Digital controller design for full-bridge Boost Rectifier using Singular Perturbation method based on pseudo continuous approach with power factor correction

The systematic approach of designing a robust digital controller to solve output regulation problem for a full bridge boost rectifier with unknown external disturbances and varying parameters is discussed. The design of digital controller based on the so-called pseudo-continuous approach by using Singular Perturbation is presented, where this controller is the result of continuous-time controller discretization. In the paper the control scheme for full bridge Boost Rectifier begins with the assertion that inductor currents are “fast” states and capacitor voltages are “slow” states. This assertion must be true for power factor correction converter to allow independent control of current and voltage. The continuous-time controller using proportional integral approach in feedback is used, and the effect of discretization at discrete time instants has been taken into account by inclusion of a zero-order hold transfer function. The pseudo-continuous-time model of a control loop with the pure time delay is used to calculate the parameters of a digital controller, where the pure delay is a result of the zero-order hold transfer function approximation. Numerical simulation for full bridge boost rectifier in discrete mode is presented