An effective interval analysis-based method for the unified steady-state analysis of PWM switching converters

In this work a new interval analysis (IA) based method for the steady-state analysis of PWM switching converters is presented. The main features can be summarized as follows: (i) no preliminary knowledge of the operation mode the circuit works in is needed, (ii) no initial guess solution is needed, and (iii) fast convergence and arbitrary accuracy are allowed. The requirements are: the state-space model of the circuit must be known, the currents and voltages controlling internally controlled switching instants (ICSIs) must be identified, the circuit must have distinct eigenvalues within each linear configuration. The method combines a unified discrete-time modeling of PWM converters with a robust and powerful IA-based technique for the calculation of ICSIs. After the type of circuit and the components are selected, the source, the load, the switching frequency, the duty-cycle and the solution tolerance may be arbitrarily chosen and the steady-state solution is automatically calculated, regardless of the operation mode. The method covers all PWM switching converters. As an example in this paper it has been applied to the steady-state analysis of a Cuk converter working in discontinuous current (DC), discontinuous voltage (DV) and discontinuous current and voltage (DCV) modes. Excellent agreement with experimental measurements has been found