Static Stabilizer (PWM-IGBT)

The static stabilizer offers a reasonable improvement on slow servo controlled stabilizer as well as other static tap changing stabilizers. This technology does not cause di/dt problems as it does not switch the power path. The basic topology is with buck-boost transformer with high primary to secondary ratio for voltage correction of ± 25%. The control voltage is imposed on the primary of this buck-boost transformer. The voltage regulation with help of buck and boost topology is achieved electronically without the step changes in voltage that occur when the system regulates. This task is accomplished through a feedback and a control system implemented by using a microcontroller.

The system uses IGBTs as power switches. Direct AC-AC converter circuit improve the overall system response and fast voltage correction. No storage capacitor increase life of the system. 20Khz PWM control operation using high end dsPIC controller to achieve correction time of 1 to 1.5 cycle. Excellent performance in voltage sensitive application.

• What is Requirement of voltage regulator?
  We don’t have any control over Input voltage source or transient/fluctuation generated by other load connected on the same grid. Electronics equipment are not designed for the wide input voltage range and in case of beyond specified input under and over voltage causes
  
  
  • Permanent Damage to the load
  • De-rate the life of load
  • Unwanted interrupt in load operation


• What are limitations of available voltage regulators?
  Since Long, conventional methods like Servo voltage stabilizer and Tap Changer AVR are used In industrial, commercial and residential application.But, these technology has following limitations,
  
  
  • Very slow correction speed
  • Slow Correction time
  • Interrupts power path at the time of regulation (tap changing method)
  • Mechanical component limitation or failure
  • Manual Bypass
  • Low reliability
  • Low regulation


• Principle
  • Delta Voltage is added and subtracted at the primary of buck-boost transformer by IGBT based AC – AC converter to regulate output voltage
  


• What is Static Voltage Regulator?
  
  • Major conventional voltage regulators are working on motor moving part or mechanical tap changing relay principle
  • Static Voltage Regulator is working on IGBT based PWM Control technique
  • At the primary of buck-boost transformer delta Voltage is added and subtracted by IGBT based AC – AC converter to regulate output voltage
  • Rating of the AC-AC convert is ¼ (as per input voltage range) of the rated power


• What are the advantages of Static Voltage Regulator?
  
  • Compact in the size compare to conventional regulator
  • Very fast correction speed of 20Khz
  • Very fast correction time of 20-30ms as compare to conventional regulator (200 – 5000ms)
  • Excellent voltage regulation of +/- 1%
  • Auto bypass
  • No moving parts so no wear and tear and high reliability No maintenance
  • Silent operation
  • Excellent load protection capabilities to ensure load life


• Key comparison of Static voltage Regulator and conventional regulators

  Technology specifications	Static Voltage Regulator	Servo voltage Regulator	Tap changing voltage Regulator
  Correction speed	Fast	Very Slow	Slow
  Correction time	20-30ms	50ms-5Sec	200ms-1Sec
  Auto bypass	Yes	No	No
  Stability	1%	2%	2%
  Reliability	Excellent	Good	Fair
  Load protection capabilities	Excellent
  Interrupts power path at the time of regulation	No	No	Yes
  Power cycling transient	No	Yes	Yes
  Size	Very Compact	Compact	Compact
  Maintenance	No	Yes	Yes (In case of Relay)

  
  

  PWM Controlled Static Voltage Stabilizer V/s Tapchanging or Servo Mechanical Stabilizer
  PWM Controlled IGBT based technology	Other Conventional Electromechanical Stabilizer
  Designed with fully solid state components to govern regulation, no moving part or tapchanging mechanism (relay / static device)	This conventional method is designed with moving part (motor) or tap changing mechanism (Relay / static device) to govern regulation
  No maintenance required	Periodic preventive maintenance required
  Due to the fully solid state drive and power circuitry which uses no mechanical parts in the regulation circuitry, operation is highly reliable, precise, noiseless, interruption-free and fast and the units are absolutely free from wear and malfunctions.	The motor driven mechanical system, motor commutators, and the moving brushes on the variable transformer need
  Exceptionally high speed of voltage correction to meet modern voltage sensitive equipment	Slow speed of voltage correction to meet modern equipment
  Because the series of Static Automatic Voltage Stabilizers function only through static electronic components, the speed of the line and load regulation is exceptionally high (of the order of 360 v/sec. line and 500 v/sec. load regulation) Ideal for modern voltage sensitive equipment.	Because of the inertia of electro-mechanical regulation gear, Motor Driven Voltage Stabilizers can only respond to regulate the voltage fluctuations at a speed of 40 v/sec. in general and 70 v/sec. maximum.
  Inbuilt auto-bypass with no transition time	In conventional stabilizer auto bypass is not there or with limitations
  PWM controlled IGBT based technology has advantage of providing auto bypass. System will get bypass if any electronics part will get failed with no transition time.	In conventional method to achieve auto bypass feature excessive switch gear is required which add cost to the system as well this solution will provide power interrupt during bypass
  Same correction speed in all power range	Correction range vary according to power range
  Static Voltage Stabilizer are manufactured through the power range from 2 KVA single phase to 600 KVA tri-phase with the same design and operation principal. Only different driver PCB's (printed circuit boards) are used all through the standard power range, so the compactness and reliability is unchanged.	The Motor-Driven Voltage Stabilizers require excessive switch gear and additional buck-boost transformers when the nominal power is increased above a certain level.

  
  
• Comparison between Suvik Static Stabilizer and Other Static Stabilizers
  

  Sr. No	Parameters	Suvik Static Stabilizer	Other Static Stabilizers
  1	Regulation	+-1%	+/-3%
  2	Standard input range	170-290VAC	175-280VAC
  3	Over Load Protection	Yes*	No (Only MCB at input)
  4	Output and input over voltage under voltage protection	Yes	No
  5	Contactor at output	Yes	No
  6	LED & LCD for Metering and parameter and fault display	Yes	No
  7	Single phase prevention in case of phase loss (Three Phase system)	Yes	No
  *	Over load protection at different load level, >150% 1minute, 300% immediate

Specification of Three Phase SVR	Single Phase Brochure
Three Phase User Manual	Single Phase User Manual