DC/DC变换器的闭环控制系统分析和仿真

摘要

Focusing on the control of the widely used small and medium forward voltage regulator switching power supply in mass transit field, this paper analyzes the closed-loop control system of the DC/DC switching power supply, gives the transfer function and Bode Diagram of various parts of the converter, and implements a specific design for the control circuit of the small and medium forward voltage regulator switching power supply by introducing PWM power supply controller. Power supply controller is composed of the main control UCC2570 chip, its clock and saw tooth form, the adaptive dead-set, regulator, isolation drive, protection, the voltage and current sampling peripherals and other sub-modules. This paper uses Matlab to set the control parameters, and uses SimPowerSystem module to simulate the closed-loop control of the power system. The simulation results show that the closed-loop control based design of switching power supply can fulfill the design requirements.%以轨道交通广泛应用的中小功率正激式稳压型开关电源控制为研究对象,通过对DC/DC开关电源的闭环控制系统的详细分析,给出了DC/DC变换器各部分的传递函数和波特图,引入PWM(脉宽调制)电源控制器对中小功率正激式稳压型开关电源控制电路进行了具体设计.稳压型开关电源的控制器由主控芯片UCC2570、外围时钟,以及锯齿波形成、自适应死区设置、电压调节、隔离驱动、保护和电压电流采样等子模块组成.利用Matlab辅助仿真软件可对开关电源的控制参数进行整定,采用仿真软件中的SimPowerSystem模块对开关电源的闭环控制系统进行仿真.仿真结果表明,基于闭环控制所设计的DC/DC稳压型开关电源是满足设计要求的.