Stability Criterion of DC-DC Converter With Different Loads Based on Mixed Potential Theory

The dc systems consisting of power electronic converters always suffer from various stability problems, and the mixed potential theory (MPT) has been widely applied to study these problems in recent years because the stability criterion in analytical form can be derived easily. However, the models of the dc-dc converters in most studies are simplified, and thus only the control parameters at system level are considered. Some work has done to propose the MPT criterion based on complete converter models which involve the control parameters of the converters but such improved MPT criterion is optimistic for system stability. This paper proposes the MPT criterion of a boost converter with different loads based on complete converter models and expounds the mathematical features and the physical implication of the proposed MPT criterion. The proposed MPT criterion can be used for the design of system parameters but it is a necessary condition for system stability. The reasons for the optimism of the proposed criterion are revealed from the expounded mathematical features and physical implication. Finally, real-time simulations are conducted in RT-LAB to verify the correctness of the theoretical analyses.