Balanced Type AVR	Carbon Roller	Inner view of AVR

ADVANTAGES
Reduction in Breakdown of the electrical equipment.
Energy Saving 5 % to 10 % possible
Improvement in power factor
Reduction in MDI
100 % depriciation as per income tax Act.

The nagative impacts of higher voltage on motor below 10 HP are very much apparent as given in the following table.

1.     It is clear from the above chart that with the increase in supply voltage the input current also increases and the power losses also increases in motors which results in premature failure of winding.

2.      This increased current of electric motor results in over loading of cables, switch gears and transformers.

3.      Due to increase in current the Power Factor of the system decreases, which needs extra capacitors to maintain the P.F which results in over loading of switch gears etc.

The higher voltage highly effects the life and lumination of lighting equipments. If the lamps are provided according to higher voltage then illumination decreases during the normal voltage period.

It is interesting to note that if a bulb designed for 230 v operated at 230 v or 240 v  lamps operated at 240 v or 250 v lamps operated at 250 v give comparable performance in respect of lumens out put & life. The information given in the table reveals the way how a 230 v lamps would perfom when opretered at 240 v & 250 v. At higher voltage, though the lumens of bulb increases but life decreases considerably. Therefore the life and efficiency of the lighting equipment will be maximum if the voltage supplied to it is accroding to the rating of lighting equipment.

From the above mentioned observation it is clear how important is the installation of the stabilizer and maintainting 400 v / 230 volts. The Motor, lighting equipment and other electronic equipment will operate up to their maximum efficiency, consuming normal power as per rating and we can avail optimum life of motors and switchgear.

Advantage of AVR than Transformer with OLTC:

The unit which have already installed OLTC with their transformers also required stabilizer because tapping of OLTC is changed when problem of very high or low voltage is observed, on the other hand AVR Moniter and Control output voltage continuously. However in case of already installed transformer with OLTC the input range of stabilizer can be kept low.

Components

GNEW Servo voltage stabilizer consists of the following items :-

1.    Linear type, plus / minus type, vertical rolling contact type regulator
The voltage regulator is a continuously tapped auto transformer with core and coils similar to those of an orthodox thransformer. A mainframe supporting the completely insulated coils and is housed in an oil cooled sheet steel tank.
Carbon Rollers move on both sides of the winding, in opposite direction, to increase or decrease the incoming voltage. The effect is to produce a variable voltage of either negative or prositive polarity, which is injected into the buck boost double wound transformer.
The contact carrier is driven by a fractional horse power high torque motor which is coupled to the chain drive. Limit Switches operated by the carrier are fitted, to prevent overrun.

2.      Double wound buck / boost transformers
Buck-Boost Transformer. - This is a conventionally designed double wound tranformer housed in regulator tank or separate sheet steel tank and it confirms to the latest Indian standards.
The secondary of the buck boost transformer is connected between the mains and the load while the primary has its voltage controlled by the motor driven regulator.
A Voltage of either positive or negative polarity, as the case may be, fed to the primary. It induces the same to the secondary thus adding to or substracting from the incomming line voltage.

3.      Electric control circuit and meter panel 
Control Panel - It is mounted on the top of the Servo Voltage Stabilizer. A voltmeter and an ammeter are incorporated in the panel to read output voltage and load current reading. Two switches, one for auto / manual mode and other for increasing/decreasing the voltage on manual mode are provided. A potentiometer is also provided to set the voltage to required output at Auto Mode.
A solid state sensor unit (IC Based) continuously monitors the output voltage from the stabilizer and any error in voltage is amplified to operate the high torque servo motor in the variable transformer.

Secondary Components

1.      Indicating & Measuring Equipments :-
       
        (a) Volt meter analogs / digital type, indicating input and ouput volts.
        (b)  Ammeter analogs/digital type, indicating input & output current.

2.      Mode switch for manual or Automatic Mode Selection

3.      Out put volt selectability level switch

4.      Senscetibity level selectability switch

5.      MCB Box provided for control panel

Optional but user friendly Features / Components.

1.      Over load protection, thermal or solid state to switch off unit if the load attains higher value than the rated current.

2.      Over and under voltage protection can be provided to switch off unit if the out put voltage found above or below certain value (preset).

Ranges & Models
Single Phase - 3KVA to 30 KVA
Three Phase - 20 KVA to 5000 KVA
Types - Balance Type & unbalance type

Efficiency Chart

Application : - Every type of Industries can be benefited by its application but the plant running for 24 hours can achieve wonderful advantage by instalation of automatic voltage controllers.