A Little Confused about Inverter Technology?

Inverters are not a new concept when it comes to power conversion, with early versions from the late nineteenth century using rotary conversions or motor-generator sets to convert DC to AC. In saying this, there has been some major changes in the way in which inverters both look and operate these days, with advances in technology allowing for more efficient and practical applications.

As the topic of inverter technology can be a little tricky, we thought we would put some basics together to help you out. If you have any further questions, give Inoplex a call on 0448 307 282 and they can help!

What is an inverter?

An inverter, otherwise known as a power inverter or frequency inverter, is an electronic device or electronic circuitry that is designed to transform direct current (DC) into alternating current (AC) and at any frequency and voltage. It can also allow a battery-based system to run different appliances through conventional home wiring.

An inverter can be entirely electronic or may be a combination of mechanical (such as a rotary component) and electronic circuitry.

How does an inverter work?

The concept behind how an inverter works is pretty simple however, in practice, it is a little trickier. When you go back to basics, a mechanical inverter is a switching unit connected to an electricity transformer. An electric motor or other type of automated switching device flips the incoming DC back and forth in the primary, simply by reversing the contacts, and that creates AC in the secondary.

The switching device is kind of like an electric doorbell – when it is connected to power, it magnetizes the switch, allowing it to open and turning it off very briefly. A spring then pulls the switch back into position, turning it on again and this process is repeated over and over.

An inverter does not produce any energy on its own – the power is provided by the DC source. The input voltage, output voltage and frequency, and overall power handling depends on the design of the specific device or circuitry.

Why have an inverter?

To explain the reasoning as to why you’d need an inverter, it is best to use an example. Say you had an appliance in your home that operates in AC 240V (60Hz frequency) but the AC power isn’t available. You can still use the appliance by powering it by using an inverter such as a 12V (DC). Inverters are great when it comes to powering electrical electrical devices by DC that work in AC.

Where are inverters used?

Inverters are used for a variety of uses, including :

• Solar power systems
• Cogeneration and other renewable energy arrangements
• Lighting
• Switching power supply
• Aircraft systems
• Backup power
• Many other applications!

In the case of cogeneration, inverters are used by companies such as Inoplex as part of the power conversion process. Inverters are used to actively rectify the raw power produced by the alternator and then to produce grid synchronized power, and also back up power when the grid is down. The unit is then being used as a backup power generator to run operationally critical equipment. 

Common inverter terms

Instead of asking you to go around and try to figure out all the terminology out there surrounding inverters and inverter technology, we thought we would put it together in one convenient little spot. The following are a few common terms that you will likely come across when it comes to inverter technology :

• The primary sections contained within an inverter’s main power circuit are :

• A rectifier/converter : The first component when it comes to power flow, the rectifier/converter rectifies incoming AC voltage into DC voltage. The converter section is comprised of diodes, silicon-controlled rectifiers (SCRs), or insulated gate bipolar transistors (IGBTs) connected in a full-wave bridge configuration
• DC bus : The second component, which is mostly made up of capacitors that store power rectified by the converter
• Inverter : The final primary section of an inverter’s main power circuit. An inverter is made up of IGBTs that create sinusoidal output current using pulsed dc bus voltage, or pulse width modulation (PWM)

The primary difference between an inverter and a DC converter is the presence of an inverter component to a system!

• Alternating current : Electric current that reverses its direction many times a second at regular intervals (typically used in power supplies)
• An alternator : An alternator converts mechanical energy into electrical energy, that will flow into the inverter. For example, in cogeneration an alternator converts the rotational energy from the engine into raw, variable electrical energy for the inverter to transform into grid synchronised power
• Direct current : Electric current that only flows in one direction
• Rotary : A rotary inverter has an AC generator driven by a DC motor
• Static : A static inverter uses electronic power to synthesise an AC waveform from a DC input. The reason it is named ‘static’ is because static inverters do not have any moving parts in the power conversion process
• Transformer : An electronic device that transforms low-voltage AC to high-voltage AC, or vice-versa, using two coils of wire (known as the primary and secondary) wound around a common iron core

Your cogeneration inverter specialists

If you are still a little confused or would like to discuss the possibility of using a cogeneration inverter, get in contact with Inoplex today! We are the experts when it comes to cogeneration across many industries, so get in contact now on 0448 307 282 or complete an online enquiry form for more information.