The Automatic Voltage Regulator – AVR:
Guide and Comparison
The Operation, Application and Comparison of Automatic Voltages Regulators in AC Power Applications
6 The Mechanical (Type) Voltage Regulator
The mechanical type voltage regulator has the greatest number of different names often reflecting their means of operation and/or purpose:
· Mechanical tap changing regulator |
· Electromechanical voltage regulator |
· Tap changer |
· Electromechanical voltage stabilizer |
· Tap-switching voltage regulator |
· Motorized variable transformer |
· Servo voltage regulator |
· Magnetic induction voltage regulator |
· Servo voltage stabilizer |
· Magnetic induction voltage stabilizer |
· Motorized variac |
· Motor-driven variable autotransformer |
· Variable autotransformer |
· Line voltage regulator |
· Line drop compensator |
· On load tap changer |
· LDC |
· OLTC |
· Step voltage regulator |
· Auto-boost regulator |
This type of voltage regulator has been in use for more than 50 years and has seen refinements throughout the years primarily with advances in control technology and servo drive systems. This type of voltage regulator dominates the electric utility market and is the most popular type outside of North America for power quality applications. As more electronics are deployed in industrial settings worldwide, the mechanical voltage regulator is being displaced by the electronic voltage regulator.
While the mechanical voltage regulator comes in a broad variety of designs they all share the characteristics of having one or more servomotors to physically move some component(s) within the unit. The purpose of this movement is to affect voltage regulation by changing the turns ratio or magnetic coupling of a transformer. Included in this type of voltage regulator are devices for power quality control as well as devices used by electric utilities for correcting voltage (line) drop in distribution lines (see Power Quality versus Line Drop Compensation below).
The two primary methods of operation used by mechanical voltage regulators are: (A) by changing the turns ratio, or (B) by altering the magnetic induction between the primary and secondary coils of a transformer by physically changing their orientation.
Contents of this section:
6 The Mechanical (Type) Voltage Regulator 6.1 Tap Changing Voltage Operation 6.2 Magnetic Induction Voltage Regulator Operation 6.3 Mechanical Voltage Regulator Characteristics – Power Quality vs Line Drop 6.4 Mechanical Voltage Regulator Advantages & Disadvantages
Quick Links
1 The AC Automatic Voltage Regulator
2 Automatic Voltage Regulators and Power Conditioners
3 The Need for Automatic Voltage Regulation
4 Automatic Voltage Regulator Function
5 The Ferroresonant Transformer (Type) Voltage Regulator
6 The Mechanical (Type) Voltage Regulator
7 The Electronic (Type) Voltage Regulator
Complete Table of Contents...