The series controller is equivalent to the controlled voltagesource that compensating the voltage harmonic and the voltage fluctuation from the power system.
In the electrotechnics basis theory, it's very convenient to solve one branch's voltage and current by the equivalent transformation between the voltagesource and current source.
利用电压源与电流源之间的等效变换求解某一支路电压、电流，是电工基础理论中非常方便的方法。
3
Output characteristic is one of the most important characteristics of voltagesource inverter, which is determined by the equivalent output impedance of the inverter.