Nonlinear adaptive normalized Huber control algorithm for 5-level distribution static compensator.

This paper proposes a new normalized Huber adaptive control algorithm for shunt compensation. A 5-level cascaded multilevel inverter (CHB-MLI) is controlled as a shunt active power filter (SAPF) unit for a medium voltage distribution system. The proposed algorithm is designed, modelled, and tested to control the SAPF unit under normal and distorted grid conditions. It is employed to extract the fundamental active power component of load current. This extracted effective component is used to generate source reference currents by multiplying with the unit vector template. Furthermore, the switching of CHB-MLI is performed using phase-shifted PWM scheme. The algorithm helps to mitigate the reactive power and unwanted harmonics generated by the nonlinear load. A single-phase scale-down prototype model is developed for experimental investigation and testing purpose in the laboratory. The associated voltage and current sensors and control circuits are controlled by the dSpace 1104 digital microprocessor. Simulation and experimental results show good performance of the proposed algorithm in steady-state and dynamic load conditions. A fair performance comparison is also done with other conventional adaptive algorithms. [ABSTRACT FROM AUTHOR]