Overview

Simply speaking, inverter is an electronic device that converts low voltage (12 or 24 volts or 48 volts) direct current to 220 volts alternating current. Because we usually rectify 220 volts alternating current into direct current for use, and the inverter does oppositely, hence the name. We are in an era of "mobile", mobile office, mobile communication, mobile leisure and entertainment. In the moving era, people not only need low-voltage direct current power supply by batteries or batteries, but also need the 220-volt alternating current that is indispensable in our daily environment. The inverter can meet our needs.​​

The inverter converts DC power (battery, storage battery) into AC power (usually 220V, 50Hz sine wave). It consists of inverter bridge, control logic and filter circuit, widely used in air conditioners, home theaters, electric grinding wheels, electric tools, sewing machines, DVDs, VCDs, computers, TVs, washing machines, range hoods, refrigerators, video recorders, massagers, fans, lighting, etc.

In foreign countries, due to the high penetration rate of automobiles, you can use the inverter to connect the battery to drive electrical appliances and various tools when you go out to work or travel. The  inverter output power specification is 20W, 40W, 80W, 120W to 150W through the cigarette lighter.

Some larger power inverter power supply should be connected to the battery through the connecting wire, variety of appliances can be used in car after connecting home appliances to the output of the power converter, including mobile phones, notebook computers, digital cameras, cameras, lighting, electric shavers, CD players, game consoles, PDAs, power tools, car refrigerators and various travel, camping, medical emergency appliances etc.

Inverter classification

According to wave form

Mainly divided into two categories, one is pure sine wave inverter, the other is square sine wave inverter. The pure wave sine inverter is the same or better sine wave alternating current as the grid we use every day, because it does not have electromagnetic pollution in the grid. The output of the square sine wave inverter is the square wave alternating current with worse quality, and its positive maximum value and negative maximum value are generated almost at the same time, thus causing severe instability to the load and inverter. At the same time, its load capacity is not good, only 40-60% of the rated load, and it cannot carry the inductive load. If the load is too large, the third harmonic component contained in the square wave current will increase the capacitive current flowing into the load, which will damage the power supply filter capacitor of the load in severe cases. Due to the above shortcomings, a quasi-sine wave (or modified sine wave, modified sine wave, analog sine wave, etc.) inverter appears, and its output waveform has a time interval from the positive maximum value to the negative maximum value. The effect has been improved, but the waveform of the quasi-sine wave is still composed of broken lines, belonging to the category of square waves, and the continuity is not good. In summary, pure sine wave inverters provide high quality AC power and can drive any kind of load, but the technical requirements and costs are high. The modified sine wave inverter can meet most of our electricity needs, with high efficiency, low noise and moderate price, so it has become the mainstream product in the market. The production of the square wave inverter adopts a simple multivibrator, and its technology belonging to the level of the 1950s and will gradually withdraw from the market.

According to the different power generation sources, inverters are divided into coal power inverters, solar inverters, wind power inverters, and nuclear power inverters. According to different uses, it is divided into independent control inverter and on-grid inverter. The efficiency of solar inverter is higher in Europe and the United States, the standard of Europe is 97.2%, but the price is relatively expensive. The efficiency of other inverters in domestic is less than 90%, but the price is much cheaper than imported ones. Besides power and waveform, it is also very important to choose the efficiency of inverter. The higher the efficiency, the less power is wasted on the inverter, and the more power is used for electrical appliances. Especially when you use a small power system, the importance of efficiency will be very obvious.

According to the nature of sources

Active inverter: it is the inverter that makes the current in the current circuit connect to the grid in the AC side without connecting to the load directly;

Passive inverter: it is the inverter that makes the current in the current circuit not connected to the grid in the AC side and connected to the load directly (it converts the DC power to a certain frequency or adjustable frequency AC power to supply the load)

By grid type

Divided into off-grid inverters and on-grid inverters

By topology

Divided into two-level inverter, three-level inverter, multi-level inverter

By power level

Divided into high-power inverters, medium-power inverters, and low-power inverters