What is automatic voltage regulator AVR?

What is automatic Voltage Regulator AVR?

Brief introduction

The voltage regulator realizes the automatic adjustment of the generator output voltage by controlling the excitation current of the generator AC exciter. The generator voltage regulator can be used for ordinary 60/50Hz and medium frequency 400Hz single or parallel generators.

Basic classification

1. The alternator voltage regulator can be divided into: according to the working principle:

(1) Contact voltage regulator

Contact type voltage regulator is applied earlier, this regulator contact vibration frequency is slow, there is mechanical inertia and electromagnetic inertia, voltage regulation accuracy is low, contacts are easy to generate sparks, large radio interference, poor reliability, short life, now Has been eliminated.

(2) Transistor regulator

With the development of semiconductor technology, transistor regulators have been adopted. The utility model has the advantages that the triode has high switching frequency, does not generate sparks, has high adjustment precision, and has the advantages of light weight, small volume, long life, high reliability, small electric wave interference, etc., and is widely used in Dongfeng, liberation and various kinds. Middle and low-end models.

(3) Integrated circuit regulator

In addition to the advantages of the transistor regulator, the integrated circuit regulator has an ultra-small size and is installed inside the generator (also known as a built-in regulator), which reduces the external wiring and improves the cooling effect. It is now widely used in Santana. . Audi and other car models.

(4) Computer Control Regulator

After the total load of the system is measured by the electric load detector, a signal is sent to the generator computer, and then the generator voltage regulator is controlled by the engine computer, and the magnetic field circuit is turned on and off in a timely manner, thereby reliably ensuring the normal operation of the electrical system. The battery is fully charged, which can reduce engine load and improve fuel economy. Such regulators are used on car generators such as Haibeike and Guangzhou Honda.

2. The voltage regulator can be divided into the following types of alternator grounding:

(1) Inner iron type regulator

A voltage regulator suitable for matching with an internal grounding type alternator is called an inner ground type regulator;

(2) External iron regulator

A voltage regulator suitable for matching with an external iron-type alternator is called an external iron-type regulator.

Working principle

Since the gear ratio of the generator to the engine is fixed, the speed of the generator will vary with the engine speed. During the operation of the car, the range of engine speed varies greatly, and the terminal voltage of the generator will also vary over a wide range as the engine speed changes. When the generator supplies power to the electrical equipment and charges the battery, the voltage is required to be stable. Therefore, in order to keep the voltage constant at a certain value, the output voltage of the generator must be adjusted.

Use and maintenance

The regulator is generally not allowed to disassemble the cover during use. Normally, a comprehensive inspection and maintenance is performed every 200 hours of operation. The contents are as follows:

1.Remove the cover and check the surface of the contact for dirt and burns. If there is dirt, wipe the contact surface with a clean paper. If the contact is ablated or the surface is not flat and the contact is poor, generally use "00" sandpaper or sand bar to smooth it, and then clean it with clean paper.

2.Check the tightness of each connector and measure the resistance and resistance of each coil. If it is damaged, repair or replace it with new ones.

3.Verify the closing voltage and reverse current of the current interrupter, the limit voltage of the voltage regulator, the limit current of the throttle, and the gaps and air gaps of various contacts. If it does not meet the requirements, it should be adjusted.

4.Check the adjusted regulator and observe the indication of the charging ammeter pointer when starting the diesel engine. If the diesel engine is running at medium or higher speed, the pointer of the ammeter still points to the "-" side, which means that the contacts of the current interrupter are not disconnected, and the grounding switch should be disconnected quickly; otherwise, the battery, regulator and charging generator will be damaged. . If the indicator of the ammeter still points to“0”after the diesel engine is started to the rated speed, the adjustment is not adjusted according to the technical requirements, and should be checked and adjusted again.