A Novel Wide Stability Control Strategy of Constant Power Load Power Converter Based on the Analysis of Lyapunov Indirect Method

In aerospace power supply system, with the increasing of the power converter loads and motor loads, constant power loads in the proportion of electricity equipment are growing. Because of the internal closed-loop control of this kind of loads, constant power loads show the constant power characteristic. This characteristic is one of the main causes of the system instability. Moreover, due to the size and weight limits, this kind of independent power supply system used in aerospace puts forward higher requirements for the design of the converter. A method of direct injecting high frequency components is presented in this paper based on inductor current to the duty cycle. This method not only reduces the size of filter capacitor, but also suppresses the instability caused by constant power loads. In this paper, the Boost converter designed for aircraft application is taken as an example. The state space model of the system is established, and the stability of the system is analyzed by Lyapunov. At last, the simulation and experimental results prove the correctness and feasibility of the proposed control strategy. In the same power output condition, this duty cycle compensation technology can reduce the filter capacitance by about 8 times.