Robust second-order sliding-mode backstepping control of the parallel active filter for harmonics and reactive power compensation-experimental validation

Power quality has become a crucial issue for public services and end consumers. This is attributable to the widespread use of non-linear loads and modern high-power electronic devices in a multitude of applications, such as renewable energy and automotive, which generate harmonics in the electrical network. This can lead to a significant deterioration in the quality of electrical energy, as well as socio-economic repercussions. It is therefore crucial to optimize the quality of electrical energy while ensuring that nonlinear loads are integrated in a manner that is compatible with the grid. The use of active power filters is one of the most effective methods for improving the quality of electrical energy and overcoming these problems. This paper proposes a control scheme that integrates backstepping and second order sliding mode (BS-2-SM), combined with the DPC-SVM strategy (direct power control, spatial vector modulation) for a parallel active filter (PAF) to reduce harmonic distortion and compensate reactive power. The proposed controller will aim at improving the PAF performance and consequently to the improvement of the grid power quality. In the proposed control approach, the active and reactive power is controlled by DPC-SVM based on two second order sliding mode regulators. The DC bus voltage is regulated by means of backstepping, in order to reduce the THD total harmonic distortion and find a unitary power factor. The proposed controller for the PAF is assessed in simulations using the MATLAB / Simulink environment, and validated in an experimental test bench in the laboratory. Simulation and experimental results prove that the BS-2-SM offers an improvement in the dynamic and steady-state performance. Our system reduces THD according to standard norms and provides perfect compensation for harmonic power with a unit power factor, thereby improving the quality of electrical energy.