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OSKAR Dynamic Voltage Restorer

OSKAR Dynamic Voltage Restorer

OSKAR is a Dynamic Voltage Restorer (DVR) which is based on state-of-the-art Power Electronics technology. It can help eliminate voltage dips/swell and voltage unbalance with utmost accuracy and reliability. This is a microcontroller-based power electronics converter detects voltage fluctuations within 200µs and can correct voltage dips or swells within 5ms or quarter cycle.

WORKING PRINCIPLE:

  • The active voltage stabilizer OSKaR® is an active three-phase voltage controller which regulates the input phase voltages to output voltages defined in phase and magnitude using a pulse rectifier (GridClass®-module -G1) and a pulse inverter (GridClass®-module -T1) together with a series transformer (-T0).
  • The range of application is the correction of short-time voltage dips caused by failures in the grid and the optimization of the voltage stability.
  • To serve also regenerative loads , the full power converter is a 4- quadrant operation converter equipped with an active front end  converter which ensures the bi-directional power flow between the source and load.

TECHNICAL SPECIFICATIONS:

  • Power ranges from 150 KVA to 3000 KVA
  • Very high operational efficiency (>99%)
  • Swells and over voltage compensations up to 20% (≤ 130% Un)
  • Correction range up to (30%Un ≤ Instantaneous voltage ≤ 130%Un ) for 1-φ
  • Correction range up to (50%Un ≤ Instantaneous voltage ≤ 120%Un ) for 3-φ 
  • ± 10 % Continuous voltage correction capability
  • Reaction time very less (<200 µS)
  • Correction time very less (<5 ms)
  • Current Crest factor is very good (>3)
  • Overload bearing capacity 150% of nominal voltage for 30 seconds 
  • Very Simple Interface using Touch panel/ log SD card/ mail
  • Communication via Ethernet (RJ45)/ FTP -server /mail server/Modbus)
  • An extra auto transformer required for 690 V, 208V and 220V nominal voltage.

PERFORMANCE FEATURES:

  • ± 10 % Continuous voltage correction capability
  • Mitigates up to 60 % voltage correction capacity, means up to 80% voltage drop without bypass
  • Short circuit power remains unchanged (No adjustment of protection equipment required)
  • Robust overload capability (150% overloading for approx. 30 seconds)
  • Economical solution → No battery storage required so very low maintenance
  • Very high Efficiency → Very low operating costs
  • Chronology of disturbances and monitoring system
  • Reduction of maintenance & repair costs
  • Highly Scalable
    • Modular system , adaptable for required power levels   
    • Customized output voltage available
    • System power extension through parallel connection
    • flexible adaptation of short circuit capability

MAINTENANCE BY PASS

  • Although OSKAR runs with only little maintenance , it must be possible to isolate it from connected electrical system for inspection or maintenance purposes.

  • To avoid any production downtime , it is possible to bypass the complete system with an additional service bypass .

  • In the continuous process industry,  Biggest advantage of it is that the production lines which are protected by OSKAR do not have to be interrupted or switch off even during maintenance .

  • Ultimately resulting in ZERO DOWNTIME 

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