基于模型预测的双PWM的一体化协调控制

Integrated control strategy based on model predictive for dual-PWM converter

针对双PWM变频器整流侧与逆变侧独立控制,电机转矩突变或制动过程时,逆变侧变化信息无法及时反馈到整流侧中,只能使用大电容以解决两侧功率平衡所产生的较大电压波动的问题,在直接功率控制策略的基础上,通过对有功功率预测,提出一种基于模型预测的控制方法,该方法整流侧采用模型预测直接功率控制,逆变侧采用模型预测直接转矩控制。同时,将负载侧功率直接反馈给整流器的功率控制环,在两侧能量流动的过程中实时地对有功功率参考值进行给定。以异步电机为负载对该系统进行仿真分析,改进的一体化协调控制很好地抑制负载突变时直流电压波动,预测控制加快了两侧动态响应速度,进一步抑制电流谐波。

When the rectifier side and the inverter side of the dual PWM inverter are independently controlled,there is a large fluctuation in the load or braking process.So,the voltage fluctuations caused by power balance can only be solved by a large capacitor,but the change information cannot be reflected in the rectifier side in time.Therefore,in the rectifier side,a model predictive direct power control(MPDPC) was adopted,and in the inverter side,a model predictive direct torque control(MPDTC) was used.Simultaneously,the load side power is fed back directly to the power control loop of the rectifier,and the active power reference value is given in real time during the energy flow on both sides.At last,the simulation analysis of the system are carried out with asynchronous motor as load.The result shows that the dual PWM frequency control scheme can further suppress the DC voltage fluctuation,accelerate the system dynamic response speed,and reduce the AC side of the input current harmonic content.