Sine wave (or pure sine wave) , the waveform is the same to which output by generator or power grid, and even more perfect than the power grid. But sine wave modulation is not a simple matter, need the complicated control circuit; the cost is bound to rise. Therefore, sine wave UPS generally only in the units which capacity is more than 5KVA, or online units or part of the online interactive units, or the back-up units which capacity is large.
Sine wave has the most efficient conversion to the power frequency transformer, can load all equipment on the market. But because of the cost, there are also many uses such as: modified sine wave sine and square wave, which is not a sine curve, but many small segments, using artificial methods make them like about a sine curve, which is modified sine wave sine, although it is better than square wave, but still not as good as the sine wave.
Square wave is more easy to make, but because the square wave from the highest point suddenly fell to the lowest, and the energy loss is huge, and if the unit capacity is large, the loss may cause the machine damage itself, so the square wave system generally does not in a big unit, and is usually in hundreds of small capacity and reserve unit voltammetry modular UPS uninterruptible power supply.
Sine wave conversion efficiency is the highest, the minimum loss, followed by modified sine wave, and then square wave.
