| Due to using the nonlinear components,such as inductance,capacitance,power transistor and other devices,switching power converter behaves as a strong nonlinear system.This nonlinearity is mainly manifested in the appearance of sub-harmonic oscillations,chaos and other nonliear phenomena.These unstable phenomena worsen the working performance of the switching power converter system and in severe case,the system may not be able to operate normally.Therefore,it is necessary to conduct in-depth research on the stability control of the switching power converter.In this thesis,DC-DC Boost converter under peak current mode is taken as the research object,it focuses on the suppression of the sub-harmonic oscillation in the circuit and tests the transient stability of the circuit to find an effective solution to improve the boost converter stable operation,the main work of the thesis and the result achieved are as follows:a.Using a constant slope compensation scheme can effectively suppress the instability in the circuit,although it can eliminate instabilities in the circuit,constant slope compensation is fixed in amplitude and cannot adapt to changes in the input voltage.Reduced input power.b.Considering the shortcomings of constant slope compensation,a dynamic optimized slope compensation scheme is proposed in this thesis.This scheme is based on the principle of resonance parametric perturbation and can not only resolve unstable phenomena such as sub-harmonic oscillation in the circuit,but also ensure the power.Under the premise of being able to adapt the change of the input voltage,in order to verify its transient stability performance,this paper also studied the stability of a switching period circuit under the condition of the input DC voltage jump,and tested the dynamic optimization of slope compensation to improve the converter stability and dynamic response performance.Through the simulation and experiments,the validity and correctness of the optimal slope compensation is verified. |
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