Power converting device and method with high-frequency inverter module compensating low-frequency inverter module

A power converting device with a high-frequency inverter module compensating a low-frequency inverter module for transmitting a direct current voltage to an alternating current load module, and the power converting device with the high-frequency inverter module compensating the low-frequency inverter module comprising:

• the low-frequency inverter module controlled by a low-frequency duty ratio, wherein the low-frequency inverter module comprises:
• a first inputting end electrically connected to the direct current voltage;
• and
• a first outputting end outputting a first current, wherein the first current comprises a low-frequency ripple current;
• and
• the high-frequency inverter module connected to the low-frequency inverter module in parallel and controlled by a high-frequency duty ratio, wherein the high-frequency inverter module comprises:
• a second inputting end electrically connected to the direct current voltage;
• and
• a second outputting end outputting a second current;
• wherein the low-frequency inverter module is controlled according to the low-frequency duty ratio to generate the first current;
• wherein the high-frequency duty ratio is adjusted according to the low-frequency ripple current, and the high-frequency inverter module is controlled according to the high-frequency duty ratio to generate the second current;
• wherein the second current is for compensating ripples of the first current, the first current and the second current are transmitted to a filter module, and the filter module outputs a load current to the alternating current load module;
• wherein the filter module has a node and comprises:
• a low-frequency inductor unit having a first end and a second end, wherein the first end of the low-frequency inductor unit is electrically connected to the first outputting end, and the first current passes through the low-frequency inductor unit;
• a high-frequency inductor unit having a first end and a second end, wherein the first end of the high-frequency inductor unit is electrically connected to the second outputting end, the second end of the high-frequency inductor unit and the second end of the low-frequency inductor unit are coupled to the node, and the second current passes through the high-frequency inductor unit;
• and
• an outputting capacitor unit electrically connected to the node and generating an outputting capacitor current through the outputting capacitor unit, wherein the node is electrically connected to the alternating current load module;
• wherein the low-frequency duty ratio is represented as the following equation:
• D
• k
• ,
• L
• ⁡
• [
• n
• +
• 1
• ]
• =
• 1
• 2
• +
• L
• ik
• ,
• L
• ,
• T
• L
• ⁡
• [
• n
• ]
• ⁢
• Δ
• ⁢
• ⁢
• i
• k
• ,
• L
• ⁡
• [
• n
• +
• 1
• ]
• 2
• ⁢
• V
• DC
• ,
• T
• L
• ⁡
• [
• n
• ]
• ⁢
• T
• s
• ,
• L
• +
• v
• ck
• ,
• T
• L
• ⁡
• [
• n
• ]
• 2
• ⁢
• V
• DC
• ,
• T
• L
• ⁡
• [
• n
• ]
• ;
• wherein Dk,L is the low-frequency duty ratio, Lik,L,TL is a low-frequency inductance of the low-frequency inductor unit, Δik,L is a low-frequency switching current error of the low-frequency inverter module, VDC,TL is the direct current voltage having a low switching frequency, Ts,L is a low-frequency sampling period, n is a given period, and vck,TL is an outputting capacitor voltage of the outputting capacitor unit.