Study Of Cascaded High-power-density High-power Aerospace Ground Power Supply

The large phased-array radars and TT&C system are the important subsystems of the space system and missile weapon system.As widely applied in The large phased-array radars and TT&C system,the high power density high power DC power supply(hereinafter referred to as the aerospace ground power supply)is taken as the object of study in this thesis to conduct a further study on key technologies of high performance DC/DC converter on the aerospace ground power supply.The simulation model and testing prototype has been established to verify the theoretical technologies.The high reliability,high power density,high efficiency and parallelable module power supply technology is shaped to lay the foundation for the military-supply industrialization of the modular power supply and meet the demands of aerospace products.The main research contents of this thesis are listed as follows:(1)the operating principle and key technologies of the two-stage DC/DC converter topology are presented in the thesis.The LLC soft switching converter and secondary-side synchronous rectifier technology are employed to achieve high efficient transformation at high switching frequency,while the LLC circuit operates with the optimal parameters.The wide range of input voltage and output voltage stabilization are guaranteed by the utilization of high performance Buck circuit and peak current control strategy.The operating principle,control strategy and operating characteristics of the two-stage Buck-LLC resonant DC/DC converter are introduced along with the circuit topology and control strategy of multi-module interleaved two-stage DC/DC converter.The simulation are conducted to verify the correctness of analysis.(2)The application of the new wide bandgap semiconductor Si C MOSFET devices in the above-mentioned power supply are studied.The efficiency of power supply are improved by using Si C MOSFET devices in the Buck circuit,whose driving circuits and operating characteristics are discussed in detail.The study on the high-efficiency and high-power-density Aerospace power supply technologies are conducted by theoretical analysis,modeling simulation and prototype tests.The simulation results verify the effectiveness of the proposed structure and method,which have certain guiding significance for the design of actual power supply.(3)The interleaving technique are used to connect the modules in parallel,which makes the power supply system flexible to meet different requirements of various applications,scatters the hot spots,improves the reliability and redundancy of the system.By using the PM-BUS protocol with high reliability,the communication of modules and parallel current sharing control are achieved.The output ripples are reduced effectively with the employed interleaved multi-module Buck-LLC circuits.