Posicast control — An assessment over classical control of active damping for LC filter resonance in VSI inverter for UPS applications

Half-cycle Posicast control which can produce nearly deadbeat or critically damped response for classical 2^nd order plant is presented in this paper. Basic frequency response characteristic is derived from Posicast feedback control using Pade's approximation. Second order transfer function case study which resembles output LC filter of inverter is taken for imposing this frequency response to reveal resonance damping. Matlab program and Simulink implementation of important part of the control is explained for the benefit of reader. In order to make further assessment of Posicast Control, and depict the simplicity of design procedure, classical method of active damping of LC filter resonance is analyzed. This gives better platform for one-to-one comparison of frequency response and dynamic performance of closed loop control of both the methods. Finally, Matlab Simulink waveforms are captured for analyzing the performance of both the methods under transient load conditions.