How Do Inverter Generators Work?

How Do Inverter Generators Work?

NOTE: If you're looking for a more basic explanation about the benefits of inverter generators, check out our post explaining their advantages here.

If you’re in the market for a new generator, you’ve probably noticed by now that there are many different types of generator – standby, portable, standard, inverter, and on and on. With so many terms, it’s easy to get lost. Fortunately, your friends at WEN are here to help clear things up. We have an extensive line of inverter generators, ranging in size from 1250 watts all the way up to 3800 watts.

To explain what an inverter generator is and how it works, let’s begin with a brief overview of how all generators produce power. Generators have two main parts – an engine and an alternator. The engine consumes a fuel, like gasoline or propane, and turns a shaft. The alternator has two main components – a rotor and a stator. The engine shaft turns the rotor, which induces power in the stator. This power goes to the control panel, where it is used to power whatever you need – power tools, appliances, and more.

In a traditional generator, the power produced by the alternator is fed (more or less) straight to the control panel. It may go through a voltage regulator or other protective devices, but the power is not necessarily “cleaned up”. Therefore, the power produced by a traditional generator has a higher total harmonic distortion (THD) than the power produced by an inverter generator. THD is a measure of how clean the power is – more on that in a moment.

An inverter generator works differently. The alternating current (AC) power produced by the alternator is sent to a rectifier, which is a device that converts the AC power to direct current (DC). This DC power is then inverted back to AC power by the computer inside the generator before it is sent to the control panel. This is where the name “inverter” comes from. Because the power to the control panel is controlled by the computer, inverter generators offer much lower THD than standard generators. THD is an important consideration when powering sensitive devices, like smartphones, tablets, computers, and televisions. These devices expect “clean” power (power that has low THD, like the wall power in your home), and can be damaged if they receive high-THD power. All WEN inverter generators use pure-sine-wave inverters, and as such, limit THD to under 1% in most cases. Traditional generators can produce THD as high as 25% in some cases.

Inverter generators are generally more compact than traditional generators, and are much quieter, but have lower maximum power outputs and are more expensive. There are two main sub-types of inverter generators: closed-frame and open-frame. Closed-frames are the most compact type of inverter generator, as well as the quietest. Their protective shell contains noise-absorbing insulation, significantly reducing their acoustic impact. They are usually portable and suitable for powering small loads. Open-frame inverter generators have no such insulation, and therefore are louder than closed-frames, but are still quieter than standard generators – usually about 50% quieter. Open-frame inverter generators produce power that is just as clean as closed-frame inverters, and may be capable of handling larger loads.

Ultimately, the right generator for you depends on your needs, including the types of devices you want to power, how much power you need, acceptable noise level and more. But no matter your need, WEN has a generator to suit you. If you have any questions or need help choosing the generator that’s right for you, feel free to give us a call at 1-800-232-1195 (M-F 8AM to 5PM CST) or drop us a message at to speak with our friendly and knowledgeable technical support team.

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