What is an Automatic Voltage Regulator (AVR) in Diesel Generators? How does it work? - avr automatic voltage regulator

An automatic voltage regulator, commonly referred to as an AVR, is essentially a solid state electronic device used in diesel generators. The AVR is designed to facilitate automatic maintenance of the generator output voltage at a preset value, especially when the generator load changes or the generator operating temperature changes. Simply put, the AVR can be said to be an integral part of the alternator excitation system.

 

  do you know? It is generally the alternator manufacturer that provides the automatic voltage regulator! After all, an AVR is essentially part of an alternator. Here, the model of AVR that comes with the alternator depends heavily on the type and the accessories mounted on the alternator.

 

AVR placement in diesel generators

 

Generally speaking, automatic voltage regulators can be found in any of the places mentioned below -

 

In the generator main control box

 

In the alternator junction box

 

Under the back cover of the alternator (usually in the case of small portable generator sets)

 

How does the diesel generator AVR work?

 

The main function of AVR is to control the generator output voltage. It does this by first detecting the voltage from the generator terminals and then comparing it to a preset stable reference to check for an error signal (if any). If there is a difference between the two, the ACR adjusts the field current by increasing or decreasing the current flowing to the exciter stator. This in turn ensures a lower or higher voltage at the main stator terminals.

 

As you probably know by now, the AVR acts as a regulating device, ensuring that the generator's voltage output remains within a predefined range. Thus, it ensures that the generator voltage never drops to the point where it causes any connected electrical equipment or electrical equipment to fail. It also helps keep the generator safe from a low battery.

 

Adjustment of the generator output becomes critical when the rpm of the generator changes - this mainly happens when the rpm of the generator engine changes, because the generator-to-engine gear ratio is fixed. A stable voltage during this time ensures the safe operation of both - the electrical equipment that powers it, as well as the generator battery.

 

 

Types of Automatic Voltage Regulators

 

According to the working principle and application, AVR can be roughly divided into the following categories

 

Contact type automatic voltage regulator

 

In this type of AVR, the voltage regulator contacts vibrate relatively slowly, resulting in low voltage regulation accuracy. It is for this reason, and the relatively short service life, that contact AVRs are no longer used in generators.

 

Transistor automatic voltage regulator

 

Transistor AVRs were developed with the development of semiconductor technology. This type of voltage stabilizer has the characteristics of high triode switching frequency, high adjustment accuracy, high reliability, and low radio interference.

 

IC automatic voltage regulator

 

IC regulators, also known as integrated circuit regulators, have all the advantages of transistor regulators. In addition to this, it has the benefit of an ultra-small size, which reduces the need for any external wiring, which enhances its cooling.

 

Computer controlled automatic voltage regulator

 

As the name suggests, a computer-controlled regulator is primarily dependent on the total load current of the system in communication with the generator computer. Here, the engine computer ensures that the magnetic field circuit is opened and closed in time according to the set value, so that the electrical system operates normally.

 

As AVR is an important part of diesel generators, it is highly recommended that you source from a reputable diesel generator manufacturer, this will ensure that you have accurate details about the part and can be assured of It is maintained and maintained.

 

 

Frequently Asked Questions about Automatic Voltage Regulator (AVR)

 

Does the AVR have a different design?

 

While most AVRs look similar, sometimes they can vary in size and color. That said, all AVRs have surprisingly similar characteristics, so there's not much difference in functionality.

 

What happens if the generator AVR fails?

 

When the AVR of the generator fails, the generator will inevitably lose its excitation, resulting in a sharp drop in voltage. This could eventually cause the generator to shut down due to an undervoltage fault. If the generator is not equipped with undervoltage protection, it may continue to operate even after a drop, causing serious damage to the equipment.