High frequency vs low frequency pure sine wave inverter & difference explanation

High frequency vs low frequency pure sine wave inverter & difference explanation

There are two types of power inverters on the market: low frequency inverter and high frequency inverter.

No matter the inverter is high or low frequency, there are pros and cons for each design.

By definition, Low frequency power inverters got the name of “low frequency” because they use high speed power transistors to invert the DC voltage to AC power, but the LF inverter drives transistors at the same power frequency (60 Hz or 50Hz) as the AC sine wave power output voltage.

High frequency power inverters typically convert the DC to AC by driving the transistors at a much higher frequency from 50 Kilo Hz to a few million Hz.

Low Frequency Inverter design with heavy duty transformer

Low Frequency Inverter design with heavy-duty transformer

 

Low frequency inverter circuit diagram

Low frequency inverter circuit diagram

 



High Frequency Inverter without large builtin transformer

High Frequency Inverter without large  builtin transformer

 

When delivering the same amount of power supply, the low frequency transformer outputs more power at each cycle, so it is required to work harder, resulting in a larger and heavier weight and package.

The high frequency inverter can deliver the same power at higher frequency with a much smaller and lighter transformer, as a result, the HF inverter is often called transformer-less inverter, or TL inverter.

With its smaller transformer, high frequency inverters typically surge at a lower rate, and/or for shorter periods of time than its low frequency counterparts.
With the new technologies implemented on power inverters, a low frequency inverter can now match or even outpace high frequency in idle consumption and max THD.

Both of the two type of inverters can be built with utility charger or solar charger and be called “inverter charger”.

Here is the major difference of them:

Thanks to the heavy-duty transformer, low frequency inverters have much higher peak power capacity and reliability.

The transformer handles  higher power spikes with longer duration than high-frequency inverters when it comes to driving inductive loads such as electric motor, pump, compressor, air conditioners.

The Sigineer low-frequency inverters can output a peak 300% surge power for 20 seconds, while high-frequency inverters can deliver 200% surge power for 5 seconds, check our HF solar power inverters.

Low-frequency inverters take power impact through its big transformer which acts like a surge relief for the circuit.

While for high-frequency inverter, their electronic parts such as the MOSFETs are directly subject to load power fluctuations.

With fewer PCBs, low-frequency inverters are easier and cheaper to repair.

12 replies
  1. don Warner
    don Warner says:

    love my signeer
    what a beast
    they actually answer the phone and reply to emails
    have a 15kw that can run my whole farm
    started with the 6kw which I love
    Don Warner

    Reply
  2. Adeyemi
    Adeyemi says:

    The final output of high and low frequency inverters should have 50 or 60Hz frequency. High frequency is utilized in a stage to raise 12v to 240v, but not in final stage. Please clarify this in your article. Thanks

    Reply
  3. Favour udofa
    Favour udofa says:

    What new technology can be used or implemented to make a low frequency inverter outmatch a high frequency inverter

    Reply
  4. Don Savat
    Don Savat says:

    I’m building a 5000 watt solar power and 240 / 120 volts. I will run 1/2 of my house on this all the time. Which system is better for my uses. Hi frequency of low frequency. and also all voltage is 110v but I was going to use a 240 / 120 system due to my transfer swith is 220 volts. do you get better power and batter draw from a 120/ 240 or 120 volts. My battery is a lifepower 45 v 100 ah. I haven’t purchess my inverter yet, any suggestion of the best one.

    Reply
  5. Kossy
    Kossy says:

    Are you saying low freq. Is better that high freq. In everything but only flawed by size, weight and price???

    Reply

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