Power deep purification principle of power frequency on-line UPS dual conversion architecture
The core of the dual conversion architecture (AC→DC→AC) of power frequency on-line UPS is to completely "break" the commercial power first, and then "generate" pure sinusoidal electricity again, so as to completely isolate and deeply purify the power grid interference, which is also the fundamental reason why it has stronger purification ability than backup and interactive UPS.
First, the complete workflow of double transformation
The whole process is divided into two forced energy conversions, and the load is always powered by the inverter regardless of whether the commercial power is normal or not:
The first stage of conversion: rectification (AC → DC)
Commercial alternating current → power frequency rectifier (with power frequency isolation transformer) → direct current.
Second-stage transformation: inverter (DC → AC)
Direct current (rectifier+battery in parallel) → inverter → pure sinusoidal alternating current → supply load.
Second, how is the deep purification achieved step by step?
1. Completely filter out all interference from the power grid.
Surges, spikes, harmonics, sags, noises, frequency drift, etc. in the commercial power are all blocked in the AC→DC rectification link:
Interference signal cannot enter the back-stage DC bus.
The power frequency transformer further realizes electrical isolation and eliminates ground loop interference.
The DC bus capacitor smoothes the voltage, which is equivalent to the "power reservoir"
2. Regenerate standard and pure sine wave.
The inverter takes power from the stable DC bus and independently generates:
Standard 50Hz sine wave
The voltage is stable and the waveform distortion is extremely low (THDi is usually less than 3%).
It has nothing to do with power grid quality.
This means that the load will never see dirty electricity, only the clean electricity newly created by UPS.
3. Seamless participation of batteries to further stabilize the voltage and purify.
DC bus connects rectifier and battery at the same time;
Commercial power is normal: rectified power supply, battery floating charge.
Abnormal mains supply: the battery takes over instantly, and the output voltage has no fluctuation or interruption.
The voltage is always clamped at a stable value to realize deep voltage stabilization.
4. The key purification function of power frequency transformer
Power frequency online standard output/isolation power frequency transformer, which brings extra:
Strong and weak electrical isolation, anti-common mode interference
Suppress zero ground voltage and protect precision equipment.
Buffer short-circuit impact and improve load adaptability
Further weaken high-frequency harmonics and electromagnetic interference.
Third, sum up the purification logic in one sentence
Double-conversion architecture eliminates all grid pollution by rectification first, then reconstructs pure sinusoidal electricity by inversion, and cooperates with power frequency transformer isolation to realize complete decoupling and deep purification of the commercial power, so that the load can always work in an ideal power environment.
