The Automatic Voltage Regulator Stabilizer, also known as the Automatic Voltage Stabilizer (AVS) and sometimes referred to as Voltage Regulator (VR) are devices that are intended to stabilize the voltage from the main power supply to a specific load.
Automatic Voltage Regulator Stabilizer Manufacturers install this feature to Line Interactive uninterruptible power supplies that provide protection from all sorts of power issues like surges, sags, and brownouts. Automatic Voltage Regulator Stabilizers have an extensive input voltage window. When the input supply voltage is very low, the Automatic Voltage Regulator Stabilizers use a transformer to boost the output voltage.
And when the input supply of voltage is very high, the Automatic Voltage Regulator Stabilizers reduces and controls the voltage to a safe and proper operating range. This entire process of regulating is known as step-down or buck.
Working Principle of Voltage Regulator (VR)
Let us begin at the basics on which the stabilizer transformer manufacturers stress on:
A basic voltage stabilizer looks like the following diagram and works in accordance with the principles of an auto-transformer, which is a single winding transformer. “Faraday’s Law of electromagnetic induction” is the scientific principle followed here. It mentions that whenever there is a relative change in a magnetic field and the conductors, an Electromotive force (EMF) is induced in the conductors.
And most often it is used in a low voltage range, in a laboratory, commercial and industrial environment.
As you can see it has two modes by controlling the relays at the output. One is the voltage reduction mode also called the buck and the other is the voltage increment mode also called the boost. In case the voltage in the grid is too low then the boost mode is used. In the case the grid voltage is higher than the specified ratings on the appliances then the buck mode is used.
When buck operation is in action the low turn ratio secondary is connected with the primary. This is done so that it subtracts the secondary voltage from the primary.
When boost operation is in action the secondary voltage is added to the primary voltage to achieve a voltage boost.
Now in the above circuits, there is a problem. The regulation of voltage is in steps, as a result when the voltages are regulated it changes with significant fluctuations which as a result has no utilization. So under this situation, a smooth regulation of the voltage is required so that when regulation takes place, the change in voltage is not fluctuating.
This problem is addressed using the following circuit.
Finally, we can say that Servo Transformer Manufacturers build their Voltage Regulator (VR) base on the principle of “detection of errors”. In an Alternating Current generator, the output voltage is obtained using a potential transformer which is later filtered rectified, and then compared with a measured reference.
The error voltage is the difference between the reference voltage and actual voltage. This error voltage is amplified by the use of an amplifier. It is then supplied to the pilot exciter or the main exciter. In this manner, the excitation of the main or pilot exciter is controlled by the amplified error signals by using a buck or a boost action (that is controls the voltage fluctuation). The main alternator terminal voltage gets controlled by the exciter output.
As already mentioned an automatic voltage regulator stabilizer controls and regulates the voltage. It grips the fluctuating voltage and swaps them into a constant voltage. The fluctuation in the voltage occurs mainly due to the difference in power load on the supply system. Power System Equipments get damaged when there is a significant or persistent fluctuation and variation in voltage.
This fluctuation and variation in the voltage are controlled by the installation of equipment to control voltage at different places in the line likes near the transformers, feeders, generator, and etc., The voltage regulator is normally provided in more than one or two-point in the power system for making a proper control in the voltage variations.
The voltage can be controlled by using the compound generators in a Direct Current supply system if the feeders are of equal length. But when the feeder is of different lengths then the voltage of each feeder is kept at the end using a feeder booster. In the case of the Alternating Current system, the voltage is controlled by making use of various other methods likes induction regulators, booster transformers, shunt condensers, and etc.,
Application of the Automatic Voltage Regulator (AVR)
The most important functions of an Automatic Voltage Regulator (AVR) are as follows.
- Automatic Voltage Regulator Stabilizer (AVR) controls the full voltage that is in the system. It also ensures that the operations of the machines are nearer to the steady state of the system.
- Automatic Voltage Regulator Stabilizer divides the reactive load operating in parallel between the two alternators.
- They reduce the overvoltage in the system which generally occurs due to the sudden drop in load on the whole system.
- They increase the excitation of the system when it is under some faulty condition and controls the maximum synchronizing power of the system that exists during the clearance of the fault.
When a sudden change in load in the alternator takes place, there should always be a change in the excitation system for providing the same amount of voltage under the new load condition. This could be done with the help of the AVR (automatic voltage regulator).
The AVR equipment as built by Automatic Voltage Regulator Stabilizer Manufacturers operates in the exciter field. Hence it changes the exciter output voltage along with it the field current. During a violent fluctuation, the automatic voltage regulator (AVR) does not give a quick response.
For a Better Understanding let us take a Practical Example
Let us say you require a Voltage Stabilizer for your home refrigerator. And judiciously assume that your home refrigerator has a power rating of 1 KVA. with an Add-on margin of 30%. That is for 1KVA it is 300 watts. So summing both, you can consider installing a 1.3 KW (1300 watts) Voltage Stabilizer for your home refrigerator. So when you purchase a Voltage Stabilizer for your home refrigerator you consider a 1.3 KW (1300 watts) Voltage Stabilizer.
Author Biography
Mr. Ravi Mahajan is the MD of Muskaan Power Infrastructure Limited. He is originally from Ludhiana, Punjab and it is his deep connection with his roots that has inspired him to venture into the industry through which he can bring great changes for the common people of the country. With a strong educational background in electrical and electronics field, Mr. Mahajan has enabled Muskaan Power Infrastructure Limited to produce the best electrical equipments with cutting edge technology. It is the sheer will power and technical knowledge of Mr. Mahajan that has enabled him to make Muskaan Power grow and thrive at its best.