Research On Power And Signal Synchronous Transmission Strategy And Intrinsic Safety Characteristics Of Parallel Buck Converters

The DC/DC converter is an important component of the DC power supply system,and reliable information transmission is the fundamental guarantee for the efficient and flexible operation of the DC power supply system.The status monitoring,fault diagnosis,remote control,and coordinated operation of multiple converters cannot be separated from the support of communication technology.It is necessary to design circuit parameters to meet the requirements of intrinsic safety characteristics for intrinsically safe switching converters operating in harsh environments.This article studies the power and signal synchronous transmission(PSST)strategy applied to parallel Buck converters.Under the constraints of the intrinsic safety performance indicators of the converter,the system parameters of the converter are optimized,and the application of PSST strategy in the intrinsically safe converter is achieved.Firstly,the working principle of the parallel Buck converters was analyzed,and a bidirectional PSST strategy of binary frequency shift keying(2FSK)and binary phase shift keying(2PSK)was proposed.Based on the modulation characteristics of its carrier frequency and phase,frequency division multiple access(FDMA)technology was used to distinguish different converters.And a power and signal composite modulation strategy combining PWM/2FSK and PWM/2PSK was proposed to achieve bidirectional communication between the two units of the parallel Buck converters.The feasibility of the three proposed PSST strategies was verified through simulation and experiments.Secondly,the switching ripple characteristics of the parallel Buck converters under the PSST strategy were analyzed,and mathematical models of the inductor current ripple and output voltage ripple of the converter under different signal modulation strategies were established.Using the non-explosive intrinsically safe criterion,the intrinsically safe parameter region was plotted in the L-C plane.The simulation and experimental results indicate that the parallel Buck converter can still meet its intrinsic safety characteristics requirements under different PSST strategies.Finally,A PSST strategy with injection at the reference voltage is proposed for the application scenario of parallel Buck converters.The PSST communication of parallel Buck converters is achieved through orthogonal frequency division multiplexing(OFDM)communication technology and direct sequence spread spectrum communication technology,respectively.Mathematical models were established for the inductance current ripple and output voltage ripple of the converter,and the intrinsically safe parameter region was plotted in the L-C plane based on the non-explosive intrinsically safe criterion.The simulation and experimental results were provided to verify the feasibility of OFDM communication strategy and direct sequence spread spectrum communication strategy in intrinsically safe parallel Buck converters.There are 81 figures,6 tables and 95 references in this thesis.