Static voltage Stabilizer using IGBT and DSP by NKB Technocrats Pvt.Ltd is an AC to AC direct buck-boost Voltage Stabilizer. It is based on high frequency PWM driven IGBT. It measures the incoming AC Voltage against the nominal voltage and adds/subtracts the required difference using DSP, to achieve precisely regulated output voltage. This gives the SVS such tight regulation and fast correction speed, which is impossible to obtain using conventional methods such as servo voltage stabilizers, SCR/triac type stabilizers, relay type stabilizers etc. It offers absolutely silent operation and pure sinewave output (no waveform distortion). It is available for capacities upto 70kVA Single Phase and 200kVA 3-Phase. IGBT based PWM controlled Static Voltage Stabilizer is the best answer to voltage fluctuations in industrial units,factories & can also be used an a main line stabilizer in homes.
The unit is highly recommended where unstable mains is available and frequent voltage fluctuations are observed. Some of the popular applications are elevators,medical instrumentation, analytical/laboratory instruments,system calibrations labs,tele-communications, BTS units, Wireless sites, broadcast transmitters, semiconductor production,industrial automation, CNC machines & PLC based machines. Static Stabilizer's ultra low impedance assures stability even with the most demanding loads.
Our solutions are approved by various government agencies including BPCL, Indian Railways, BSNL, IOCL, HPCL. We are exporting these IGBT based PWM controlled Static Voltage Stabilizers to various countries like UK, Australia, Lebanon, Dubai, Holland, etc
1. Direct AC-AC conversion without rectifying to DC improves the efficiency, reliability and reduces the components.
2. Rapid cycle by cycle correction of output. It can correct sudden fluctuation in the line voltage. For example using a welding machine in the same line will cause sudden fluctuation in the line voltage which can not be corrected with conventional relay type and servo controlled voltage stabilizers, where Static Voltage Stabilizer can correct it.
3. Output regulation of +/- 1% which is impossible in conventional stabilizer.
4. No distortion in output waveform.
5. Overload cutoff and short circuit cut off
6. Over voltage and under voltage cutoff.
7. Automatic bypass in case of failure.
8. LCD display for displaying all parameters.
9. Small transformer size (1/5th of the capacity)
10. Compact size and light weight
11. 20KHz PWM control
12. IGBT power stage. Highly reliable.
13. Fully solid state. No moving part, hence more life and no maintenance.
14. Silent operation.
The servo voltage stabilizer achieves correction in the voltage load by increasing or decreasing the number of windings in the auto transformer with the help of the shaft of the servo motor. This results in increase or decrease of the voltage across the primary of the Buck or Boost transformer in place of the Buck or Boost transformer thereby correcting the output voltage. Therefore the reliability of the servo voltage regulators mainly depends on the reliability of the servo motor. Similarly, the reliability of the static voltage stabilizer depends on the reliability of the IGBT power stage. But if we do a general comparison the static IGBT power stage has proved to be more reliable than the electromechanical servo motor, thus the static voltage stabilizer is more reliable than the servo stabilizer.
As the Static Voltage stabilizer does not have any moving part, it has a pure electric circuit to achieve the corrections in voltage. Thus, the static stabilizer has an extremely low correction time of 2-3 millisecond and an exceptionally high voltage correction speed ranging from 300 to 500 Volt/sec.
On the other hand, the Servo Stabilizer uses a moving servo motor controlled stabilization system, which helps it to achieve correction in the voltage. The servo stabilizer is an electromechanical device, thus its voltage correction speed (100 Volt/sec) is slower than that of static voltage stabilizer while its servo stabilizer correction time is of 50 milliseconds to 5 seconds.
There is no doubt that while a stabilizer controls voltage fluctuations it should also provide protection to the heavy machinery from under and over current faults that result from short circuits. The DSP control board present in the static voltage stabilizer continuously senses the input voltage; the output voltage, the IGBT current and the load current as part of its working principle. When a short circuit happens at the output of static voltage stabilizer, the load current increases to an extremely high level which automatically gets sensed by the DSP controller which makes it cut the output and switches of IGBT power stage- this is done instantly to clear over current fault. Therefore, the over current fault gets clear in the static voltage stabilizer extremely quickly and without the need to add any extra hardware. But in the case of servo stabilizer, the over current protection can be achieved only with the help of extra hardware such as MCCB, CB etc.- but this process of clearing faults is not instant.
As we already know that the servo stabilizer functions with the help of a motor and having a motor will regularly result in wear and tear which needs frequent maintenance. On the other hand the Static voltage stabilizer is static in nature and does not require regular maintenance.
The auto bypass in a static voltage stabilizer is very easy, due to the fast electronic nature of the static voltage stabilizer, it can transfer to bypass automatically without any break in the output voltage (Zero Transition Time), even in case of a fault. While the servo stabilizer is complicated in making the auto bypass mechanism work, due to this complication even if it is provided, the whole process becomes very costly. Also even if it this mechanism is provided it will be with break in the output voltage that is it will need a transition time.