The classification and characteristics of AC regulated power supply
A power supply that can provide a stable voltage and frequency is called an AC stable power supply. At present, the work done by most domestic manufacturers is to stabilize the AC voltage. The following is a brief description of the classification characteristics of some AC regulated power supplies in the market. Parameter adjustment (resonance) type stabilized power supply, the basic principle of voltage stabilization is LC series resonance, and the magnetic saturation stabilizer that appeared in the early days belongs to this category. Its advantages are simple structure, no many components, The reliability is quite high, the voltage regulation range is quite wide, and the anti-interference and anti-overload capabilities are strong. The disadvantages are high energy consumption, high noise, bulky and high cost. On the basis of the principle of magnetic saturation, the parametric voltage stabilizer developed and formed and the "magnetic amplifier adjustable electronic AC voltage stabilizer" popular in the 1950s in our country
Self-coupling (ratio) adjustment type
1. Mechanical voltage regulating type, that is, the servo motor drives the carbon brush to move on the sliding surface of the winding of the autotransformer, changing the ratio of Vo to Vi to realize the adjustment and stability of the output voltage. This kind of voltage regulator can be from hundreds of watts to several kilowatts. It is characterized by simple structure, low cost, and small output waveform distortion; however, the sliding contact of the carbon brush is easy to generate electric sparks, causing the brush to be damaged or even burned to failure; and the voltage adjustment speed is slow.
2. Change the tap type, make the autotransformer into multiple fixed taps, and use 10 relays or thyristors (solid state relays) as switches to automatically change the tap position, thereby realizing the stability of the output voltage. The advantages of this type of voltage regulator are simple circuit, wide range of voltage regulation (130V-280V), high efficiency (≥95%), and low price. The disadvantage is that the precision of the voltage regulation is low (± 8 ~ 10%) and the working life is short. It is suitable for powering the air conditioner in the home. High-power compensation type—purification type voltage stabilizer (including precision type voltage stabilizer), which uses compensation links to stabilize the output voltage, and is easy to realize microcomputer control. Its advantages are good anti-interference performance, high precision of voltage regulation (≤±1%), fast response (40-60ms), simple circuit and reliable operation. The disadvantages are: there is low-frequency oscillation phenomenon when there are nonlinear loads such as computers and program-controlled switches; the input side current distortion is large, and the source power factor is low; the output voltage has a phase shift with respect to the input voltage. Units with high anti-interference requirements are suitable for use in cities. When the computer is powered, a voltage stabilizer about 2-3 times the total power of the computer must be used.
Because of the advantages of voltage stabilization, anti-interference, fast response, moderate price, etc., it is widely used. Switching AC Stabilized Power Supply It is used in high-frequency pulse width modulation technology. The difference from general switching power supply is that its output must be an AC voltage with the same frequency and phase as the input side. Its output voltage waveforms include quasi-square wave, trapezoidal wave, sine wave, etc. The uninterruptible power supply (UPS) on the market removes the storage power supply and charger, which is a voltage regulator of a switching AC regulated power supply. Good performance, strong control function, easy to realize intelligence, it is a very promising AC regulated power supply. However, because of its complex circuit and high price, promotion is slow.
Types of regulated power supplies
