Probably almost everyone knows that there is 220V/50Hz in the grid and the form of voltage is sinusoidal. For those who don’t – Google is always ready to help. The 230V standard has long been introduced, but out of habit people still assume that the rating is 220V. So, why is the shape sinusoidal? Because a sine is the projection of a rotating point on the coordinate axis. If the second coordinate axis is time, then a sine will appear on the graph.
Since we are talking about rotation, it is already clear that the main fan of pure sine is an AC motor (single-phase or three-phase). In the sinusoidal form, there is only one frequency – 50Hz. If the shape is distorted, then there are harmonics and higher frequencies – 100, 150, 200, 250Hz, etc. Higher speeds do not help the motor, but overheat its windings, besides, there is a hum.
Therefore, it is better to always have exactly 220V, 50Hz and pure sine than to worry about the damage from harmonics. In this case, there will be no hassle, because the connected equipment will work properly, because for any electronics, motor or lamp designed for 220 / 50Hz, these will be ideal operating conditions. How do Quant household voltage regulators correct the sine? Easily: makes measurements of the voltage in the network 40,000 times per second (800 points per network frequency period), and at each point compares with the sample sine in the memory. If there is no response, it makes corrections by adjusting the instantaneous values of the output voltage.
By the way, about the frequency. This is the only thing that never needs to be fixed in our grids. We have a single power system, and if this frequency was not maintained throughout the country, the system would not work. Therefore, the story that “under heavy load the frequency sags”, “decreases” is from the category of “urban legends”. That’s why the output of the Quant inverter voltage regulator is always the same frequency as the input.