一种改进型IPOS模块化LCC谐振变换器控制策略

模块化技术可有效提高变换器容量,广泛应用于高压大功率场合.但由于模块间参数差异,各模块输出电压往往难以均衡,使得变换器难以稳定工作.针对输入并联输出串联IPOS(input-parallel output-series)模块化LCC谐振变换器,提出了一种改进型控制策略,主模块采用脉频调制PFM(pulse freque...

Improved Control Strategy for IPOS Modular LCC Resonant Converter

The modular technology is widely applied in high-voltage and high-power scenarios since it can significantly increase the converter capacity. However, due to the difference in parameters among modules, the output voltage from each module is often difficult to equalize, making the stable operation of the converter difficult. For input-parallel output-series (IPOS) modular LCC resonant converters, an improved control strategy is proposed in this paper. The master module regulates voltage by means of the pulse frequency modulation (PFM) method, whose accurate adjustment step is given based on a mathematical model. In addition, the slave module employs the pulse width modulation-pulse frequency modulation (PWM-PFM) method. The control flow of the proposed control strategy is established, providing a basis for the software implementation of the control algorithm. The simulation analyses of the master-slave modules are carried out to verify the feasibility of the proposed control strategy. Experimental results of a three-module converter show that the proposed control strategy can realize the voltage equalization control between modules and the constant voltage output from the system, which has advantages of good steady-state performance, fast transient response and strong anti-disturbance capability.