Power is an integral part of your life and society now. You use it for almost everything, every day. It keeps your lights, appliances, gadgets, and machines working to make your life easier. However, not all electronic devices are designed to work with just one type of power. This is why power inverters are invented and used.
Unfortunately, many are still confused about how this device works. That’s why this article will explain why you need to convert one power type to another. You’ll also examine the conversion process to answer the question, “How does a power inverter work?”
Overview: What Does a Power Inverter Do
Power inverters convert direct current (DC) to alternating current (AC). Our current appliances and electronic devices are made to make non-usable power (DC) usable. They utilize different DC power sources for a variety of AC-based residential, commercial, and industrial applications.
Over the years, there have been many configurations and advancements made to increase the efficiency of our power inverters. You can now use them to supply power to the following:
- Air conditioning units
- Inverter refrigerators
- Power tools
- Other kitchen appliances
- Electric lights, and more.
Why Do We Need to Convert DC to AC?
The DC to AC conversion that happens using an inverter serves many purposes in different applications. These include:
Most electrical devices and appliances, even machines and equipment, are designed to operate using alternating current or AC. By being able to convert DC power to AC, you’re letting these devices work seamlessly with the available power source. For instance, if you’re using batteries as your main power source, the DC power stored would need to be converted using a power inverter for you to be able to use it.
For Power Quality and Stability
It’s easier to regulate AC power systems for frequency and voltage stability than DC systems. With conversion, you have better control over the quality and stability of your power supply. If you don’t convert DC to AC, issues may arise from unstable and low-quality power output.
For Grid Integration
If you’re using renewable energy sources and are still connected to your local electrical grid, you need a way to make money out of your extra generated power. In many places, grids deliver AC power. If you have an inverter and are able to convert DC to AC, you can feed the excess energy from your sources back into the grid. This is one way to sell surplus power back to utility companies and join in net metering programs.
How Does a Power Inverter Work?
Remember that the majority of electrical devices we use today won’t function using DC power. That’s why the inverter is a fundamental component in different power systems. It basically converts direct current (DC) into alternating current (AC) to be used by homes and electronic devices.
Here’s a more detailed explanation of how an inverter system works:
The primary function of the inverter is to transform the DC electricity from the power supply, like batteries or fuel cells, into AC electricity. This whole process involves changing the direction of the current flow and altering the voltage to generate or produce a sinusoidal AC waveform. The conversion happens right at the very first step.
The inverter’s circuit is composed of transistors or insulated gate bipolar transistors (IGBTs), capacitors, and control circuitry. These components work together to change the current flow trend from a unidirectional pattern to an oscillating pattern. Technically, this is achieved by rapidly switching the polarity of the current from positive to negative, in an alternating manner. In this initial conversion, square waves are usually produced.
Sine Wave Generation
The goal of this stage is to modify the initially produced AC waveform and make it more uniform and suitable for use. Remember, inverters are designed to generate an AC waveform that closely resembles a sinusoidal or sine waveform. This is the standard form of AC power from grids, which is compatible with appliances and electronic devices.
Pulse Width Modulation (PWM)
Current modern inverters have rectifiers that use the Pulse Width Modulation (PWM) technique to generate the AC waveform. This is where transistors are switched on and off in a rapid sequence to vary the width of the pulses. Adjusting these pulse widths enables the power inverter to control the magnitude of the output voltage. By using the rectifiers, an inverter can modify the square wave AC to pure (or modified) sine wave AC, which is ready to be used.
Keep in mind that after the initial conversion, it’s common for the initial output to have a higher voltage and lower current than the input.
This is the second to the last stage of the process and this is where the output voltage and frequency are regulated. After the final waveform is generated, the control circuitry of the inverter ensures that the output power or the generated AC waveform matches the specifications required for safe and effective operations of connected devices.
In this last step, the inverter’s components such as inductors and capacitors perform filtering. Inverters have filters to minimize electromagnetic interference(EMI) and provide reliable operation. This is an unwanted noise or interference that can cause electronics to malfunction, operate poorly, or stop working completely.
These components help smooth out any fluctuations and harmonics in the AC output. This is to ensure that the AC power is high-quality and doesn’t have any unwanted noise or distortions so it can be used safely without damaging our appliances and devices.
If you plan on installing and using backup power sources or switching to renewable sources, you need to know that you can’t directly use the DC power you’ll collect. Electrical devices work well with AC power only. That’s why you need to make sure to get a power inverter. How does a power inverter work? It basically converts the unusable DC power into usable AC power.
Looking for high-quality inverter options? Check out our massive power inverter collection. We offer different types of inverters for different kinds of power and system needs.