全桥移相铸轧超声波电源调功系统设计

为满足轻质合金超声铸轧过程中对超声波功率稳定及可调的要求,同时为改善传统超声波电源功率调节中存在的开关损耗大、功率因数低等缺点,设计了一种基于STM32的全桥移相超声波电源调功系统,并进行了理论研究和实际的电路实验。采用STM32产生全桥移相(phase-shifted,PS)PWM信号,驱动逆变器工作,同时通过采样换能器的电流和电压,实现功率反馈,采用增量式PID控制算法,调节移相角实现对输出功率的闭环控制。实验结果表明,基于全桥移相PWM控制策略的调功方式能够实现功率的连续可调,同时,由于逆变器开关管工作在零电压开通状态,因而开关损耗小,功率因数高。

Design of Power Regulation System of Full-Bridge Phase-Shifted Casting Ultrasonic Power

In order to meet the demand of stability and adjustability of power in the process of light alloy casting, and in order to improve the shortcomings of large switching loss and low power factor in the power regulation of traditional ultrasonic power, a kind of power regulation system based on full-bridge phase-shifting. Theoretical study and actual circuit experiment is performed at the same time. Phase-shifted pulse width modulation signal generated by STM32 is used to drive inverter to work. The power feedback can be realized by sampling the voltage and current of the transducer. Then making use of the algorithm of incremental PID to adjust the phase-shifted angle, the close-loop power control can be realized. The experimental result shows that the full-bridged phase-shifted strategy can regulate power continuously. And at the time, the switching device is worked in the state of zero voltage switching, so the switching loss is low and power factor is high.