Fig. 11. Verification of optimized ESR.
component balances the voltages of the energy storage elements
(batteries or capacitors) that supply the current source. Since the
voltage sources (CDC1 and CDC2 in Fig. 4) represent dc signals
with fairly large time constants, a proportional–integral control
is used to ensure zero steady-state error. The third component
is used to inject active power into the dc bus from the energy
source. Overall, the control is much simpler than that of the acside
active power filters [14], [15].