Multiscale Modeling and Analysis of Boost Converter Based on Device Mechanism Model and Continuous Switching Function

There are multiscale coupling relationships during the operation of dc/dc converters, where the macroscale is the overall working principle of the circuit and the microscale is the device mechanism model of the circuit components. Modeling only at the macroscale cannot reflect the effect of the device's internal effects on the circuit, while modeling the device at the microscale cannot show the operating characteristics of the circuit. To obtain the analytical solutions of the state variables for dc/dc converters at circuit- and device-level scales, a method for establishing a multiscale model of a dc/dc converter is proposed. Firstly, the device mechanism at the microscale is appropriately combined with the circuit model at the macroscale. Secondly, the traditional piecewise switching function that represents the switching state is replaced by a continuous switching fitting function. Thereby, a continuous multiscale unified model of the dc/dc converter is reached. Afterward, by adopting the improved equivalent small parameter (ESP) method proposed in this article, the steady-state analytical solutions of the model in the open- and closed-loop states can be obtained, respectively. Finally, the steady-state analytical solutions are compared with the results of simulation and experiment.