How does the pulse width modulation method of variable frequency power supply affect other devices?
　　Nowadays,all frequency conversion power supplies produced on the market are using pulse width modulation.This modulation method will generate harmonic currents during normal operation of frequency conversion power supplies.Of course,such harmonic currents will cause distortion of voltage waveforms,which will then cause extremely serious impacts and interference on the power supply system.So,at this point,we need to take protective measures when using variable frequency power supplies to reduce and protect the damage caused by interference to surrounding equipment.Below,we will tell you how to reduce and prevent the impact on surrounding equipment?
　　The following methods can be used:
　　(1)Using a dedicated transformer to power the variable frequency power supply,separate from other power supply systems.
　　(2)Install filtering reactors or multiple rectifier bridge circuits on the input side of the variable frequency power supply to reduce high-order harmonic components.
　　(3)For situations where there is a leading capacitor,the increase in capacitor current due to high-order harmonic currents causes severe heating,and a reactor must be connected in series before the capacitor.
　　What are the characteristics of capacitor filtering and inductor filtering in variable frequency power supplies compared to each other?
　　1.The conduction angle of the rectifier diode in an inductive filtering circuit isθ=π.
　　2.The output voltage of inductive filtering is lower than that of capacitive filtering,and generally inductive filtering is suitable for situations where the output voltage is not high,the output current is large,and the load changes are significant.
　　3.Inductive filtering has good external and pulsating characteristics.