How DC/AC Power Converters Work

The conversion of DC (direct current) to AC (alternating current) has been critical in the transition to renewable energy.

DC to AC power inverters are essential if you want to use electricity from:

  • Solar panels
  • Solar batteries
  • Car or RV batteries
  • Domestic wind turbines

On the one hand, the systems mentioned above primarily generate, store, and use DC electricity. AC electricity is the international standard for electrical devices and home appliances. As a result, an efficient DC to AC power converter is required for both domestic and industrial applications.

Ac and Dc

AC and DC are two different types of electric currents. An electric current is the movement of charged particles (electrons) through a conductor, such as an electric wire.

Let’s look at why there are two kinds of electric currents.

What Is Dc?

DC is an abbreviation for Direct Current. DC current flows in only one direction, as the name implies. Electrons flow from the negative pole to the positive pole.

A continuous straight line could be used to represent it on a graph.

Solar panels, for example, can generate DC electricity, which can then be stored in batteries, which also deliver DC electricity.

What Is Ac?

AC is an abbreviation for alternating current. In alternating current (AC), current flows alternately in both directions at a standard frequency of 60Hz. To put it another way, the current changes direction 60 times per second.

In nuclear, hydroelectric, coal, and gas power plants, for example, an alternator generates alternating current electricity. AC is used in all home appliances and electric machines as an international standard.

Now that you understand what AC and DC are, let’s compare them and see which one is superior.

Ac Vs Dc – What Is Best?

Westinghouse and Tesla were able to demonstrate the superiority of alternating current (AC) electricity over Thomas Edison’s previously established direct current (DC).

Let’s take a closer look at the benefits and drawbacks of both types of electric current.

Pros And Cons Of Dc

One of the main advantages of DC electricity is that it is easier to store than AC. In addition, DC motors and appliances are more efficient. For example, a DC water pump could be two times more efficient than an AC model with the same wattage.

DC plays a major role in renewable energies and electric vehicles. Indeed, it can be directly produced by solar panels and stored in batteries.

This is quite ironic for the Tesla company, which mainly relies on DC power but uses the name of the great advocate of AC electricity.

Another noticeable fact is that all electronic equipment operates under DC and the conversion of AC to DC results in 5 to 20% loss to power your laptop, cellphone and other electronic devices.

Finally, although both electric currents are dangerous, AC is more likely to cause heart fibrillation and death.

Pros And Cons Of Ac

The primary advantage of alternating current is its ability to be transported over long distances with minimal energy loss (the wire will not overheat). As a result, the size of the wires and the cost of energy transmission are reduced.

In addition, producing AC from an alternator is less expensive than producing DC.

Although alternating current (AC) is the most common electric current, direct current (DC) is still widely used, and with the rise of renewables, batteries, and electronic devices, it is expected to regain popularity in the coming years.

In the section that follows, we’ll look at how power inverters convert DC to AC.

How To Convert Dc To Ac – The Inverter

The inverter is an electronic device that converts DC to AC in two steps:

It first converts DC to AC, then increases the input voltage (12V, 24V…) to achieve a 230V output that can be used by all appliances.

There are two types of inverters:

  • Pure sine wave (PSW)
  • Modified sine-wave (MSW)

The challenge of converting DC to AC is to convert a straight signal with minimal loss into an alternating wave.

To do so, we could begin with a simple switch that alternately turns the DC straight line ON and OFF. So we now have an alternating signal, but the current is still flowing in one direction and we are still far from the AC wave.

Transistors are used in ac inverters to allow current to flow in both directions. Electronic switches are transistors. To put it simply, inverters use a 4-way switching bridge of transistors to reroute direct current through the load at a predetermined frequency.

We now have alternating current. Inverters use diodes and other electronic components to smooth the signal so that it can be converted into a pure sine wave.

Modified sine-wave inverters will only produce a sine wave approximation, as shown below. Pure sine-wave inverters produce a perfect sine-wave, which is similar to utility electricity.

High-quality electronic components are used in pure sine wave inverters. As a result, they cost more than modified sine waves.

Step-Up The Voltage To 230v Ac: The Transformer

DC voltage is typically lower than the 230V AC voltage required by our appliances. As a result, the voltage must be increased. That is the function of the built-in transformer.

Transformers are essentially made of an iron core with two coils of copper wire: the primary and secondary circuits. The primary coil receives the lower voltage current, while the secondary coil receives the higher voltage current. Through electromagnetic induction, current flows from one coil to the other.

The output voltage is controlled by the wiring density of the two coils. The secondary coil requires more wiring density than the primary coil to increase the voltage.

When do you need a dc to ac inverters?

We use inverters on a daily basis, and they are ubiquitous. When you use a wall plug to charge your phone or laptop, you are using a micro-inverter (from AC to DC), because electronic devices only work with DC.

DC electricity can be generated by solar panels and batteries. As a result, if you want to connect your regular appliances, you will need a DC to ac inverter.

What can you run with dc?

DC appliances help you save money!

As previously stated, there are numerous advantages to using direct current, the most important of which is its higher efficiency when compared to alternating current. DC-only appliances require less power to operate. A 500W DC water pump, for example, will perform the same as a 1000W AC water pump.

As a result, many appliances have been designed to operate solely on direct current (DC), such as:

  • Refrigerator/freezer
  • Electric pump
  • Electric fan
  • Cooker
  • LED TV

DC is expected to play a larger role in our power systems as solar energy and local electricity production develop.

Final Thoughts

You may be aware that we are in the process of transitioning from a fossil-fuel-based economy to a zero-carbon economy. The role of electricity in this energy transformation is significant.

In fact, global electricity consumption has increased by 40% in the last decade. Furthermore, global electricity demand is expected to grow two times faster than primary energy demand over the next 20 years.

The most significant contributors to the increase in electricity use are electric vehicles (EV) with batteries and renewable energy production systems (solar, wind).

All of them use DC electricity, which is up to two times more efficient than AC. As a result, DC power will almost certainly regain popularity in micro-grid systems in the near future. In the meantime, DC and AC systems will coexist, with DC to AC converters playing an important role.