Bifurcation Control Method for Buck-Boost Converters Based on Energy Balance Principle

With the variation of parameters, the performance of the buck-boost converters may degrade due to the nonlinear phenomenon, such as Neimark–Sacker bifurcation, period doubling bifurcation, even chaos. In this article, a method to suppress the bifurcation and improve system stability through improving the control principle is indicated. By changing the control principle of the conventional one-cycle control (OCC), the proposed one-cycle energy balance control method achieves the one cycle control by keeping the energy balance of the circuit in each switching cycle. Then the poles of system transfer function are adjusted and the parameter stability range is extended, which achieve the objective of suppressing the bifurcation. Furthermore, such adjustments do not increase the order of the transfer function, thus there is no increase in the computational complexity. Compared with the conventional OCC method, the theoretical analysis based on the sampled-data model demonstrates the ability of the proposed method to suppress the bifurcation and extend the parameter range. Further simulation and experimental results also validate the theoretical analysis.