It is an electrical device that adjusts and controls the AC voltage, and within the specified voltage input range, can stabilize the output voltage within the specified range through voltage regulation.
Fundamental
Although there are many types of AC voltage regulators, the working principle of the main circuit is different, but basically (except for AC parameter voltage regulators) are basically input switch sampling circuits, control circuits, voltage
1. Input switch: As the input working switch of the voltage stabilizer, the air switch type small circuit breaker with limited current protection is generally used.
The voltage stabilizer and electrical equipment play a protective role.
2. Voltage regulating device: It is a device that can adjust the output voltage. It can increase or decrease the output voltage, which is the most important part of the voltage stabilizer.
3. Sampling circuit: it detects the output voltage and current of the voltage stabilizer, and transmits the change of the output voltage to the control circuit.
4. Driving device: Since the control electrical signal of the control circuit is weak, it is necessary to use a driving device for power amplification and conversion.
5. Drive protection device: a device that connects and disconnects the output of the voltage stabilizer. Generally, relays or contactors or fuses are commonly used.
6. Control circuit: It analyzes the sampled circuit detection model. When the output voltage is high, it sends a control signal to reduce the voltage to the driving device, and the driving device will drive the voltage regulator to lower the output voltage. When the voltage is low, a control signal for increasing the voltage is sent to the driving device, and the driving device will drive the voltage regulating device to increase the output voltage, so as to stabilize the output voltage to achieve the purpose of stable output.
When it is detected that the output voltage or current is outside the control range of the regulator. The control circuit will control the output protection device to disconnect the output to protect the electrical equipment, while the output protection device is connected to the output under normal conditions, and the electrical equipment can obtain a stable voltage supply.
Machine classification
An electronic device that can provide stable AC power to the load. Also known as AC voltage stabilizer. For the parameters and quality indicators of the AC stabilized power supply, please refer to the DC stabilized power supply. Various electronic devices require a relatively stable AC power supply, especially when computer technology is applied to various fields, the direct power supply from the AC power grid without taking any measures can no longer meet the needs.
The AC stabilized power supply has a wide range of uses and many types, which can be roughly divided into the following six types.
① Ferromagnetic resonance AC voltage stabilizer: An AC voltage stabilizer device made of a combination of a saturated choke coil and a corresponding capacitor with constant voltage and volt-ampere characteristics. The magnetic saturation type is the early typical structure of this kind of regulator. It has simple structure, convenient manufacture, wide allowable variation range of input voltage, reliable operation and strong overload capacity. But the waveform distortion is large and the stability is not high. The recently developed voltage stabilizer transformer is also a power supply device that realizes voltage stabilization by means of the nonlinearity of electromagnetic components. The difference between it and the magnetic saturation regulator lies in the difference in the structure of the magnetic circuit, and the basic working principle is the same. It realizes the dual functions of voltage regulation and voltage transformation at the same time on one iron core, so it is superior to ordinary power transformers and magnetic saturation voltage regulators.
②Magnetic amplifier type AC voltage stabilizer: a device that connects the magnetic amplifier and the autotransformer in series, and uses the electronic circuit to change the impedance of the magnetic amplifier to stabilize the output voltage. Its circuit form can be linear amplification or pulse width modulation. This type of regulator has a closed-loop system with feedback control, so it has high stability and good output waveform. However, due to the use of magnetic amplifiers with larger inertia, the recovery time is longer. Because of the self-coupling method, the anti-interference ability is poor.
③Sliding AC voltage stabilizer: A device that changes the position of the sliding contact of the transformer to stabilize the output voltage, that is, an automatic voltage regulating AC voltage stabilizer driven by a servo motor. This type of regulator has high efficiency, good output voltage waveform, and no special requirements for the nature of the load. But the stability is low and the recovery time is long.
④ Inductive AC voltage stabilizer: a device that stabilizes the output AC voltage by changing the phase difference between the secondary voltage of the transformer and the primary voltage. It is similar in structure to a wire wound asynchronous motor, and in principle is similar to an induction voltage regulator. Its voltage regulation range is wide, the output voltage waveform is good, and the power can reach hundreds of kilowatts. However, because the rotor is often locked, the power consumption is large and the efficiency is low. In addition, due to the large amount of copper and iron materials, less production is required.
⑤Thyristor AC voltage stabilizer: An AC voltage stabilizer that uses thyristor as a power adjustment element. It has the advantages of high stability, fast response and no noise. However, due to the damage to the mains waveform, it will cause interference to communication equipment and electronic equipment.
⑥Relay AC voltage stabilizer: use relay as an AC voltage stabilizer to adjust the winding of the autotransformer. It has the advantages of wide voltage regulation range, fast response speed and low production cost. It is used for street lighting and remote home use.
With the development of power supply technology, the following three new types of AC stabilized power supply appeared in the 1980s. ①Compensated AC voltage stabilizer: also known as partial adjustment voltage stabilizer. The additional voltage of the compensation transformer is connected in series between the power supply and the load. With the level of the input voltage, an intermittent AC switch (contactor or thyristor) or a continuous servo motor is used to change the size or polarity of the additional voltage. To achieve the purpose of voltage regulation, subtract (or add) the higher part (or insufficient part) of the input voltage. The capacity of the compensation transformer is only about 1/7 of the output power, and it has the advantages of simple structure and low cost, but the stability is not high. ②Numerical control AC voltage stabilizer and stepping voltage stabilizer: The control circuit is composed of logic elements or microprocessors, and the primary turns of the transformer are converted according to the input voltage, so that the output voltage can be stabilized. ③Purified AC voltage stabilizer: It is used because of its good isolation effect, which can eliminate the peak interference from the power grid.
Post time: Mar-29-2022
