感应加热过程调频锁相-移相调功复合控制

The compound control scheme of phase-lock by frequency adjustment and power regulation by phase-shift for induction heating process

摘要:

串联谐振感应加热过程包括调频锁相和移相调功两个控制环节,二者具有较强的非线性和耦合性；在分析逆变频率、输出功率同锁相角、移相角关系的基础上，提出了基于频率分离原理的调频锁相-移相调功复合控制方案，将锁相-调功过程分解为快-慢子系统，并对两个过程分别设计了具有鲁棒稳定性的锁相控制器和移相控制器,解决了感应加热电源的调频锁相-移相调功环节的协调控制问题；将调频锁相-移相调功复合控制方案应用于额定功率20kW，输出电流40A的超音频串联谐振感应电源中，验证了该控制方案在确保逆变过程开关器件安全可靠的同时，提高了功率输出的效率；在保证了调功灵活性的同时，又实现了电源的阻抗自匹配。

Abstract:

The series resonant induction heating process, with phase-lock loop by frequency adjustment and power regulation function by phase-shift, has strong nonlinearity and coupling. After analyzing the relationship between inverter frequency, output power, phase-lock angle and phase-shift angle, a compound control scheme for the phase-lock and phase-shift process of induction heating is proposed based on frequency domain separation principle. The heating control process is decomposed into the fast-slow subsystems, and the phase-lock controller and the phase-shift controllers with robust stability are designed separately. The coordination control problem between phase-lock control by frequency adjustment and power regulation by phase-shift is solved. The compound control scheme is applied to the supersonic frequency series resonant induction power supply of 20kW/40A. It is indicated that the safety of power switch devices in the inverter process is ensured, and the efficiency of power is improved. And the control scheme not only ensures the flexibility of power regulation, but also realizes the impedance self-matching of power supply.