A Fast and Exact Time-Domain Simulation of Switched-Mode Power Regulators

A new approach for the time-domain simulation of switched-mode power regulators is developed. The concept of this approach is to model each switch element by a linear time-varying nodal equation, thus formulating a modified nodal equation system that describes the global dynamic behavior of the power regulator. By using the symbolic Laplace transform inversion, the time-domain expressions can be obtained in a closed and continuous form, which allows a fast and exact simulation of the system. The time efficiency of the proposed approach is testified by comparing with a standard numerical integration method. Various transient responses of a practical switched-mode power regulator due to the start-up, the step change in input voltage and the step change in reference voltage has been simulated. The simulations include the overcurrent protection limitation, the duty-cycle limitation control, the discontinuous conduction mode, and the continuous conduction mode of operation.