Industry News

Sine wave inverter

2020-09-23

Introduced sine wave inverter technology, expounded the working principle of typical inverter mode in the development of sine wave inverter, and the working process of typical inverter circuit. The content includes: the basic form of the inverter main circuit, such as voltage type current type...

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There are two main categories, one is sine wave inverter, and the other is square wave inverter.

The output of the sine wave inverter is the same or better sine wave AC power as the grid we use daily, because it does not have electromagnetic pollution in the grid.

The square-wave inverter outputs poor-quality square-wave alternating current, and its maximum value in the positive direction to the maximum value in the negative direction are generated almost at the same time, which will cause severe and unstable effects on the load and the inverter itself. At the same time, its load capacity is poor, only 40-60% of the rated load, and no inductive load is allowed. 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 filter capacitor of the load in severe cases.

In response to the above shortcomings, quasi-sine wave (or improved sine wave, modified sine wave, analog sine wave, etc.) inverters have appeared, and there is a time interval between the output waveform from the positive maximum to the negative maximum. The use effect has been improved, but the waveform of the quasi-sine wave is still composed of polyline, which belongs to the category of square wave and has poor continuity.

All in all, sine wave inverters provide high-quality alternating current, which can drive any kind of load, but the technical requirements and costs are high. Quasi-sine wave inverters can meet most of our electricity needs, with high efficiency, low noise, and moderate price, so they have become mainstream products in the market. The production of the square wave inverter adopts a simple multivibrator whose technology belongs to the level of the 1950s and will gradually withdraw from the market.

Inverters are classified into coal power inverters, solar inverters, wind power inverters, and nuclear power inverters according to different power sources. According to different uses, it is divided into independent control inverter and grid-connected inverter.

In the world, the efficiency of solar inverters in Europe and the United States is higher. The European standard is 97.2%, but the price is relatively expensive. Other domestic inverters have efficiencies below 90%, but the price is much cheaper than imports.

In addition to power and waveform, the efficiency of the inverter is also very important. 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 low-power system. The importance of one point is more obvious.