梳理机用齿条感应加热电源频率跟踪的控制策略

Control Strategy for Induction Heating Power with Freqency-tracking System on Card Wires

利用感应加热技术对梳理机用齿条进行在线退火热处理，可以显著提高其生产效率和产品质量。由于梳理机用齿条在加热过程因参数变化会导致感应加热电源的谐振频率变化，致使电源的利用率降低。为提高电源的利用效率和功率因数，要求电源的输出电压与谐振电流的频率、相位严格保持一致。根据梳理机用齿条热处理工艺的要求，采用积分分离法与DPLL（数字锁相环）相结合的频率跟踪策略，设计了一台100kHz／5kW的高频感应加热电源，对齿条进行在线退火处理。该电源采用Buck斩波实现功率控制；采用负载串联谐振式逆变桥进行频率控制，实现对负载谐振频率的跟踪和软开关。电源的功率调节范围为1％～99％，输出功率因数迭到99％，与传统技术相比，该高频感应加热电源具有调功范围大、结构简单、抗干扰能力强、节能显著、加热温度均匀等优点。

In consideration of the process of card wire heating operation, a strategy of frequency-tracking with integral action separation and DPLL （digital phase-locked loop） is employed to work out a high frequency induction heating power with 100 kHz/5 kW for on-line card wire annealing. The buck chopper is used to control power while the load-series resonant frequency is used to control operating frequency of inverter hence to track and to achieve ZCS soft switching operation. Power ranges from 1% to 99 % and output power factor is above 99%. As compared with the conventional products,it is characterized as big adjustment range, simple structure,strong anti-jamming, power economy, well prepotioned heating and such.