Voltage sensorless control of single-phase active power filter based on the second-order generalized integrator algorithm

A single-phase active power filter is presented for small-scale, single-phase loads based on the second-order generalized integrator control method is presented in this article. The proposed system does not require voltage sensors on the AC and/or DC side. Only two current sensors are used to measure load and converter currents. Consequently, a proportional-integral regulator is not used, and there is no need for additional calculations for the determination of the grid-current amplitude. To obtain the correct reference grid current, the distorted load current is first processed by using the second-order generalized integrator algorithm, which does not require voltage information. A step-by-step performance study, in a real-time environment, shows that the proposed control technique is able to generate the proper compensating reference current for small-scale non-linear loads. As a result, the total harmonic distortion of the grid current is reduced from 25.33 to 3.80%, which meets the recommended IEEE 519-1992 Standard.