Abstract
An LCL capacitor current compensation and control method based on division and summation technique, comprising following steps: calculating new reference current i*lr=power grid reference current (Igr)+estimated capacitor current (); calculating duty cycle ratio d of respective switches in inverter to obtain inductor current (il), through using corresponding division-and-summation digital control characteristic equation (A), (B), (C), or (D), as based on inverter code of various inverter types; calculating power grid current (ig)=inductor current (il)−capacitor current (ic); calculating voltage across inductor at power grid side (vc−vp)=impedance (Zg) of said inductor at power grid side x power grid current (ig); utilizing equation (4) to calculate voltage across capacitor (vc); estimating capacitor current ()=voltage across said capacitor (vc)/filtering capacitor impedance (Zc); and utilizing equation (3) to estimate capacitor current ().