单相PWM整流器定频模型预测功率控制算法

针对传统单相PWM整流器开关表直接功率控制算法的系统功率脉动大、开关频率不固定、网侧谐波高等问题,借鉴三相PWM整流器的模型预测直接功率控制(MP-DPC)算法,提出了一种基于占空比优化的单相PWM整流器MP-DPC算法。首先,依据瞬时功率理论,通过虚拟坐标系构造网侧电压与电流的旋转矢量,给出了一种单相系统功率求解算法;然后,研究不同开关状态对系统功率的影响,给出了单相PWM整流器最优开关状态选择与占空比求解的MP-DPC方法;最后,分别对滞环开关表DPC与MP-DPC算法进行了计算机仿真及半实物实验对比研究,结果表明:与滞环开关表DPC算法相比,该MP-DPC算法具有控制精度高、开关频率恒定、网侧电流谐波含量低等优点,也验证了该算法的有效性和优越性。

Model predictive power control scheme for single-phase PWM rectifiers with constant switching frequency

For these drawbacks of traditional switching-table direct power control(DPC) in single-phase PWM rectifiers such as large power ripple,variable switching frequency and large harmonic components of the grid-side current,a single-phase model predictive DPC ( MP-DPC) scheme with duty cycle optimiza-tion was proposed,on the basis of three-phase model predictive direct power control scheme.Firstly,the grid-side voltage/current rotating vectors were constructed through fictive-axis emulation,and a power cal-culation algorithm for single-phase system was presented on the basis of instantaneous power theory.Then, combining with the effect of different switching-states on instantaneous power, a MP-DPC scheme with switching-state selection and duty cycle optimization was proposed for single-phase PWM rectifier.Final-ly,computer simulations and hardware in loop experiments were adopted to test and compare traditional hysteresis switching-table DPC and MP-DPC,respectively.Simulation and experimental results show that the proposed MP-DPC scheme achieves higher precision,lower harmonics and constant switching frequen-cy compared with hysteresis switch-table DPC.Feasibility and correctness of the proposed MP-DPC scheme are also verified.