What is the selection capacity of the inverter bus capacitor and the relationship between output current and output voltage?

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What is the selection capacity of the inverter bus capacitor and the relationship between output current and output voltage? [Copy link]

Generally, the 380V voltage level inverter selects busbar support capacitors according to the output rated current, 40-50uF capacitor per ampere. This is the conventional method, which is the actual capacitance value under the rated output voltage and rated output current conditions;

If the output voltage of the inverter is limited to 300V, but it still needs to output the rated current, how should the capacitor capacity be selected at this time? What is the quantitative relationship between the output voltage, output current, and capacitor capacity?

Jacktang

If you don’t know how to calculate or don’t understand it, you can refer to the recommended values provided by the inverter manufacturer.

ksqb2098295

The fundamental frequency of the three-phase bridge rectifier ripple is 300Hz. To ensure stable operation, the product of the filter capacitor C and the DC equivalent load R must be more than 6 times the fundamental period of the ripple, generally 6 to 8 times.

R*C = (6~8)/300 s = (20~27)*1000 us

So C = (20~27)*1000/R = (20~27)*1000*I/U uF.

For three-phase 380V power supply, U is 500V, then C = (40~54)*I uF.