The core difference between power frequency and high frequency on-line UPS is whether there is a built-in power frequency isolation transformer, which directly determines their differences in impact resistance, load adaptability, efficiency, volume and cost, and then adapts to completely different industry scenarios. The core principles of selection are: choose power frequency for harsh industrial/strong impact loads, and choose high frequency for clean IT/high-efficiency energy-saving scenarios.
I comparison of core characteristics (selection basis)
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Contrast dimension power frequency online UPS high frequency online UPS
The core structure includes power frequency isolation transformer (50/60hz) without transformer and IGBT high frequency inverter (20kHz+).
Strong impact resistance, can withstand 5-10 times the rated current impact is weak, generally 125%-150% rated load.
Load adaptability and omnipotence: Resistive/inductive/capacitive/nonlinear load is suitable for pure electronic load, but not suitable for motor inductive load.
Strong electrical isolation, filtering out harmonics, surges and zero-ground voltage interference, no physical isolation, and relying on electronic filtering.
Low efficiency (90%-93%), high transformer loss (95%-99%), and remarkable energy saving.
The volume/weight is heavy, the space occupied is large and light, the volume is 30% smaller, and it is easy to deploy.
The purchase cost is high, the operating electricity cost is high, and the initial and operation and maintenance costs are low.
Suitable for environment, industrial dust, humidity, strong electromagnetic interference, bad power grid, clean machine room, office environment and stable power grid.
Second, the industry scene targeted selection guide
1. Industrial manufacturing and heavy industry (preferred: industrial frequency UPS)
Scene characteristics:
Load: CNC machine tools, punching machines, injection molding machines, industrial robots, frequency converters, motors and other strong impact and inductive loads.
Environment: Power grid fluctuates greatly, with heavy harmonic pollution, much dust, humidity and vibration.
Requirements: Super overload, anti-interference, long-term stability, huge downtime loss.
Key points of selection:
Power frequency machine must be selected, with built-in isolation transformer, which can resist the large current impact when the motor is started.
The protection level is IP31 or above, which is suitable for harsh working conditions.
Wide voltage input range (25%), supporting short-term 200% overload.
Typical cases: automobile production line, metallurgy, mining, petrochemical, paper mill.
2. Data center and IT room (high-frequency UPS preferred)
Scene characteristics:
Load: pure electronic IT load such as servers, switches and storage devices, with high power factor.
Environment: constant temperature and humidity, cleanliness and stable power grid.
Requirements: high efficiency, high density, low TCO, easy expansion and mute.
Key points of selection:
Small and medium-sized computer room/edge computing: high-frequency tower/rack UPS is preferred to save space and electricity.
Large data center: High-frequency modular UPS is preferred, which supports N+X redundancy and online hot plug expansion.
Pursue the ultimate PUE, efficiency > 95%, adapt to high-density cabinets.
Exception: core financial transaction/super-calculation center, optional power frequency UPS or high frequency+isolation transformer to improve fault tolerance.
Third, the formula of type selection decision (quick judgment)
Look at the load: there are inductive impact loads such as motor/compressor/laser → choose power frequency; All servers/computers → select high frequency.
Look at the environment: dust/humidity/strong interference/old power grid → choose power frequency; Clean the computer room/office → select high frequency.
Look at the cost: long-term electricity bills are sensitive and space is limited → choose high frequency; Reliability first, regardless of initial investment → power frequency selection.
Fourth, the special compromise plan
When the scene is between the two (such as industrial electronic load, old computer room renovation), you can use:
High-frequency UPS+external isolation transformer: Considering efficiency and isolation, the cost is lower than pure power frequency.
Industrial-grade high-frequency UPS: The new high-frequency machine enhances the overload and anti-interference ability, and is suitable for mild industrial scenes.
