What is DC LINK VOLTAGE

Please can anybody really explain to me what dc link voltage really is? Am having problem understanding its relevant in inverters

[Muhammed Fasil]

Inverter converts DC to AC. So DC voltage is the input required. This DC voltage is modulated to create AC

Answer 1

[Mohamed Eldin]

Hello Muhammed!

If your application is an electric vehicle with dc machine so I think you don't need the dc link voltage,

If the electric vehicle is provided with AC 3 phase machine, here you should take care about the ripples or the oscillations of the current inside your system.

so the source is dc battery, the dc current follows from the battery through the inverter to convert the dc current to AC one using PWM due to the PWM switching the current will not be dc anymore and he carried some ripples so you need a capacitor to smooth these oscillations

DC current_source = DC link current (rms not continous current) + current follows in the capacitor

please see this video you find some basic information

Bus capacitors for eMobility inverters - YouTube

Mod-08 Lec-28 DC link current and DC capacitor current in a voltage source inverter - YouTube

Have a nice day!

Mohamed