Reference values for three-phase active power filter

This paper analyses a three-phase active power filter, where reference values calculation of filter current is based on instantaneous real and imaginary power. The instantaneous real and imaginary power depends on the rectangular components of the voltage and current Park vector. Both real and imaginary powers have dc and ac components. For nonlinear load current we obtain four terms. There are two ways to obtain the reference value of the active power filter current. We have developed a simple algorithm for calculus of the instantaneous reference values of the filter current, based on instantaneous real and imaginary power. Also, it was simulated, built and experimented an active power filter, connected on a nonlinear load which consists of an uncontrolled rectifier with a serial RL load. By using the active filter the main supply currents is almost sinusoidal and in phase with the main supply voltage.