Description
A static voltage stabilizer (SVS) is an electronic power conditioning equipment that processes to give a constant output voltage, at very high speed voltage correction, even when the input voltage fluctuates. IGBT's are employed in SVS's.
Things to know about Static Stabilizers:
Responds to input voltage changes at a very high speed, say around 50-100 micro seconds.
Correction speed is around 5,000-20,000V/s which amounts to around 100-500V/cycle of 20ms (50 Hz)
Voltage range: SVS's can correct voltage variations within a range of -25% to +25%. They can also be configured for wider voltage ranges, up to -60% to +60%.
Maintenance: SVS's have no moving parts, so they require little maintenance.
Output waveform: SVS's regulate output voltage without distorting the waveform.
Efficiency: SVS's are efficient and reliable because they have a simple design with fewer components.
Range
- Single phase: 1 to 30kVA
- 3 phase: 5 to 200kVA
- Working Principle
Voltage is added to or subtracted from a Buck-Boost transformer (BBT). The induction of voltage to BBT is done from the primary of BBT, through IGBT switches by varying the PWM pulses, in a closed loop control system. Input voltages, output voltages and the respective currents are sensed, measured and processed by a very high end digital signal processor (DSP) to vary the PWM pulse widths to give a constant output.
Single phase Buck only or Buck Boost Static Voltage Stabilizer or optimizer is a power conditioning equipment.
It maintains its average output voltage constant (close to 1% regulation) irrespective of input supply variations.
It protects:
- CNC machines
- Pumps & Motors (like in Petrol Pumps)
- Electrical & Electronic equipment
- Medical equipment
- Lab equipment
- Audio & Video equipment in residences, Studios etc.
This is a new and innovative technology to replace the conventional Servo Voltage Stabilizers (using Variac/Dimmer & servo motor) employing Micro controller (DSP controller) along with IGBTs which increases the rate of voltage correction to 5,000V/second (rate of voltage correction of a Servo is between 10V/s—70V/s) & by using SCRs.
Specifications
| Description | Single Phase |
|---|---|
| Rating/Capacity | 1kVA—30kVA |
| Cooling method | Air-cooled |
| Input range | 300V to 520V -customized design, as per the rating 45Hz—65Hz |
| Output | Average output to 380V/400V/415V + 1% (Factory set) (% of voltage difference, at the input will get reflected in the output) (For Buck only: Output = input for voltages <380V/400V/415V, because it is a Buck stabilizer. i.e. it will be in Bypass, connecting the load, directly, on to the Mains input supply) Output frequency = input frequency Output waveform = input waveform Output power factor = input power factor This power conditioning equipment does not alter input waveform, input frequency and input power factor |
| Efficiency (for >20% Load) | >98% |
| Efficiency (for <20% Load) | >97% |
| Correction speed | 5,000V/second |
| Voltage Sag/Voltage dip elimination | Yes, within 10ms |
| Surge & Spike suppression | 1.5kV or 2.5kV surge suppression can be achieved by an external SPD-optional |
| Regenerative Load handling | Static stabilizer is a bi-directional converter. This means the stabilizer output can be fed, say, from a Grid-tied inverter and the energy can be fed to the Grid. I.e., the regenerative energy can go to the grid from the output of the stabilizer. Our stabilizer 100% supports the regenerative energies. These regenerative energies do develop during the operation of the induction motor loads. |
| Reverse energy injection to the Mains | This is a very complicated design to have a robust system and to save power |
| Response time to change the PWM | <55 µs |
| Response time to inject opposite polarity for the voltage spike or sag, to correct the voltage, without unbalancing the waveform | <55 µs |
| Response time to correct the Voltage, effectively | <10 ms (1/2 cycle) |
| Response time to act against Short Circuit or to make the PWM zero | <5 ns |
| Response time to act against High Voltage surges & Spikes | <60 µs |
| Control system | Micro controller based IGBT PWM switching |
| Duty Cycle | Continuous |
|
Over Load & Surge Load: 1. Static Stabilizer takes unlimited surge, for 3s 2. it takes >3—20 times surge load, for 3s, without going to auto-bypass and with proper voltage regulation 3. the load is transferred onto Auto Bypass uninterrupted, very smoothly, without any glitch or break 4. auto-bypassing from direct supply Line to Stabilizer mode and from Stabilizer mode to supply Line mode is uninterrupted, soft transfer without any glitch or break 5. Semiconductor devices/IGBTs & Relays are used in Auto-bypass. To transfer to Auto-bypass, IGBTs are employed, initially, while simultaneously switching on the Relay. This Relay switching is very unique. The relay's coil is subjected to a high voltage pulse, initially, which stabilizes to 12V. This technique is employed so that the transfer happens within 0.5ms or 1ms, instead of 7--10ms. The Load is transferred through IGBTs followed by the Relays. Both of them are in parallel. 6. overload cut off happens after 3s For Buck only stabilizers, the surge load, more than 21 times, the unit goes to the auto bypass mode, without any interruption. This is a very unique and the most sought-after feature in power conditioning equipment. This particular feature is so unique that many of the companies in the world are not capable enough to offer this feature. This shows the robustness of this static stabilizer. 7. From 101% till 119% load, the load is cut-off, after 1 minute |
|
| Short Circuit Protection | Yes, by electronic current limiting technique |
| Response time to act against Short Circuit or to make the PWM zero | <5 ns |
| Input MCB/MCCB | Provided |
| IGBT modules internal protection |
Short Circuit protection |
| Under/Over Voltage cut-off | Yes |
| Single Phase prevention | Yes |
| Phase reversal | Yes |
| Input high voltage trip | Yes |
| Earth Fault Trip | Yes |
| Sudden change in voltage like a spike or sag | Doesn't allow because of quick response, of 5,000V/sec |
| Mains high voltage surge |
High voltage trip protection is provided. The surge voltage does not get passed on to the output load. Therefore, the stabilizer saves itself and the connected load. Even 630V ac can be applied, at the input and it will sustain. |
| Other Features | |
| Switching devices | IGBTs which are very rugged |
| Switching Frequency | 20 kHz |
| Effect of Load on Power Factor | Nil |
| Waveform distortion | Nil |
| Are any current Harmonics induced, because of 20 kHz switching? | No |
| Auto Bypass, with synchronized switchover | Provided |
| Switchover time from Stabilizer mode to Bypass mode | 0 |
| Switchover time from Bypass mode to Stabilizer mode | 0 |
| No Load consumption of a 90kVA | < 100VA |
| Reset Mode | Provided |
| Trip & Restart | Auto, with a timer |
| Remote alarm facility | Available (will be incorporated, in future) |
| Input & Output terminations | Copper Lug Terminations on to a Terminal Box |
| Operating parameters |
Operating Temperature: 0—50º C Humidity: 0~95% RH @0~50º C (non-condensing) |
| Wi-Fi connectivity | Available (on demand at extra cost) |
| Web / Cloud connectivity | Available (on demand at extra cost) |
| Event Log | Available (on demand at extra cost) |
| Dimensions (Width x Depth x Height & Approximate weight) | |
| 5-22kVA with + 43V Buck-Boost | 300mm x 500mm x 500mm ≤ 50 kg (Apprx.) |
| 25kVA—40kVA | 360mm x 750mm x 500mm ≤ 75 kg |
| 45kVA—90kVA | 360mm x 750mm x 500mm ≤ 150 kg |
| 100kVA—200kVA | 360mm x 600mm x 600mm 300 kg |
|
Forced cooling Exhaust fan, 3” till 90kVA Exhaust fan, 4” till 200kVA These fans turn on only and only if the temperature of the heat sink exceeds the set values else the whole unit remains silent Transformer cooling is a natural process, in both lower and higher kVA ratings. |
|
Advantages
- Micro controller (DSP controller) based circuitry
- Industrial grade OLED Display for Parameter
- Overload Protection
- Low foot print
- Highly efficient
- Auto & Manual bypass arrange
- Input and output filter
- 100% Unbalanced load is handled
Servo Stabilizer's rate of voltage correction is between 10V-70V/second
Therefore, let us take a more popular value of 50V/second
50V / second = 50V/1,000ms
= (50 x 1V) / (20ms * 50)
= (50 x 1V) / (20ms * 50)
= 1V/20ms (20ms=1 cycle of 50Hz)
It means that the Servo stabilizer is capable of correcting just 1V in 1 cycle of 20ms or 50Hz.
If the Servo stabilizer input is 200V and the set output is 230V. the stabilizer outputs 230V, in normal
conditions. If the input voltage jumps to 300V then the Stabilizer passes on this high voltage on to the
output, to the connected Load (in fact, it will pass on more than 300V to the output).
After 1st cycle the Servo stabilizer output is 299V
After 2nd cycle the Servo stabilizer output is 298V
After 3rd cycle the Servo stabilizer output is 297V
Therefore, it takes 70 cycles (300V-230V) to buck 70V to give an output of 230V.
Most of the equipment get burnt in the 1st or 2nd or 3rd cycles because of high voltages.
An inductive load like a transformer or a motor or a pump or a compressor or a normal electrical ceiling
fan has copper or Aluminium winding. The endurance to high voltages is a little higher than electronic
loads. It can endure a few (20ms) cycles. Therefore, it doesn't burn or get damaged immediately. But if
this inductive load is subjected to repeated high voltages, its life gets shortened and will end up in
burning out.
Therefore, connecting even an inductive load to the Servo stabilizer is technically incorrect.
Servo Stabilizer is a DUMB & USELESS product
Note: Input waveform or supply waveform is of 50Hz which is equivalent to 20ms (Formula is t=1/f)—basic electrical fundamentals
Refer to the below figure.
And 1 second = 1,000 ms = 20 ms * 50 times (5th standard Mathematics fundamental)
Static Stabilizer rate of correction for 3Phase is 5,000V/s = 5000V/1000ms
= (100V * 50)/(20ms * 50) = 100V/20ms
= 100V in 1 cycle of 50Hz
Static Stabilizer rate of correction for 1Phase is 20,000V/s = 20,000V/1000ms
= (400V * 50)/(20ms * 50) = 400V/20ms
= 400V in 1 cycle of 50Hz
A video showing the variation of the intensity of the bulbs connected to
- Raw supply line
- To the output of a Servo Stabilizer
- To the output of a Static Stabilizer
In the shared video, it can be clearly seen that the Servo Stabilizer can't address the below problems,
namely:
- Voltage Fluctuations
- Voltage Surges
- And the Servo Stabilizer passes on the high voltage input to the output, to the connected load, thereby damaging it.
And a comparative statement of Servo v/s Static has been enclosed. Kindly go through it.
With the above it can be, clearly, understood that Servo stabilizer should not be connected to
any equipment for its protection, as it doesn't act fast enough to protect the equipment.
| Description | Static Stabilizer | Conventional Servo Stabilizer | Remarks |
|---|---|---|---|
| Load burning / damagingdue to high voltage surges | Load is protected | Load gets burnt / damaged | Servo stabilizer is useless Static stabilizer protects the load, 100% |
| Load burning / damagingdue to Neutral disconnection/ Neutral Leakage / Neutral Floating | Protects itself and the connected loads | Load gets burnt / damaged | Servo stabilizer is uselessStatic stabilizer protects the load, 100% |
| Mains voltageFLUCTUATIONS (Refer to the video) |
Outputs a constant voltage | Output fluctuates | Servo stabilizer is useless Fluctuations affect the connected load and sometimes, if they are sensitive, they may malfunction Therefore, it is risky to depend upon Servo stabilizers capability to protect against voltage fluctuations |
| Mains voltagecontinuous fluctuations(Refer to the video) | Outputs a constant voltage | Output fluctuates just as the input | Servo stabilizers should not be used, at all, for any application |
| Rate of voltage correction (Refer to the write up) | 5,000V/second Can correct the voltage within ½ cycle i.e. 10ms | 10V-70V/secondCorrects 60V in 1s = Corrects 30V in 0.5sCorrects 1V in 20ms i.e in 1 cycle | There is, absolutely, no comparison Servo stabilizer's speed can't even be compared with that of static stabilizer |
| Mains high voltage protection | High voltage trip protection is provided.The surge voltage does not get passed on to the output load. Therefore, the Static stabilizer saves itself and the connected load. Even 630V ac, for single phase Stabilizer can be applied, at the input and it will sustain |
High voltage cut offs are given, but they don't protect the loads >500V in case of single phase, the servo stabilizer itself gets damaged |
It is useless to have a servo stabilizer that can't even protect itself, not to speak of the connected loads Static stabilizer provides excellent protection against high voltages. It protects itself and the connected loads |
| Neutral Generation(to solve the above Neutral floating/leakage problems) | Optional (Capable of providing) |
No (this option is not common with, almost all of the Servo stabilizer manufacturers) |
It is a technically competent company, to provide any kind of solution in electrical/power electronics |
| Cloud connectedOr IoT enabled | Has the option(will be made default, after a while) | Servo stabilizer manufacturers are not digital tech savvy99% of them will not have this feature | Static stabilizer is one of the most advanced power conditioning equipment with advanced featuresThe unit can be monitored and controlled either from a laptop or mobile phone |
| This feature enables us to go for automation or can be easily integrated into a power management or a BMS | |||
| Over Load & Surge Load capabilities | Can handle unlimited surge, for 2sCan handle >20 times surge load, for 3s | Can handle 1.5/2 times for 1s | Static stabilizer is outstanding No other power conditioning equipment can come anywhere near, with respect to its unmatched performance |
| Auto-Bypass, with synchronized switchover | Yes | No | It is mandatory to have auto-bypass facility in every power conditioning equipmentSub-standard manufacturers can't afford to have this feature, as it is a costly affair, as it costs 10% of the cost of the whole unit |
| Manual Bypass arrangement | Yes, by default | Optional | Required for maintenance or in emergency breakdowns static stabilizers doesn't compromise on quality & looks at customer's perspective |
| Noise | Silent | Noisy | Voltage & Current spikes are generated and passed on |
| Switching Frequency is around 20kHz, out of the audible spectrum and therefore, no noise | Generates noise when the brushes move | to the output while the brushes make movement, in a Servo stabilizerServo stabilizer is not good for any load, especially, the sensitive loads | |
| Sparking while voltage is corrected | Does not happen(as there is no moving part, in power path) | Yes,Generates sparks when the brushes move | Voltage & Current spikes are generated because of this sparking and passed on to the output while the brushes make movement, in a Servo stabilizerCarbon formation happens because of sparking which needs regular maintenance and replacementServo stabilizer needs constant maintenance |
| Parts count | Buck Transformer with a filter cardElectronic module (with a power supply card+ control card+ IGBT card + SCR unit +OLED display unit) | Buck-Boost Transformer (BBT)Variac/Dimmer (Auto-Transformer)Brushes around the VariacServo MotorControl unit for Servo motorDisplay section:3 small sensing transformers3 individual 7-segment display units3 Conventional CTs for current measurementFew indication lamps | Lesser the parts more the reliabilityTherefore, static stabilizer has a distinctive advantage over Servo stabilizer, as the no. of parts is just 2 in static stabilizer against >6 in Servo stabilizerThere are 2 transformers in Servo stabilizers. Therefore, there will be transformer losses, in both these transformers.There is only 1 transformer in static stabilizers. Therefore the efficiency levels are quite high And static stabilizers are very compact, because there is only 1 transformer |
| Topology type | Static EmploysIGBTs/semiconducto rs | Non-static having brushes which move around a Variac/Dimmer, for correcting the voltage | Moving parts are involved in Servo stabilizer, which are prone to failure and therefore, the reliability is high with Static stabilizer |
Note:
Servo Stabilizer is a dumb and useless equipment which is not capable of offering protection against high surge voltages, Neutral leakage problems and voltage fluctuations.
Therefore, connecting your load, directly, on raw Mains supply or a Servo stabilizer is almost the same, except that the Servo stabilizer can act as a variable transformer.
