【摘要】 在分析三电平整流器数学模型的基础上,结合瞬时功率理论,提出基于能量—电流双闭环控制策略。通过对系统瞬时功率的分析,找出功率与直流电压之间的关系,使外环以直流母线电容的储能(与电压的平方呈正比)为控制量,实现对电压的间接控制;电流内环采用电流前馈解耦控制方法,实现对有功和无功电流的独立控制。对系统的能量和电流环路进行了具体的参数设计,并针对三电平固有的中点电位平衡问题,采用了基于零序电压注入分量的SPWM调制策略。实验验证了理论分析的正确性,并将能量—电流控制策略和电压—电流控制策略的实验结果进行对比,证明前者具有更好的动态性能。更多还原

【Abstract】 On the basis of analyzing the mathematical model of three-level rectifiers and the theory of instantaneous power,an energy-current dual closed loop control strategy is proposed in this paper. By analyzing the instantaneous power of the system,the relationship of the power and the DC voltage can be found. Thus the energy storage of the DC bus capacitor can be taken as the controlling variable of the outer loop to regulate the DC voltage indirectly. In order to control the active current and the reactive current independently,the current feedforward decoupling method is adopted by the inner current loop. Parameters of the energy-current loops are also designed in this paper. The SPWM modulation strategy based on the zero-sequence voltage component injection is adopted for balancing the neutral-point-potential of the three-level rectifier. Correctness of the theoretical analysis is proved by the experiment. By comparing the results of the energy-current control strategy and the voltage-current control strategy,the former demonstrates better dynamic performance.更多还原