What does an inverter do, and how does an inverter work?

What is an inverter

An inverter is a power electronic device whose core function is to convert direct current (DC) to alternating current (AC). In modern power systems, inverters play a vital role because they convert DC power into AC power for a variety of devices and systems. Whether it is household power, industrial equipment or renewable energy systems, inverters play an indispensable role.

How inverters work and what they do

The working principle of inverter is based on the on-off control of semiconductor switching devices. When these switching devices work according to a specific frequency and timing, the electrical energy in the DC power supply will be converted into AC electrical energy. Specifically, the inverter cuts the DC power into a series of pulses through high-frequency switching control, and then converts these pulses into stabilized AC power through filtering circuits.

The main function of an inverter is to convert DC power into AC power to meet the power needs of different devices and systems. For example, in a solar photovoltaic power generation system, the DC power generated by solar panels needs to be converted to AC power by an inverter before it can be used by household or industrial power equipment. Similarly, in an electric vehicle charging pile, the inverter is responsible for converting the AC power provided by the grid into DC power to charge the battery of the electric vehicle.

Operating Characteristics and Efficiency

The working characteristics of inverters are mainly reflected in their high efficiency, stability and reliability. Modern inverters use advanced control technology and efficient switching devices, which can realize high-efficiency energy conversion and reduce energy loss. At the same time, the inverter also has good stability and reliability, and can operate stably in various harsh environments to ensure the safe power supply of the power system.

Advantages and disadvantages of inverters

The advantages and disadvantages of inverters can be summarized as follows:

Advantages:

High efficiency and energy saving: inverters can efficiently convert DC power into AC power, making the PV power generation system able to directly transmit power to the utility, which is not only efficient and energy-saving, but also brings economic benefits.
Strong stability: the inverter has the characteristic of stabilizing the output of DC power, which can effectively protect the electrical equipment and prolong the service life of the equipment. In the case of insufficient voltage or negative voltage, etc., it can also better maintain the performance unchanged.
Good flexibility: the inverter has the function of adjusting output voltage and frequency, which can meet the needs of different equipment and adapt to the environment of different voltage and frequency.
Convenient installation: the inverter is small in size and light in weight, convenient to install, easy to carry and install.
High safety: When the inverter is developed, the countermeasures for short circuit, negative voltage, over temperature and other situations are taken into consideration, and it has various protection functions such as short circuit, overload, over/under voltage, over temperature, etc., which ensures the safety of use.
Good physical properties: the inverter usually adopts an all-aluminum shell, which has good heat dissipation performance, hard oxidation treatment on the surface, good friction resistance, and resistance to extrusion or bumping by certain external forces.

Disadvantages:

High cost: as an important part of the PV power generation system, the inverter needs to be invested at a higher cost, which increases the investment cost of the PV power generation system.
Troublesome maintenance: the inverter needs regular maintenance and upkeep, if not maintained in time, it will affect the service life and performance of the inverter.
Noisy: inverter will produce large noise during operation, affecting the use of experience, need to consider the scope of noise impact.
Unstable output voltage: The inverter will be affected by many factors in the process of outputting AC power, such as temperature, humidity, etc., which is prone to the problem of unstable voltage and needs to be adjusted precisely.
Influenced by the environment: Inverters are affected by the environment, climate and other factors, which need to be fully considered before use.
System dependent: In some application scenarios, such as PV power generation systems in remote rural areas, the inverter may not operate properly due to unstable grid conditions.
DC converter box failure rate: Higher DC converter box failure rate may affect the stable operation of the whole system.
Narrow MPPT voltage range: The MPPT voltage range of centralized inverters is narrow, generally 450-875V, with inflexible component configuration and short power generation time under specific climatic conditions (e.g., cloudy and rainy days, lots of fog).
Difficulty in installation and deployment: Difficulty in installing and deploying inverter machine rooms, requiring specialized machine rooms and equipment, increasing the complexity and cost of the system.

Classification of inverters

Inverters can be divided according to different classification standards. According to the different output waveforms, inverters can be divided into sine wave inverters and square wave inverters. Sine wave inverter output AC waveform is close to sinusoidal waveform, which is suitable for equipment with high requirements on power quality; while square wave inverter output AC waveform is square wave, which is suitable for some occasions with low requirements on power quality. According to the different uses, inverters can also be divided into household inverters, industrial inverters, photovoltaic inverters and so on.

To learn more about classifying inverters, read Learn about the types and features of inverters in one article

Specific application scenarios of inverters

The application scenarios of inverters are very wide. In the family, the inverter can be used as a backup power source to provide a stable power supply for household appliances. In industrial production, inverters are widely used in motor control, welding equipment, automation equipment and other fields. In addition, inverters also play an important role in renewable energy systems, such as solar photovoltaic power generation system, wind power generation system and so on.

Solar Inverter : Inverters play a central role in home and commercial solar systems. Solar panels convert solar energy into direct current (DC) power, while inverters convert this DC power into alternating current (AC) power needed for home and commercial electricity consumption. This allows the solar system to power homes and commercial premises and provide a steady source of electricity.
Backup Power: Inverters, when used in conjunction with a battery system, can provide backup power for homes and commercial premises in the event of a grid power outage. When grid power is interrupted, the inverter can quickly convert the DC power in the battery to AC power to ensure the normal operation of critical equipment such as refrigerators and computers.
Vehicle inverter: Inverters are also common in vehicle applications, which can convert the 12V DC power provided by the car battery into 220V AC power, so that passengers in the car can also use a variety of electronic devices, such as laptops, chargers and so on.
Industrial automation system: In the industrial field, inverters are widely used to drive various industrial machines and equipment. By converting DC power to AC power through inverters, precise control of motors can be realized, thus improving the efficiency of industrial production and energy utilization.
UPS Uninterruptible Power Supply Systems: In the industrial and commercial sectors, UPS systems are essential to ensure continuous operation of critical equipment during power interruptions. As the core component of a UPS system, inverters are able to quickly convert DC power to AC power during power interruptions, providing stable power support for equipment.
Transportation system: Inverters are also widely used in the transportation field. In railroad systems, inverters are used to monitor the electronic equipment of the system, such as acceleration sensors and temperature sensors. In aircraft systems, inverters convert engine DC power to AC power to provide power for cockpit and cabin equipment. In automotive systems, inverters are used to convert the vehicle’s DC power to AC power to power on-board electronic equipment.

How to install an inverter

When installing an inverter, first of all, you need to choose a dry, ventilated indoor or outdoor installation location that is out of direct sunlight, and make sure that the chosen location has enough support to withstand the weight and vibration of the inverter. Next, carefully plan and connect the power and ground cables according to the inverter’s instruction manual to ensure that all connections are firm and reliable, with no exposed wires or potential risk of leakage. During the installation process, pay special attention to safety, avoid working with electricity, and ensure that all operations comply with electrician safety codes. Upon completion of the installation, a thorough circuit check and commissioning should be carried out to ensure that the inverter is able to operate properly and meet the power requirements of the system. In addition, it is also necessary to clean the surface of the inverter regularly to maintain its good heat dissipation performance, and regularly check the operating status of the inverter to find and solve problems in time to ensure the long-term stable operation of the inverter.

What is the difference between inverter and charger

Although both inverters and chargers involve the conversion of electrical energy, there are significant differences in their functions and uses. A charger is mainly used to convert AC power to DC power to charge batteries. An inverter, on the other hand, converts DC power to AC power to meet the power needs of various devices and systems. Simply put, the charger is “charging” electricity, while the inverter is “changing” electricity.

Frequently Asked Questions about Inverters

1. How to calculate the inverter efficiency?
Inverter efficiency is the ratio of inverter output power to input power. Generally speaking, the higher the inverter efficiency, the lower the energy loss.

2. How to maintain the inverter?
Maintenance of inverter mainly includes cleaning, checking and replacing damaged parts. Regularly checking the operation status of the inverter, timely finding and solving problems can ensure the long-term stable operation of the inverter.

3.How to choose an inverter?
When choosing an inverter, you need to choose according to the specific application scenario and needs. Factors to be considered include the power of the inverter, output waveform, protection function, etc.. At the same time, you also need to choose regular brands and high-quality products to ensure the quality and performance of the inverter.