Three-pole/four-pole topologies of current-controlled voltage source inverters (CC-VSI) used as active filter (AF) are considered. The proposed AF system employs power balance theory, which is implemented using a TMS320C31 DSP. A four-pole topology for the AF system exhibits the facility of operating it as a three-pole device. A prototype model of the AF system has been designed and tested with a non-linear load to demonstrate its effectiveness for harmonic elimination, reactive power compensation and power-factor correction. After the control scheme was verified through extensive experimental investigations on a three-pole AF system, it was applied to demonstrate the performance of a four-pole AF system through simulation with different possibilities for the non-linear loads in field applications. Simulation and experimental results of the developed model of the AF system are given and discussed in detail.