Why does the voltage of the frequency converter change proportionally to the frequency?
Any motor electromagnetic torque is the result of the interaction of current and flux, the current is not allowed to exceed the rated value, otherwise it will cause the motor heat. Therefore, if the magnetic flux decreases, the electromagnetic torque will be reduced, resulting in reduced load capacity.
From the formula E = 4.44 * K * F * N * Φ can be seen in the frequency control, the motor circuit with the operating frequency fX is a considerable range of changes, it is very easy to make the motor circuit serious Saturation, resulting in serious distortion of the excitation current waveform, resulting in peak high peak current.
Therefore, the frequency and voltage to be proportional to change, that is, change the frequency at the same time control the inverter output voltage, so that the motor flux to maintain a certain, to avoid the weak magnetic and magnetic saturation phenomenon. This type of control for the fan, pump energy-saving inverter.