The Automatic Voltage Regulator – AVR:
Guide and Comparison
The Operation, Application and Comparison of Automatic Voltages Regulators in AC Power Applications
1 The AC Automatic Voltage Regulator
The automatic voltage regulator or AVR, as the name implies, is a device intended to regulate voltage automatically: that is to take a varying voltage level and turn it into a constant voltage level.
There is tremendous diversity in the size and type of devices that could qualify to be called an automatic voltage regulator. To get a sense of the degree of diversity among AVRs, consider an analogy about the term “spotlight” which can mean pixel-sized all solid state elements found in display devices to truck-mounted, power guzzlers to illuminate the night sky.
AVRs range in size from small ones that can be mounted on printed circuit boards to those the size of a small house. This discussion looks at automatic voltage regulators typical for AC applications of about 1,000 VA (roughly the requirement of a hand-held hair dryer) and larger.
The diversity of automatic voltage regulators in size and design is reflected in the tremendous variety of names for AVRs:
· Ferroresonant transformer |
· Constant voltage transformer |
· Ferro |
· CVT |
· Ferroresonant voltage regulator |
· Constant voltage regulator |
· 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 |
· Electronic tap switching voltage regulator |
· Auto-boost regulator |
· Double conversion electronic voltage regulator |
· Electronic voltage regulator |
EVR |
In the sections describing the different types of voltage regulators, the common names for each type will be identified and used interchangeably along with generic names such as AVR and automatic voltage regulator. Also note that the descriptions, operational explanations and other commentary provided about the different types of AVRs is for informational purposes only and is intended to provide an overview of variations among a class of products generically called “automatic voltage regulators”.
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...