基于ZCS-PWM的超音频感应焊接电源的研究

介绍一种基于ZCS-PWM(零电流开关-脉宽调制)技术的新型超音频感应焊接电源。利用ZCS频率跟踪电路，控制串联谐振式逆变器的开关频率始终跟踪负载的固有谐振频率，使逆变器的输出功率因数接近1，同时显著减小了开关器件的功率损耗，提高了整机的效率。所设计的系统采用直流斩波调压实现输出功率调节，降低了电源输入侧高次谐波，改善了传统的焊接工艺。研制的实用型焊接电源的最大功率为80kW、最高工作频率30kHz、全部采用IGBT器件，装置具有体积小、功率因数高、效率高、焊接速度快等优点。

Study on ultra audio frequency induction welding power based on ZCS-PWM

The paper presents a novel ultra-audio frequency (UAF) induction welding power based on ZCS-PWM(Zero Current Switching-Pulse Width Modulation) technology. Using a ZCS frequency phase locked loop, the switching frequencies of proposed serial-resonant inverter consistently trace the load resonant frequencies to guarantee the output power factor of inverter up to unity. In this way, the actual power conversion efficiency is higher and the switching loss is lower in the proposed welding power than in a traditional one. To regulate the output power of the supply, a DC/DC buck-chopper converter is designed to vary the DC voltage and reduce obviously high class harmonics of the input supply simultaneously and develop the traditional technique. The maximum captivity and operating frequency of the power supply realized are up to 80 kW and 30 kHz respectively. The power supply showed many good characteristics such as smaller size, higher power factor and efficiency as well as faster welding speed.