基于MPC的感应加热LLC谐振负载功率控制

LLC Resonant Load Power Regulation Based on Model Predictive Control for Induction Heating

针对感应加热LLC谐振负载,以提高输出功率控制精度、消除比例积分(PI)参数整定过程为目标,提出一种基于模型预测控制(MPC)的功率控制方法。该方法从谐振负载模型出发,通过对所提控制策略进行数学推导,得到控制量的预测表达式。随后分析了逆变电流变化对电磁感应加热LLC负载电流的影响,提出一种通过改变逆变电流来调节输出功率的方法。同时,为保证最大输出功率,还引入了相位控制来跟踪谐振频率。最后,在35.59~36.1kHz的工作频率范围内进行了仿真和实验,验证了该方法的有效性。

As for the resonant load of induction heating LLC, aiming at improving the output power control accuracy and eliminating the proportional integral (PI) parameter tuning process, a power control method based on model predictive control (MPC) is proposed. Based on the resonant load model and the mathematical derivation of the proposed control strategy, the predictive expression of the control quantity is obtained by this method.Then the influence of inverter current change on electromagnetic induction heating LLC load current is analyzed,and a method to adjust the output power by changing the inverter current is proposed. At the same tim e, in order to ensure the maximum output power,phase limit control is also introduced to track the resonant frequency.Finally, the simulation and experiment are carried out within the operating frequency range of 35.59~36.1 kHz,and the validity of the method is verified.