It allows to connect high-speed circuit-breaker (installed on trolley) to power busbar without mechanical efforts.

Convenience of rolling out of trolley with circuit-breaker and two-pole EDT type disconnector is reached by original disconnector design. Each pole has two rows of lamels, which are opened in initial (tripped) condition so that connected busbars enter lamels area easily without mechanical resistance. Only when carriage-type element is in operational position, all interlockings confirm permission for disconnector activation, servodrive starts to close lamels and they squeeze busbars. At that, owing to original mechanics, lamels wear in busbar surface, stripping oxide film of silver. Each lamel is pressed by individual spring, not connected with other lamels and works independently. In case of breakdown of one lamel (weakened spring, etc.) other lamels continue operation and no emergencies happen. Moreover, according to total area of contact lamels, disconnector has fourfold reserve of contact surface.

EST and EDT disconnectors refer to maintenance-free type with 10,000 cycles before maintenance (or ten years). Disconnectors have noiseless low-powered electric drive with power of 18W. Application of electric drives controlled by automatics system sufficiently decreases risk of disconnectors damage in case of wrong actions of operating staff.

DC Switchgears are equipped with special earthing disconnector excluding necessity of operation staff application of temporary ground. Earthing disconnector has the same design as described above operating busbar disconnector. Disconnector is controlled by servodrive or manually. Upon maintenance or repair there is no need in personnel access to busbar section. It sufficiently decreases risk of electrical shock.

Table 2. Technical characteristics of EDT and EST


Name of parameter 

 EST 1000 

 EDT 2500 

1. Rated current, A 



2. Maximum value of short-time current, kA 



3. Mechanical strength (maximum amount of switchings) 



4. Drive force, N 



5. Frequency of maintenance 

  After 10000 cycles or in 10 years 


Control section of DC switchgear


 Fig. 5 
Control section of DC Switchgear

Switchgears are equipped with control, monitoring and protection system, which includes: 

1) industrial controller 20, 

2) traction network monitoring and protection system SMTN-2 or SMTN-3,

3) visualization power panel 65.

DC Switchgears are equipped with industrial controllers of Bernecker & Rainer (Austria) production. All algorithms are implemented in program level, and control of servodrives, actuating mechanisms, high-speed circuit-breakers is fulfilled by means of electronic switching elements.

Visualization power panel PP65 produced by Bernecker & Rainer (Austria) is applied for visualization and control of switchgear components. Visualization power panel makes it easy and convenient to display the needed information and to control switching devices by touching.

SMTN2 or SMTN-3traction network monitoring system during whole operation period of switchgears provides constant oscillography of traction network parameters of voltage and current. It records slow and quick trace. System is able to differentiate real transient process (overload, short-circuit) from bursts created by rolling stock.

Control, protection and monitoring system keeps protocol of events occurring at traction substation, records of emergencies, traction network monitoring (feeder lines loads, traction network voltage). Nonvolatile protocol preserved in computer memory serves for fixation and registration of all processes occurring at traction substation, detection of staff mistakes preceding emergency.

Fig. 6 
Protection and monitoring system SMTN-3

Features of operation of control, protection and monitoring system of traction substation: 

  • functions as main protections: di/dt, Δi/Δt, maximum current protection, minimum voltage protection, current-time ptotection; 
  • receives commands from devices of higher control level and processes them in accordance with set algorithm, issues confirmation of commands fulfillment; 
  • issues control commands to end devices; 
  • records in controller memory all events in time and provides communication in network through interfaces RS-232, RS-485, CAN; 
  • has possibility to integrate in network with upper level system and to build-in in global automated traction substations control systems.

DC Switchgears in substation of line Lidingöbanan (Sweden)


DC Switchgears in "Kievpastrans" (Kiev, Ukraine)


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