Research on the Current Status of AC Stabilized Power Supply Market

A power supply　　that can provide a stable AC voltage and frequency is an AC stabilized power supply . The AC stabilized power supplies on the market are roughly divided into the following categories:

　　Parameter adjustment (resonance) type

　　The basic principle of voltage regulation of this type of voltage regulator is LC series resonance. The early voltage regulator containing magnetic saturation type voltage regulator belongs to this category. Its advantages are simple structure, fewer components required, wide voltage regulation range, high reliability, strong anti-interference and anti-overload capabilities. The disadvantages are high energy consumption, high noise, bulky and high cost.

　　Auto-coupling (ratio) adjustment type

　　1 Mechanical pressure regulating type

　　The servo motor drives the carbon brush to move on the sliding surface of the winding of the autotransformer to change the ratio of the output voltage (Vo) to the input voltage (Vi) to achieve the adjustment and stabilization of the output voltage of the voltage-stabilized power supply. It is characterized by simple structure, low cost and small output waveform distortion. However, due to the sliding of the carbon brush, the contact is prone to sparks, causing the brush to be damaged or even burned and fail, and the voltage adjustment speed is slow.

　　2 Change the tap type

　　The autotransformer is made into multiple fixed taps, and the tap position is automatically changed through relays or thyristors (solid-state relays) as switch controls to achieve stable output voltage. This type of voltage-stabilized power supply has the advantages of simple circuit, wide voltage-stabilization range (130V-280V), high efficiency (≥95%), and low price. The disadvantages are low voltage-stabilization accuracy (±8～10%) and short service life. It is suitable for home use to power air conditioners.

　　3. High-power compensation type - purification type voltage stabilizer (including precision voltage stabilizer)

　　This type of voltage-stabilized power supply uses a compensation link to achieve output voltage stability and is easy to implement microcomputer control. Its advantages are good anti-interference performance, high voltage stabilization accuracy (≤±1%), fast response (40-60ms), simple circuit, and reliable operation. The disadvantages are low-frequency oscillation when it is connected to nonlinear loads such as computers and programmable switches; the input current distortion is large, the source power factor is low; the output voltage has a phase shift to the input voltage. Due to its advantages of voltage stabilization, anti-interference, fast response speed, and moderate price, it is widely used.

　　Switching AC Power Supply

　　It is applied to high-frequency pulse width modulation technology. The difference from general switching power supply is that its output must be the same frequency and the same AC voltage as the input end. Its output voltage waveform includes quasi-square wave, trapezoidal wave, sine wave, etc. The uninterruptible power supply (UPS) on the market is a switching AC voltage stabilizer power supply without the storage power supply and charger. The switching AC voltage stabilizer power supply has good voltage stability, strong control power, and is easy to realize intelligentization. It is a very promising AC voltage stabilizer power supply. However, due to its complex circuit and high price, its promotion is slow.