An advanced guide to Understanding DC to AC inverters

February 13, 2024
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10 minutes
An advanced guide to Understanding DC to AC inverters

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While most homes have several appliances, very few residents know the difference between AC and DC power. Should people actually care if appliances use AC or DC power? Yes! Knowing the difference will help you understand energy efficiency better and may even save you some money. Understanding the concept also allows you to recognize the importance of a DC-to-AC inverter.

But what is the difference between DC power and AC power? Also, what is an inverter and a power converter and how can you tell the difference?

There is a common misconception that a home requires a DC to AC inverter to translate electricity efficiently for home use. The truth is that an inverter is actually what does all that essential work. Read on to learn more about electricity and to get an advanced look at the inner workings of your electrical system!

HOW DOES ELECTRICITY WORK?

Electricity, which is the flow of electrical power or charge, is present in nature and at home. The electricity at home is a secondary source of energy because it is converted from primary sources, which can be any of the following:

According to the US Energy Information Administration, natural gas (38%) is the most common primary source of electricity, followed by coal (22%) and renewable sources (20%) that can be wind, hydro, solar, biomass, and geothermal. Some 19% use nuclear energy, which is controversial because of safety and environmental concerns.


Photo from U.S. Energy Information Administration

Everything starts with atoms which are composed of electrons, neutrons, and protons. Electricity is produced when a force causes the electrons to flow from one atom to another. This flow of electrons is known as an electric current.

There are two kinds of electric currents: alternating current or AC power and direct current or DC power:

DC power is often used in low-voltage, low-current applications such as charging the batteries of your electronic devices. DC is also present in solar panels. So, photovoltaic technology, or the use of solar power to produce electricity, is essentially using DC.

When it comes to most homes, though, the AC power supply is more common. AC is also more often used among regular appliances because it is much easier to generate and transport AC over long distances.

On the other hand, direct current is the constant and unidirectional flow of electricity. It provides a continuous stream of current or voltage.

DC VOLTAGE EXPLAINED

As the name implies, DC power means that current flows directly or in one direction. Electrons move from one atom to another in a straight line. It is common among home appliances and electronic devices that use batteries, solar cells, and thermocouples.


Photo from Wikipedia

ADVANTAGES OF DC

There are several advantages to DC voltage, including the lack of delay in the circuit. Because it is unidirectional, voltage is constant, and there is no advance in the circuit.

As the current flows in one direction, the electricity always passes through the load, which means there is no reactive power. The advantage is that power can be used efficiently, thereby conserving energy and saving you some money. Additionally, DC can also be stored in batteries and capacitors.

DISADVANTAGES OF DC

The major disadvantage of direct current is the commutation problem which means it’s hard to produce electric power at high DC voltage. Doing so will require extra equipment, such as a rectifier and inverter.

AC POWER EXPLAINED

Alternating current,however, does not flow in one direction. The positive and negative sides are constantly changing or alternating, and so does the direction in which electrons flow. It is typically a pure sine wave which is a steady and continuous wave with smooth and periodic oscillation.

Photo from Wikipedia

A perfect example of AC power is the electric current produced in power plants and sent to people’s homes. It’s the ideal type of transmission for long distances.

ADVANTAGES OF AC

The transmission of AC power from power plants to homes, industrial areas, and other spaces will need a high voltage of around 155,000 to 765,000 volts. With that much voltage, there will be less power loss.
However, when the power is distributed to residential homes and offices, it must be lowered. Homes and offices only need around 120v-240v. The good thing about AC is that it is easily lowered or modified using a transformer.

Moreover, AC is easier to shut down even when the transmission is ongoing because its alternating nature allows the voltage to drop down to zero now and then.

DISADVANTAGES OF AC

One of the downsides of AC power is it requires higher voltage than necessary because of its constantly changing nature. Also, it is heavily affected by coils and capacitors, the terminal devices used to build circuits. Coils and capacitors induce the current to flow in the opposite direction, which results in lag.

IS THERE A DC TO AC CONVERTER?

The transition of DC to AC power is called an inversion, while the less common AC and DC transition is called a conversion. Both have different energy flows, but a DC-to-AC power inverter is sometimes necessary for a household. The typical electricity supplied to homes is 120v-240v in AC. However, some home appliances and consumer electronics are in volts DC.

To translate DC to AC power, you need inverters. Various electronics have an input of either 12, 24, or 28 DC voltage, and in order to use appliances with an AC output voltage, you must have a power inverter.

Among the more practical applications of AC inverters are the following:

  • Uninterrupted power supplies – the inverter translates DC to AC power according to the required DC voltage
  • Photovoltaic (PV) systems – the inverter changes DC electricity generated from solar panels to AC electricity
  • Home appliances – refrigerators and air conditioning units need an inverter to control the compressor and regulate power
  • Electric vehicles – the inverter is necessary for power regulation and conversion

HOW A DC-TO-AC POWER INVERTER WORKS

The inversion from DC to AC isn’t simple because the current flow must be reversed at a given frequency. It needs an oscillator to achieve this.

An AC inverter usually relies on the following:

  • Capacitor – A device that stores electrical energy and consists of two conductors located closely but insulated from each other.
  • Resistor – An electric component that regulates the current within a circuit.
  • Transistor – A miniature semiconductor that controls voltage flow and amplifies electrical signals.

Here’s how the inversion from DC to AC happens:

1. FILTER

From the direct current, the input filter removes the disturbance through ripple or frequency. The process will result in clean voltage delivered to the inverter circuit.

2. INVERTER

The most important part of the main circuit. It’s where DC is converted to AC, particularly a multi-level pulse width modulation (PWM) waveform. It is a mechanism that lets you use low-frequency output signals.

3. OUTPUT FILTER

In this step, the output filter removes high-frequency structure from the PWM wave.

TYPES OF DC-TO-AC POWER INVERTERS

There are three major types of ways inverters convert DC to AC power:

1. PURE SINE WAVE INVERTERS

Also referred to as a true sine wave, this power inverter is characterized by a waveform that is normally sourced from hydroelectric power or a generator. Most, if not all, types of equipment sold on the market are pure sine wave inverters.


Photo from Wikimedia Commons

Pure sine wave inverters are more complex equipment, which is why they are more expensive than regular appliances. Examples are bread makers and some battery chargers.

2. MODIFIED SINE WAVE INVERTERS

A modified sine wave features a stepped wave or square wave with an extra step which means it is not a true sine wave. Depending on the situation, it can be as good as the pure sine wave. It can save energy when running on a small load.


Photo from Wikimedia Commons

Motors and appliances are among the products that work on modified sine wave inverters. There are some cases where the equipment or accessories would need a pure sine wave power converter.

3. SQUARE WAVE INVERTERS

The square wave inverter is considered the most affordable among inverters. To simplify, it is the opposite of the pure sine wave inverter.


Photo from Wikimedia Commons

Among the products that run on square wave inverters are universal motors.

CHOOSING THE RIGHT DC-TO-AC INVERTERS

Safety is just as important as efficiency when dealing with electronics and appliances. Choosing the right inverter for your DC electronics and appliances would be best.

Different products need different inverters, so it’s crucial that you have the right specs to transform DC power. Moreover, you need to find the UL certification on electric and electronic items, including inverters, to ensure they have been tested and approved for United States distribution.

PRACTICAL APPLICATIONS FOR DC-TO-AC INVERTER

While home outlets run on alternating current, many appliances and electronics run on direct current. The norm has always catered to AC outlets because they can traverse long distances. On the other hand, DC is more energy efficient, which makes it ideal for appliances and electronics.

Since that is the case, there is often a need to invert DC to AC. Modern appliances and electronics are equipped with converters so that the AC power from outlets is converted back to DC power.

For example, a laptop inverter, which has a thin elongated circuit board usually the size of a pen, is located inside the device. Generally, the laptop runs on low voltage, around 12v on DC power. To charge the laptop, you need to plug the wire into an outlet that is at least 120v in alternating current. The inverter will do its work and allow the laptop to function as it should.

In mobile phones, inverters are in the batteries which run on direct current.

Regarding vehicles, a DC-to-AC inverter is necessary to charge the battery. A car usually has a 12V battery, although bigger vehicles use 24V. It is necessary to understand the voltage because it allows you to use the proper AC inverters for it. The process involves the battery running on DC with the flow of current going in one direction from the negative pole or terminal to the positive terminal.

The whole process involves enhancing the DC voltage and transforming it into AC before transmitting current to the device. Another popular application is in wind turbine and solar energy systems.

HOW SOLAR POWER INVERTERS WORK

Solar panels function when the sun shines down on them. When that happens, the panels, which have positive and negative layers, will absorb the energy from the sun and deliver it to the PV cell.

The energy is the force that sets electrons loose, allowing them to move between the positive and negative points and produce direct current. The current can be stored in the solar batteries and used at a later time or it can go directly to the inverter to change DC.

On the part of the inverter, it will direct the energy into a transformer which will switch it to an alternating current. There are five different types of solar inverters:

1. BATTERY INVERTER

A solar inverter battery for home is a system that works as a battery, which charges or powers things, and as an inverter. It is also known as an off-grid solar system because it works independently as long as it has some stored solar power. It is cheaper than other types of solar inverters but it also has limited capacity.

2. STRING INVERTER

String inverters are multiple solar panels that are connected in a series with the panel strings located in the inverter converting DC power to AC power. It is not as expensive as other types because of its proximity to the fuse box and electric meter. The main issue with this type of setup is when a single solar panel loses efficiency, it will affect the other panels because of their connectivity.

3. CENTRAL INVERTER

The central inverter also uses strings, which are stored in a bus bar to protect the system from possible damage. It is perfect for large properties.

4. MICRO INVERTER

The central inverter also uses strings, which are stored in a bus bar to protect the system from possible damage. It is perfect for large properties.

5. HYBRID INVERTER

This type of inverter blends battery and inverter installation for a more versatile system that is easy to operate. It provides DC power to the battery while adding AC power through the solar hybrid inverter. Extra solar power is sent to the power grid once the battery fully charges.

WHY YOU SHOULD GO SOLAR

People are more conscious nowadays of where they get their power. Many are committed to making more environmentally friendly choices. Going solar is an option that is not just good for the environment but it is also easy on the pocket—at least, in the long run. Check out a few of the top reasons you should upgrade to solar:

LOWER ENERGY COSTS

Electricity is more expensive than ever, but your electricity bill will be at a minimum if you go solar. With zero-down solar and low monthly payments, your total electricity expenses can be lower than ever. Also, there are financing programs that make the investment more affordable.

INCREASE IN HOME VALUE

There are reports that installing solar panels at home could increase property value. Solar systems are linked with a potential increase in the selling prices of homes as many people are now looking for more green and energy-efficient homes to purchase.

ENJOY GOVERNMENT INCENTIVES

Homeowners with solar panels may qualify for the federal solar tax credit. So, not only are you potentially reducing your energy bills, but you may also lower your taxes. It will provide a 26% tax credit for solar panel systems installed from 2020 to 2022. Those installed in 2023 will merit a 22% tax credit. Some states also provide additional incentives for going green, and you can contact a professional to see if you qualify.

ENVIRONMENTAL SUSTAINABILITY

Global warming is getting worse, and using non-renewable energy sources only aggravates the situation. Solar energy has a significantly lower carbon footprint than natural gas and coal, which are among the more common sources of electricity.

GO SOLAR EASILY!

Now that you have an idea of how inverters convert DC to AC power, it’s time to go solar! Solar panels provide energy efficiency that gives you the opportunity to save money while contributing fewer greenhouse gasses in the process.

If you’re intimidated or worried about having solar panels set up, Meraki Solutions will make it easy for you. We offer zero-down solar, and we can help you identify other savings that may be available. For more information or to schedule your FREE consultation, contact us.

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